from __future__ import absolute_import, unicode_literals

import pytest

from datetime import datetime
from pickle import loads, dumps

from case import Mock, patch, skip

from celery import states
from celery import uuid
from celery.exceptions import ImproperlyConfigured

try:
    import sqlalchemy  # noqa
except ImportError:
    DatabaseBackend = Task = TaskSet = retry = None  # noqa
    SessionManager = session_cleanup = None  # noqa
else:
    from celery.backends.database import (
        DatabaseBackend, retry, session_cleanup,
    )
    from celery.backends.database import session
    from celery.backends.database.session import SessionManager
    from celery.backends.database.models import Task, TaskSet


class SomeClass(object):

    def __init__(self, data):
        self.data = data


@skip.unless_module('sqlalchemy')
class test_session_cleanup:

    def test_context(self):
        session = Mock(name='session')
        with session_cleanup(session):
            pass
        session.close.assert_called_with()

    def test_context_raises(self):
        session = Mock(name='session')
        with pytest.raises(KeyError):
            with session_cleanup(session):
                raise KeyError()
        session.rollback.assert_called_with()
        session.close.assert_called_with()


@skip.unless_module('sqlalchemy')
@skip.if_pypy()
@skip.if_jython()
class test_DatabaseBackend:

    def setup(self):
        self.uri = 'sqlite:///test.db'
        self.app.conf.result_serializer = 'pickle'

    def test_retry_helper(self):
        from celery.backends.database import DatabaseError

        calls = [0]

        @retry
        def raises():
            calls[0] += 1
            raise DatabaseError(1, 2, 3)

        with pytest.raises(DatabaseError):
            raises(max_retries=5)
        assert calls[0] == 5

    def test_missing_dburi_raises_ImproperlyConfigured(self):
        self.app.conf.database_url = None
        with pytest.raises(ImproperlyConfigured):
            DatabaseBackend(app=self.app)

    def test_missing_task_id_is_PENDING(self):
        tb = DatabaseBackend(self.uri, app=self.app)
        assert tb.get_state('xxx-does-not-exist') == states.PENDING

    def test_missing_task_meta_is_dict_with_pending(self):
        tb = DatabaseBackend(self.uri, app=self.app)
        meta = tb.get_task_meta('xxx-does-not-exist-at-all')
        assert meta['status'] == states.PENDING
        assert meta['task_id'] == 'xxx-does-not-exist-at-all'
        assert meta['result'] is None
        assert meta['traceback'] is None

    def test_mark_as_done(self):
        tb = DatabaseBackend(self.uri, app=self.app)

        tid = uuid()

        assert tb.get_state(tid) == states.PENDING
        assert tb.get_result(tid) is None

        tb.mark_as_done(tid, 42)
        assert tb.get_state(tid) == states.SUCCESS
        assert tb.get_result(tid) == 42

    def test_is_pickled(self):
        tb = DatabaseBackend(self.uri, app=self.app)

        tid2 = uuid()
        result = {'foo': 'baz', 'bar': SomeClass(12345)}
        tb.mark_as_done(tid2, result)
        # is serialized properly.
        rindb = tb.get_result(tid2)
        assert rindb.get('foo') == 'baz'
        assert rindb.get('bar').data == 12345

    def test_mark_as_started(self):
        tb = DatabaseBackend(self.uri, app=self.app)
        tid = uuid()
        tb.mark_as_started(tid)
        assert tb.get_state(tid) == states.STARTED

    def test_mark_as_revoked(self):
        tb = DatabaseBackend(self.uri, app=self.app)
        tid = uuid()
        tb.mark_as_revoked(tid)
        assert tb.get_state(tid) == states.REVOKED

    def test_mark_as_retry(self):
        tb = DatabaseBackend(self.uri, app=self.app)
        tid = uuid()
        try:
            raise KeyError('foo')
        except KeyError as exception:
            import traceback
            trace = '\n'.join(traceback.format_stack())
            tb.mark_as_retry(tid, exception, traceback=trace)
            assert tb.get_state(tid) == states.RETRY
            assert isinstance(tb.get_result(tid), KeyError)
            assert tb.get_traceback(tid) == trace

