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):
        self.assertEqual(
            connection.ops.sql_flush(
                no_style(),
                [Person._meta.db_table, Tag._meta.db_table],
                reset_sequences=True,
            ),
            [
                'DELETE FROM "backends_person";',
                'DELETE FROM "backends_tag";',
                'UPDATE "sqlite_sequence" SET "seq" = 0 WHERE "name" IN '
                '(\'backends_person\', \'backends_tag\');',
            ],
        )

    def test_sql_flush_sequences_allow_cascade(self):
        statements = connection.ops.sql_flush(
            no_style(),
            [Person._meta.db_table, Tag._meta.db_table],
            reset_sequences=True,
            allow_cascade=True,
        )
        self.assertEqual(
            # The tables are processed in an unordered set.
            sorted(statements[:-1]),
            [
                'DELETE FROM "backends_person";',
                'DELETE FROM "backends_tag";',
                'DELETE FROM "backends_verylongmodelnamezzzzzzzzzzzzzzzzzzzzzz'
                'zzzzzzzzzzzzzzzzzzzz_m2m_also_quite_long_zzzzzzzzzzzzzzzzzzzz'
                'zzzzzzzzzzzzzzzzzzzzzzz";',
            ],
        )
        self.assertIs(statements[-1].startswith(
            'UPDATE "sqlite_sequence" SET "seq" = 0 WHERE "name" IN ('
        ), True)
        self.assertIn("'backends_person'", statements[-1])
        self.assertIn("'backends_tag'", statements[-1])
        self.assertIn(
            "'backends_verylongmodelnamezzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz"
            "zzzz_m2m_also_quite_long_zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz"
            "zzz'",
            statements[-1],
        )