import unittest
from unittest import mock

from migrations.test_base import OperationTestBase

from django.db import NotSupportedError, connection
from django.db.migrations.state import ProjectState
from django.db.models import Index
from django.db.utils import ProgrammingError
from django.test import modify_settings, override_settings, skipUnlessDBFeature
from django.test.utils import CaptureQueriesContext

from . import PostgreSQLTestCase

try:
    from django.contrib.postgres.indexes import BrinIndex, BTreeIndex
    from django.contrib.postgres.operations import (
        AddIndexConcurrently, BloomExtension, CreateCollation, CreateExtension,
        RemoveCollation, RemoveIndexConcurrently,
    )
except ImportError:
    pass


@unittest.skipUnless(connection.vendor == 'postgresql', 'PostgreSQL specific tests.')
@modify_settings(INSTALLED_APPS={'append': 'migrations'})
class AddIndexConcurrentlyTests(OperationTestBase):
    app_label = 'test_add_concurrently'

    def test_requires_atomic_false(self):
        project_state = self.set_up_test_model(self.app_label)
        new_state = project_state.clone()
        operation = AddIndexConcurrently(
            'Pony',
            Index(fields=['pink'], name='pony_pink_idx'),
        )
        msg = (
            'The AddIndexConcurrently operation cannot be executed inside '
            'a transaction (set atomic = False on the migration).'
        )
        with self.assertRaisesMessage(NotSupportedError, msg):
            with connection.schema_editor(atomic=True) as editor:
                operation.database_forwards(self.app_label, editor, project_state, new_state)

    def test_add(self):
        project_state = self.set_up_test_model(self.app_label, index=False)
        table_name = '%s_pony' % self.app_label
        index = Index(fields=['pink'], name='pony_pink_idx')
        new_state = project_state.clone()
        operation = AddIndexConcurrently('Pony', index)
        self.assertEqual(
            operation.describe(),
            'Concurrently create index pony_pink_idx on field(s) pink of '
            'model Pony'
        )
        operation.state_forwards(self.app_label, new_state)
        self.assertEqual(len(new_state.models[self.app_label, 'pony'].options['indexes']), 1)
        self.assertIndexNotExists(table_name, ['pink'])
        # Add index.
        with connection.schema_editor(atomic=False) as editor:
            operation.database_forwards(self.app_label, editor, project_state, new_state)
        self.assertIndexExists(table_name, ['pink'])
        # Reversal.
        with connection.schema_editor(atomic=False) as editor:
            operation.database_backwards(self.app_label, editor, new_state, project_state)
        self.assertIndexNotExists(table_name, ['pink'])
        # Deconstruction.
        name, args, kwargs = operation.deconstruct()
        self.assertEqual(name, 'AddIndexConcurrently')
        self.assertEqual(args, [])
        self.assertEqual(kwargs, {'model_name': 'Pony', 'index': index})

    def test_add_other_index_type(self):
        project_state = self.set_up_test_model(self.app_label, index=False)
        table_name = '%s_pony' % self.app_label
        new_state = project_state.clone()
        operation = AddIndexConcurrently(
            'Pony',
            BrinIndex(fields=['pink'], name='pony_pink_brin_idx'),
        )
        self.assertIndexNotExists(table_name, ['pink'])
        # Add index.
        with connection.schema_editor(atomic=False) as editor:
            operation.database_forwards(self.app_label, editor, project_state, new_state)
        self.assertIndexExists(table_name, ['pink'], index_type='brin')
        # Reversal.
        with connection.schema_editor(atomic=False) as editor:
            operation.database_backwards(self.app_label, editor, new_state, project_state)
        self.assertIndexNotExists(table_name, ['pink'])

    def test_add_with_options(self):
        project_state = self.set_up_test_model(self.app_label, index=False)
        table_name = '%s_pony' % self.app_label
        new_state = project_state.clone()
        index = BTreeIndex(fields=['pink'], name='pony_pink_btree_idx', fillfactor=70)
        operation = AddIndexConcurrently('Pony', index)
        self.assertIndexNotExists(table_name, ['pink'])
        # Add index.
        with connection.schema_editor(atomic=False) as editor:
            operation.database_forwards(self.app_label, editor, project_state, new_state)
        self.assertIndexExists(table_name, ['pink'], index_type='btree')
        # Reversal.
        with connection.schema_editor(atomic=False) as editor:
            operation.database_backwards(self.app_label, editor, new_state, project_state)
        self.assertIndexNotExists(table_name, ['pink'])


