# Copyright 2014 Google Inc. 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.

"""App Engine memcache based cache for the discovery document."""

import logging

# This is only an optional dependency because we only import this
# module when google.appengine.api.memcache is available.
from google.appengine.api import memcache

from . import base
from ..discovery_cache import DISCOVERY_DOC_MAX_AGE

LOGGER = logging.getLogger(__name__)

NAMESPACE = "google-api-client"


class Cache(base.Cache):
    """A cache with app engine memcache API."""

    def __init__(self, max_age):
        """Constructor.

        Args:
          max_age: Cache expiration in seconds.
        """
        self._max_age = max_age

    def get(self, url):
        try:
            return memcache.get(url, namespace=NAMESPACE)
        except Exception as e:
            LOGGER.warning(e, exc_info=True)

    def set(self, url, content):
        try:
            memcache.set(url, content, time=int(self._max_age), namespace=NAMESPACE)
        except Exception as e:
            LOGGER.warning(e, exc_info=True)


cache = Cache(max_age=DISCOVERY_DOC_MAX_AGE)