from django.db import connection
from django.db.backends.ddl_references import (
    Columns,
    Expressions,
    ForeignKeyName,
    IndexName,
    Statement,
    Table,
)
from django.db.models import ExpressionList, F
from django.db.models.functions import Upper
from django.db.models.indexes import IndexExpression
from django.db.models.sql import Query
from django.test import SimpleTestCase, TransactionTestCase

from .models import Person


class TableTests(SimpleTestCase):
    def setUp(self):
        self.reference = Table("table", lambda table: table.upper())

    def test_references_table(self):
        self.assertIs(self.reference.references_table("table"), True)
        self.assertIs(self.reference.references_table("other"), False)

    def test_rename_table_references(self):
        self.reference.rename_table_references("other", "table")
        self.assertIs(self.reference.references_table("table"), True)
        self.assertIs(self.reference.references_table("other"), False)
        self.reference.rename_table_references("table", "other")
        self.assertIs(self.reference.references_table("table"), False)
        self.assertIs(self.reference.references_table("other"), True)

    def test_repr(self):
        self.assertEqual(repr(self.reference), "<Table 'TABLE'>")

    def test_str(self):
        self.assertEqual(str(self.reference), "TABLE")


class ColumnsTests(TableTests):
    def setUp(self):
        self.reference = Columns(
            "table", ["first_column", "second_column"], lambda column: column.upper()
        )

    def test_references_column(self):
        self.assertIs(self.reference.references_column("other", "first_column"), False)
        self.assertIs(self.reference.references_column("table", "third_column"), False)
        self.assertIs(self.reference.references_column("table", "first_column"), True)

    def test_rename_column_references(self):
        self.reference.rename_column_references("other", "first_column", "third_column")
        self.assertIs(self.reference.references_column("table", "first_column"), True)
        self.assertIs(self.reference.references_column("table", "third_column"), False)
        self.assertIs(self.reference.references_column("other", "third_column"), False)
        self.reference.rename_column_references("table", "third_column", "first_column")
        self.assertIs(self.reference.references_column("table", "first_column"), True)
        self.assertIs(self.reference.references_column("table", "third_column"), False)
        self.reference.rename_column_references("table", "first_column", "third_column")
        self.assertIs(self.reference.references_column("table", "first_column"), False)
        self.assertIs(self.reference.references_column("table", "third_column"), True)

    def test_repr(self):
        self.assertEqual(
            repr(self.reference), "<Columns 'FIRST_COLUMN, SECOND_COLUMN'>"
        )

    def test_str(self):
        self.assertEqual(str(self.reference), "FIRST_COLUMN, SECOND_COLUMN")


class IndexNameTests(ColumnsTests):
    def setUp(self):
        def create_index_name(table_name, column_names, suffix):
            return ", ".join(
                "%s_%s_%s" % (table_name, column_name, suffix)
                for column_name in column_names
            )

        self.reference = IndexName(
            "table", ["first_column", "second_column"], "suffix", create_index_name
        )

    def test_repr(self):
        self.assertEqual(
            repr(self.reference),
            "<IndexName 'table_first_column_suffix, table_second_column_suffix'>",
        )

    def test_str(self):
        self.assertEqual(
            str(self.reference), "table_first_column_suffix, table_second_column_suffix"
        )


class ForeignKeyNameTests(IndexNameTests):
    def setUp(self):
        def create_foreign_key_name(table_name, column_names, suffix):
            return ", ".join(
                "%s_%s_%s" % (table_name, column_name, suffix)
                for column_name in column_names
            )

        self.reference = ForeignKeyName(
            "table",
            ["first_column", "second_column"],
            "to_table",
            ["to_first_column", "to_second_column"],
            "%(to_table)s_%(to_column)s_fk",
            create_foreign_key_name,
        )

    def test_references_table(self):
        super().test_references_table()
        self.assertIs(self.reference.references_table("to_table"), True)

    def test_references_column(self):
        super().test_references_column()
        self.assertIs(
            self.reference.references_column("to_table", "second_column"), False
        )
        self.assertIs(
            self.reference.references_column("to_table", "to_second_column"), True
        )

    def test_rename_table_references(self):
        super().test_rename_table_references()
        self.reference.rename_table_references("to_table", "other_to_table")
        self.assertIs(self.reference.references_table("other_to_table"), True)
        self.assertIs(self.reference.references_table("to_table"), False)

    def test_rename_column_references(self):
        super().test_rename_column_references()
        self.reference.rename_column_references(
            "to_table", "second_column", "third_column"
        )
        self.assertIs(self.reference.references_column("table", "second_column"), True)
        self.assertIs(
            self.reference.references_column("to_table", "to_second_column"), True
        )
        self.reference.rename_column_references(
            "to_table", "to_first_column", "to_third_column"
        )
        self.assertIs(
            self.reference.references_column("to_table", "to_first_column"), False
        )
        self.assertIs(
            self.reference.references_column("to_table", "to_third_column"), True
        )

    def test_repr(self):
        self.assertEqual(
            repr(self.reference),
            "<ForeignKeyName 'table_first_column_to_table_to_first_column_fk, "
            "table_second_column_to_table_to_first_column_fk'>",
        )

    def test_str(self):
        self.assertEqual(
            str(self.reference),
            "table_first_column_to_table_to_first_column_fk, "
            "table_second_column_to_table_to_first_column_fk",
        )


