# Copyright 2017 Google LLC All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import glob
import json
import os
import unittest

import mock
from google.cloud.firestore_v1beta1.proto import common_pb2
from google.cloud.firestore_v1beta1.proto import test_pb2
from google.protobuf import text_format

class TestCrossLanguage(unittest.TestCase):

    def test_cross_language(self):
        filenames = sorted(glob.glob('tests/unit/testdata/*.textproto'))
        for test_filename in filenames:
            bytes = open(test_filename, 'r').read()
            test_proto = test_pb2.Test()
            text_format.Merge(bytes, test_proto)
            desc = '%s (%s)' % (
                test_proto.description,
                os.path.splitext(os.path.basename(test_filename))[0])
            if test_proto.WhichOneof("test") == "get":
                pass # The Get tests assume a call to GetDocument, but Python
                     # calls BatchGetDocuments.
                     # TODO: make this work.
            else:
                self.run_write_test(test_proto, desc)

    def run_write_test(self, test_proto, desc):
        from google.cloud.firestore_v1beta1.proto import firestore_pb2
        from google.cloud.firestore_v1beta1.proto import write_pb2

        # Create a minimal fake GAPIC with a dummy result.
        firestore_api = mock.Mock(spec=['commit'])
        commit_response = firestore_pb2.CommitResponse(
            write_results=[write_pb2.WriteResult()],
        )
        firestore_api.commit.return_value = commit_response

        kind = test_proto.WhichOneof("test")
        call = None
        if kind == "create":
            tp = test_proto.create
            client, doc = self.setup(firestore_api, tp)
            data = convert_data(json.loads(tp.json_data))
            call = lambda: doc.create(data)
        elif kind == "set":
            tp = test_proto.set
            client, doc = self.setup(firestore_api, tp)
            data = convert_data(json.loads(tp.json_data))
            # TODO: call doc.set.
        elif kind == "update":
            tp = test_proto.update
            client, doc = self.setup(firestore_api, tp)
            data = convert_data(json.loads(tp.json_data))
            if tp.HasField("precondition"):
                option = convert_precondition(tp.precondition)
            else:
                option = None
            call = lambda: doc.update(data, option)
        elif kind == "update_paths":
            # Python client doesn't have a way to call update with
            # a list of field paths.
            pass
        else:
            assert kind == "delete"
            tp = test_proto.delete
            client, doc = self.setup(firestore_api, tp)
            if tp.HasField("precondition"):
                option = convert_precondition(tp.precondition)
            else:
                option = None
            call = lambda: doc.delete(option)

        if call is None:
            # TODO: remove this when we handle all kinds.
            return
        if tp.is_error:
            # TODO: is there a subclass of Exception we can check for?
            with self.assertRaises(Exception):
                call()
        else:
            call()
            firestore_api.commit.assert_called_once_with(
                client._database_string,
                list(tp.request.writes),
                transaction=None,
                options=client._call_options)


    def setup(self, firestore_api, proto):
        from google.cloud.firestore_v1beta1 import Client
        from google.cloud.firestore_v1beta1.client import DEFAULT_DATABASE
        import google.auth.credentials

        _, project, _, database, _, doc_path = proto.doc_ref_path.split('/', 5)
        self.assertEqual(database, DEFAULT_DATABASE)

        # Attach the fake GAPIC to a real client.
        credentials = mock.Mock(spec=google.auth.credentials.Credentials)
        client = Client(project=project, credentials=credentials)
        client._firestore_api_internal = firestore_api
        return client, client.document(doc_path)


def convert_data(v):
    # Replace the strings 'ServerTimestamp' and 'Delete' with the corresponding
    # sentinels.
    from google.cloud.firestore_v1beta1 import SERVER_TIMESTAMP, DELETE_FIELD

    if v == 'ServerTimestamp':
        return SERVER_TIMESTAMP
    elif v == 'Delete':
        return DELETE_FIELD
    elif isinstance(v, list):
        return [convert_data(e) for e in v]
    elif isinstance(v, dict):
        return {k : convert_data(v2) for k, v2 in v.items()}
    else:
        return v


def convert_precondition(precond):
    from google.cloud.firestore_v1beta1 import Client

    if precond.HasField('exists'):
        return Client.write_option(exists=precond.exists)
    else:  # update_time
        return Client.write_option(last_update_time=precond.update_time)
