import unittest
from concurrent.futures import ProcessPoolExecutor, as_completed
from functools import partial
from unittest.mock import patch

import duckdb
from pandas.testing import assert_frame_equal

import sqlglot
from sqlglot import exp, optimizer, parse_one
from sqlglot.errors import ANSI_RESET, ANSI_UNDERLINE, OptimizeError, SchemaError
from sqlglot.optimizer.annotate_types import annotate_types
from sqlglot.optimizer.canonicalize_internal_names import canonicalize_internal_names
from sqlglot.optimizer.normalize import normalization_distance
from sqlglot.optimizer.qualify import qualify
from sqlglot.optimizer.scope import build_scope, traverse_scope, walk_in_scope
from sqlglot.schema import MappingSchema
from tests.helpers import (
    TPCDS_SCHEMA,
    TPCH_SCHEMA,
    assert_logger_contains,
    load_sql_fixture_pairs,
    load_sql_fixtures,
    string_to_bool,
)


def parse_and_optimize(func, sql, read_dialect, **kwargs):
    return func(parse_one(sql, read=read_dialect), **kwargs)


def qualify_then_canonicalize(expression, **qualify_kwargs):
    return canonicalize_internal_names(qualify(expression, **qualify_kwargs))


def qualify_columns(expression, validate_qualify_columns=True, **kwargs):
    expression = optimizer.qualify.qualify(
        expression,
        infer_schema=True,
        validate_qualify_columns=validate_qualify_columns,
        identify=False,
        **kwargs,
    )
    return expression


def pushdown_projections(expression, **kwargs):
    expression = optimizer.qualify_tables.qualify_tables(expression)
    expression = optimizer.qualify_columns.qualify_columns(expression, infer_schema=True, **kwargs)
    expression = optimizer.pushdown_projections.pushdown_projections(expression, **kwargs)
    return expression


def normalize(expression, **kwargs):
    schema = kwargs.get("schema")

    expression = optimizer.normalize.normalize(expression, dnf=False)
    expression = annotate_types(expression, schema=schema)
    return optimizer.simplify.simplify(expression)


def simplify(expression, **kwargs):
    dialect = kwargs.get("dialect")
    schema = kwargs.get("schema")

    expression = annotate_types(expression, schema=schema)
    return optimizer.simplify.simplify(
        expression, constant_propagation=True, coalesce_simplification=True, dialect=dialect
    )


def pushdown_ctes(expression, **kwargs):
    optimizer.qualify_columns.pushdown_cte_alias_columns(build_scope(expression))
    return expression


def annotate_functions(expression, **kwargs):
    dialect = kwargs.get("dialect")
    schema = kwargs.get("schema")

    annotated = annotate_types(expression, dialect=dialect, schema=schema)

    return annotated.expressions[0]


class TestOptimizer(unittest.TestCase):
    maxDiff = None

    @classmethod
    def setUpClass(cls):
        sqlglot.schema = MappingSchema()
        cls.conn = duckdb.connect()
        cls.conn.execute(
            """
        CREATE TABLE x (a INT, b INT);
        CREATE TABLE y (b INT, c INT);
        CREATE TABLE z (b INT, c INT);
        CREATE TABLE w (d TEXT, e TEXT);

        INSERT INTO x VALUES (1, 1);
        INSERT INTO x VALUES (2, 2);
        INSERT INTO x VALUES (2, 2);
        INSERT INTO x VALUES (3, 3);
        INSERT INTO x VALUES (null, null);

        INSERT INTO y VALUES (2, 2);
        INSERT INTO y VALUES (2, 2);
        INSERT INTO y VALUES (3, 3);
        INSERT INTO y VALUES (4, 4);
        INSERT INTO y VALUES (null, null);

        INSERT INTO y VALUES (3, 3);
        INSERT INTO y VALUES (3, 3);
        INSERT INTO y VALUES (4, 4);
        INSERT INTO y VALUES (5, 5);
        INSERT INTO y VALUES (null, null);

        INSERT INTO w VALUES ('a', 'b');
        """
        )

    def setUp(self):
        self.schema = {
            "x": {
                "a": "INT",
                "b": "INT",
            },
            "y": {
                "b": "INT",
                "c": "INT",
            },
            "z": {
                "b": "INT",
                "c": "INT",
            },
            "w": {
                "d": "TEXT",
                "e": "TEXT",
            },
            "temporal": {
                "d": "DATE",
                "t": "DATETIME",
            },
            "structs": {
                "one": "STRUCT<a_1 INT, b_1 VARCHAR>",
                "nested_0": "STRUCT<a_1 INT, nested_1 STRUCT<a_2 INT, nested_2 STRUCT<a_3 INT>>>",
                "quoted": 'STRUCT<"foo bar" INT>',
            },
            "t_bool": {
                "a": "BOOLEAN",
            },
        }

    def check_file(
        self,
        file,
        func,
        pretty=False,
        execute=False,
        only=None,
        **kwargs,
    ):
        with ProcessPoolExecutor() as pool:
            results = {}

            for i, (meta, sql, expected) in enumerate(
                load_sql_fixture_pairs(f"optimizer/{file}.sql"), start=1
            ):
                title = meta.get("title") or f"{i}, {sql}"
                if only and title != only:
                    continue

                dialect = meta.get("dialect")
                leave_tables_isolated = meta.get("leave_tables_isolated")
                validate_qualify_columns = meta.get("validate_qualify_columns")
                canonicalize_table_aliases = meta.get("canonicalize_table_aliases")

                func_kwargs = kwargs.copy()

                if leave_tables_isolated is not None:
                    func_kwargs["leave_tables_isolated"] = string_to_bool(leave_tables_isolated)

                if validate_qualify_columns is not None:
                    func_kwargs["validate_qualify_columns"] = string_to_bool(
                        validate_qualify_columns
                    )
                if dialect:
                    func_kwargs["dialect"] = dialect
                if canonicalize_table_aliases is not None:
                    func_kwargs["canonicalize_table_aliases"] = string_to_bool(
                        canonicalize_table_aliases
                    )

                future = pool.submit(parse_and_optimize, func, sql, dialect, **func_kwargs)
                results[future] = (
                    sql,
                    title,
                    expected,
                    dialect,
                    execute if meta.get("execute") is None else False,
                )

        for future in as_completed(results):
            sql, title, expected, dialect, execute = results[future]

            with self.subTest(title):
                optimized = future.result()
                actual = optimized.sql(pretty=pretty, dialect=dialect)
                self.assertEqual(
                    expected,
                    actual,
                )
                for expression in optimized.walk():
                    for arg_key, arg in expression.args.items():
                        if isinstance(arg, exp.Expr):
                            self.assertEqual(arg_key, arg.arg_key)
                            self.assertIs(arg.parent, expression)

                if string_to_bool(execute):
                    with self.subTest(f"(execute) {title}"):
                        df1 = self.conn.execute(
                            sqlglot.transpile(sql, read=dialect, write="duckdb")[0]
                        ).df()
                        df2 = self.conn.execute(optimized.sql(dialect="duckdb")).df()
                        assert_frame_equal(df1, df2)

    @patch("sqlglot.generator.logger")
    def test_optimize(self, logger):
        self.assertEqual(optimizer.optimize("x = 1 + 1", identify=False).sql(), "x = 2")

        schema = {
            "x": {"a": "INT", "b": "INT"},
            "y": {"b": "INT", "c": "INT"},
            "z": {"a": "INT", "c": "INT"},
            "u": {"f": "INT", "g": "INT", "h": "TEXT"},
        }

        self.check_file(
            "optimizer",
            optimizer.optimize,
            infer_schema=True,
            pretty=True,
            execute=True,
            schema=schema,
        )

    def test_isolate_table_selects(self):
        self.check_file(
            "isolate_table_selects",
            optimizer.isolate_table_selects.isolate_table_selects,
            schema=self.schema,
        )

    def test_qualify_tables(self):
        tables = set()
        optimizer.qualify.qualify(
            parse_one("with foo AS (select * from bar) select * from foo join baz"),
            qualify_columns=False,
            on_qualify=lambda t: tables.add(t.name),
        )
        self.assertEqual(tables, {"bar", "baz"})

        self.assertEqual(
            optimizer.qualify.qualify(
                parse_one("WITH tesT AS (SELECT * FROM t1) SELECT * FROM test", "bigquery"),
                db="db",
                catalog="catalog",
                dialect="bigquery",
                quote_identifiers=False,
            ).sql("bigquery"),
            "WITH test AS (SELECT * FROM catalog.db.t1 AS t1) SELECT * FROM test AS test",
        )

        self.assertEqual(
            optimizer.qualify_tables.qualify_tables(
                parse_one(
                    "WITH cte AS (SELECT * FROM t) SELECT * FROM cte PIVOT(SUM(c) FOR v IN ('x', 'y'))"
                ),
                db="db",
                catalog="catalog",
            ).sql(),
            "WITH cte AS (SELECT * FROM catalog.db.t AS t) SELECT * FROM cte AS cte PIVOT(SUM(c) FOR v IN ('x', 'y')) AS _0",
        )

        self.assertEqual(
            optimizer.qualify_tables.qualify_tables(
                parse_one(
                    "WITH cte AS (SELECT * FROM t) SELECT * FROM cte PIVOT(SUM(c) FOR v IN ('x', 'y')) AS pivot_alias"
                ),
                db="db",
                catalog="catalog",
            ).sql(),
            "WITH cte AS (SELECT * FROM catalog.db.t AS t) SELECT * FROM cte AS cte PIVOT(SUM(c) FOR v IN ('x', 'y')) AS pivot_alias",
        )

        self.assertEqual(
            optimizer.qualify_tables.qualify_tables(
                parse_one("select a from b"), catalog="catalog"
            ).sql(),
            "SELECT a FROM b AS b",
        )

        self.assertEqual(
            optimizer.qualify_tables.qualify_tables(parse_one("select a from b"), db='"DB"').sql(),
            'SELECT a FROM "DB".b AS b',
        )

        self.check_file(
            "qualify_tables",
            optimizer.qualify_tables.qualify_tables,
            db="db",
            catalog="c",
        )

    def test_qualify_tables_copies_typed_alias_columns(self):
        expression = parse_one('SELECT * FROM JSON_TO_RECORDSET(z) AS y("rank" INT)')

        original = expression.find(exp.Table).args["alias"].columns[0]
        self.assertIsInstance(original, exp.ColumnDef)

        optimizer.qualify_tables.qualify_tables(expression, canonicalize_table_aliases=True)

        new = expression.find(exp.Table).args["alias"].columns[0]
        self.assertIsInstance(new, exp.ColumnDef)
        self.assertIsNot(original, new)
        self.assertEqual(original.sql(), new.sql())

    def test_normalize(self):
        self.assertEqual(
            optimizer.normalize.normalize(
                parse_one("x AND (y OR z)"),
                dnf=True,
            ).sql(),
            "(x AND y) OR (x AND z)",
        )

        self.assertEqual(
            optimizer.normalize.normalize(
                parse_one("x AND (y OR z)"),
            ).sql(),
            "x AND (y OR z)",
        )

        self.check_file("normalize", normalize, schema=self.schema)

    @patch("sqlglot.generator.logger")
    def test_qualify_columns(self, logger):
        self.assertEqual(
            optimizer.qualify.qualify(
                parse_one(
                    """
                    SELECT Teams.Name, count(*)
                    FROM raw.TeamMemberships as TeamMemberships
                    join raw.Teams
                        on Teams.Id = TeamMemberships.TeamId
                    GROUP BY 1
                    """,
                    read="bigquery",
                ),
                schema={
                    "raw": {
                        "TeamMemberships": {
                            "Id": "INTEGER",
                            "UserId": "INTEGER",
                            "TeamId": "INTEGER",
                        },
                        "Teams": {
                            "Id": "INTEGER",
                            "Name": "STRING",
                        },
                    }
                },
                dialect="bigquery",
            ).sql(dialect="bigquery"),
            "SELECT `teams`.`name` AS `name`, count(*) AS `_col_1` FROM `raw`.`TeamMemberships` AS `teammemberships` JOIN `raw`.`Teams` AS `teams` ON `teams`.`id` = `teammemberships`.`teamid` GROUP BY `teams`.`name`",
        )
        self.assertEqual(
            optimizer.qualify.qualify(
                parse_one(
                    "SELECT `my_db.my_table`.`my_column` FROM `my_db.my_table`",
                    read="bigquery",
                ),
                dialect="bigquery",
            ).sql(dialect="bigquery"),
            "SELECT `my_table`.`my_column` AS `my_column` FROM `my_db.my_table` AS `my_table`",
        )

        self.assertEqual(
            optimizer.qualify_columns.qualify_columns(
                parse_one(
                    "WITH RECURSIVE t AS (SELECT 1 AS x UNION ALL SELECT x + 1 FROM t AS child WHERE x < 10) SELECT * FROM t"
                ),
                schema={},
                infer_schema=False,
            ).sql(),
            "WITH RECURSIVE t AS (SELECT 1 AS x UNION ALL SELECT child.x + 1 AS _col_0 FROM t AS child WHERE child.x < 10) SELECT t.x AS x FROM t",
        )

        self.assertEqual(
            optimizer.qualify_columns.qualify_columns(
                parse_one("WITH x AS (SELECT a FROM db.y) SELECT * FROM db.x"),
                schema={"db": {"x": {"z": "int"}, "y": {"a": "int"}}},
                expand_stars=False,
            ).sql(),
            "WITH x AS (SELECT y.a AS a FROM db.y) SELECT * FROM db.x",
        )

        self.assertEqual(
            optimizer.qualify_columns.qualify_columns(
                parse_one("WITH x AS (SELECT a FROM db.y) SELECT z FROM db.x"),
                schema={"db": {"x": {"z": "int"}, "y": {"a": "int"}}},
                infer_schema=False,
            ).sql(),
            "WITH x AS (SELECT y.a AS a FROM db.y) SELECT x.z AS z FROM db.x",
        )

        self.assertEqual(
            optimizer.qualify_columns.qualify_columns(
                parse_one("select y from x"),
                schema={},
                infer_schema=False,
            ).sql(),
            "SELECT y AS y FROM x",
        )

        self.assertEqual(
            optimizer.qualify.qualify(
                parse_one(
                    "WITH X AS (SELECT Y.A FROM DB.y CROSS JOIN a.b.INFORMATION_SCHEMA.COLUMNS) SELECT `A` FROM X",
                    read="bigquery",
                ),
                dialect="bigquery",
            ).sql(),
            'WITH "x" AS (SELECT "y"."a" AS "a" FROM "DB"."y" AS "y" CROSS JOIN "a"."b"."INFORMATION_SCHEMA.COLUMNS" AS "columns") SELECT "x"."a" AS "a" FROM "x" AS "x"',
        )

        self.assertEqual(
            optimizer.qualify.qualify(
                parse_one(
                    "CREATE FUNCTION udfs.`myTest`(`x` FLOAT64) AS (1)",
                    read="bigquery",
                ),
                dialect="bigquery",
            ).sql(dialect="bigquery"),
            "CREATE FUNCTION `udfs`.`myTest`(`x` FLOAT64) AS (1)",
        )

        self.assertEqual(
            optimizer.qualify.qualify(
                parse_one("SELECT `bar_bazfoo_$id` FROM test", read="spark"),
                schema={"test": {"bar_bazFoo_$id": "BIGINT"}},
                dialect="spark",
            ).sql(dialect="spark"),
            "SELECT `test`.`bar_bazfoo_$id` AS `bar_bazfoo_$id` FROM `test` AS `test`",
        )

        qualified = optimizer.qualify.qualify(
            parse_one("WITH t AS (SELECT 1 AS c) (SELECT c FROM t)")
        )
        self.assertIs(qualified.selects[0].parent, qualified)
        self.assertEqual(
            qualified.sql(),
            'WITH "t" AS (SELECT 1 AS "c") SELECT "t"."c" AS "c" FROM "t" AS "t"',
        )