class MockReference:
    def __init__(self, representation, referenced_tables, referenced_columns):
        self.representation = representation
        self.referenced_tables = referenced_tables
        self.referenced_columns = referenced_columns

    def references_table(self, table):
        return table in self.referenced_tables

    def references_column(self, table, column):
        return (table, column) in self.referenced_columns

    def rename_table_references(self, old_table, new_table):
        if old_table in self.referenced_tables:
            self.referenced_tables.remove(old_table)
            self.referenced_tables.add(new_table)

    def rename_column_references(self, table, old_column, new_column):
        column = (table, old_column)
        if column in self.referenced_columns:
            self.referenced_columns.remove(column)
            self.referenced_columns.add((table, new_column))

    def __str__(self):
        return self.representation


class StatementTests(SimpleTestCase):
    def test_references_table(self):
        statement = Statement(
            "", reference=MockReference("", {"table"}, {}), non_reference=""
        )
        self.assertIs(statement.references_table("table"), True)
        self.assertIs(statement.references_table("other"), False)

    def test_references_column(self):
        statement = Statement(
            "", reference=MockReference("", {}, {("table", "column")}), non_reference=""
        )
        self.assertIs(statement.references_column("table", "column"), True)
        self.assertIs(statement.references_column("other", "column"), False)

    def test_rename_table_references(self):
        reference = MockReference("", {"table"}, {})
        statement = Statement("", reference=reference, non_reference="")
        statement.rename_table_references("table", "other")
        self.assertEqual(reference.referenced_tables, {"other"})

    def test_rename_column_references(self):
        reference = MockReference("", {}, {("table", "column")})
        statement = Statement("", reference=reference, non_reference="")
        statement.rename_column_references("table", "column", "other")
        self.assertEqual(reference.referenced_columns, {("table", "other")})

    def test_repr(self):
        reference = MockReference("reference", {}, {})
        statement = Statement(
            "%(reference)s - %(non_reference)s",
            reference=reference,
            non_reference="non_reference",
        )
        self.assertEqual(repr(statement), "<Statement 'reference - non_reference'>")

    def test_str(self):
        reference = MockReference("reference", {}, {})
        statement = Statement(
            "%(reference)s - %(non_reference)s",
            reference=reference,
            non_reference="non_reference",
        )
        self.assertEqual(str(statement), "reference - non_reference")


class ExpressionsTests(TransactionTestCase):
    available_apps = []

    def setUp(self):
        compiler = Person.objects.all().query.get_compiler(connection.alias)
        self.editor = connection.schema_editor()
        self.expressions = Expressions(
            table=Person._meta.db_table,
            expressions=ExpressionList(
                IndexExpression(F("first_name")),
                IndexExpression(F("last_name").desc()),
                IndexExpression(Upper("last_name")),
            ).resolve_expression(compiler.query),
            compiler=compiler,
            quote_value=self.editor.quote_value,
        )

    def test_references_table(self):
        self.assertIs(self.expressions.references_table(Person._meta.db_table), True)
        self.assertIs(self.expressions.references_table("other"), False)

    def test_references_column(self):
        table = Person._meta.db_table
        self.assertIs(self.expressions.references_column(table, "first_name"), True)
        self.assertIs(self.expressions.references_column(table, "last_name"), True)
        self.assertIs(self.expressions.references_column(table, "other"), False)

    def test_rename_table_references(self):
        table = Person._meta.db_table
        self.expressions.rename_table_references(table, "other")
        self.assertIs(self.expressions.references_table(table), False)
        self.assertIs(self.expressions.references_table("other"), True)
        self.assertIn(
            "%s.%s"
            % (
                self.editor.quote_name("other"),
                self.editor.quote_name("first_name"),
            ),
            str(self.expressions),
        )

    def test_rename_table_references_without_alias(self):
        compiler = Query(Person, alias_cols=False).get_compiler(connection=connection)
        table = Person._meta.db_table
        expressions = Expressions(
            table=table,
            expressions=ExpressionList(
                IndexExpression(Upper("last_name")),
                IndexExpression(F("first_name")),
            ).resolve_expression(compiler.query),
            compiler=compiler,
            quote_value=self.editor.quote_value,
        )
        expressions.rename_table_references(table, "other")
        self.assertIs(expressions.references_table(table), False)
        self.assertIs(expressions.references_table("other"), True)
        expected_str = "(UPPER(%s)), %s" % (
            self.editor.quote_name("last_name"),
            self.editor.quote_name("first_name"),
        )
        self.assertEqual(str(expressions), expected_str)

    def test_rename_column_references(self):
        table = Person._meta.db_table
        self.expressions.rename_column_references(table, "first_name", "other")
        self.assertIs(self.expressions.references_column(table, "other"), True)
        self.assertIs(self.expressions.references_column(table, "first_name"), False)
        self.assertIn(
            "%s.%s" % (self.editor.quote_name(table), self.editor.quote_name("other")),
            str(self.expressions),
        )

    def test_str(self):
        table_name = self.editor.quote_name(Person._meta.db_table)
        expected_str = "%s.%s, %s.%s DESC, (UPPER(%s.%s))" % (
            table_name,
            self.editor.quote_name("first_name"),
            table_name,
            self.editor.quote_name("last_name"),
            table_name,
            self.editor.quote_name("last_name"),
        )
        self.assertEqual(str(self.expressions), expected_str)