# Miro - an RSS based video player application
# Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011
# Participatory Culture Foundation
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
#
# In addition, as a special exception, the copyright holders give
# permission to link the code of portions of this program with the OpenSSL
# library.
#
# You must obey the GNU General Public License in all respects for all of
# the code used other than OpenSSL. If you modify file(s) with this
# exception, you may extend this exception to your version of the file(s),
# but you are not obligated to do so. If you do not wish to do so, delete
# this exception statement from your version. If you delete this exception
# statement from all source files in the program, then also delete it here.

import cmd
import threading
import time
import Queue

from miro import app
from miro import dialogs
from miro import eventloop
from miro import item
from miro import folder
from miro import tabs
from miro.frontends.cli import clidialog
from miro.plat import resources

############################################################################
#
# Start of mirobridge.py import additions - All to get feed updates,
# auto downloads and OPML import working
#
############################################################################
import os, sys, subprocess, re, fnmatch, string
import logging
from miro import moviedata
from miro import commandline
from miro import autodler
from miro import downloader
from miro import iconcache
from miro.clock import clock
from miro import feed
from miro.commandline import parse_command_line_args
from miro import fileutil
from miro import autoupdate
from miro import startup
from miro import filetypes
from miro import messages
from miro import config
from miro import prefs
from miro import workerprocess
##########################################################################
#
# End of mirobridge.py import additions - All to get feed updates, auto
# downloads and OPML import working
#
##########################################################################

def run_in_event_loop(func):
    def decorated(*args, **kwargs):
        return_hack = []
        event = threading.Event()
        def runThenSet():
            try:
                return_hack.append(func(*args, **kwargs))
            finally:
                event.set()
        eventloop.add_urgent_call(runThenSet, 'run in event loop')
        event.wait()
        if return_hack:
            return return_hack[0]
    decorated.__doc__ = func.__doc__
    return decorated

class FakeTab:
    def __init__(self, tab_type, tab_template_base):
        self.type = tab_type
        self.tab_template_base = tab_template_base

class MiroInterpreter(cmd.Cmd):
    def __init__(self):
        cmd.Cmd.__init__(self)
        self.quit_flag = False
        self.tab = None
        self.init_database_objects()

    def emptyline(self):
        print "Type \"help\" for help."

    @run_in_event_loop
    def init_database_objects(self):
        self.feed_tabs = tabs.TabOrder.feed_order()
        self.playlist_tabs = tabs.TabOrder.playlist_order()
        self.tab_changed()

    def tab_changed(self):
        """Calculate the current prompt.  This method access database objects,
        so it should only be called from the backend event loop
        """
        if self.tab is None:
            self.prompt = "> "
            self.selection_type = None

        elif self.tab.type == 'feed':
            if isinstance(self.tab, folder.ChannelFolder):
                self.prompt = "channel folder: %s > " % self.tab.get_title()
                self.selection_type = 'channel-folder'
            else:
                self.prompt = "channel: %s > " % self.tab.get_title()
                self.selection_type = 'feed'

        elif self.tab.type == 'playlist':
            self.prompt = "playlist: %s > " % self.tab.get_title()
            self.selection_type = 'playlist'

        elif (self.tab.type == 'statictab' and
              self.tab.tab_template_base == 'downloadtab'):
            self.prompt = "downloads > "
            self.selection_type = 'downloads'
        else:
            raise ValueError("Unknown tab type")

    def postcmd(self, stop, line):
        # HACK
        # If the last command results in a dialog, give it a little time to
        # pop up
        time.sleep(0.1)
        while True:
            try:
                dialog = app.cli_events.dialog_queue.get_nowait()
            except Queue.Empty:
                break
            clidialog.handle_dialog(dialog)

        return self.quit_flag

    def do_help(self, line):
        """help -- Lists commands and help."""
        commands = [m for m in dir(self) if m.startswith("do_")]
        for mem in commands:
            docstring = getattr(self, mem).__doc__
            print "  ", docstring.strip()

    def do_quit(self, line):
        """quit -- Quits Miro cli."""
        self.quit_flag = True

    @run_in_event_loop
    def do_feed(self, line):
        """feed <name> -- Selects a feed by name."""
        for tab in self.feed_tabs.get_all_tabs():
            if tab.get_title() == line:
                self.tab = tab
                self.tab.type = "feed"
                self.tab_changed()
                return
        print "Error: %s not found." % line

    @run_in_event_loop
    def do_rmfeed(self, line):
        """rmfeed <name> -- Deletes a feed."""
        for tab in self.feed_tabs.get_all_tabs():
            if tab.get_title() == line:
                tab.remove()
                return
        print "Error: %s not found." % line

    @run_in_event_loop
    def complete_feed(self, text, line, begidx, endidx):
        return self.handle_tab_complete(text,
                                        list(self.feed_tabs.get_all_tabs()))

