import pytest

from gti_discovery.read_only import validate_read_only


def test_accepts_and_normalizes_select_query():
    assert validate_read_only("  SELECT   *  FROM RDB$DATABASE ;  ") == (
        "SELECT * FROM RDB$DATABASE"
    )


def test_accepts_with_query():
    sql = "WITH x AS (SELECT 1 AS n FROM RDB$DATABASE) SELECT n FROM x"
    assert validate_read_only(sql) == sql


@pytest.mark.parametrize(
    "sql",
    [
        "INSERT INTO X VALUES (1)",
        "UPDATE X SET A=1",
        "DELETE FROM X",
        "CREATE TABLE X(A INT)",
        "ALTER TABLE X ADD A INT",
        "DROP TABLE X",
        "TRUNCATE TABLE X",
        "EXECUTE PROCEDURE P",
        "WITH x AS (SELECT 1 FROM RDB$DATABASE) INSERT INTO X VALUES (1)",
    ],
)
def test_rejects_write_or_side_effect_sql(sql):
    with pytest.raises(ValueError):
        validate_read_only(sql)


@pytest.mark.parametrize(
    "sql",
    [
        "SELECT 1 FROM RDB$DATABASE; SELECT 2 FROM RDB$DATABASE",
        "SELECT 1 FROM RDB$DATABASE -- comment",
        "SELECT 1 /* comment */ FROM RDB$DATABASE",
        "",
        "VACUUM TABLE X",
    ],
)
def test_rejects_multiple_statements_comments_and_non_queries(sql):
    with pytest.raises(ValueError):
        validate_read_only(sql)


@pytest.mark.parametrize(
    "sql",
    [
        "SELECT * FROM SIDE_EFFECTING_PROC(1)",
        "SELECT GEN_ID(MY_GENERATOR, 1) FROM RDB$DATABASE",
        "SELECT NEXT VALUE FOR MY_GENERATOR FROM RDB$DATABASE",
        "SELECT * FROM X WITH LOCK",
        "SELECT * FROM X FOR UPDATE",
        "SELECT * FROM PKG . SELECTABLE_PROC (1)",
    ],
)
def test_rejects_known_side_effecting_select_constructs(sql):
    with pytest.raises(ValueError):
        validate_read_only(sql)


@pytest.mark.parametrize(
    "sql",
    [
        "SELECT IIF(RDB$SYSTEM_FLAG = 1, 'SYSTEM', 'USER') FROM RDB$RELATIONS",
        "SELECT EXTRACT(YEAR FROM CURRENT_DATE) FROM RDB$DATABASE",
        "SELECT COALESCE(RDB$RELATION_NAME, '') FROM RDB$RELATIONS",
    ],
)
def test_accepts_legitimate_firebird_read_only_expressions(sql):
    assert validate_read_only(sql) == sql


@pytest.mark.parametrize(
    "sql",
    [
        "SELECT EXECUTE(1) FROM RDB$DATABASE",
        "SELECT GEN_ID(MY_GENERATOR, 1) FROM RDB$DATABASE",
        "SELECT * FROM SELECTABLE_PROC(1)",
        "SELECT * FROM PKG . SELECTABLE_PROC (1)",
        "SELECT * FROM PKG\t.\tSELECTABLE_PROC\t(1)",
    ],
)
def test_rejects_explicit_unsafe_callable_forms(sql):
    with pytest.raises(ValueError):
        validate_read_only(sql)


@pytest.mark.parametrize(
    "sql",
    [
        "SELECT SIDE_EFFECTING_UDF(ID) FROM X",
        "SELECT PKG . SIDE_EFFECTING_UDF(ID) FROM X",
    ],
)
def test_rejects_unknown_callable_in_select_projection(sql):
    with pytest.raises(ValueError, match="callable"):
        validate_read_only(sql)


def test_normalization_does_not_change_quoted_literal_contents():
    sql = " SELECT  '  keep   spaces  ; -- text '  FROM RDB$DATABASE ; "
    assert validate_read_only(sql) == (
        "SELECT '  keep   spaces  ; -- text ' FROM RDB$DATABASE"
    )