        # can't coalesce USING columns because they don't exist in every already-joined table
        self.assertEqual(
            optimizer.qualify_columns.qualify_columns(
                parse_one(
                    "SELECT id, dt, v FROM (SELECT t1.id, t1.dt, sum(coalesce(t2.v, 0)) AS v FROM t1 AS t1 LEFT JOIN lkp AS lkp USING (id) LEFT JOIN t2 AS t2 USING (other_id, dt, common) WHERE t1.id > 10 GROUP BY 1, 2) AS `_0`",
                    dialect="bigquery",
                ),
                schema=MappingSchema(
                    schema={
                        "t1": {"id": "int64", "dt": "date", "common": "int64"},
                        "lkp": {"id": "int64", "other_id": "int64", "common": "int64"},
                        "t2": {"other_id": "int64", "dt": "date", "v": "int64", "common": "int64"},
                    },
                    dialect="bigquery",
                ),
            ).sql(dialect="bigquery"),
            "SELECT `_0`.id AS id, `_0`.dt AS dt, `_0`.v AS v FROM (SELECT t1.id AS id, t1.dt AS dt, sum(coalesce(t2.v, 0)) AS v FROM t1 AS t1 LEFT JOIN lkp AS lkp ON t1.id = lkp.id LEFT JOIN t2 AS t2 ON lkp.other_id = t2.other_id AND t1.dt = t2.dt AND COALESCE(t1.common, lkp.common) = t2.common WHERE t1.id > 10 GROUP BY t1.id, t1.dt) AS `_0`",
        )

        # Detection of correlation where columns are referenced in derived tables nested within subqueries
        self.assertEqual(
            optimizer.qualify.qualify(
                parse_one(
                    "SELECT a.g FROM a WHERE a.e < (SELECT MAX(u) FROM (SELECT SUM(c.b) AS u FROM c WHERE  c.d = f GROUP BY c.e) w)"
                ),
                schema={
                    "a": {"g": "INT", "e": "INT", "f": "INT"},
                    "c": {"d": "INT", "e": "INT", "b": "INT"},
                },
                quote_identifiers=False,
            ).sql(),
            "SELECT a.g AS g FROM a AS a WHERE a.e < (SELECT MAX(w.u) AS _col_0 FROM (SELECT SUM(c.b) AS u FROM c AS c WHERE c.d = a.f GROUP BY c.e) AS w)",
        )

        # Detection of correlation where columns are referenced in derived tables nested within lateral joins
        self.assertEqual(
            optimizer.qualify.qualify(
                parse_one(
                    "SELECT u.user_id, l.log_date FROM users AS u CROSS JOIN LATERAL (SELECT l1.log_date FROM (SELECT l.log_date FROM logs AS l WHERE l.user_id = u.user_id AND l.log_date <= 100 ORDER BY l.log_date LIMIT 1) AS l1) AS l",
                    dialect="postgres",
                ),
                schema={
                    "users": {"user_id": "text", "log_date": "date"},
                    "logs": {"user_id": "text", "log_date": "date"},
                },
                quote_identifiers=False,
            ).sql("postgres"),
            "SELECT u.user_id AS user_id, l.log_date AS log_date FROM users AS u CROSS JOIN LATERAL (SELECT l1.log_date AS log_date FROM (SELECT l.log_date AS log_date FROM logs AS l WHERE l.user_id = u.user_id AND l.log_date <= 100 ORDER BY l.log_date LIMIT 1) AS l1) AS l",
        )

        self.assertEqual(
            optimizer.qualify.qualify(
                parse_one(
                    "SELECT A.b_id FROM A JOIN B ON A.b_id=B.b_id JOIN C USING(c_id)",
                    dialect="postgres",
                ),
                schema={
                    "A": {"b_id": "int"},
                    "B": {"b_id": "int", "c_id": "int"},
                    "C": {"c_id": "int"},
                },
                quote_identifiers=False,
            ).sql("postgres"),
            "SELECT a.b_id AS b_id FROM a AS a JOIN b AS b ON a.b_id = b.b_id JOIN c AS c ON b.c_id = c.c_id",
        )
        self.assertEqual(
            optimizer.qualify.qualify(
                parse_one(
                    "SELECT A.b_id FROM A JOIN B ON A.b_id=B.b_id JOIN C ON B.b_id = C.b_id JOIN D USING(d_id)",
                    dialect="postgres",
                ),
                schema={
                    "A": {"b_id": "int"},
                    "B": {"b_id": "int", "d_id": "int"},
                    "C": {"b_id": "int"},
                    "D": {"d_id": "int"},
                },
                quote_identifiers=False,
            ).sql("postgres"),
            "SELECT a.b_id AS b_id FROM a AS a JOIN b AS b ON a.b_id = b.b_id JOIN c AS c ON b.b_id = c.b_id JOIN d AS d ON b.d_id = d.d_id",
        )

        self.assertEqual(
            optimizer.qualify.qualify(
                parse_one(
                    """
                    SELECT
                      (SELECT SUM(c.amount)
                       FROM UNNEST(credits) AS c
                       WHERE type != 'promotion') as total
                    FROM billing
                    """,
                    read="bigquery",
                ),
                schema={"billing": {"credits": "ARRAY<STRUCT<amount FLOAT64, type STRING>>"}},
                dialect="bigquery",
            ).sql(dialect="bigquery"),
            "SELECT (SELECT SUM(`c`.`amount`) AS `_col_0` FROM UNNEST(`billing`.`credits`) AS `c` WHERE `type` <> 'promotion') AS `total` FROM `billing` AS `billing`",
        )

        self.assertEqual(
            optimizer.qualify.qualify(
                parse_one(
                    """
                    WITH cte AS (SELECT * FROM base_table)
                    SELECT
                      (SELECT SUM(item.price)
                       FROM UNNEST(items) AS item
                       WHERE category = 'electronics') as electronics_total
                    FROM cte
                    """,
                    read="bigquery",
                ),
                schema={
                    "base_table": {
                        "id": "INT64",
                        "items": "ARRAY<STRUCT<price FLOAT64, category STRING>>",
                    }
                },
                dialect="bigquery",
            ).sql(dialect="bigquery"),
            "WITH `cte` AS (SELECT `base_table`.`id` AS `id`, `base_table`.`items` AS `items` FROM `base_table` AS `base_table`) SELECT (SELECT SUM(`item`.`price`) AS `_col_0` FROM UNNEST(`cte`.`items`) AS `item` WHERE `category` = 'electronics') AS `electronics_total` FROM `cte` AS `cte`",
        )

        self.check_file(
            "qualify_columns",
            qualify_columns,
            execute=True,
            schema=self.schema,
        )
        self.check_file("qualify_columns_ddl", qualify_columns, schema=self.schema)

        self.assertEqual(
            optimizer.qualify.qualify(
                parse_one(
                    """
                    SELECT
                    (
                        SELECT
                        col_st.value
                        FROM UNNEST(col_st) AS col_st
                    ) AS vcol1
                    FROM t AS b
                    """,
                    read="bigquery",
                ),
                schema={
                    "t": {
                        "col_st": "ARRAY<STRUCT<key STRING, value INT>>",
                    }
                },
                dialect="bigquery",
            ).sql(dialect="bigquery"),
            "SELECT (SELECT `col_st`.`value` AS `value` FROM UNNEST(`b`.`col_st`) AS `col_st`) AS `vcol1` FROM `t` AS `b`",
        )

        # Schema-qualified table joined twice (once unaliased, once aliased) should resolve correctly
        self.assertEqual(
            optimizer.qualify.qualify(
                parse_one(
                    "SELECT 1 FROM dbo.a JOIN dbo.b ON dbo.b.id = dbo.a.id JOIN dbo.b AS x ON x.id = dbo.a.id"
                ),
            ).sql(),
            'SELECT 1 AS "1" FROM "dbo"."a" AS "a" JOIN "dbo"."b" AS "b" ON "b"."id" = "a"."id" JOIN "dbo"."b" AS "x" ON "x"."id" = "a"."id"',
        )

        self.assertEqual(
            optimizer.qualify.qualify(
                parse_one("SELECT * FROM t"),
                schema={"t": {"end": "text"}},
                quote_identifiers=False,
            ).sql(),
            "SELECT t.end AS end FROM t AS t",
        )

        self.assertEqual(
            optimizer.qualify.qualify(
                parse_one(
                    "WITH produce AS (SELECT 'Kale' AS product, 51 AS q1, 23 AS q2) "
                    "SELECT * FROM produce UNPIVOT(sales FOR quarter IN (q1, q2))",
                    dialect="bigquery",
                ),
                dialect="bigquery",
            ).sql(dialect="bigquery"),
            "WITH `produce` AS (SELECT 'Kale' AS `product`, 51 AS `q1`, 23 AS `q2`) "
            "SELECT `produce`.`product` AS `product`, `produce`.`quarter` AS `quarter`, "
            "`produce`.`sales` AS `sales` FROM `produce` AS `produce` "
            "UNPIVOT(`sales` FOR `quarter` IN (`produce`.`q1`, `produce`.`q2`)) AS `produce`",
        )

        self.assertEqual(
            optimizer.qualify.qualify(
                parse_one(
                    "WITH cte AS (SELECT 1 AS a, 2 AS b, 3 AS c) "
                    "SELECT u.val, u.name FROM cte UNPIVOT(val FOR name IN (a, b, c)) AS u"
                ),
            ).sql(),
            'WITH "cte" AS (SELECT 1 AS "a", 2 AS "b", 3 AS "c") '
            'SELECT "u"."val" AS "val", "u"."name" AS "name" FROM "cte" AS "cte" '
            'UNPIVOT("val" FOR "name" IN ("cte"."a", "cte"."b", "cte"."c")) AS "u"',
        )

        self.assertEqual(
            optimizer.qualify.qualify(
                parse_one(
                    "WITH produce AS (SELECT 'Kale' AS product, 51 AS q1, 23 AS q2, 45 AS q3, 3 AS q4) "
                    "SELECT * FROM produce UNPIVOT((first_half, second_half) FOR semesters "
                    "IN ((q1, q2) AS 'h1', (q3, q4) AS 'h2'))",
                    dialect="bigquery",
                ),
                dialect="bigquery",
            ).sql(dialect="bigquery"),
            "WITH `produce` AS (SELECT 'Kale' AS `product`, 51 AS `q1`, 23 AS `q2`, 45 AS `q3`, 3 AS `q4`) "
            "SELECT `produce`.`product` AS `product`, `produce`.`semesters` AS `semesters`, "
            "`produce`.`first_half` AS `first_half`, `produce`.`second_half` AS `second_half` "
            "FROM `produce` AS `produce` UNPIVOT((`first_half`, `second_half`) FOR `semesters` "
            "IN ((`produce`.`q1`, `produce`.`q2`) AS 'h1', (`produce`.`q3`, `produce`.`q4`) AS 'h2')) AS `produce`",
        )

    def test_validate_columns(self):
        with self.assertRaisesRegex(
            OptimizeError, "Column 'foo' could not be resolved. Line: 1, Col: 10"
        ):
            optimizer.qualify.qualify(
                parse_one("select foo from x"),
                schema={"foo": {"y": "int"}},
            )

        # Test ambiguous columns error with PIVOT (which skips "could not be resolved" check)
        with self.assertRaisesRegex(OptimizeError, "Ambiguous column 'a'"):
            expression = parse_one(
                "SELECT * FROM (SELECT a, b, c FROM x) PIVOT (SUM(b) FOR c IN ('x', 'y'))"
            )
            qualified = optimizer.qualify_columns.qualify_columns(
                expression, schema={"x": {"a": "int", "b": "int", "c": "str"}}
            )
            optimizer.qualify_columns.validate_qualify_columns(qualified)

        schema = {"my_table": {"items": "ARRAY<STRUCT<name STRING, age INT>>"}}
        expression = annotate_types(
            optimizer.qualify.qualify(
                parse_one(
                    "SELECT ci.name, ci.age FROM my_table LATERAL VIEW EXPLODE(items) ci AS ci",
                    read="spark",
                ),
                schema=schema,
                dialect="spark",
            ),
            schema=schema,
            dialect="spark",
        )
        self.assertEqual(
            expression.sql(dialect="spark"),
            "SELECT `ci`.`name` AS `name`, `ci`.`age` AS `age` FROM `my_table` AS `my_table` LATERAL VIEW EXPLODE(`my_table`.`items`) ci AS `ci`",
        )
        self.assertEqual(expression.selects[0].type, exp.DataType.build("STRING", dialect="spark"))
        self.assertEqual(expression.selects[1].type, exp.DataType.build("INT", dialect="spark"))

        schema = {"my_table": {"items": "ARRAY<STRUCT<amount FLOAT, type STRING>>"}}
        expression = annotate_types(
            optimizer.qualify.qualify(
                parse_one(
                    "SELECT (SELECT SUM(ci.amount) FROM my_table LATERAL VIEW EXPLODE(items) ci AS ci WHERE ci.type = 'promotion') AS total FROM my_table",
                    read="spark",
                ),
                schema=schema,
                dialect="spark",
            ),
            schema=schema,
            dialect="spark",
        )
        self.assertEqual(
            expression.sql(dialect="spark"),
            "SELECT (SELECT SUM(`ci`.`amount`) AS `_col_0` FROM `my_table` AS `my_table` LATERAL VIEW EXPLODE(`my_table`.`items`) ci AS `ci` WHERE `ci`.`type` = 'promotion') AS `total` FROM `my_table` AS `my_table`",
        )
        self.assertEqual(expression.selects[0].type, exp.DataType.build("DOUBLE", dialect="spark"))

    def test_qualify_columns__with_invisible(self):
        schema = MappingSchema(self.schema, {"x": {"a"}, "y": {"b"}, "z": {"b"}})
        self.check_file("qualify_columns__with_invisible", qualify_columns, schema=schema)

    def test_pushdown_cte_alias_columns(self):
        self.check_file(
            "pushdown_cte_alias_columns",
            pushdown_ctes,
        )

    def test_qualify_columns__invalid(self):
        for sql in load_sql_fixtures("optimizer/qualify_columns__invalid.sql"):
            with self.subTest(sql):
                with self.assertRaises((OptimizeError, SchemaError)):
                    expression = optimizer.qualify_columns.qualify_columns(
                        parse_one(sql), schema=self.schema
                    )
                    optimizer.qualify_columns.validate_qualify_columns(expression)

        # this makes sure the fallback scenario in get_table in resolver is covered
        # and the error message is column cannot be resolved instead of unknown table
        sql = """
            SELECT
            INLINE_VIEW.a AS ACCOUNT
            FROM (
            (
                SELECT
                a
                FROM table1
            ) inline_view
            LEFT JOIN table2
                ON a = table2.id
            )
            LEFT JOIN table3
            ON inline_view.a = table3.a
        """

        with self.assertRaises(OptimizeError) as ctx:
            schema = MappingSchema()
            schema.add_table("table3", ["a"])

            expression = optimizer.qualify_columns.qualify_columns(parse_one(sql), schema=schema)
            optimizer.qualify_columns.validate_qualify_columns(expression)

        error_msg = str(ctx.exception)
        self.assertIn("Column 'a' could not be resolved", error_msg)

    def test_optimize_error_highlighting(self):
        # highlighting works with sql parameter
        sql = "SELECT nonexistent FROM x"

        with self.assertRaises(OptimizeError) as ctx:
            optimizer.optimize(sql, schema=self.schema, sql=sql)

        error_msg = str(ctx.exception)
        self.assertIn("Column 'nonexistent' could not be resolved", error_msg)
        self.assertIn(f"{ANSI_UNDERLINE}nonexistent{ANSI_RESET}", error_msg)