    def test_mark_as_failure(self):
        tb = DatabaseBackend(self.uri, app=self.app)

        tid3 = uuid()
        try:
            raise KeyError('foo')
        except KeyError as exception:
            import traceback
            trace = '\n'.join(traceback.format_stack())
            tb.mark_as_failure(tid3, exception, traceback=trace)
            assert tb.get_state(tid3) == states.FAILURE
            assert isinstance(tb.get_result(tid3), KeyError)
            assert tb.get_traceback(tid3) == trace

    def test_forget(self):
        tb = DatabaseBackend(self.uri, backend='memory://', app=self.app)
        tid = uuid()
        tb.mark_as_done(tid, {'foo': 'bar'})
        tb.mark_as_done(tid, {'foo': 'bar'})
        x = self.app.AsyncResult(tid, backend=tb)
        x.forget()
        assert x.result is None

    def test_process_cleanup(self):
        tb = DatabaseBackend(self.uri, app=self.app)
        tb.process_cleanup()

    @pytest.mark.usefixtures('depends_on_current_app')
    def test_reduce(self):
        tb = DatabaseBackend(self.uri, app=self.app)
        assert loads(dumps(tb))

    def test_save__restore__delete_group(self):
        tb = DatabaseBackend(self.uri, app=self.app)

        tid = uuid()
        res = {'something': 'special'}
        assert tb.save_group(tid, res) == res

        res2 = tb.restore_group(tid)
        assert res2 == res

        tb.delete_group(tid)
        assert tb.restore_group(tid) is None

        assert tb.restore_group('xxx-nonexisting-id') is None

    def test_cleanup(self):
        tb = DatabaseBackend(self.uri, app=self.app)
        for i in range(10):
            tb.mark_as_done(uuid(), 42)
            tb.save_group(uuid(), {'foo': 'bar'})
        s = tb.ResultSession()
        for t in s.query(Task).all():
            t.date_done = datetime.now() - tb.expires * 2
        for t in s.query(TaskSet).all():
            t.date_done = datetime.now() - tb.expires * 2
        s.commit()
        s.close()

        tb.cleanup()

    def test_Task__repr__(self):
        assert 'foo' in repr(Task('foo'))

    def test_TaskSet__repr__(self):
        assert 'foo', repr(TaskSet('foo' in None))


@skip.unless_module('sqlalchemy')
class test_SessionManager:

    def test_after_fork(self):
        s = SessionManager()
        assert not s.forked
        s._after_fork()
        assert s.forked

    @patch('celery.backends.database.session.create_engine')
    def test_get_engine_forked(self, create_engine):
        s = SessionManager()
        s._after_fork()
        engine = s.get_engine('dburi', foo=1)
        create_engine.assert_called_with('dburi', foo=1)
        assert engine is create_engine()
        engine2 = s.get_engine('dburi', foo=1)
        assert engine2 is engine

    @patch('celery.backends.database.session.sessionmaker')
    def test_create_session_forked(self, sessionmaker):
        s = SessionManager()
        s.get_engine = Mock(name='get_engine')
        s._after_fork()
        engine, session = s.create_session('dburi', short_lived_sessions=True)
        sessionmaker.assert_called_with(bind=s.get_engine())
        assert session is sessionmaker()
        sessionmaker.return_value = Mock(name='new')
        engine, session2 = s.create_session('dburi', short_lived_sessions=True)
        sessionmaker.assert_called_with(bind=s.get_engine())
        assert session2 is not session
        sessionmaker.return_value = Mock(name='new2')
        engine, session3 = s.create_session(
            'dburi', short_lived_sessions=False)
        sessionmaker.assert_called_with(bind=s.get_engine())
        assert session3 is session2

    def test_coverage_madness(self):
        prev, session.register_after_fork = (
            session.register_after_fork, None,
        )
        try:
            SessionManager()
        finally:
            session.register_after_fork = prev