#!/usr/bin/env python
# encoding: utf-8
# Copyright 2011 Fanficdownloader team
#
# 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.
#

"""
remover.py

Created by Roman on 2010-06-20.
Copyright 2011 Fanficdownloader team
"""

import datetime
import logging

from google.appengine.ext.webapp import util
from google.appengine.ext import webapp
from google.appengine.api import users
from google.appengine.api import taskqueue
from google.appengine.api import memcache

from ffstorage import *

class Remover(webapp.RequestHandler):
    def get(self):
        logging.debug("Starting r3m0v3r")
        user = users.get_current_user()
        logging.debug("Working as user %s" % user)
        theDate = datetime.datetime.now() - datetime.timedelta(days=7) # days=7
        logging.debug("Will delete stuff older than %s" % theDate)
        
        fics = DownloadMeta.all()
        fics.filter("date <",theDate).order("date")
        
        results = fics.fetch(100)
        logging.debug([x.name for x in results])

        num=0
        for d in results:
            d.delete()
            for c in d.data_chunks:
                c.delete()
            num += 1
            logging.debug('Delete '+d.url)

        logging.info('Deleted instances: %d' % num)
        self.response.out.write('Deleted instances: %d<br>' % num)

class RemoveOrphanDataChunks(webapp.RequestHandler):

    def get(self):
        logging.debug("Starting RemoveOrphanDataChunks")
        user = users.get_current_user()
        logging.debug("Working as user %s" % user)

        ## Can't search for all chunks in web req because it's too
        ## long.  Can't do it in a queue task, because it's still too
        ## long.  Can't try ordering by id or download because the ids
        ## are not increasing.  Instead, use a saved cursor to walk
        ## all the way through over time, then starting at the top
        ## again when finished.
        
        chunks = DownloadData.all()

        cursor = memcache.get('orphan_search_cursor')
        if cursor:
            chunks.with_cursor(cursor)

        deleted = 0
        num = 0
        step = 100
        results = chunks.fetch(step)
        for d in results:
            ## This is the only way to test for orphans I could find.
            try:
                meta = d.download
            except db.ReferencePropertyResolveError:
                ## delete orphan chunk.
                d.delete()
                deleted += 1
            num += 1
        if num < step:
            memcache.delete('orphan_search_cursor')
            logging.warn('Orphan search reached end, starting over next time.')
        else:
            memcache.set('orphan_search_cursor',chunks.cursor())
        
        logging.info('Deleted %d orphan chunks from %d total.' % (deleted,num))
        self.response.out.write('Deleted %d orphan chunks from %d total.' % (deleted,num))

def main():
    application = webapp.WSGIApplication([('/r3m0v3r', Remover),
                                          ('/r3m0v3rOrphans', RemoveOrphanDataChunks)],
                                         debug=False)
    util.run_wsgi_app(application)


if __name__ == '__main__':
    logging.getLogger().setLevel(logging.DEBUG)
    main()