from datetime import datetime
from pickle import dumps, loads
from unittest.mock import Mock

import pytest

from celery import states
from celery.exceptions import ImproperlyConfigured
from celery.utils.objects import Bunch

CASSANDRA_MODULES = [
    'cassandra',
    'cassandra.auth',
    'cassandra.cluster',
    'cassandra.query',
]


class test_CassandraBackend:

    def setup_method(self):
        self.app.conf.update(
            cassandra_servers=['example.com'],
            cassandra_keyspace='celery',
            cassandra_table='task_results',
        )

    @pytest.mark.patched_module(*CASSANDRA_MODULES)
    def test_init_no_cassandra(self, module):
        # should raise ImproperlyConfigured when no python-driver
        # installed.
        from celery.backends import cassandra as mod
        prev, mod.cassandra = mod.cassandra, None
        try:
            with pytest.raises(ImproperlyConfigured):
                mod.CassandraBackend(app=self.app)
        finally:
            mod.cassandra = prev

    @pytest.mark.patched_module(*CASSANDRA_MODULES)
    def test_init_with_and_without_LOCAL_QUROM(self, module):
        from celery.backends import cassandra as mod
        mod.cassandra = Mock()

        cons = mod.cassandra.ConsistencyLevel = Bunch(
            LOCAL_QUORUM='foo',
        )

        self.app.conf.cassandra_read_consistency = 'LOCAL_FOO'
        self.app.conf.cassandra_write_consistency = 'LOCAL_FOO'

        mod.CassandraBackend(app=self.app)
        cons.LOCAL_FOO = 'bar'
        mod.CassandraBackend(app=self.app)

        # no servers and no bundle_path raises ImproperlyConfigured
        with pytest.raises(ImproperlyConfigured):
            self.app.conf.cassandra_servers = None
            self.app.conf.cassandra_secure_bundle_path = None
            mod.CassandraBackend(
                app=self.app, keyspace='b', column_family='c',
            )

        # both servers no bundle_path raises ImproperlyConfigured
        with pytest.raises(ImproperlyConfigured):
            self.app.conf.cassandra_servers = ['localhost']
            self.app.conf.cassandra_secure_bundle_path = (
                '/home/user/secure-connect-bundle.zip')
            mod.CassandraBackend(
                app=self.app, keyspace='b', column_family='c',
            )

    def test_init_with_cloud(self):
        # Tests behavior when Cluster.connect works properly
        # and cluster is created with 'cloud' param instead of 'contact_points'
        from celery.backends import cassandra as mod

        class DummyClusterWithBundle:

            def __init__(self, *args, **kwargs):
                if args != ():
                    # this cluster is supposed to be created with 'cloud=...'
                    raise ValueError('I should be created with kwargs only')
                pass

            def connect(self, *args, **kwargs):
                return Mock()

        mod.cassandra = Mock()
        mod.cassandra.cluster = Mock()
        mod.cassandra.cluster.Cluster = DummyClusterWithBundle

        self.app.conf.cassandra_secure_bundle_path = '/path/to/bundle.zip'
        self.app.conf.cassandra_servers = None

        x = mod.CassandraBackend(app=self.app)
        x._get_connection()
        assert isinstance(x._cluster, DummyClusterWithBundle)

    @pytest.mark.patched_module(*CASSANDRA_MODULES)
    @pytest.mark.usefixtures('depends_on_current_app')
    def test_reduce(self, module):
        from celery.backends.cassandra import CassandraBackend
        assert loads(dumps(CassandraBackend(app=self.app)))

    @pytest.mark.patched_module(*CASSANDRA_MODULES)
    def test_get_task_meta_for(self, module):
        from celery.backends import cassandra as mod
        mod.cassandra = Mock()

        x = mod.CassandraBackend(app=self.app)
        session = x._session = Mock()
        execute = session.execute = Mock()
        result_set = Mock()
        result_set.one.return_value = [
            states.SUCCESS, '1', datetime.now(), b'', b''
        ]
        execute.return_value = result_set
        x.decode = Mock()
        meta = x._get_task_meta_for('task_id')
        assert meta['status'] == states.SUCCESS

        result_set.one.return_value = []
        x._session.execute.return_value = result_set
        meta = x._get_task_meta_for('task_id')
        assert meta['status'] == states.PENDING

    def test_as_uri(self):
        # Just ensure as_uri works properly
        from celery.backends import cassandra as mod
        mod.cassandra = Mock()

        x = mod.CassandraBackend(app=self.app)
        x.as_uri()
        x.as_uri(include_password=False)

