from unittest.mock import MagicMock, Mock, sentinel

import pytest

from celery import states
from celery.app import backends
from celery.backends import couchdb as module
from celery.backends.couchdb import CouchBackend
from celery.exceptions import ImproperlyConfigured

try:
    import pycouchdb
except ImportError:
    pycouchdb = None

COUCHDB_CONTAINER = 'celery_container'

pytest.importorskip('pycouchdb')


class test_CouchBackend:

    def setup_method(self):
        self.Server = self.patching('pycouchdb.Server')
        self.backend = CouchBackend(app=self.app)

    def test_init_no_pycouchdb(self):
        """test init no pycouchdb raises"""
        prev, module.pycouchdb = module.pycouchdb, None
        try:
            with pytest.raises(ImproperlyConfigured):
                CouchBackend(app=self.app)
        finally:
            module.pycouchdb = prev

    def test_get_container_exists(self):
        self.backend._connection = sentinel._connection
        connection = self.backend.connection
        assert connection is sentinel._connection
        self.Server.assert_not_called()

    def test_get(self):
        """test_get

        CouchBackend.get should return  and take two params
        db conn to couchdb is mocked.
        """
        x = CouchBackend(app=self.app)
        x._connection = Mock()
        get = x._connection.get = MagicMock()
        assert x.get('1f3fab') == get.return_value['value']
        x._connection.get.assert_called_once_with('1f3fab')

    def test_get_non_existent_key(self):
        x = CouchBackend(app=self.app)
        x._connection = Mock()
        get = x._connection.get = MagicMock()
        get.side_effect = pycouchdb.exceptions.NotFound
        assert x.get('1f3fab') is None
        x._connection.get.assert_called_once_with('1f3fab')

    @pytest.mark.parametrize("key", ['1f3fab', b'1f3fab'])
    def test_set(self, key):
        x = CouchBackend(app=self.app)
        x._connection = Mock()

        x._set_with_state(key, 'value', states.SUCCESS)

        x._connection.save.assert_called_once_with({'_id': '1f3fab',
                                                    'value': 'value'})

    @pytest.mark.parametrize("key", ['1f3fab', b'1f3fab'])
    def test_set_with_conflict(self, key):
        x = CouchBackend(app=self.app)
        x._connection = Mock()
        x._connection.save.side_effect = (pycouchdb.exceptions.Conflict, None)
        get = x._connection.get = MagicMock()

        x._set_with_state(key, 'value', states.SUCCESS)

        x._connection.get.assert_called_once_with('1f3fab')
        x._connection.get('1f3fab').__setitem__.assert_called_once_with(
            'value', 'value')
        x._connection.save.assert_called_with(get('1f3fab'))
        assert x._connection.save.call_count == 2

    def test_delete(self):
        """test_delete

        CouchBackend.delete should return and take two params
        db conn to pycouchdb is mocked.
        TODO Should test on key not exists

        """
        x = CouchBackend(app=self.app)
        x._connection = Mock()
        mocked_delete = x._connection.delete = Mock()
        mocked_delete.return_value = None
        # should return None
        assert x.delete('1f3fab') is None
        x._connection.delete.assert_called_once_with('1f3fab')

    def test_backend_by_url(self, url='couchdb://myhost/mycoolcontainer'):
        from celery.backends.couchdb import CouchBackend
        backend, url_ = backends.by_url(url, self.app.loader)
        assert backend is CouchBackend
        assert url_ == url

    def test_backend_params_by_url(self):
        url = 'couchdb://johndoe:mysecret@myhost:123/mycoolcontainer'
        with self.Celery(backend=url) as app:
            x = app.backend
            assert x.container == 'mycoolcontainer'
            assert x.host == 'myhost'
            assert x.username == 'johndoe'
            assert x.password == 'mysecret'
            assert x.port == 123