        # no highlighting when sql is None
        sql = "SELECT nonexistent FROM x"

        with self.assertRaises(OptimizeError) as ctx:
            optimizer.optimize(sql, schema=self.schema, sql=None)

        error_msg = str(ctx.exception)
        self.assertIn("Column 'nonexistent' could not be resolved", error_msg)
        self.assertNotIn(f"{ANSI_UNDERLINE}nonexistent{ANSI_RESET}", error_msg)

    def test_normalize_identifiers(self):
        self.check_file(
            "normalize_identifiers",
            optimizer.normalize_identifiers.normalize_identifiers,
        )

        self.assertEqual(optimizer.normalize_identifiers.normalize_identifiers("a%").sql(), '"a%"')

    def test_quote_identifiers(self):
        self.check_file(
            "quote_identifiers",
            optimizer.qualify_columns.quote_identifiers,
        )

    def test_pushdown_projection(self):
        self.check_file("pushdown_projections", pushdown_projections, schema=self.schema)

    def test_simplify(self):
        self.check_file("simplify", simplify, schema=self.schema)

        # Stress test with huge union query
        union_sql = "SELECT 1 UNION ALL " * 1000 + "SELECT 1"
        expression = parse_one(union_sql)
        self.assertEqual(optimizer.simplify.simplify(expression).sql(), union_sql)

        # Ensure simplify mutates the AST properly
        expression = parse_one("SELECT 1 + 2")
        simplify(expression.selects[0])
        self.assertEqual(expression.sql(), "SELECT 3")

        expression = parse_one("SELECT a, c, b FROM table1 WHERE 1 = 1")
        self.assertEqual(simplify(simplify(expression.find(exp.Where))).sql(), "WHERE TRUE")

        expression = parse_one("TRUE AND TRUE AND TRUE")
        self.assertEqual(exp.true(), optimizer.simplify.simplify(expression))

        # CONCAT in (e.g.) Presto is parsed as Concat instead of SafeConcat which is the default type
        # This test checks that simplify_concat preserves the corresponding expression types.
        concat = parse_one("CONCAT('a', x, 'b', 'c')", read="presto")
        simplified_concat = optimizer.simplify.simplify(concat)

        safe_concat = parse_one("CONCAT('a', x, 'b', 'c')")
        simplified_safe_concat = optimizer.simplify.simplify(safe_concat)

        self.assertEqual(simplified_concat.args["safe"], False)
        self.assertEqual(simplified_safe_concat.args["safe"], True)

        self.assertEqual("CONCAT('a', x, 'bc')", simplified_concat.sql(dialect="presto"))
        self.assertEqual("CONCAT('a', x, 'bc')", simplified_safe_concat.sql())

        anon_unquoted_str = parse_one("anonymous(x, y)")
        self.assertEqual(optimizer.simplify.gen(anon_unquoted_str), "ANONYMOUS(x,y)")

        query = parse_one("SELECT x FROM t")
        self.assertEqual(optimizer.simplify.gen(query), optimizer.simplify.gen(query.copy()))

        anon_unquoted_identifier = exp.Anonymous(
            this=exp.to_identifier("anonymous"),
            expressions=[exp.column("x"), exp.column("y")],
        )
        self.assertEqual(optimizer.simplify.gen(anon_unquoted_identifier), "ANONYMOUS(x,y)")

        anon_quoted = parse_one('"anonymous"(x, y)')
        self.assertEqual(optimizer.simplify.gen(anon_quoted), '"anonymous"(x,y)')

        with self.assertRaises(ValueError) as e:
            anon_invalid = exp.Anonymous(this=5)
            optimizer.simplify.gen(anon_invalid)

        self.assertIn(
            "Anonymous.this expects a str or an Identifier, got 'int'.",
            str(e.exception),
        )

        sql = parse_one(
            """
        WITH cte AS (select 1 union select 2), cte2 AS (
            SELECT ROW() OVER (PARTITION BY y) FROM (
                (select 1) limit 10
            )
        )
        SELECT
          *,
          a + 1,
          a div 1,
          filter("B", (x, y) -> x + y)
          FROM (z AS z CROSS JOIN z) AS f(a) LEFT JOIN a.b.c.d.e.f.g USING(n) ORDER BY 1
        """
        )
        self.assertEqual(
            optimizer.simplify.gen(sql),
            """
SELECT :with_,WITH :expressions,CTE :this,UNION :this,SELECT :expressions,1,:expression,SELECT :expressions,2,:distinct,True,:alias, AS cte,CTE :this,SELECT :expressions,WINDOW :this,ROW(),:partition_by,y,:over,OVER,:from_,FROM ((SELECT :expressions,1):limit,LIMIT :expression,10),:alias, AS cte2,:expressions,STAR,a + 1,a DIV 1,FILTER("B",LAMBDA :this,x + y,:expressions,x,y),:from_,FROM (z AS z:joins,JOIN :this,z,:kind,CROSS) AS f(a),:joins,JOIN :this,a.b.c.d.e.f.g,:side,LEFT,:using,n,:order,ORDER :expressions,ORDERED :this,1,:nulls_first,True
""".strip(),
        )
        self.assertEqual(
            optimizer.simplify.gen(parse_one("select item_id /* description */"), comments=True),
            "SELECT :expressions,item_id /* description */",
        )

    def test_simplify_nested(self):
        sql = """
        SELECT x, 1 + 1
        FROM foo
        WHERE x > (((select x + 1 + 1, sum(y + 1 + 1) FROM bar GROUP BY x + 1 + 1)))
        """

        self.assertEqual(
            parse_one("""
            SELECT x, 2
            FROM foo
            WHERE x > (((
                select x + 1 + 1, sum(y + 2)
                FROM bar
                GROUP BY x + 1 + 1
            )))
            """).sql(pretty=True),
            optimizer.simplify.simplify(parse_one(sql)).sql(pretty=True),
        )

    def test_unnest_subqueries(self):
        self.check_file("unnest_subqueries", optimizer.unnest_subqueries.unnest_subqueries)

    def test_pushdown_predicates(self):
        self.check_file("pushdown_predicates", optimizer.pushdown_predicates.pushdown_predicates)

    def test_expand_alias_refs(self):
        # check negative integer literal as group by column
        self.assertEqual(
            optimizer.optimize("SELECT -99 AS e GROUP BY e").sql(),
            'SELECT -99 AS "e" GROUP BY 1',
        )

        # check order of lateral expansion with no schema
        self.assertEqual(
            optimizer.optimize("SELECT a + 1 AS d, d + 1 AS e FROM x WHERE e > 1 GROUP BY e").sql(),
            'SELECT "x"."a" + 1 AS "d", "x"."a" + 1 + 1 AS "e" FROM "x" AS "x" WHERE ("x"."a" + 2) > 1 GROUP BY "x"."a" + 1 + 1',
        )

        unused_schema = {"l": {"c": "int"}}
        self.assertEqual(
            optimizer.qualify_columns.qualify_columns(
                parse_one("SELECT CAST(x AS INT) AS y FROM z AS z"),
                schema=unused_schema,
                infer_schema=False,
            ).sql(),
            "SELECT CAST(x AS INT) AS y FROM z AS z",
        )

        # BigQuery expands overlapping alias only for GROUP BY + HAVING
        sql = "WITH data AS (SELECT 1 AS id, 2 AS my_id, 'a' AS name, 'b' AS full_name) SELECT id AS my_id, CONCAT(id, name) AS full_name FROM data WHERE my_id = 1 GROUP BY my_id, full_name HAVING my_id = 1"
        self.assertEqual(
            optimizer.qualify_columns.qualify_columns(
                parse_one(sql, dialect="bigquery"),
                schema=MappingSchema(schema=unused_schema, dialect="bigquery"),
            ).sql(),
            "WITH data AS (SELECT 1 AS id, 2 AS my_id, 'a' AS name, 'b' AS full_name) SELECT data.id AS my_id, CONCAT(data.id, data.name) AS full_name FROM data WHERE data.my_id = 1 GROUP BY data.id, CONCAT(data.id, data.name) HAVING data.id = 1",
        )

        # Clickhouse expands overlapping alias across the entire query
        self.assertEqual(
            optimizer.qualify_columns.qualify_columns(
                parse_one(sql, dialect="clickhouse"),
                schema=MappingSchema(schema=unused_schema, dialect="clickhouse"),
            ).sql(),
            "WITH data AS (SELECT 1 AS id, 2 AS my_id, 'a' AS name, 'b' AS full_name) SELECT data.id AS my_id, CONCAT(data.id, data.name) AS full_name FROM data WHERE data.id = 1 GROUP BY data.id, CONCAT(data.id, data.name) HAVING data.id = 1",
        )

        # Edge case: BigQuery shouldn't expand aliases in complex expressions
        sql = "WITH data AS (SELECT 1 AS id) SELECT FUNC(id) AS id FROM data GROUP BY FUNC(id)"
        self.assertEqual(
            optimizer.qualify_columns.qualify_columns(
                parse_one(sql, dialect="bigquery"),
                schema=MappingSchema(schema=unused_schema, dialect="bigquery"),
            ).sql(),
            "WITH data AS (SELECT 1 AS id) SELECT FUNC(data.id) AS id FROM data GROUP BY FUNC(data.id)",
        )

        sql = "SELECT x.a, max(x.b) as x FROM x AS x GROUP BY 1 HAVING x > 1"
        self.assertEqual(
            optimizer.qualify_columns.qualify_columns(
                parse_one(sql, dialect="bigquery"),
                schema=MappingSchema(schema=unused_schema, dialect="bigquery"),
            ).sql(),
            "SELECT x.a AS a, MAX(x.b) AS x FROM x AS x GROUP BY 1 HAVING x > 1",
        )

    def test_optimize_joins(self):
        self.check_file(
            "optimize_joins",
            optimizer.optimize_joins.optimize_joins,
        )

    def test_eliminate_joins(self):
        self.check_file(
            "eliminate_joins",
            optimizer.eliminate_joins.eliminate_joins,
            pretty=True,
        )

    def test_eliminate_ctes(self):
        self.check_file(
            "eliminate_ctes",
            optimizer.eliminate_ctes.eliminate_ctes,
            pretty=True,
        )

    @patch("sqlglot.generator.logger")
    def test_merge_subqueries(self, logger):
        optimize = partial(
            optimizer.optimize,
            rules=[
                optimizer.qualify_tables.qualify_tables,
                optimizer.qualify_columns.qualify_columns,
                optimizer.merge_subqueries.merge_subqueries,
            ],
        )

        self.check_file("merge_subqueries", optimize, execute=True, schema=self.schema)

    def test_eliminate_subqueries(self):
        self.check_file("eliminate_subqueries", optimizer.eliminate_subqueries.eliminate_subqueries)

    def test_canonicalize_internal_names(self):
        schema = {
            **self.schema,
            "jtbl": {"j": "JSON"},
            "pvt": {"c": "TEXT", "v": "INT"},
        }

        self.check_file(
            "canonicalize_internal_names",
            qualify_then_canonicalize,
            schema=schema,
            catalog="c",
            db="db",
        )

        # Physical table identity is part of the data contract: reading the same columns
        # from a different table is a real change and must produce a different canonical form.
        # (Tables are assumed to be qualified with catalog.db.table; an unqualified table
        # name is treated as an internal handle and canonicalized, like a CTE reference.)
        canon_a = qualify_then_canonicalize(
            parse_one("SELECT id, name FROM cat.db.users WHERE id > 5"),
            schema={"cat": {"db": {"users": {"id": "INT", "name": "TEXT"}}}},
        )
        canon_diff_table = qualify_then_canonicalize(
            parse_one("SELECT id, name FROM cat.db.employees WHERE id > 5"),
            schema={"cat": {"db": {"employees": {"id": "INT", "name": "TEXT"}}}},
        )
        self.assertNotEqual(canon_a.sql(), canon_diff_table.sql())

        # Renaming a base-table column is likewise a data-contract change and must be
        # detected even when everything else about the query shape is identical.
        canon_rename = qualify_then_canonicalize(
            parse_one("SELECT emp_id, full_name FROM cat.db.users WHERE emp_id > 5"),
            schema={"cat": {"db": {"users": {"emp_id": "INT", "full_name": "TEXT"}}}},
        )
        self.assertNotEqual(canon_a.sql(), canon_rename.sql())

        # User-chosen table alias is an internal handle with no semantic effect — the same
        # query with a different alias produces the same canonical form.
        canon_alias_a = qualify_then_canonicalize(
            parse_one("SELECT foo.id FROM users AS foo"),
            schema={"users": {"id": "INT"}},
        )
        canon_alias_b = qualify_then_canonicalize(
            parse_one("SELECT bar.id FROM users AS bar"),
            schema={"users": {"id": "INT"}},
        )
        self.assertEqual(canon_alias_a.sql(), canon_alias_b.sql())

        # Aliases on sources whose columns are never referenced are still internal
        # handles and must be canonicalized — otherwise structurally identical queries
        # would diverge purely on user-chosen names.
        canon_unref_a = qualify_then_canonicalize(
            parse_one("SELECT 1 FROM users AS foo CROSS JOIN logs AS bar"),
            schema={"users": {"id": "INT"}, "logs": {"id": "INT"}},
        )
        canon_unref_b = qualify_then_canonicalize(
            parse_one("SELECT 1 FROM users AS baz CROSS JOIN logs AS qux"),
            schema={"users": {"id": "INT"}, "logs": {"id": "INT"}},
        )
        self.assertEqual(canon_unref_a.sql(), canon_unref_b.sql())

        canon_exists_a = qualify_then_canonicalize(
            parse_one("SELECT 1 FROM t WHERE EXISTS(SELECT 1 FROM s AS abc)"),
            schema={"t": {"id": "INT"}, "s": {"id": "INT"}},
        )
        canon_exists_b = qualify_then_canonicalize(
            parse_one("SELECT 1 FROM t WHERE EXISTS(SELECT 1 FROM s AS xyz)"),
            schema={"t": {"id": "INT"}, "s": {"id": "INT"}},
        )
        self.assertEqual(canon_exists_a.sql(), canon_exists_b.sql())

        # Physical table identity is preserved for real tables (only the alias is
        # canonicalized); base-table column names and top-level output aliases are
        # preserved because they're part of the query's outward data contract.
        canon = qualify_then_canonicalize(
            parse_one("SELECT a FROM x"),
            schema={"x": {"a": "INT"}},
            db="mydb",
            catalog="cat",
        )
        self.assertEqual(canon.sql(), 'SELECT "_t0"."a" AS "a" FROM "cat"."mydb"."x" AS "_t0"')

        # Top-level output alias is part of the contract — renaming it changes the
        # canonical form even though the underlying data is identical.
        canon_named = qualify_then_canonicalize(
            parse_one("SELECT a AS alpha FROM x"), schema={"x": {"a": "INT"}}
        )
        canon_renamed = qualify_then_canonicalize(
            parse_one("SELECT a AS beta FROM x"), schema={"x": {"a": "INT"}}
        )
        self.assertNotEqual(canon_named.sql(), canon_renamed.sql())

        # Internal alias inside a CTE is self-consistent (the outer query must use the
        # same name for the rename to be valid SQL), so renaming it with the top-level
        # contract name held constant must not change the canonical form.
        canon_inner_a = qualify_then_canonicalize(
            parse_one("WITH t AS (SELECT a AS foo FROM x) SELECT foo AS result FROM t"),
            schema={"x": {"a": "INT"}},
        )
        canon_inner_b = qualify_then_canonicalize(
            parse_one("WITH t AS (SELECT a AS bar FROM x) SELECT bar AS result FROM t"),
            schema={"x": {"a": "INT"}},
        )
        self.assertEqual(canon_inner_a.sql(), canon_inner_b.sql())

        # Changing which base-table column a CTE reads must be detected as a real
        # change even when the outer query is byte-for-byte identical (the CTE
        # internally aliases the column so the outer reference name doesn't move).
        canon_cte_col_a = qualify_then_canonicalize(
            parse_one("WITH t AS (SELECT a AS x FROM src) SELECT x FROM t"),
            schema={"src": {"a": "INT", "b": "INT"}},
        )
        canon_cte_col_b = qualify_then_canonicalize(
            parse_one("WITH t AS (SELECT b AS x FROM src) SELECT x FROM t"),
            schema={"src": {"a": "INT", "b": "INT"}},
        )
        self.assertNotEqual(canon_cte_col_a.sql(), canon_cte_col_b.sql())