@unittest.skipUnless(connection.vendor == 'postgresql', 'PostgreSQL specific tests.')
@modify_settings(INSTALLED_APPS={'append': 'migrations'})
class RemoveIndexConcurrentlyTests(OperationTestBase):
    app_label = 'test_rm_concurrently'

    def test_requires_atomic_false(self):
        project_state = self.set_up_test_model(self.app_label, index=True)
        new_state = project_state.clone()
        operation = RemoveIndexConcurrently('Pony', 'pony_pink_idx')
        msg = (
            'The RemoveIndexConcurrently operation cannot be executed inside '
            'a transaction (set atomic = False on the migration).'
        )
        with self.assertRaisesMessage(NotSupportedError, msg):
            with connection.schema_editor(atomic=True) as editor:
                operation.database_forwards(self.app_label, editor, project_state, new_state)

    def test_remove(self):
        project_state = self.set_up_test_model(self.app_label, index=True)
        table_name = '%s_pony' % self.app_label
        self.assertTableExists(table_name)
        new_state = project_state.clone()
        operation = RemoveIndexConcurrently('Pony', 'pony_pink_idx')
        self.assertEqual(
            operation.describe(),
            'Concurrently remove index pony_pink_idx from Pony',
        )
        operation.state_forwards(self.app_label, new_state)
        self.assertEqual(len(new_state.models[self.app_label, 'pony'].options['indexes']), 0)
        self.assertIndexExists(table_name, ['pink'])
        # Remove index.
        with connection.schema_editor(atomic=False) as editor:
            operation.database_forwards(self.app_label, editor, project_state, new_state)
        self.assertIndexNotExists(table_name, ['pink'])
        # Reversal.
        with connection.schema_editor(atomic=False) as editor:
            operation.database_backwards(self.app_label, editor, new_state, project_state)
        self.assertIndexExists(table_name, ['pink'])
        # Deconstruction.
        name, args, kwargs = operation.deconstruct()
        self.assertEqual(name, 'RemoveIndexConcurrently')
        self.assertEqual(args, [])
        self.assertEqual(kwargs, {'model_name': 'Pony', 'name': 'pony_pink_idx'})


class NoMigrationRouter():
    def allow_migrate(self, db, app_label, **hints):
        return False


@unittest.skipUnless(connection.vendor == 'postgresql', 'PostgreSQL specific tests.')
class CreateExtensionTests(PostgreSQLTestCase):
    app_label = 'test_allow_create_extention'

    @override_settings(DATABASE_ROUTERS=[NoMigrationRouter()])
    def test_no_allow_migrate(self):
        operation = CreateExtension('tablefunc')
        project_state = ProjectState()
        new_state = project_state.clone()
        # Don't create an extension.
        with CaptureQueriesContext(connection) as captured_queries:
            with connection.schema_editor(atomic=False) as editor:
                operation.database_forwards(self.app_label, editor, project_state, new_state)
        self.assertEqual(len(captured_queries), 0)
        # Reversal.
        with CaptureQueriesContext(connection) as captured_queries:
            with connection.schema_editor(atomic=False) as editor:
                operation.database_backwards(self.app_label, editor, new_state, project_state)
        self.assertEqual(len(captured_queries), 0)

    def test_allow_migrate(self):
        operation = CreateExtension('tablefunc')
        self.assertEqual(operation.migration_name_fragment, 'create_extension_tablefunc')
        project_state = ProjectState()
        new_state = project_state.clone()
        # Create an extension.
        with CaptureQueriesContext(connection) as captured_queries:
            with connection.schema_editor(atomic=False) as editor:
                operation.database_forwards(self.app_label, editor, project_state, new_state)
        self.assertEqual(len(captured_queries), 4)
        self.assertIn('CREATE EXTENSION IF NOT EXISTS', captured_queries[1]['sql'])
        # Reversal.
        with CaptureQueriesContext(connection) as captured_queries:
            with connection.schema_editor(atomic=False) as editor:
                operation.database_backwards(self.app_label, editor, new_state, project_state)
        self.assertEqual(len(captured_queries), 2)
        self.assertIn('DROP EXTENSION IF EXISTS', captured_queries[1]['sql'])