    @run_in_event_loop
    def complete_rmfeed(self, text, line, begidx, endidx):
        return self.handle_tab_complete(text,
                                        list(self.feed_tabs.get_all_tabs()))

    @run_in_event_loop
    def complete_playlist(self, text, line, begidx, endidx):
        return self.handle_tab_complete(text,
                                        self.playlist_tabs.get_all_tabs())

    def handle_tab_complete(self, text, view_items):
        text = text.lower()
        matches = []
        for tab in view_items:
            if tab.get_title().lower().startswith(text):
                matches.append(tab.get_title())
        return matches

    def handle_item_complete(self, text, view, filterFunc=lambda i: True):
        text = text.lower()
        matches = []
        for item_ in view:
            if (item_.get_title().lower().startswith(text) and
                    filterFunc(item_)):
                matches.append(item_.get_title())
        return matches

    ######################################################################
    #
    # Start of mirobridge specific routines - Part 1
    #
    ######################################################################
    @run_in_event_loop
    def do_mythtv_check_downloading(self, line):
        """Check if any items are being downloaded. Set True or False"""
        self.downloading = False
        downloadingItems = item.Item.only_downloading_view()
        count = downloadingItems.count()
        for it in downloadingItems:
            logging.info(
            u"(%s - %s) video is downloading with (%0.0f%%) complete" % (
                it.get_channel_title(True).replace(u'/',u'-'),
                it.get_title().replace(u'/',u'-'), it.download_progress()))
        if not count:
            logging.info(u"No items downloading")
        if count:
            self.downloading = True

    @run_in_event_loop
    def do_mythtv_import_opml(self, filename):
        """Import an OPML file"""
        try:
            messages.ImportFeeds(filename).send_to_backend()
            logging.info(
                u"Import of OPML file (%s) sent to Miro" % (filename))
        except Exception, e:
            logging.info(
                u"Import of OPML file (%s) failed, error (%s)" % (filename, e))

    @run_in_event_loop
    def do_mythtv_updatewatched(self, line):
        """Process MythTV update watched videos"""
        items = item.Item.downloaded_view()
        for video in self.videofiles:
            for it in items:
                if it.get_filename() == video:
                     break
            else:
                logging.info(
                    u"Item for Miro video (%s) not found, skipping" % video)
                continue
            if self.simulation:
                logging.info(
                    u"Simulation: Item (%s - %s) marked as seen and watched" % (
                    it.get_channel_title(True), it.get_title()))
            else:
                it.mark_watched(mark_other_items=True)
                self.statistics[u'Miro_marked_watch_seen']+=1
                logging.info(
                    u"Item (%s - %s) marked as seen and watched" % (
                    it.get_channel_title(True), it.get_title()))

    @run_in_event_loop
    def do_mythtv_getunwatched(self, line):
        """Process MythTV get all un-watched video details"""
        if self.verbose:
             print
             print u"Getting details on un-watched Miro videos"
        self.videofiles = []
        if item.Item.unwatched_downloaded_items().count():
            if self.verbose:
                print u"%-20s %-10s %s" % (u"State", u"Size", u"Name")
                print u"-" * 70
            for it in item.Item.unwatched_downloaded_items():
                # Skip any audio file as MythTV Internal player may abort
                # the MythTV Frontend on a MP3
                state = it.get_state()
                if not state == u'newly-downloaded':
                    continue
                # Skip any bittorrent video downloads for legal concerns
                if hasattr(it.get_parent(), u'url'):
                    if filetypes.is_torrent_filename(it.get_parent().url):
                        continue

                # Any item without a proper file name needs to be removed
                # as Miro metadata is corrupt
                if it.get_filename() == None:
                    it.expire()
                    self.statistics[u'Miro_videos_deleted']+=1
                    logging.info(
u'Unwatched video (%s) has been removed from Miro as item had no valid file name' % it.get_title())
                    continue

                self.printItems(it)
                self.videofiles.append(self._get_item_dict(it))
            if self.verbose:
                print
        if not len(self.videofiles):
             logging.info(u"No un-watched Miro videos")

    @run_in_event_loop
    def do_mythtv_getwatched(self, line):
        """Process MythTV get all watched/saved video details"""
        if self.verbose:
           print
           print u"Getting details on watched/saved Miro videos"
        self.videofiles = []
        if item.Item.downloaded_view().count():
            if self.verbose:
                print u"%-20s %-10s %s" % (u"State", u"Size", u"Name")
                print u"-" * 70
            for it in item.Item.downloaded_view():
                state = it.get_state()
                if state == u'newly-downloaded':
                    continue
                # Skip any bittorrent video downloads for legal concerns
                if hasattr(it.get_parent(), u'url'):
                    if filetypes.is_torrent_filename(it.get_parent().url):
                        continue