        # UNION BY NAME: different column-name sets must produce different canonical forms
        # (two branches share no column name => NULL-padded) vs (both share "a" => unified)
        schema_ux = {"x": {"a": "INT"}, "y": {"a": "INT", "b": "INT"}}
        canon_match = qualify_then_canonicalize(
            parse_one("SELECT a FROM x UNION BY NAME SELECT a FROM y", dialect="duckdb"),
            schema=schema_ux,
            dialect="duckdb",
        ).sql(dialect="duckdb")
        canon_diff = qualify_then_canonicalize(
            parse_one("SELECT a FROM x UNION BY NAME SELECT b FROM y", dialect="duckdb"),
            schema=schema_ux,
            dialect="duckdb",
        ).sql(dialect="duckdb")
        self.assertNotEqual(canon_match, canon_diff)

        # UNION BY NAME with a nested rhs: swapping the source column inside the nested
        # branch must still be caught as a data-contract change.
        schema_nested = {
            "x": {"a": "INT"},
            "y": {"b": "INT"},
            "z": {"c": "INT", "d": "INT"},
        }
        canon_nested_a = qualify_then_canonicalize(
            parse_one(
                "SELECT a + 1 AS shared FROM x UNION BY NAME "
                "(SELECT b AS shared FROM y UNION BY NAME SELECT c AS shared FROM z)",
                dialect="duckdb",
            ),
            schema=schema_nested,
            dialect="duckdb",
        ).sql(dialect="duckdb")
        canon_nested_b = qualify_then_canonicalize(
            parse_one(
                "SELECT a + 1 AS shared FROM x UNION BY NAME "
                "(SELECT b AS shared FROM y UNION BY NAME SELECT d AS shared FROM z)",
                dialect="duckdb",
            ),
            schema=schema_nested,
            dialect="duckdb",
        ).sql(dialect="duckdb")
        self.assertNotEqual(canon_nested_a, canon_nested_b)

        # Case-folding semantics: in case-insensitive dialects (e.g. postgres, lowercase-folding)
        # unquoted `a` and quoted `"a"` refer to the same column and must match.
        pg_schema = {"x": {"a": "INT", "b": "INT"}}
        canon_pg_a = qualify_then_canonicalize(
            parse_one("SELECT a FROM x", dialect="postgres"), schema=pg_schema, dialect="postgres"
        ).sql(dialect="postgres")
        canon_pg_qa = qualify_then_canonicalize(
            parse_one('SELECT "a" FROM x', dialect="postgres"), schema=pg_schema, dialect="postgres"
        ).sql(dialect="postgres")
        self.assertEqual(canon_pg_a, canon_pg_qa)

        # In Snowflake (upper-folding), unquoted `a` becomes `A`, while quoted `"a"` stays
        # lowercase — they reference *different* columns. Base-table names are preserved,
        # and the quote state on the lowercase column is retained because dropping it
        # would let Snowflake re-case-fold `a` back to `A` (changing semantics).
        sf_schema = {"X": {"A": "INT", '"a"': "INT"}}
        canon_sf = qualify_then_canonicalize(
            parse_one('SELECT a, "a" FROM x', dialect="snowflake"),
            schema=sf_schema,
            dialect="snowflake",
        ).sql(dialect="snowflake")
        self.assertEqual(
            canon_sf,
            'SELECT "_t0"."A" AS "A", "_t0"."a" AS "a" FROM "_t0" AS "_t0"',
        )

        # But unquoted `A` and quoted `"A"` reference the same column — they must coalesce
        # to the same canonical form.
        sf_schema2 = {"X": {"A": "INT"}}
        canon_sf2 = qualify_then_canonicalize(
            parse_one('SELECT A, "A" FROM x', dialect="snowflake"),
            schema=sf_schema2,
            dialect="snowflake",
        ).sql(dialect="snowflake")
        self.assertEqual(canon_sf2, 'SELECT "_t0"."A" AS "A", "_t0"."A" AS "A" FROM "_t0" AS "_t0"')

        # Multiple references to the same source within a single scope (self-join on a
        # CTE) must produce distinct per-reference aliases. Forcing each Table.alias to
        # match the source's canonical name collapses both into `_tN AS _tN` and breaks
        # downstream consumers (lineage's Scope.selected_sources raises "Alias already
        # used"); column qualifiers like `x.foo` and `y.foo` also collapse to identical
        # AST nodes, losing the distinction between the two references.
        cte_self_join_schema = {"src": {"foo": "INT", "bar": "INT"}}
        canon_self_join = qualify_then_canonicalize(
            parse_one(
                "WITH t AS (SELECT * FROM src) "
                "SELECT x.foo AS l, y.bar AS r FROM t AS x JOIN t AS y ON x.foo = y.foo"
            ),
            schema=cte_self_join_schema,
        )
        self.assertEqual(
            canon_self_join.sql(),
            'WITH "_t1" AS (SELECT "_t0"."foo" AS "_c0", "_t0"."bar" AS "_c1" FROM "_t0" AS "_t0") '
            'SELECT "_t2"."_c0" AS "l", "_t3"."_c1" AS "r" '
            'FROM "_t1" AS "_t2" JOIN "_t1" AS "_t3" ON "_t2"."_c0" = "_t3"."_c0"',
        )

        # Three references to the same CTE: each gets its own alias from the global
        # `_tN` sequence, and column refs are correctly disambiguated per reference.
        canon_triple = qualify_then_canonicalize(
            parse_one(
                "WITH t AS (SELECT * FROM src) "
                "SELECT a.foo, b.foo, c.foo FROM t AS a "
                "JOIN t AS b ON a.foo = b.foo "
                "JOIN t AS c ON b.foo = c.foo"
            ),
            schema=cte_self_join_schema,
        )
        # Re-walking the canonicalized AST must succeed (this is exactly what lineage
        # does when computing Scope.selected_sources, and where the bug surfaced).
        # selected_sources on the outer scope must contain three distinct entries —
        # one per Table reference — even though they all back the same CTE source.
        canon_triple_scope = build_scope(canon_triple)
        assert canon_triple_scope is not None
        outer_table_aliases = [t.alias for t in canon_triple_scope.tables]
        self.assertEqual(len(set(outer_table_aliases)), 3, outer_table_aliases)
        self.assertEqual(len(canon_triple_scope.selected_sources), 3)

    def test_canonicalize(self):
        optimize = partial(
            optimizer.optimize,
            rules=[
                optimizer.qualify.qualify,
                optimizer.qualify_columns.quote_identifiers,
                annotate_types,
                optimizer.canonicalize.canonicalize,
            ],
        )
        self.check_file("canonicalize", optimize, schema=self.schema)

        # In T-SQL and Redshift, SELECT a + b can produce a NULL, so we can't transpile it
        # into a CONCAT in Postgres, because that coalesces NULL values with empty strings
        ast = optimize("SELECT CAST(a AS TEXT) + CAST(b AS TEXT) FROM t", dialect="tsql")
        self.assertEqual(
            ast.sql("postgres"),
            'SELECT CAST("t"."a" AS TEXT) || CAST("t"."b" AS TEXT) AS "_col_0" FROM "t" AS "t"',
        )

    def test_tpch(self):
        self.check_file("tpc-h/tpc-h", optimizer.optimize, schema=TPCH_SCHEMA, pretty=True)

    def test_tpcds(self):
        self.check_file("tpc-ds/tpc-ds", optimizer.optimize, schema=TPCDS_SCHEMA, pretty=True)

    def test_file_schema(self):
        self.assertEqual(
            optimizer.optimize(
                "SELECT * FROM foo",
                on_qualify=lambda table: table.replace(exp.to_table("bar")),
            ).sql(),
            'SELECT * FROM "bar"',
        )

    def test_scope(self):
        ast = parse_one("SELECT IF(a IN UNNEST(b), 1, 0) AS c FROM t", dialect="bigquery")
        self.assertEqual(build_scope(ast).columns, [exp.column("a"), exp.column("b")])

        many_unions = parse_one(" UNION ALL ".join(["SELECT x FROM t"] * 10000))
        scopes_using_traverse = list(build_scope(many_unions).traverse())
        scopes_using_traverse_scope = traverse_scope(many_unions)
        self.assertEqual(len(scopes_using_traverse), len(scopes_using_traverse_scope))
        assert all(
            x.expression is y.expression
            for x, y in zip(scopes_using_traverse, scopes_using_traverse_scope)
        )

        sql = """
        WITH q AS (
          SELECT x.b FROM x
        ), r AS (
          SELECT y.b FROM y
        ), z as (
          SELECT cola, colb FROM (VALUES(1, 'test')) AS tab(cola, colb)
        )
        SELECT
          r.b,
          s.b
        FROM r
        JOIN (
          SELECT y.c AS b FROM y
        ) s
        ON s.b = r.b
        WHERE s.b > (SELECT MAX(x.a) FROM x WHERE x.b = s.b)
        """
        expression = parse_one(sql)
        for scopes in traverse_scope(expression), list(build_scope(expression).traverse()):
            self.assertEqual(len(scopes), 7)
            self.assertEqual(scopes[0].expression.sql(), "SELECT x.b FROM x")
            self.assertEqual(scopes[1].expression.sql(), "SELECT y.b FROM y")
            self.assertEqual(scopes[2].expression.sql(), "(VALUES (1, 'test')) AS tab(cola, colb)")
            self.assertEqual(
                scopes[3].expression.sql(),
                "SELECT cola, colb FROM (VALUES (1, 'test')) AS tab(cola, colb)",
            )
            self.assertEqual(scopes[4].expression.sql(), "SELECT y.c AS b FROM y")
            self.assertEqual(scopes[5].expression.sql(), "SELECT MAX(x.a) FROM x WHERE x.b = s.b")
            self.assertEqual(scopes[6].expression.sql(), parse_one(sql).sql())

            self.assertEqual(set(scopes[6].sources), {"q", "z", "r", "s"})
            self.assertEqual(len(scopes[6].columns), 6)
            self.assertEqual({c.table for c in scopes[6].columns}, {"r", "s"})
            self.assertEqual(scopes[6].source_columns("q"), [])
            self.assertEqual(len(scopes[6].source_columns("r")), 2)
            self.assertEqual({c.table for c in scopes[6].source_columns("r")}, {"r"})

            self.assertEqual({c.sql() for c in scopes[-1].find_all(exp.Column)}, {"r.b", "s.b"})
            self.assertEqual(scopes[-1].find(exp.Column).sql(), "r.b")
            self.assertEqual({c.sql() for c in scopes[0].find_all(exp.Column)}, {"x.b"})

        # Check that we can walk in scope from an arbitrary node
        self.assertEqual(
            {
                node.sql()
                for node in walk_in_scope(expression.find(exp.Where))
                if isinstance(node, exp.Column)
            },
            {"s.b"},
        )

        # Check that parentheses don't introduce a new scope unless an alias is attached
        sql = "SELECT * FROM (((SELECT * FROM (t1 JOIN t2) AS t3) JOIN (SELECT * FROM t4)))"
        expression = parse_one(sql)
        for scopes in traverse_scope(expression), list(build_scope(expression).traverse()):
            self.assertEqual(len(scopes), 4)

            self.assertEqual(scopes[0].expression.sql(), "t1, t2")
            self.assertEqual(set(scopes[0].sources), {"t1", "t2"})

            self.assertEqual(scopes[1].expression.sql(), "SELECT * FROM (t1, t2) AS t3")
            self.assertEqual(set(scopes[1].sources), {"t3"})

            self.assertEqual(scopes[2].expression.sql(), "SELECT * FROM t4")
            self.assertEqual(set(scopes[2].sources), {"t4"})

            self.assertEqual(
                scopes[3].expression.sql(),
                "SELECT * FROM (((SELECT * FROM (t1, t2) AS t3), (SELECT * FROM t4)))",
            )
            self.assertEqual(set(scopes[3].sources), {""})

        inner_query = "SELECT bar FROM baz"
        for udtf in (f"UNNEST(({inner_query}))", f"LATERAL ({inner_query})"):
            sql = f"SELECT a FROM foo CROSS JOIN {udtf}"
            expression = parse_one(sql)

            for scopes in traverse_scope(expression), list(build_scope(expression).traverse()):
                self.assertEqual(len(scopes), 3)

                self.assertEqual(scopes[0].expression.sql(), inner_query)
                self.assertEqual(set(scopes[0].sources), {"baz"})

                self.assertEqual(scopes[1].expression.sql(), udtf)
                self.assertEqual(set(scopes[1].sources), {"", "foo"})  # foo is a lateral source

                self.assertEqual(scopes[2].expression.sql(), f"SELECT a FROM foo CROSS JOIN {udtf}")
                self.assertEqual(set(scopes[2].sources), {"", "foo"})

        # Check DML statement scopes
        sql = (
            "UPDATE customers SET total_spent = (SELECT 1 FROM t1) WHERE EXISTS (SELECT 1 FROM t2)"
        )
        self.assertEqual(len(traverse_scope(parse_one(sql))), 3)

        sql = "UPDATE tbl1 SET col = 1 WHERE EXISTS (SELECT 1 FROM tbl2 WHERE tbl1.id = tbl2.id)"
        self.assertEqual(len(traverse_scope(parse_one(sql))), 1)

        sql = "UPDATE tbl1 SET col = 0"
        self.assertEqual(len(traverse_scope(parse_one(sql))), 0)

        sql = "SELECT * FROM t LEFT JOIN UNNEST(a) AS a1 LEFT JOIN UNNEST(a1.a) AS a2"
        scope = build_scope(parse_one(sql, read="bigquery"))
        self.assertEqual(set(scope.selected_sources), {"t", "a1", "a2"})

        # Correlated subquery must be detected even when the outer table name collides with a CTE name
        sql = "WITH x AS (SELECT 1 AS id) SELECT x.id, (SELECT MAX(x2.id) FROM x AS x2 WHERE x2.id = x.id) AS mx FROM x"
        scopes = traverse_scope(parse_one(sql))
        subquery_scope = next(s for s in scopes if s.is_subquery)
        self.assertTrue(subquery_scope.is_correlated_subquery)
        self.assertIn("x.id", [c.sql() for c in subquery_scope.external_columns])

        # Correlated subquery referencing a CTE defined in the same WITH clause as another CTE used in the outer query
        sql = "WITH x AS (SELECT 1 AS id), y AS (SELECT 2 AS id) SELECT (SELECT y.id FROM y WHERE y.id = x.id) FROM x"
        scopes = traverse_scope(parse_one(sql))
        subquery_scope = next(s for s in scopes if s.is_subquery)
        self.assertTrue(subquery_scope.is_correlated_subquery)
        self.assertIn("x.id", [c.sql() for c in subquery_scope.external_columns])

        # Correlated subquery referencing outer CTE through a derived table
        sql = "WITH x AS (SELECT 1 AS id) SELECT (SELECT x.id FROM (SELECT * FROM x) AS sub) FROM x"
        scopes = traverse_scope(parse_one(sql))
        subquery_scope = next(s for s in scopes if s.is_subquery)
        self.assertTrue(subquery_scope.is_correlated_subquery)
        self.assertIn("x.id", [c.sql() for c in subquery_scope.external_columns])