    def test_create_existing_extension(self):
        operation = BloomExtension()
        self.assertEqual(operation.migration_name_fragment, 'create_extension_bloom')
        project_state = ProjectState()
        new_state = project_state.clone()
        # Don't create an existing extension.
        with CaptureQueriesContext(connection) as captured_queries:
            with connection.schema_editor(atomic=False) as editor:
                operation.database_forwards(self.app_label, editor, project_state, new_state)
        self.assertEqual(len(captured_queries), 3)
        self.assertIn('SELECT', captured_queries[0]['sql'])

    def test_drop_nonexistent_extension(self):
        operation = CreateExtension('tablefunc')
        project_state = ProjectState()
        new_state = project_state.clone()
        # Don't drop a nonexistent extension.
        with CaptureQueriesContext(connection) as captured_queries:
            with connection.schema_editor(atomic=False) as editor:
                operation.database_backwards(self.app_label, editor, project_state, new_state)
        self.assertEqual(len(captured_queries), 1)
        self.assertIn('SELECT', captured_queries[0]['sql'])


@unittest.skipUnless(connection.vendor == 'postgresql', 'PostgreSQL specific tests.')
class CreateCollationTests(PostgreSQLTestCase):
    app_label = 'test_allow_create_collation'

    @override_settings(DATABASE_ROUTERS=[NoMigrationRouter()])
    def test_no_allow_migrate(self):
        operation = CreateCollation('C_test', locale='C')
        project_state = ProjectState()
        new_state = project_state.clone()
        # Don't create a collation.
        with CaptureQueriesContext(connection) as captured_queries:
            with connection.schema_editor(atomic=False) as editor:
                operation.database_forwards(self.app_label, editor, project_state, new_state)
        self.assertEqual(len(captured_queries), 0)
        # Reversal.
        with CaptureQueriesContext(connection) as captured_queries:
            with connection.schema_editor(atomic=False) as editor:
                operation.database_backwards(self.app_label, editor, new_state, project_state)
        self.assertEqual(len(captured_queries), 0)

    def test_create(self):
        operation = CreateCollation('C_test', locale='C')
        self.assertEqual(operation.migration_name_fragment, 'create_collation_c_test')
        self.assertEqual(operation.describe(), 'Create collation C_test')
        project_state = ProjectState()
        new_state = project_state.clone()
        # Create a collation.
        with CaptureQueriesContext(connection) as captured_queries:
            with connection.schema_editor(atomic=False) as editor:
                operation.database_forwards(self.app_label, editor, project_state, new_state)
        self.assertEqual(len(captured_queries), 1)
        self.assertIn('CREATE COLLATION', captured_queries[0]['sql'])
        # Creating the same collation raises an exception.
        with self.assertRaisesMessage(ProgrammingError, 'already exists'):
            with connection.schema_editor(atomic=True) as editor:
                operation.database_forwards(self.app_label, editor, project_state, new_state)
        # Reversal.
        with CaptureQueriesContext(connection) as captured_queries:
            with connection.schema_editor(atomic=False) as editor:
                operation.database_backwards(self.app_label, editor, new_state, project_state)
        self.assertEqual(len(captured_queries), 1)
        self.assertIn('DROP COLLATION', captured_queries[0]['sql'])
        # Deconstruction.
        name, args, kwargs = operation.deconstruct()
        self.assertEqual(name, 'CreateCollation')
        self.assertEqual(args, [])
        self.assertEqual(kwargs, {'name': 'C_test', 'locale': 'C'})

    @skipUnlessDBFeature('supports_non_deterministic_collations')
    def test_create_non_deterministic_collation(self):
        operation = CreateCollation(
            'case_insensitive_test',
            'und-u-ks-level2',
            provider='icu',
            deterministic=False,
        )
        project_state = ProjectState()
        new_state = project_state.clone()
        # Create a collation.
        with CaptureQueriesContext(connection) as captured_queries:
            with connection.schema_editor(atomic=False) as editor:
                operation.database_forwards(self.app_label, editor, project_state, new_state)
        self.assertEqual(len(captured_queries), 1)
        self.assertIn('CREATE COLLATION', captured_queries[0]['sql'])
        # Reversal.
        with CaptureQueriesContext(connection) as captured_queries:
            with connection.schema_editor(atomic=False) as editor:
                operation.database_backwards(self.app_label, editor, new_state, project_state)
        self.assertEqual(len(captured_queries), 1)
        self.assertIn('DROP COLLATION', captured_queries[0]['sql'])
        # Deconstruction.
        name, args, kwargs = operation.deconstruct()
        self.assertEqual(name, 'CreateCollation')
        self.assertEqual(args, [])
        self.assertEqual(kwargs, {
            'name': 'case_insensitive_test',
            'locale': 'und-u-ks-level2',
            'provider': 'icu',
            'deterministic': False,
        })