    @pytest.mark.patched_module(*CASSANDRA_MODULES)
    def test_store_result(self, module):
        from celery.backends import cassandra as mod
        mod.cassandra = Mock()

        x = mod.CassandraBackend(app=self.app)
        session = x._session = Mock()
        session.execute = Mock()
        x._store_result('task_id', 'result', states.SUCCESS)

    def test_timeouting_cluster(self):
        # Tests behavior when Cluster.connect raises
        # cassandra.OperationTimedOut.
        from celery.backends import cassandra as mod

        class OTOExc(Exception):
            pass

        class VeryFaultyCluster:
            def __init__(self, *args, **kwargs):
                pass

            def connect(self, *args, **kwargs):
                raise OTOExc()

            def shutdown(self):
                pass

        mod.cassandra = Mock()
        mod.cassandra.OperationTimedOut = OTOExc
        mod.cassandra.cluster = Mock()
        mod.cassandra.cluster.Cluster = VeryFaultyCluster

        x = mod.CassandraBackend(app=self.app)

        with pytest.raises(OTOExc):
            x._store_result('task_id', 'result', states.SUCCESS)
        assert x._cluster is None
        assert x._session is None

    def test_create_result_table(self):
        # Tests behavior when session.execute raises
        # cassandra.AlreadyExists.
        from celery.backends import cassandra as mod

        class OTOExc(Exception):
            pass

        class FaultySession:
            def __init__(self, *args, **kwargs):
                pass

            def execute(self, *args, **kwargs):
                raise OTOExc()

        class DummyCluster:

            def __init__(self, *args, **kwargs):
                pass

            def connect(self, *args, **kwargs):
                return FaultySession()

        mod.cassandra = Mock()
        mod.cassandra.cluster = Mock()
        mod.cassandra.cluster.Cluster = DummyCluster
        mod.cassandra.AlreadyExists = OTOExc

        x = mod.CassandraBackend(app=self.app)
        x._get_connection(write=True)
        assert x._session is not None

    def test_init_session(self):
        # Tests behavior when Cluster.connect works properly
        from celery.backends import cassandra as mod

        class DummyCluster:

            def __init__(self, *args, **kwargs):
                pass

            def connect(self, *args, **kwargs):
                return Mock()

        mod.cassandra = Mock()
        mod.cassandra.cluster = Mock()
        mod.cassandra.cluster.Cluster = DummyCluster

        x = mod.CassandraBackend(app=self.app)
        assert x._session is None
        x._get_connection(write=True)
        assert x._session is not None

        s = x._session
        x._get_connection()
        assert s is x._session

    def test_auth_provider(self):
        # Ensure valid auth_provider works properly, and invalid one raises
        # ImproperlyConfigured exception.
        from celery.backends import cassandra as mod

        class DummyAuth:
            ValidAuthProvider = Mock()

        mod.cassandra = Mock()
        mod.cassandra.auth = DummyAuth

        # Valid auth_provider
        self.app.conf.cassandra_auth_provider = 'ValidAuthProvider'
        self.app.conf.cassandra_auth_kwargs = {
            'username': 'stuff'
        }
        mod.CassandraBackend(app=self.app)

        # Invalid auth_provider
        self.app.conf.cassandra_auth_provider = 'SpiderManAuth'
        self.app.conf.cassandra_auth_kwargs = {
            'username': 'Jack'
        }
        with pytest.raises(ImproperlyConfigured):
            mod.CassandraBackend(app=self.app)

    def test_options(self):
        # Ensure valid options works properly
        from celery.backends import cassandra as mod

        mod.cassandra = Mock()
        # Valid options
        self.app.conf.cassandra_options = {
            'cql_version': '3.2.1',
            'protocol_version': 3
        }
        mod.CassandraBackend(app=self.app)