    @patch("sqlglot.optimizer.scope.logger")
    def test_scope_warning(self, logger):
        self.assertEqual(len(traverse_scope(parse_one("WITH q AS (@y) SELECT * FROM q"))), 1)
        assert_logger_contains(
            "Cannot traverse scope %s with type '%s'",
            logger,
            level="warning",
        )

    def test_annotate_types(self):
        for i, (meta, sql, expected) in enumerate(
            load_sql_fixture_pairs("optimizer/annotate_types.sql"), start=1
        ):
            title = meta.get("title") or f"{i}, {sql}"
            dialect = meta.get("dialect")
            result = parse_and_optimize(annotate_types, sql, dialect, dialect=dialect)

            with self.subTest(title):
                self.assertEqual(
                    result.type.sql(dialect),
                    exp.DataType.build(expected, dialect=dialect).sql(dialect),
                )

    def test_annotate_funcs(self):
        test_schema = {
            "tbl": {
                "bin_col": "BINARY",
                "str_col": "STRING",
                "bignum_col": "BIGNUMERIC",
                "date_col": "DATE",
                "decfloat_col": "DECFLOAT",
                "float_col": "FLOAT",
                "timestamp_col": "TIMESTAMP",
                "double_col": "DOUBLE",
                "bigint_col": "BIGINT",
                "obj_col": "OBJECT",
                "int_col": "INT",
                "bool_col": "BOOLEAN",
                "bytes_col": "BYTES",
                "interval_col": "INTERVAL",
                "array_col": "ARRAY<STRING>",
            }
        }

        for i, (meta, sql, expected) in enumerate(
            load_sql_fixture_pairs("optimizer/annotate_functions.sql"), start=1
        ):
            title = meta.get("title") or f"{i}, {sql}"
            dialect = meta.get("dialect") or ""
            sql = f"SELECT {sql} FROM tbl"

            for dialect in dialect.split(", "):
                with self.subTest(title):
                    result = parse_and_optimize(
                        annotate_functions, sql, dialect, schema=test_schema, dialect=dialect
                    )

                    self.assertEqual(
                        result.type.sql(dialect),
                        exp.DataType.build(expected, dialect=dialect).sql(dialect),
                    )

    def test_cast_type_annotation(self):
        expression = annotate_types(parse_one("CAST('2020-01-01' AS TIMESTAMPTZ(9))"))
        self.assertEqual(expression.type.this, exp.DataType.Type.TIMESTAMPTZ)
        self.assertEqual(expression.this.type.this, exp.DataType.Type.VARCHAR)
        self.assertEqual(expression.args["to"].type.this, exp.DataType.Type.TIMESTAMPTZ)
        self.assertEqual(expression.args["to"].expressions[0].this.type.this, exp.DataType.Type.INT)

        expression = annotate_types(parse_one("ARRAY(1)::ARRAY<INT>"))
        self.assertEqual(expression.type, parse_one("ARRAY<INT>", into=exp.DataType))

        expression = annotate_types(parse_one("CAST(x AS INTERVAL)"))
        self.assertEqual(expression.type.this, exp.DataType.Type.INTERVAL)
        self.assertEqual(expression.this.type.this, exp.DataType.Type.UNKNOWN)
        self.assertEqual(expression.args["to"].type.this, exp.DataType.Type.INTERVAL)

    def test_cache_annotation(self):
        expression = annotate_types(
            parse_one("CACHE LAZY TABLE x OPTIONS('storageLevel' = 'value') AS SELECT 1")
        )
        self.assertEqual(expression.expression.expressions[0].type.this, exp.DataType.Type.INT)

    def test_binary_annotation(self):
        expression = annotate_types(parse_one("SELECT 0.0 + (2 + 3)")).expressions[0]

        self.assertEqual(expression.type.this, exp.DataType.Type.DOUBLE)
        self.assertEqual(expression.left.type.this, exp.DataType.Type.DOUBLE)
        self.assertEqual(expression.right.type.this, exp.DataType.Type.INT)
        self.assertEqual(expression.right.this.type.this, exp.DataType.Type.INT)
        self.assertEqual(expression.right.this.left.type.this, exp.DataType.Type.INT)
        self.assertEqual(expression.right.this.right.type.this, exp.DataType.Type.INT)

        for numeric_type in ("BIGINT", "DOUBLE", "INT"):
            query = f"SELECT '1' + CAST(x AS {numeric_type})"
            expression = annotate_types(parse_one(query)).expressions[0]
            self.assertEqual(expression.type, exp.DataType.build(numeric_type))

    def test_typeddiv_annotation(self):
        expressions = annotate_types(
            parse_one("SELECT 2 / 3, 2 / 3.0", dialect="presto")
        ).expressions

        self.assertEqual(expressions[0].type.this, exp.DataType.Type.BIGINT)
        self.assertEqual(expressions[1].type.this, exp.DataType.Type.DOUBLE)

        expressions = annotate_types(
            parse_one("SELECT SUM(2 / 3), CAST(2 AS DECIMAL) / 3", dialect="mysql")
        ).expressions

        self.assertEqual(expressions[0].type.this, exp.DataType.Type.DOUBLE)
        self.assertEqual(expressions[0].this.type.this, exp.DataType.Type.DOUBLE)
        self.assertEqual(expressions[1].type.this, exp.DataType.Type.DECIMAL)

    def test_bracket_annotation(self):
        expression = annotate_types(parse_one("SELECT A[:]")).expressions[0]

        self.assertEqual(expression.type.this, exp.DataType.Type.UNKNOWN)
        self.assertEqual(expression.expressions[0].type.this, exp.DataType.Type.UNKNOWN)

        expression = annotate_types(parse_one("SELECT ARRAY[1, 2, 3][1]")).expressions[0]
        self.assertEqual(expression.this.type.sql(), "ARRAY<INT>")
        self.assertEqual(expression.type.this, exp.DataType.Type.INT)

        expression = annotate_types(parse_one("SELECT ARRAY[1, 2, 3][1 : 2]")).expressions[0]
        self.assertEqual(expression.this.type.sql(), "ARRAY<INT>")
        self.assertEqual(expression.type.sql(), "ARRAY<INT>")

        expression = annotate_types(
            parse_one("SELECT ARRAY[ARRAY[1], ARRAY[2], ARRAY[3]][1][2]")
        ).expressions[0]
        self.assertEqual(expression.this.this.type.sql(), "ARRAY<ARRAY<INT>>")
        self.assertEqual(expression.this.type.sql(), "ARRAY<INT>")
        self.assertEqual(expression.type.this, exp.DataType.Type.INT)

        expression = annotate_types(
            parse_one("SELECT ARRAY[ARRAY[1], ARRAY[2], ARRAY[3]][1:2]")
        ).expressions[0]
        self.assertEqual(expression.type.sql(), "ARRAY<ARRAY<INT>>")

        expression = annotate_types(parse_one("MAP(1.0, 2, '2', 3.0)['2']", read="spark"))
        self.assertEqual(expression.type.this, exp.DataType.Type.DOUBLE)

        expression = annotate_types(parse_one("MAP(1.0, 2, x, 3.0)[2]", read="spark"))
        self.assertEqual(expression.type.this, exp.DataType.Type.UNKNOWN)

        expression = annotate_types(parse_one("MAP(ARRAY(1.0, x), ARRAY(2, 3.0))[x]"))
        self.assertEqual(expression.type.this, exp.DataType.Type.DOUBLE)

        expression = annotate_types(
            parse_one("SELECT MAP(1.0, 2, 2, t.y)[2] FROM t", read="spark"),
            schema={"t": {"y": "int"}},
        ).expressions[0]
        self.assertEqual(expression.type.this, exp.DataType.Type.INT)

    def test_interval_math_annotation(self):
        schema = {
            "x": {
                "a": "DATE",
                "b": "DATETIME",
            }
        }
        for sql, expected_type in [
            (
                "SELECT '2023-01-01' + INTERVAL '1' DAY",
                exp.DataType.Type.DATE,
            ),
            (
                "SELECT '2023-01-01' + INTERVAL '1' HOUR",
                exp.DataType.Type.DATETIME,
            ),
            (
                "SELECT '2023-01-01 00:00:01' + INTERVAL '1' HOUR",
                exp.DataType.Type.DATETIME,
            ),
            ("SELECT 'nonsense' + INTERVAL '1' DAY", exp.DataType.Type.UNKNOWN),
            ("SELECT x.a + INTERVAL '1' DAY FROM x AS x", exp.DataType.Type.DATE),
            (
                "SELECT x.a + INTERVAL '1' HOUR FROM x AS x",
                exp.DataType.Type.DATETIME,
            ),
            ("SELECT x.b + INTERVAL '1' DAY FROM x AS x", exp.DataType.Type.DATETIME),
            ("SELECT x.b + INTERVAL '1' HOUR FROM x AS x", exp.DataType.Type.DATETIME),
            (
                "SELECT DATE_ADD('2023-01-01', 1, 'DAY')",
                exp.DataType.Type.DATE,
            ),
            (
                "SELECT DATE_ADD('2023-01-01 00:00:00', 1, 'DAY')",
                exp.DataType.Type.DATETIME,
            ),
            ("SELECT DATE_ADD(x.a, 1, 'DAY') FROM x AS x", exp.DataType.Type.DATE),
            (
                "SELECT DATE_ADD(x.a, 1, 'HOUR') FROM x AS x",
                exp.DataType.Type.DATETIME,
            ),
            ("SELECT DATE_ADD(x.b, 1, 'DAY') FROM x AS x", exp.DataType.Type.DATETIME),
            ("SELECT DATE_TRUNC('DAY', x.a) FROM x AS x", exp.DataType.Type.DATE),
            ("SELECT DATE_TRUNC('DAY', x.b) FROM x AS x", exp.DataType.Type.DATETIME),
            (
                "SELECT DATE_TRUNC('SECOND', x.a) FROM x AS x",
                exp.DataType.Type.DATETIME,
            ),
            (
                "SELECT DATE_TRUNC('DAY', '2023-01-01') FROM x AS x",
                exp.DataType.Type.DATE,
            ),
            (
                "SELECT DATEDIFF('2023-01-01', '2023-01-02', DAY) FROM x AS x",
                exp.DataType.Type.INT,
            ),
        ]:
            with self.subTest(sql):
                expression = annotate_types(parse_one(sql), schema=schema)
                self.assertEqual(expected_type, expression.expressions[0].type.this)
                self.assertEqual(sql, expression.sql())

    def test_lateral_annotation(self):
        expression = optimizer.optimize(
            parse_one("SELECT c FROM (select 1 a) as x LATERAL VIEW EXPLODE (a) AS c")
        ).expressions[0]
        self.assertEqual(expression.type.this, exp.DataType.Type.INT)

    def test_derived_tables_column_annotation(self):
        schema = {"x": {"cola": "INT"}, "y": {"cola": "FLOAT"}}
        sql = """
            SELECT a.cola AS cola
            FROM (
                SELECT x.cola + y.cola AS cola
                FROM (
                    SELECT x.cola AS cola
                    FROM x AS x
                ) AS x
                JOIN (
                    SELECT y.cola AS cola
                    FROM y AS y
                ) AS y
            ) AS a
        """

        expression = annotate_types(parse_one(sql), schema=schema)
        self.assertEqual(
            expression.expressions[0].type.this, exp.DataType.Type.FLOAT
        )  # a.cola AS cola

        addition_alias = expression.args["from_"].this.this.expressions[0]
        self.assertEqual(
            addition_alias.type.this, exp.DataType.Type.FLOAT
        )  # x.cola + y.cola AS cola

        addition = addition_alias.this
        self.assertEqual(addition.type.this, exp.DataType.Type.FLOAT)
        self.assertEqual(addition.this.type.this, exp.DataType.Type.INT)
        self.assertEqual(addition.expression.type.this, exp.DataType.Type.FLOAT)

    def test_cte_column_annotation(self):
        schema = {"x": {"cola": "CHAR"}, "y": {"colb": "TEXT", "colc": "BOOLEAN"}}
        sql = """
            WITH tbl AS (
                SELECT x.cola + 'bla' AS cola, y.colb AS colb, y.colc AS colc
                FROM (
                    SELECT x.cola AS cola
                    FROM x AS x
                ) AS x
                JOIN (
                    SELECT y.colb AS colb, y.colc AS colc
                    FROM y AS y
                ) AS y
            )
            SELECT tbl.cola + tbl.colb + 'foo' AS col
            FROM tbl AS tbl
            WHERE tbl.colc = True
        """

        expression = annotate_types(parse_one(sql), schema=schema)
        self.assertEqual(
            expression.expressions[0].type.this, exp.DataType.Type.TEXT
        )  # tbl.cola + tbl.colb + 'foo' AS col

        outer_addition = expression.expressions[0].this  # (tbl.cola + tbl.colb) + 'foo'
        self.assertEqual(outer_addition.type.this, exp.DataType.Type.TEXT)
        self.assertEqual(outer_addition.left.type.this, exp.DataType.Type.TEXT)
        self.assertEqual(outer_addition.right.type.this, exp.DataType.Type.VARCHAR)

        inner_addition = expression.expressions[0].this.left  # tbl.cola + tbl.colb
        self.assertEqual(inner_addition.left.type.this, exp.DataType.Type.VARCHAR)
        self.assertEqual(inner_addition.right.type.this, exp.DataType.Type.TEXT)

        # WHERE tbl.colc = True
        self.assertEqual(expression.args["where"].this.type.this, exp.DataType.Type.BOOLEAN)

        cte_select = expression.args["with_"].expressions[0].this
        self.assertEqual(
            cte_select.expressions[0].type.this, exp.DataType.Type.VARCHAR
        )  # x.cola + 'bla' AS cola
        self.assertEqual(
            cte_select.expressions[1].type.this, exp.DataType.Type.TEXT
        )  # y.colb AS colb
        self.assertEqual(
            cte_select.expressions[2].type.this, exp.DataType.Type.BOOLEAN
        )  # y.colc AS colc

        cte_select_addition = cte_select.expressions[0].this  # x.cola + 'bla'
        self.assertEqual(cte_select_addition.type.this, exp.DataType.Type.VARCHAR)
        self.assertEqual(cte_select_addition.left.type.this, exp.DataType.Type.CHAR)
        self.assertEqual(cte_select_addition.right.type.this, exp.DataType.Type.VARCHAR)

        # Check that x.cola AS cola and y.colb AS colb have types CHAR and TEXT, respectively
        for d, t in zip(
            cte_select.find_all(exp.Subquery),
            [exp.DataType.Type.CHAR, exp.DataType.Type.TEXT],
        ):
            self.assertEqual(d.this.expressions[0].this.type.this, t)

    def test_function_annotation(self):
        schema = {"x": {"cola": "VARCHAR", "colb": "CHAR"}}
        sql = (
            "SELECT x.cola || TRIM(x.colb) AS col, DATE(x.colb), DATEFROMPARTS(y, m, d) FROM x AS x"
        )

        expression = annotate_types(parse_one(sql), schema=schema)
        concat_expr_alias = expression.expressions[0]
        self.assertEqual(concat_expr_alias.type.this, exp.DataType.Type.VARCHAR)

        concat_expr = concat_expr_alias.this
        self.assertEqual(concat_expr.type.this, exp.DataType.Type.VARCHAR)
        self.assertEqual(concat_expr.left.type.this, exp.DataType.Type.VARCHAR)  # x.cola
        self.assertEqual(concat_expr.right.type.this, exp.DataType.Type.VARCHAR)  # TRIM(x.colb)
        self.assertEqual(concat_expr.right.this.type.this, exp.DataType.Type.CHAR)  # x.colb

        date_expr = expression.expressions[1]
        self.assertEqual(date_expr.type.this, exp.DataType.Type.DATE)

        date_expr = expression.expressions[2]
        self.assertEqual(date_expr.type.this, exp.DataType.Type.DATE)

        sql = "SELECT CASE WHEN 1=1 THEN x.cola ELSE x.colb END AS col FROM x AS x"

        case_expr_alias = annotate_types(parse_one(sql), schema=schema).expressions[0]
        self.assertEqual(case_expr_alias.type.this, exp.DataType.Type.VARCHAR)

        case_expr = case_expr_alias.this
        self.assertEqual(case_expr.type.this, exp.DataType.Type.VARCHAR)
        self.assertEqual(case_expr.args["default"].type.this, exp.DataType.Type.CHAR)

        case_ifs_expr = case_expr.args["ifs"][0]
        self.assertEqual(case_ifs_expr.type.this, exp.DataType.Type.VARCHAR)
        self.assertEqual(case_ifs_expr.args["true"].type.this, exp.DataType.Type.VARCHAR)

        timestamp = annotate_types(parse_one("TIMESTAMP(x)"))
        self.assertEqual(timestamp.type.this, exp.DataType.Type.TIMESTAMP)

        timestamptz = annotate_types(parse_one("TIMESTAMP(x)", read="bigquery"))
        self.assertEqual(timestamptz.type.this, exp.DataType.Type.TIMESTAMPTZ)

    def test_unknown_annotation(self):
        schema = {"x": {"cola": "VARCHAR"}}
        sql = "SELECT x.cola + SOME_ANONYMOUS_FUNC(x.cola) AS col FROM x AS x"

        concat_expr_alias = annotate_types(parse_one(sql), schema=schema).expressions[0]
        self.assertEqual(concat_expr_alias.type.this, exp.DataType.Type.UNKNOWN)

        concat_expr = concat_expr_alias.this
        self.assertEqual(concat_expr.type.this, exp.DataType.Type.UNKNOWN)
        self.assertEqual(concat_expr.left.type.this, exp.DataType.Type.VARCHAR)  # x.cola
        self.assertEqual(
            concat_expr.right.type.this, exp.DataType.Type.UNKNOWN
        )  # SOME_ANONYMOUS_FUNC(x.cola)
        self.assertEqual(
            concat_expr.right.expressions[0].type.this, exp.DataType.Type.VARCHAR
        )  # x.cola (arg)