    def test_create_collation_alternate_provider(self):
        operation = CreateCollation(
            'german_phonebook_test',
            provider='icu',
            locale='de-u-co-phonebk',
        )
        project_state = ProjectState()
        new_state = project_state.clone()
        # Create an collation.
        with CaptureQueriesContext(connection) as captured_queries:
            with connection.schema_editor(atomic=False) as editor:
                operation.database_forwards(self.app_label, editor, project_state, new_state)
        self.assertEqual(len(captured_queries), 1)
        self.assertIn('CREATE COLLATION', captured_queries[0]['sql'])
        # Reversal.
        with CaptureQueriesContext(connection) as captured_queries:
            with connection.schema_editor(atomic=False) as editor:
                operation.database_backwards(self.app_label, editor, new_state, project_state)
        self.assertEqual(len(captured_queries), 1)
        self.assertIn('DROP COLLATION', captured_queries[0]['sql'])

    def test_nondeterministic_collation_not_supported(self):
        operation = CreateCollation(
            'case_insensitive_test',
            provider='icu',
            locale='und-u-ks-level2',
            deterministic=False,
        )
        project_state = ProjectState()
        new_state = project_state.clone()
        msg = 'Non-deterministic collations require PostgreSQL 12+.'
        with connection.schema_editor(atomic=False) as editor:
            with mock.patch(
                'django.db.backends.postgresql.features.DatabaseFeatures.'
                'supports_non_deterministic_collations',
                False,
            ):
                with self.assertRaisesMessage(NotSupportedError, msg):
                    operation.database_forwards(self.app_label, editor, project_state, new_state)


@unittest.skipUnless(connection.vendor == 'postgresql', 'PostgreSQL specific tests.')
class RemoveCollationTests(PostgreSQLTestCase):
    app_label = 'test_allow_remove_collation'

    @override_settings(DATABASE_ROUTERS=[NoMigrationRouter()])
    def test_no_allow_migrate(self):
        operation = RemoveCollation('C_test', locale='C')
        project_state = ProjectState()
        new_state = project_state.clone()
        # Don't create a collation.
        with CaptureQueriesContext(connection) as captured_queries:
            with connection.schema_editor(atomic=False) as editor:
                operation.database_forwards(self.app_label, editor, project_state, new_state)
        self.assertEqual(len(captured_queries), 0)
        # Reversal.
        with CaptureQueriesContext(connection) as captured_queries:
            with connection.schema_editor(atomic=False) as editor:
                operation.database_backwards(self.app_label, editor, new_state, project_state)
        self.assertEqual(len(captured_queries), 0)

    def test_remove(self):
        operation = CreateCollation('C_test', locale='C')
        project_state = ProjectState()
        new_state = project_state.clone()
        with connection.schema_editor(atomic=False) as editor:
            operation.database_forwards(self.app_label, editor, project_state, new_state)

        operation = RemoveCollation('C_test', locale='C')
        self.assertEqual(operation.migration_name_fragment, 'remove_collation_c_test')
        self.assertEqual(operation.describe(), 'Remove collation C_test')
        project_state = ProjectState()
        new_state = project_state.clone()
        # Remove a collation.
        with CaptureQueriesContext(connection) as captured_queries:
            with connection.schema_editor(atomic=False) as editor:
                operation.database_forwards(self.app_label, editor, project_state, new_state)
        self.assertEqual(len(captured_queries), 1)
        self.assertIn('DROP COLLATION', captured_queries[0]['sql'])
        # Removing a nonexistent collation raises an exception.
        with self.assertRaisesMessage(ProgrammingError, 'does not exist'):
            with connection.schema_editor(atomic=True) as editor:
                operation.database_forwards(self.app_label, editor, project_state, new_state)
        # Reversal.
        with CaptureQueriesContext(connection) as captured_queries:
            with connection.schema_editor(atomic=False) as editor:
                operation.database_backwards(self.app_label, editor, new_state, project_state)
        self.assertEqual(len(captured_queries), 1)
        self.assertIn('CREATE COLLATION', captured_queries[0]['sql'])
        # Deconstruction.
        name, args, kwargs = operation.deconstruct()
        self.assertEqual(name, 'RemoveCollation')
        self.assertEqual(args, [])
        self.assertEqual(kwargs, {'name': 'C_test', 'locale': 'C'})
