# Copyright 2008 Google Inc.
#
# 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 base64
import logging
import cStringIO
import pickle

from google.appengine.ext import db

import models
from backup_pb2 import *
from internal.util import automatic_retry

class GetLostError(Exception):
  pass

KINDS = {
  "ApprovalRight": models.ApprovalRight,
  "Project": models.Project,
  "Branch": models.Branch,
  "RevisionId": models.RevisionId,
  "BuildAttempt": models.BuildAttempt,
  "Change": models.Change,
  "PatchSetFilenames": models.PatchSetFilenames,
  "PatchSet": models.PatchSet,
  "Message": models.Message,
  "DeltaContent": models.DeltaContent,
  "Patch": models.Patch,
  "Comment": models.Comment,
  "Bucket": models.Bucket,
  "ReviewStatus": models.ReviewStatus,
  "Account": models.Account,
  "AccountGroup": models.AccountGroup,
}

class BackupServiceImp(BackupService):
  @automatic_retry
  def NextChunk(self, rpc_controller, req, done):
    if not self.http_request.user_is_admin:
      raise GetLostError()

    rsp = NextChunkResponse()

    try:
      cls = KINDS[req.kind]
    except KeyError:
      done(rsp)
      return

    if req.last_key:
      q = models.gql(cls,
                     'WHERE __key__ > :1 ORDER BY __key__',
                      db.Key(req.last_key))
    else:
      q = models.gql(cls, 'ORDER BY __key__')

    sz = 20
    for o in q.fetch(sz):
      e = rsp.entity.add()
      if o.key().id() is not None:
        e.key_id = o.key().id()
      if o.key().name() is not None:
        e.key_name = o.key().name()
      e.key = str(o.key())
      e.last_backed_up = o.last_backed_up

      buf = cStringIO.StringIO()
      pickle.dump(o, buf, -1)
      e.data = buf.getvalue()
    done(rsp)