        # Ensures we don't raise if there are unqualified columns
        annotate_types(parse_one("select x from y lateral view explode(y) as x")).expressions[0]

        # NULL <op> UNKNOWN should yield UNKNOWN
        self.assertEqual(
            annotate_types(parse_one("SELECT NULL + ANONYMOUS_FUNC()")).expressions[0].type.this,
            exp.DataType.Type.UNKNOWN,
        )

    def test_udf_annotation(self):
        # Unqualified UDF
        schema = MappingSchema(
            schema={"t": {"col": "INT"}},
            udf_mapping={"my_func": "VARCHAR"},
        )
        expr = annotate_types(parse_one("SELECT my_func(col) FROM t"), schema=schema)
        self.assertEqual(expr.selects[0].type.this, exp.DataType.Type.VARCHAR)

        # Qualified UDF (2-level)
        schema = MappingSchema(
            schema={"db": {"t": {"col": "INT"}}},
            udf_mapping={"db": {"my_func": "DOUBLE"}},
        )
        expr = annotate_types(parse_one("SELECT db.my_func(col) FROM db.t"), schema=schema)
        anon = expr.selects[0].find(exp.Anonymous)
        self.assertEqual(anon.type.this, exp.DataType.Type.DOUBLE)
        # Dot parent should also have the type
        self.assertEqual(expr.selects[0].type.this, exp.DataType.Type.DOUBLE)

        # Qualified UDF (3-level)
        schema = MappingSchema(
            schema={"cat": {"db": {"t": {"col": "INT"}}}},
            udf_mapping={"cat": {"db": {"my_func": "BOOLEAN"}}},
        )
        expr = annotate_types(parse_one("SELECT cat.db.my_func(col) FROM cat.db.t"), schema=schema)
        anon = expr.selects[0].find(exp.Anonymous)
        self.assertEqual(anon.type.this, exp.DataType.Type.BOOLEAN)

        # Unknown UDF returns UNKNOWN
        schema = MappingSchema(
            schema={"t": {"col": "INT"}},
            udf_mapping={"known_func": "DATE"},
        )
        expr = annotate_types(parse_one("SELECT unknown_func(col) FROM t"), schema=schema)
        self.assertEqual(expr.selects[0].type.this, exp.DataType.Type.UNKNOWN)

        # Test get_udf_type with string input
        schema = MappingSchema(udf_mapping={"my_func": "INT"})
        self.assertEqual(schema.get_udf_type("my_func(x)").this, exp.DataType.Type.INT)

        schema = MappingSchema(udf_mapping={"db": {"my_func": "FLOAT"}})
        self.assertEqual(schema.get_udf_type("db.my_func(x, y)").this, exp.DataType.Type.FLOAT)

        schema = MappingSchema(udf_mapping={"cat": {"db": {"my_func": "DATE"}}})
        self.assertEqual(
            schema.get_udf_type("cat.db.my_func(a, b, c)").this, exp.DataType.Type.DATE
        )

        # Unknown UDF string returns UNKNOWN
        schema = MappingSchema(udf_mapping={"known": "INT"})
        self.assertEqual(schema.get_udf_type("unknown(x)").this, exp.DataType.Type.UNKNOWN)

    def test_predicate_annotation(self):
        expression = annotate_types(parse_one("x BETWEEN a AND b"))
        self.assertEqual(expression.type.this, exp.DataType.Type.BOOLEAN)

        expression = annotate_types(parse_one("x IN (a, b, c, d)"))
        self.assertEqual(expression.type.this, exp.DataType.Type.BOOLEAN)

    def test_aggfunc_annotation(self):
        schema = {"x": {"cola": "SMALLINT", "colb": "FLOAT", "colc": "TEXT", "cold": "DATE"}}

        tests = {
            ("AVG", "cola"): exp.DataType.Type.DOUBLE,
            ("SUM", "cola"): exp.DataType.Type.BIGINT,
            ("SUM", "colb"): exp.DataType.Type.DOUBLE,
            ("MIN", "cola"): exp.DataType.Type.SMALLINT,
            ("MIN", "colb"): exp.DataType.Type.FLOAT,
            ("MAX", "colc"): exp.DataType.Type.TEXT,
            ("MAX", "cold"): exp.DataType.Type.DATE,
            ("COUNT", "colb"): exp.DataType.Type.BIGINT,
            ("STDDEV", "cola"): exp.DataType.Type.DOUBLE,
            ("ABS", "cola"): exp.DataType.Type.SMALLINT,
            ("ABS", "colb"): exp.DataType.Type.FLOAT,
        }

        for (func, col), target_type in tests.items():
            expression = annotate_types(
                parse_one(f"SELECT {func}(x.{col}) AS _col_0 FROM x AS x"),
                schema=schema,
            )
            self.assertEqual(expression.expressions[0].type.this, target_type)

    def test_concat_annotation(self):
        expression = annotate_types(parse_one("CONCAT('A', 'B')"))
        self.assertEqual(expression.type.this, exp.DataType.Type.VARCHAR)

    def test_root_subquery_annotation(self):
        expression = annotate_types(parse_one("(SELECT 1, 2 FROM x) LIMIT 0"))
        self.assertIsInstance(expression, exp.Subquery)
        self.assertEqual(exp.DataType.Type.INT, expression.selects[0].type.this)
        self.assertEqual(exp.DataType.Type.INT, expression.selects[1].type.this)

    def test_nested_type_annotation(self):
        schema = {
            "order": {
                "customer_id": "bigint",
                "item_id": "bigint",
                "item_price": "numeric",
            }
        }
        sql = """
            SELECT ARRAY_AGG(DISTINCT order.item_id) FILTER (WHERE order.item_price > 10) AS items,
            FROM order AS order
            GROUP BY order.customer_id
        """
        expression = annotate_types(parse_one(sql), schema=schema)

        self.assertEqual(exp.DataType.Type.ARRAY, expression.selects[0].type.this)
        self.assertEqual(expression.selects[0].type.sql(), "ARRAY<BIGINT>")

        expression = annotate_types(
            parse_one("SELECT ARRAY_CAT(ARRAY[1,2,3], ARRAY[4,5])", read="postgres")
        )
        self.assertEqual(exp.DataType.Type.ARRAY, expression.selects[0].type.this)
        self.assertEqual(expression.selects[0].type.sql(), "ARRAY<INT>")

        schema = MappingSchema({"t": {"c": "STRUCT<`f` STRING>"}}, dialect="bigquery")
        expression = annotate_types(parse_one("SELECT t.c, [t.c] FROM t"), schema=schema)

        self.assertEqual(expression.selects[0].type.sql(dialect="bigquery"), "STRUCT<`f` STRING>")
        self.assertEqual(
            expression.selects[1].type.sql(dialect="bigquery"),
            "ARRAY<STRUCT<`f` STRING>>",
        )

        expression = annotate_types(
            parse_one("SELECT unnest(t.x) FROM t AS t", dialect="postgres"),
            schema={"t": {"x": "array<int>"}},
        )
        self.assertTrue(expression.selects[0].is_type("int"))

    def test_type_annotation_cache(self):
        sql = "SELECT 1 + 1"
        expression = annotate_types(parse_one(sql))

        self.assertEqual(exp.DataType.Type.INT, expression.selects[0].type.this)

        expression.selects[0].this.replace(parse_one("1.2"))
        expression = annotate_types(expression)

        self.assertEqual(exp.DataType.Type.DOUBLE, expression.selects[0].type.this)

    def test_user_defined_type_annotation(self):
        schema = MappingSchema({"t": {"x": "int"}}, dialect="postgres")
        expression = annotate_types(parse_one("SELECT CAST(x AS IPADDRESS) FROM t"), schema=schema)

        self.assertEqual(exp.DataType.Type.USERDEFINED, expression.selects[0].type.this)
        self.assertEqual(expression.selects[0].type.sql(dialect="postgres"), "IPADDRESS")

    def test_unnest_annotation(self):
        expression = annotate_types(
            optimizer.qualify.qualify(
                parse_one(
                    """
                SELECT a, a.b, a.b.c FROM x, UNNEST(x.a) AS a
                """,
                    read="bigquery",
                )
            ),
            schema={"x": {"a": "ARRAY<STRUCT<b STRUCT<c int>>>"}},
        )
        self.assertEqual(expression.selects[0].type, exp.DataType.build("STRUCT<b STRUCT<c int>>"))
        self.assertEqual(expression.selects[1].type, exp.DataType.build("STRUCT<c int>"))
        self.assertEqual(expression.selects[2].type, exp.DataType.build("int"))

        self.assertEqual(
            annotate_types(
                optimizer.qualify.qualify(
                    parse_one(
                        "SELECT x FROM UNNEST(GENERATE_DATE_ARRAY('2021-01-01', current_date(), interval 1 day)) AS x"
                    )
                )
            )
            .selects[0]
            .type,
            exp.DataType.build("date"),
        )

        self.assertEqual(
            annotate_types(
                optimizer.qualify.qualify(
                    parse_one(
                        "SELECT x FROM UNNEST(GENERATE_TIMESTAMP_ARRAY('2016-10-05 00:00:00', '2016-10-06 02:00:00', interval 1 day)) AS x"
                    )
                )
            )
            .selects[0]
            .type,
            exp.DataType.build("timestamp"),
        )

    def test_unnest_struct_field_annotation(self):
        """Test that UNNEST of struct array without column aliases exposes struct fields with proper types"""
        expression = annotate_types(
            optimizer.qualify.qualify(
                parse_one(
                    """
                    WITH data AS (
                      SELECT [STRUCT('Bob' AS first_name, 'Smith' AS last_name)] AS users
                    )
                    SELECT first_name, last_name
                    FROM data, UNNEST(users)
                    """,
                    dialect="bigquery",
                ),
                dialect="bigquery",
            ),
            dialect="bigquery",
        )
        self.assertEqual(
            expression.selects[0].type, exp.DataType.build("VARCHAR", dialect="bigquery")
        )
        self.assertEqual(
            expression.selects[1].type, exp.DataType.build("VARCHAR", dialect="bigquery")
        )

        expression = annotate_types(
            optimizer.qualify.qualify(
                parse_one(
                    """
                    SELECT person
                    FROM UNNEST([STRUCT('Charlie' AS name, 40 AS age)]) AS person
                    """,
                    dialect="bigquery",
                ),
                dialect="bigquery",
            ),
            dialect="bigquery",
        )
        select_type = expression.selects[0].type
        self.assertTrue(select_type.is_type(exp.DataType.Type.STRUCT))
        self.assertEqual(len(select_type.expressions), 2)
        fields = {col_def.name: col_def.kind for col_def in select_type.expressions}
        self.assertEqual(fields.get("name"), exp.DataType.build("VARCHAR", dialect="bigquery"))
        self.assertEqual(fields.get("age"), exp.DataType.build("INT", dialect="bigquery"))

        expression = annotate_types(
            optimizer.qualify.qualify(
                parse_one(
                    """
                    WITH data AS (
                      SELECT [STRUCT('Bob' AS first_name, 'Smith' AS last_name)] AS users
                    )
                    SELECT first_name, last_name
                    FROM data, UNNEST(users) AS p
                    """,
                    dialect="bigquery",
                ),
                dialect="bigquery",
            ),
            dialect="bigquery",
        )
        self.assertEqual(
            expression.selects[0].type, exp.DataType.build("VARCHAR", dialect="bigquery")
        )
        self.assertEqual(
            expression.selects[1].type, exp.DataType.build("VARCHAR", dialect="bigquery")
        )

        expression = annotate_types(
            optimizer.qualify.qualify(
                parse_one(
                    """
                    SELECT name
                    FROM UNNEST([STRUCT('Charlie' AS name, 40 AS age)]) AS person
                    """,
                    dialect="bigquery",
                ),
                dialect="bigquery",
            ),
            dialect="bigquery",
        )
        select_type = expression.selects[0].type
        self.assertTrue(select_type.is_type(exp.DataType.build("VARCHAR", dialect="bigquery")))

    def test_map_annotation(self):
        # ToMap annotation
        expression = annotate_types(parse_one("SELECT MAP {'x': 1}", read="duckdb"))
        self.assertEqual(expression.selects[0].type, exp.DataType.build("MAP(VARCHAR, INT)"))

        # Map annotation
        expression = annotate_types(
            parse_one("SELECT MAP(['key1', 'key2', 'key3'], [10, 20, 30])", read="duckdb")
        )
        self.assertEqual(expression.selects[0].type, exp.DataType.build("MAP(VARCHAR, INT)"))

        # VarMap annotation
        expression = annotate_types(parse_one("SELECT MAP('a', 'b')", read="spark"))
        self.assertEqual(expression.selects[0].type, exp.DataType.build("MAP(VARCHAR, VARCHAR)"))

    def test_union_annotation(self):
        for left, right, expected_type in (
            ("SELECT 1::INT AS c", "SELECT 2::BIGINT AS c", "BIGINT"),
            ("SELECT 1::INT AS c", "SELECT 2::BIGDECIMAL AS c", "BIGDECIMAL"),
            ("SELECT 1 AS c", "SELECT NULL AS c", "INT"),
            ("SELECT FOO() AS c", "SELECT 1 AS c", "UNKNOWN"),
            ("SELECT FOO() AS c", "SELECT BAR() AS c", "UNKNOWN"),
        ):
            with self.subTest(f"left: {left}, right: {right}, expected: {expected_type}"):
                lr = annotate_types(parse_one(f"SELECT t.c FROM ({left} UNION ALL {right}) t(c)"))
                rl = annotate_types(parse_one(f"SELECT t.c FROM ({right} UNION ALL {left}) t(c)"))
                assert lr.selects[0].type == rl.selects[0].type == exp.DataType.build(expected_type)

        union_by_name = annotate_types(
            parse_one(
                "SELECT t.a, t.d FROM (SELECT 1 a, 3 d, UNION ALL BY NAME SELECT 7.0 d, 8::BIGINT a) AS t(a, d)"
            )
        )
        self.assertEqual(union_by_name.selects[0].type.this, exp.DataType.Type.BIGINT)
        self.assertEqual(union_by_name.selects[1].type.this, exp.DataType.Type.DOUBLE)

