import unittest

from django.core.management.color import no_style
from django.db import connection
from django.test import TestCase

from ..models import Person, Tag


@unittest.skipUnless(connection.vendor == 'sqlite', 'SQLite tests.')
class SQLiteOperationsTests(TestCase):
    def test_sql_flush(self):
        self.assertEqual(
            connection.ops.sql_flush(
                no_style(),
                [Person._meta.db_table, Tag._meta.db_table],
                [],
            ),
            [
                'DELETE FROM "backends_person";',
                'DELETE FROM "backends_tag";',
            ],
        )

    def test_sql_flush_allow_cascade(self):
        statements = connection.ops.sql_flush(
            no_style(),
            [Person._meta.db_table, Tag._meta.db_table],
            [],
            allow_cascade=True,
        )
        self.assertEqual(
            # The tables are processed in an unordered set.
            sorted(statements),
            [
                'DELETE FROM "backends_person";',
                'DELETE FROM "backends_tag";',
                'DELETE FROM "backends_verylongmodelnamezzzzzzzzzzzzzzzzzzzzzz'
                'zzzzzzzzzzzzzzzzzzzz_m2m_also_quite_long_zzzzzzzzzzzzzzzzzzzz'
                'zzzzzzzzzzzzzzzzzzzzzzz";',
            ],
        )

    def test_sql_flush_sequences(self):
        # sequences doesn't change statements on SQLite.
        self.assertEqual(
            connection.ops.sql_flush(
                no_style(),
                [Person._meta.db_table, Tag._meta.db_table],
                [
                    {
                        'table': Person._meta.db_table,
                        'column': Person._meta.pk.db_column,
                    },
                    {
                        'table': Tag._meta.db_table,
                        'column': Tag._meta.pk.db_column,
                    },
                ],
            ),
            [
                'DELETE FROM "backends_person";',
                'DELETE FROM "backends_tag";',
            ],
        )

    def test_sql_flush_sequences_allow_cascade(self):
        # sequences doesn't change statements on SQLite.
        statements = connection.ops.sql_flush(
            no_style(),
            [Person._meta.db_table, Tag._meta.db_table],
            [
                {
                    'table': Person._meta.db_table,
                    'column': Person._meta.pk.db_column,
                },
                {
                    'table': Tag._meta.db_table,
                    'column': Tag._meta.pk.db_column,
                },
            ],
            allow_cascade=True,
        )
        self.assertEqual(
            # The tables are processed in an unordered set.
            sorted(statements),
            [
                'DELETE FROM "backends_person";',
                'DELETE FROM "backends_tag";',
                'DELETE FROM "backends_verylongmodelnamezzzzzzzzzzzzzzzzzzzzzz'
                'zzzzzzzzzzzzzzzzzzzz_m2m_also_quite_long_zzzzzzzzzzzzzzzzzzzz'
                'zzzzzzzzzzzzzzzzzzzzzzz";',
            ],
        )