        # Test chained UNIONs
        sql = """
            WITH t AS
            (
                SELECT NULL AS col
                UNION
                SELECT NULL AS col
                UNION
                SELECT 'a' AS col
                UNION
                SELECT NULL AS col
                UNION
                SELECT NULL AS col
            )
            SELECT col FROM t;
        """
        self.assertEqual(optimizer.optimize(sql).selects[0].type.this, exp.DataType.Type.VARCHAR)

        # Test UNIONs with nested subqueries
        sql = """
            WITH t AS
            (
                SELECT NULL AS col
                UNION
                (SELECT NULL AS col UNION ALL SELECT 'a' AS col)
            )
            SELECT col FROM t;
        """
        self.assertEqual(optimizer.optimize(sql).selects[0].type.this, exp.DataType.Type.VARCHAR)

        sql = """
            WITH t AS
            (
                (SELECT NULL AS col UNION ALL SELECT 'a' AS col)
                UNION
                SELECT NULL AS col
            )
            SELECT col FROM t;
        """
        self.assertEqual(optimizer.optimize(sql).selects[0].type.this, exp.DataType.Type.VARCHAR)

        # BigQuery: STRING coerces to temporal types in UNION
        for left, right, expected_type in (
            ("SELECT '2010-01-01' AS c", "SELECT DATE '2020-02-02' AS c", "DATE"),
            (
                "SELECT '2010-01-01 00:00:00' AS c",
                "SELECT DATETIME '2020-02-02 00:00:00' AS c",
                "DATETIME",
            ),
            ("SELECT '00:00:00' AS c", "SELECT TIME '00:01:00' AS c", "TIME"),
            (
                "SELECT '2010-01-01 00:00:00' AS c",
                "SELECT TIMESTAMP '2020-02-02 00:00:00' AS c",
                "TIMESTAMP",
            ),
        ):
            with self.subTest(f"left: {left}, right: {right}, expected: {expected_type}"):
                lr = annotate_types(
                    parse_one(
                        f"SELECT t.c FROM ({left} UNION ALL {right}) t(c)", dialect="bigquery"
                    ),
                    dialect="bigquery",
                )
                rl = annotate_types(
                    parse_one(
                        f"SELECT t.c FROM ({right} UNION ALL {left}) t(c)", dialect="bigquery"
                    ),
                    dialect="bigquery",
                )
                assert (
                    lr.selects[0].type
                    == rl.selects[0].type
                    == exp.DataType.build(expected_type, dialect="bigquery")
                )

    def test_udtf_annotation(self):
        table_udtf = parse_one(
            "SELECT * FROM TABLE(GENERATOR(ROWCOUNT => 100000))",
            read="snowflake",
        )
        self.assertEqual(
            annotate_types(table_udtf, dialect="snowflake").sql("snowflake"),
            "SELECT * FROM TABLE(GENERATOR(ROWCOUNT => 100000))",
        )

    def test_recursive_cte(self):
        query = parse_one(
            """
            with recursive t(n) AS
            (
              select 1
              union all
              select n + 1
              FROM t
              where n < 3
            ), y AS (
              select n
              FROM t
              union all
              select n + 1
              FROM y
              where n < 2
            )
            select * from y
            """
        )

        scope_t, scope_y = build_scope(query).cte_scopes
        self.assertEqual(set(scope_t.cte_sources), {"t"})
        self.assertEqual(set(scope_y.cte_sources), {"t", "y"})

    def test_schema_with_spaces(self):
        schema = {
            "a": {
                "b c": "text",
                '"d e"': "text",
            }
        }

        self.assertEqual(
            optimizer.optimize(parse_one("SELECT * FROM a"), schema=schema),
            parse_one('SELECT "a"."b c" AS "b c", "a"."d e" AS "d e" FROM "a" AS "a"'),
        )

    def test_quotes(self):
        schema = {
            "example": {
                '"source"': {
                    "id": "text",
                    '"name"': "text",
                    '"payload"': "text",
                }
            }
        }

        expected = parse_one(
            """
            SELECT
             "source"."ID" AS "ID",
             "source"."name" AS "name",
             "source"."payload" AS "payload"
            FROM "EXAMPLE"."source" AS "source"
            """,
            read="snowflake",
        ).sql(pretty=True, dialect="snowflake")

        for func in (optimizer.qualify.qualify, optimizer.optimize):
            source_query = parse_one('SELECT * FROM example."source" AS "source"', read="snowflake")
            transformed = func(source_query, dialect="snowflake", schema=schema)
            self.assertEqual(transformed.sql(pretty=True, dialect="snowflake"), expected)

    def test_no_pseudocolumn_expansion(self):
        schema = {
            "a": {
                "a": "text",
                "b": "text",
                "_PARTITIONDATE": "date",
                "_PARTITIONTIME": "timestamp",
            }
        }

        self.assertEqual(
            optimizer.optimize(
                parse_one("SELECT * FROM a"),
                schema=MappingSchema(schema, dialect="bigquery"),
            ),
            parse_one('SELECT "a"."a" AS "a", "a"."b" AS "b" FROM "a" AS "a"'),
        )

    def test_semistructured(self):
        query = parse_one("select a.b:c from d", read="snowflake")
        qualified = optimizer.qualify.qualify(query)
        self.assertEqual(qualified.expressions[0].alias, "c")

    def test_gen(self):
        for func in exp.ALL_FUNCTIONS:
            self.assertIsInstance(optimizer.simplify.gen(func()), str)

    def test_normalization_distance(self):
        def gen_expr(depth: int) -> exp.Expr:
            return parse_one(" OR ".join("a AND b" for _ in range(depth)))

        self.assertEqual(4, normalization_distance(gen_expr(2), max_=100))
        self.assertEqual(18, normalization_distance(gen_expr(3), max_=100))
        self.assertEqual(110, normalization_distance(gen_expr(10), max_=100))

    def test_manually_annotate_snowflake(self):
        dialect = "snowflake"
        schema = {
            "SCHEMA": {
                "TBL": {"COL": "INT", "col2": "VARCHAR"},
            }
        }
        example_query = 'SELECT * FROM "SCHEMA"."TBL"'

        expression = parse_one(example_query, dialect=dialect)
        qual = optimizer.qualify.qualify(expression, schema=schema, dialect=dialect)
        annotated = optimizer.annotate_types.annotate_types(qual, schema=schema, dialect=dialect)

        self.assertTrue(annotated.selects[0].is_type("INT"))
        self.assertTrue(annotated.selects[1].is_type("VARCHAR"))

    def test_annotate_table_as_struct_bigquery(self):
        dialect = "bigquery"
        schema = {"d": {"s": {"t": {"c1": "int64", "c2": "struct<f1 int64, f2 string>"}}}}

        def _annotate(query: str) -> exp.Expr:
            expression = parse_one(query, dialect=dialect)
            qual = optimizer.qualify.qualify(expression, schema=schema, dialect=dialect)
            return optimizer.annotate_types.annotate_types(qual, schema=schema, dialect=dialect)

        example_query = "SELECT t FROM d.s.t"
        annotated = _annotate(example_query)

        self.assertIsInstance(annotated.selects[0].this, exp.TableColumn)
        self.assertEqual(annotated.sql("bigquery"), "SELECT `t` AS `t` FROM `d`.`s`.`t` AS `t`")
        self.assertTrue(
            annotated.selects[0].is_type("STRUCT<c1 BIGINT, c2 STRUCT<f1 BIGINT, f2 TEXT>>")
        )

        example_query = "SELECT subq FROM (SELECT * from d.s.t) subq"
        annotated = _annotate(example_query)

        self.assertTrue(
            annotated.selects[0].is_type("STRUCT<c1 BIGINT, c2 STRUCT<f1 BIGINT, f2 TEXT>>")
        )

        example_query = "WITH t AS (SELECT 1 AS c) SELECT t FROM t"
        annotated = _annotate(example_query)

        self.assertTrue(annotated.selects[0].is_type("STRUCT<c INT>"))

        example_query = "WITH t AS (SELECT FOO() AS c) SELECT t FROM t"
        annotated = _annotate(example_query)

        self.assertTrue(annotated.selects[0].is_type("UNKNOWN"))

        for query in ("SELECT 'foo'", "(SELECT 'foo')"):
            query = f"SELECT ARRAY({query})"
            with self.subTest(f"Annotating '{query}' in BigQuery"):
                self.assertTrue(_annotate(query).selects[0].is_type("ARRAY<VARCHAR>"))

    def test_semi_anti_join(self):
        # - Do not remove semi/anti join
        # - Do not remove CTEs/subqueries that participate in anti/semi joins, even though they do not count as selected sources
        for join_kind in ("LEFT ANTI", "ANTI", "SEMI"):
            query = f"WITH x AS (SELECT 1 AS b UNION ALL SELECT 2 AS b) SELECT x.b FROM x {join_kind} JOIN (SELECT 1 AS b) AS sub ON x.b = sub.b"

            self.assertEqual(
                optimizer.optimize(query).sql(),
                f'WITH "x" AS (SELECT 1 AS "b" UNION ALL SELECT 2 AS "b"), "sub" AS (SELECT 1 AS "b") SELECT "x"."b" AS "b" FROM "x" AS "x" {join_kind} JOIN "sub" AS "sub" ON "sub"."b" = "x"."b"',
            )

    def test_qualify_group_by_conflict_bigquery(self):
        dialect = "bigquery"
        schema = {"custom_fields": {"id": "int", "col": "struct<fld string>"}}

        query = "SELECT id, ARRAY_AGG(col) AS custom_fields FROM custom_fields AS custom_fields GROUP BY id HAVING id >= 1"
        qual = optimizer.qualify.qualify(
            parse_one(query, dialect=dialect),
            schema=schema,
            dialect=dialect,
        )

        sql = qual.sql(dialect=dialect)
        self.assertEqual(
            sql,
            "SELECT `custom_fields`.`id` AS `id`, ARRAY_AGG(`custom_fields`.`col`) AS `custom_fields` FROM `custom_fields` AS `custom_fields` GROUP BY `id` HAVING `id` >= 1",
        )

    def test_struct_annotation_bigquery(self):
        sql = """
        WITH t1 AS (SELECT 'foo' AS c),
             t2 AS (SELECT ARRAY_AGG(STRUCT(c)) AS arr FROM t1)
        SELECT arr[0].c FROM t2
        """

        query = parse_one(sql, dialect="bigquery")
        qualified = optimizer.qualify.qualify(query, dialect="bigquery")
        annotated = optimizer.annotate_types.annotate_types(qualified, dialect="bigquery")

        assert annotated.selects[0].type == exp.DataType.build("VARCHAR")

    def test_bigquery_unnest_alias_shadowing(self):
        """Test that BigQuery UNNEST table alias shadows column names from other tables."""
        sql = """
            SELECT timeline_date
            FROM UNNEST(GENERATE_DATE_ARRAY('2020-01-01', '2020-01-03')) AS timeline_date
            LEFT JOIN production_tier ON production_tier.timeline_date = timeline_date
        """
        schema = {"production_tier": {"timeline_date": "DATE", "id": "INT"}}

        result = optimizer.qualify.qualify(
            parse_one(sql, dialect="bigquery"),
            schema=schema,
            dialect="bigquery",
        )

        result_sql = result.sql(dialect="bigquery")
        self.assertEqual(
            result_sql,
            "SELECT `timeline_date` AS `timeline_date` "
            "FROM UNNEST(GENERATE_DATE_ARRAY('2020-01-01', '2020-01-03', INTERVAL '1' DAY)) AS `timeline_date` "
            "LEFT JOIN `production_tier` AS `production_tier` "
            "ON `production_tier`.`timeline_date` = `timeline_date`",
        )

    def test_struct_field_case_sensitivity_annotation(self):
        schema = {"t": {"struct_col": "STRUCT<fooBar STRING>"}}

        def _assert_dot_annotation(query: str, dialect: str, expected: exp.DataType.Type):
            parsed = parse_one(query, dialect=dialect)
            qualified = optimizer.qualify.qualify(parsed, schema=schema, dialect=dialect)
            annotated = optimizer.annotate_types.annotate_types(
                qualified, schema=schema, dialect=dialect
            )
            self.assertEqual(annotated.selects[0].type.this, expected)

        # BigQuery is case-insensitive: exact field name match
        _assert_dot_annotation(
            "SELECT struct_col.fooBar FROM t", "bigquery", exp.DataType.Type.TEXT
        )

        # BigQuery: lower case
        _assert_dot_annotation(
            "SELECT struct_col.foobar FROM t", "bigquery", exp.DataType.Type.TEXT
        )

        # BigQuery: different case
        _assert_dot_annotation(
            "SELECT struct_col.Foobar FROM t", "bigquery", exp.DataType.Type.TEXT
        )

        # ClickHouse is case-sensitive: exact field name match
        _assert_dot_annotation(
            "SELECT struct_col.fooBar FROM t", "clickhouse", exp.DataType.Type.TEXT
        )

        # ClickHouse: lower case
        _assert_dot_annotation(
            "SELECT struct_col.foobar FROM t", "clickhouse", exp.DataType.Type.UNKNOWN
        )

    def test_annotate_object_construct(self):
        sql = "SELECT OBJECT_CONSTRUCT('foo', 'bar', 'a b', 'c d') AS c"

        query = parse_one(sql, dialect="snowflake")
        annotated = optimizer.annotate_types.annotate_types(query, dialect="snowflake")

        self.assertEqual(
            annotated.selects[0].type.sql("snowflake"), 'OBJECT("foo" VARCHAR, "a b" VARCHAR)'
        )

    def test_nonnull_annotation(self):
        for literal_sql in ("1", "'foo'", "2.5"):
            with self.subTest(f"Test NULL annotation for literal: {literal_sql}"):
                sql = f"SELECT {literal_sql}"
                query = parse_one(sql)
                annotated = annotate_types(query)
                assert annotated.selects[0].meta.get("nonnull") is True

        schema = {"foo": {"id": "INT"}}

        operand_pairs = (
            ("1", "1", True),
            ("foo.id", "foo.id", None),
            ("1", "foo.id", None),
            ("foo.id", "1", None),
        )

        for predicate in (">", "<", ">=", "<=", "=", "!=", "<>", "LIKE", "NOT LIKE"):
            for operand1, operand2, nonnull in operand_pairs:
                sql_predicate = f"{operand1} {predicate} {operand2}"
                with self.subTest(f"Test NULL propagation for predicate: {predicate}"):
                    sql = f"SELECT {sql_predicate} FROM foo"
                    query = parse_one(sql)
                    annotated = annotate_types(query, schema=schema)
                    assert annotated.selects[0].meta.get("nonnull") is nonnull

        for predicate in ("IS NULL", "IS NOT NULL"):
            sql_predicate = f"foo.id {predicate}"
            with self.subTest(f"Test NULL propagation for predicate: {predicate}"):
                sql = f"SELECT {sql_predicate} FROM foo"
                query = parse_one(sql)
                annotated = annotate_types(query, schema=schema)
                assert annotated.selects[0].meta.get("nonnull") is True

        for connector in ("AND", "OR"):
            for predicate in (">", "<", ">=", "<=", "=", "!=", "<>", "LIKE", "NOT LIKE"):
                for operand1, operand2, nonnull in operand_pairs:
                    sql_predicate = f"({operand1} {predicate} {operand2})"
                    sql_connector = f"{sql_predicate} {connector} {sql_predicate}"
                    with self.subTest(
                        f"Test NULL propagation for connector: {connector} with predicates: {predicate}"
                    ):
                        sql = f"SELECT {sql_connector} FROM foo"
                        query = parse_one(sql)
                        annotated = annotate_types(query, schema=schema)
                        assert annotated.selects[0].meta.get("nonnull") is nonnull

        for unary in ("NOT", "-"):
            for value, nonnull in (("1", True), ("foo.id", None)):
                with self.subTest(f"Test NULL propagation for unary: {unary} with value: {value}"):
                    sql = f"SELECT {unary} {value} FROM foo"
                    query = parse_one(sql)
                    annotated = annotate_types(query, schema=schema)
                    assert annotated.selects[0].meta.get("nonnull") is nonnull

        ch_query = parse_one("select c1, c2 from t")
        ch_schema = {"t": {"c1": "Int32", "c2": "Nullable(Int32)"}}
        qualified_query = qualify_columns(ch_query, schema=ch_schema, dialect="clickhouse")
        annotated = annotate_types(qualified_query, schema=ch_schema, dialect="clickhouse")
        assert annotated.selects[0].meta.get("nonnull") is True
        assert annotated.selects[1].meta.get("nonnull") is None

    def test_case_sensitive_json_dot_access(self):
        schema = {
            "t": {
                "col": "JSON",
                "struct_col": "STRUCT<STRUCT<STRUCT<VARCHAR>>>",
            }
        }

        def _parse_and_optimize(query: str, dialect: str) -> exp.Expr:
            query = parse_one(query, dialect=dialect)
            optimized = optimizer.optimize(query, schema=schema, dialect=dialect)
            return optimized.sql(dialect=dialect)

        # BigQuery
        for dot_access in ("col.fOo.BaR.BaZ", "t.col.fOo.BaR.BaZ"):
            with self.subTest(f"Test case sensitive JSON dot access for BigQuery: {dot_access}"):
                dot_access_normalized = "`t`.`col`.`fOo`.`BaR`.`BaZ`"

                sql = _parse_and_optimize(
                    f"SELECT JSON_VALUE({dot_access}, '$') AS col FROM t", dialect="bigquery"
                )
                assert (
                    sql
                    == f"SELECT JSON_VALUE({dot_access_normalized}, '$') AS `col` FROM `t` AS `t`"
                )

                sql = _parse_and_optimize(f"SELECT {dot_access} AS col FROM t", dialect="bigquery")
                assert sql == f"SELECT {dot_access_normalized} AS `col` FROM `t` AS `t`"

        # BigQuery: STRUCT field accesses are still normalized
        sql = _parse_and_optimize(
            "SELECT struct_col.FlD1.flD2.FLD3 AS col FROM t", dialect="bigquery"
        )
        assert sql == "SELECT `t`.`struct_col`.`fld1`.`fld2`.`fld3` AS `col` FROM `t` AS `t`"

        # Databricks
        sql = _parse_and_optimize("SELECT col:A.a, col:a.A FROM t", dialect="databricks")
        assert sql == "SELECT `t`.`col`:A.a AS `a`, `t`.`col`:a.A AS `A` FROM `t` AS `t`"

        # Clickhouse
        sql = _parse_and_optimize("SELECT col.A.a, col.a.A FROM t", dialect="clickhouse")
        assert sql == 'SELECT "t"."col"."A"."a" AS "a", "t"."col"."a"."A" AS "A" FROM "t" AS "t"'

        # DuckDB
        sql = _parse_and_optimize("SELECT col.A.a, col.a.A FROM t", dialect="duckdb")
        assert sql == 'SELECT "t"."col"."A"."a" AS "a", "t"."col"."a"."A" AS "a" FROM "t" AS "t"'

        # Snowflake
        sql = _parse_and_optimize("SELECT col:A.a, col:a.A FROM t", dialect="snowflake")
        assert (
            sql
            == '''SELECT GET_PATH("T"."COL", 'A.a') AS "a", GET_PATH("T"."COL", 'a.A') AS "A" FROM "T" AS "T"'''
        )

        query = parse_one(
            "SELECT JSON_VALUE(item.id) FROM UNNEST(JSON_QUERY_ARRAY(PARSE_JSON('[{\"id\": 1}]'))) AS item",
            dialect="bigquery",
        )
        optimized = optimizer.optimize(query, dialect="bigquery")
        for i in optimized.find_all(exp.Identifier):
            self.assertNotIsInstance(i.this, exp.Identifier)
        assert (
            optimized.sql("bigquery")
            == "SELECT JSON_VALUE(`item`.`id`, '$') AS `_col_0` FROM UNNEST(JSON_QUERY_ARRAY(PARSE_JSON('[{\"id\": 1}]'), '$')) AS `item`"
        )

    def test_deep_ast_type_annotation(self):
        union_sql = "SELECT 1 UNION ALL " * 2000 + "SELECT 1"
        annotated = annotate_types(parse_one(union_sql))
        self.assertEqual(annotated.sql(), union_sql)
        self.assertEqual(annotated.selects[0].type.this, exp.DataType.Type.INT)

        binary_sql = "SELECT " + "t.a + " * 2000 + "t.a FROM t"
        annotated = annotate_types(parse_one(binary_sql), schema={"t": {"a": "INT"}})
        self.assertEqual(annotated.sql(), binary_sql)
        self.assertEqual(annotated.selects[0].type.this, exp.DataType.Type.INT)

    def test_null_coerce_annotation(self):
        null_sql = "SELECT t.foo FROM (SELECT CAST(1 AS BIGDECIMAL) AS foo UNION ALL SELECT NULL AS foo) AS t"
        annotated = parse_and_optimize(annotate_types, null_sql, "bigquery", dialect="bigquery")

        self.assertEqual(annotated.sql(), null_sql)
        self.assertEqual(annotated.selects[0].type.this, exp.DataType.Type.BIGDECIMAL)

        null_sql = "SELECT t.foo FROM (SELECT NULL AS foo UNION ALL SELECT CAST(1 AS BIGDECIMAL) AS foo) AS t"
        annotated = parse_and_optimize(annotate_types, null_sql, "bigquery", dialect="bigquery")
        self.assertEqual(annotated.sql(), null_sql)
        self.assertEqual(annotated.selects[0].type.this, exp.DataType.Type.BIGDECIMAL)

    def test_correlated_subqueries_annotation(self):
        correlated_sql = "SELECT (SELECT col) FROM t"

        query = parse_one(correlated_sql, dialect="bigquery")
        qualified = optimizer.qualify.qualify(
            query, dialect="bigquery", schema={"t": {"col": "BIGNUMERIC"}}
        )
        annotated = optimizer.annotate_types.annotate_types(
            qualified, dialect="bigquery", schema={"t": {"col": "BIGNUMERIC"}}
        )

        self.assertEqual(
            annotated.sql("bigquery"),
            "SELECT (SELECT `t`.`col` AS `col`) AS `_col_0` FROM `t` AS `t`",
        )
        assert annotated.selects[0].type == exp.DataType.build("BIGNUMERIC", dialect="bigquery")

        correlated_sql = """
        SELECT
        (
            SELECT
            MAX(u_x)
            FROM UNNEST([1, d_x]) AS u_x
            WHERE
            u_x < d_z
        ) AS c_i
        FROM (
        SELECT
            CAST(20 AS BIGNUMERIC) AS d_x,
            30 AS d_z
        ) AS d_t
        """

        query = parse_one(correlated_sql, dialect="bigquery")
        qualified = optimizer.qualify.qualify(
            query, dialect="bigquery", schema={"d_t": {"d_x": "STRING"}}
        )
        annotated = optimizer.annotate_types.annotate_types(
            qualified, dialect="bigquery", schema={"d_t": {"d_x": "STRING"}}
        )

        self.assertEqual(
            annotated.sql("bigquery"),
            "SELECT (SELECT MAX(`u_x`) AS `_col_0` FROM UNNEST([1, `d_t`.`d_x`]) AS `u_x` WHERE `u_x` < `d_t`.`d_z`) AS `c_i` FROM (SELECT CAST(20 AS BIGNUMERIC) AS `d_x`, 30 AS `d_z`) AS `d_t`",
        )
        assert annotated.selects[0].type == exp.DataType.build("BIGNUMERIC", dialect="bigquery")

        correlated_sql = "SELECT (SELECT col FROM t) as u FROM (SELECT 1 AS col) AS t"
        query = parse_one(correlated_sql)
        qualified = optimizer.qualify.qualify(query, schema={"t": {"col": "TEXT"}})
        annotated = optimizer.annotate_types.annotate_types(
            qualified, schema={"t": {"col": "TEXT"}}
        )

        self.assertEqual(
            annotated.sql(),
            'SELECT (SELECT "t"."col" AS "col" FROM "t" AS "t") AS "u" FROM (SELECT 1 AS "col") AS "t"',
        )
        assert annotated.selects[0].type == exp.DataType.build("TEXT")

    def test_order_by_alias_annotation(self):
        schema = {
            "t": {"x": "INT", "z": "TEXT", "category": "TEXT", "col": "INT"},
            "u": {"a": "INT", "x": "INT"},
        }

        def _order_types(sql):
            query = optimizer.qualify.qualify(parse_one(sql), schema=schema)
            annotated = optimizer.annotate_types.annotate_types(query, schema=schema)
            order = annotated.find(exp.Order)
            assert order, f"No ORDER BY found in: {sql}"
            return [o.this.type for o in order.expressions]

        INT = exp.DataType.build("INT")
        TEXT = exp.DataType.build("TEXT")
        BIGINT = exp.DataType.build("BIGINT")
        VARCHAR = exp.DataType.build("VARCHAR")

        # Basic alias resolution
        self.assertEqual(_order_types("SELECT x + 1 AS y FROM t ORDER BY y"), [INT])
        self.assertEqual(_order_types("SELECT x, z FROM t ORDER BY x"), [INT])
        self.assertEqual(
            _order_types("SELECT category, COUNT(*) AS cnt FROM t GROUP BY category ORDER BY cnt"),
            [BIGINT],
        )
        self.assertEqual(
            _order_types(
                "SELECT CASE WHEN x > 0 THEN 'a' ELSE 'b' END AS label FROM t ORDER BY label"
            ),
            [VARCHAR],
        )
        self.assertEqual(_order_types("SELECT CAST(x AS TEXT) AS s FROM t ORDER BY s"), [TEXT])

        # Alias shadows column name
        self.assertEqual(_order_types("SELECT z AS x FROM t ORDER BY x"), [TEXT])

        # Alias shadows column from joined table (ambiguous column, alias wins)
        self.assertEqual(_order_types("SELECT t.x + u.a AS a FROM t, u ORDER BY a"), [INT])

        # Alias shadows column across cross-join (u also has x)
        self.assertEqual(_order_types("SELECT t.z AS x FROM t, u ORDER BY x"), [TEXT])

        # CTE name collides with alias
        self.assertEqual(
            _order_types("WITH y AS (SELECT 999 AS v) SELECT x + 1 AS y FROM t ORDER BY y"),
            [INT],
        )

        # Column name equals alias name (self-referential guard)
        self.assertEqual(_order_types("SELECT x FROM t ORDER BY x"), [INT])

        # Multiple ORDER BY columns
        self.assertEqual(
            _order_types("SELECT x + 1 AS y, z AS w FROM t ORDER BY y, w"), [INT, TEXT]
        )

        # Sort modifiers
        self.assertEqual(_order_types("SELECT x + 1 AS y FROM t ORDER BY y DESC"), [INT])
        self.assertEqual(_order_types("SELECT x + 1 AS y FROM t ORDER BY y NULLS FIRST"), [INT])
        self.assertEqual(_order_types("SELECT x + 1 AS y FROM t ORDER BY y DESC NULLS LAST"), [INT])

        # Three-column sort with mixed ASC/DESC
        self.assertEqual(
            _order_types(
                "SELECT x + 1 AS y, z AS w, category AS c FROM t ORDER BY y ASC, w DESC, c ASC"
            ),
            [INT, TEXT, TEXT],
        )

        # Compound expressions using aliases
        self.assertEqual(_order_types("SELECT x + 1 AS y FROM t ORDER BY y + 1"), [INT])
        self.assertEqual(_order_types("SELECT x + 1 AS y FROM t ORDER BY (y + 1) * 2"), [INT])
        self.assertEqual(_order_types("SELECT x + 1 AS y FROM t ORDER BY ((y + 1) * 2) + 3"), [INT])
        self.assertEqual(_order_types("SELECT x + 1 AS y FROM t ORDER BY ABS(y + 1)"), [INT])
        self.assertEqual(
            _order_types("SELECT x + 1 AS y FROM t ORDER BY COALESCE(y, 0) + 1"), [INT]
        )
        self.assertEqual(
            _order_types("SELECT x AS a, z AS b FROM t ORDER BY CONCAT(b, CAST(a AS TEXT))"),
            [VARCHAR],
        )

        # Non-projected column in ORDER BY
        self.assertEqual(_order_types("SELECT x FROM t ORDER BY z"), [TEXT])

        # Mixed alias + expression
        self.assertEqual(_order_types("SELECT x + 1 AS y FROM t ORDER BY y, x + 2"), [INT, INT])

        # GROUP BY + ORDER BY alias
        self.assertEqual(_order_types("SELECT x + 1 AS y FROM t GROUP BY y ORDER BY y"), [INT])

        # Set operations
        self.assertEqual(
            _order_types("SELECT x AS y FROM t UNION ALL SELECT a FROM u ORDER BY y"),
            [INT],
        )
        self.assertEqual(
            _order_types("SELECT x AS y FROM t UNION SELECT a FROM u ORDER BY y"),
            [INT],
        )
        self.assertEqual(
            _order_types("SELECT x AS y FROM t INTERSECT SELECT a FROM u ORDER BY y"),
            [INT],
        )
        self.assertEqual(
            _order_types("SELECT x AS y FROM t EXCEPT SELECT a FROM u ORDER BY y"),
            [INT],
        )
        self.assertEqual(
            _order_types("SELECT x AS y FROM t UNION ALL SELECT a FROM u ORDER BY y + 1"),
            [INT],
        )
        self.assertEqual(
            _order_types("SELECT x AS y FROM t UNION ALL SELECT a FROM u ORDER BY 1"),
            [INT],
        )

        # Subquery with ORDER BY
        self.assertEqual(
            _order_types("SELECT * FROM (SELECT x AS y FROM t ORDER BY y) AS sub"),
            [INT],
        )

        # Window function alias (SUM is typed, unlike ROW_NUMBER)
        self.assertEqual(_order_types("SELECT SUM(x) OVER () AS s FROM t ORDER BY s"), [BIGINT])

        # Subquery-as-projection alias
        self.assertEqual(
            _order_types("SELECT (SELECT MAX(a) FROM u) AS m FROM t ORDER BY m"), [INT]
        )

        # Alias name collides with table name
        self.assertEqual(
            _order_types("SELECT (SELECT MAX(a) FROM u) AS u FROM t ORDER BY u"), [INT]
        )

        # Type coercion through lazy annotation
        self.assertEqual(
            _order_types(
                "SELECT CASE WHEN x > 0 THEN x ELSE CAST(x AS BIGINT) END AS y FROM t ORDER BY y"
            ),
            [BIGINT],
        )

        # Subquery in ORDER BY with alias name clash (inner col is table-qualified)
        self.assertEqual(
            _order_types("SELECT x AS a FROM t ORDER BY (SELECT MAX(a) FROM u)"), [INT]
        )

        # CAST in ORDER BY using alias
        self.assertEqual(_order_types("SELECT x AS y FROM t ORDER BY CAST(y AS TEXT)"), [TEXT])

        # Duplicate alias (last wins, consistent with _expand_alias_refs)
        self.assertEqual(_order_types("SELECT x AS y, z AS y FROM t ORDER BY y"), [TEXT])

        # Compound ORDER BY with subquery (reannotation skips inner scope)
        self.assertEqual(
            _order_types("SELECT x AS y FROM t ORDER BY y + (SELECT MAX(a) FROM u)"),
            [INT],
        )

        # Regression: correlated subquery — no recursion error
        sql = "SELECT (SELECT col) FROM t"
        query = optimizer.qualify.qualify(parse_one(sql), schema=schema)
        optimizer.annotate_types.annotate_types(query, schema=schema)

        # Regression: self-referential alias (BigQuery pseudocolumn pattern)
        sql = "SELECT _col AS _col FROM t"
        schema_ext = {"t": {"_col": "INT"}}
        query = optimizer.qualify.qualify(parse_one(sql), schema=schema_ext)
        optimizer.annotate_types.annotate_types(query, schema=schema_ext)