                # Any item without a proper file name needs to be removed as Miro metadata is corrupt
                if it.get_filename() == None:
                    it.expire()
                    self.statistics[u'Miro_videos_deleted']+=1
                    logging.info(
u'Watched video (%s) has been removed from Miro as item had no valid file name' % it.get_title())
                    continue

                self.printItems(it)
                self.videofiles.append(self._get_item_dict(it))
            if self.verbose:
                print
        if not len(self.videofiles):
             logging.info(u"No watched/saved Miro videos")

    ###########################################################
    # START - Function used for debugging - DO NOT UNCOMMENT
    #
    ###########################################################
#    @run_in_event_loop
#    def do_mythtv_test_views(self, line):
#        """Process MythTV get all watched/saved video details"""
#        print
#        print u"Testing various views"
#        print

#        print "Download view count (%s)" % item.Item.downloaded_view().count()
#        print "Newly Download view count (%s)" % item.Item.newly_downloaded_view().count()
#        print "Tab View Download view count (%s)" % item.Item.download_tab_view().count()
#        print "unwatched Download view count (%s)" % item.Item.unwatched_downloaded_items().count()
#        print "unique Download view count (%s)" % item.Item.unique_new_video_view().count()

#        print

#        if item.Item.downloaded_view().count():
#            print u"%-20s %-10s %s" % (u"State", u"Size", u"Name")
#            print u"-" * 70
#            for it in item.Item.downloaded_view():
#                state = it.get_state()
#                self.printItems(it)
#            print
    ###########################################################
    # END - Function used for debugging - DO NOT UNCOMMENT
    #
    ###########################################################

    def printItems(self, it):
        if not self.verbose:
            return
        state = it.get_state()
        if state == u'downloading':
            state += u' (%0.0f%%)' % it.download_progress()
        print u"%-20s %-10s %s" % (state, it.get_size_for_display(),
            it.get_title())
    # end printItems()

    @run_in_event_loop
    def do_mythtv_item_remove(self, args):
        """Removes an item from Miro by file name or Channel and title"""
        for it in item.Item.downloaded_view():
             if isinstance(args, list):
                if not args[0] or not args[1]:
                    continue
                if filter(
                        self.is_not_punct_char,
                        it.get_channel_title(True).lower()) == filter(
                        self.is_not_punct_char, args[0].lower()) and (
                        filter(self.is_not_punct_char,
                            it.get_title().lower())).startswith(
                            filter(self.is_not_punct_char, args[1].lower())):
                    break
             elif args:
                if filter(self.is_not_punct_char,
                        it.get_filename().lower()) == filter(
                            self.is_not_punct_char, args.lower()):
                    break
        else:
            logging.info(u"No item named %s" % args)
            return
        if it.is_downloaded():
            if self.simulation:
                logging.info(
u"Simulation: Item (%s - %s) has been removed from Miro" % (
                        it.get_channel_title(True), it.get_title()))
            else:
                it.expire()
                self.statistics[u'Miro_videos_deleted']+=1
                logging.info(u'%s has been removed from Miro' % it.get_title())
        else:
            logging.info(u'%s is not downloaded' % it.get_title())

    def _get_item_dict(self, it):
        """Take an item and convert all elements into a dictionary
        return a dictionary of item elements
        """
        def compatibleGraphics(filename):
            if filename:
                (dirName, fileName) = os.path.split(filename)
                (fileBaseName, fileExtension)=os.path.splitext(fileName)
                if not fileExtension[1:] in [u"png", u"jpg", u"bmp", u"gif"]:
                    return u''
                else:
                    return filename
            else:
                return u''

        def useImageMagick(screenshot):
            """ Using ImageMagick's utility 'identify'. Decide whether the screen shot is worth using.
            >>> useImageMagick('identify screenshot.jpg')
            >>> Example returned information "rose.jpg JPEG 640x480 DirectClass 87kb 0.050u 0:01"
            >>> u'' if the screenshot quality is too low
            >>> screenshot if the quality is good enough to use
            """
            if not self.imagemagick: # If imagemagick is not installed do not bother checking
               return u''

            width_height = re.compile(
u'''^(.+?)[ ]\[?([0-9]+)x([0-9]+)[^\\/]*$''', re.UNICODE)
            p = subprocess.Popen(u'identify "%s"' % (screenshot),
                                shell=True, bufsize=4096,
                                stdin=subprocess.PIPE,
                                stdout=subprocess.PIPE,
                                stderr=subprocess.PIPE, close_fds=True)

            response = p.stdout.readline()
            if response:
                match = width_height.match(response)
                if match:
                    dummy, width, height = match.groups()
                    width, height = int(width), int(height)
                    if width >= 320:
                        return screenshot
                return u''
            else:
                return u''
            return screenshot
        # end useImageMagick()

        item_icon_filename = it.icon_cache.filename
        channel_icon = it.get_feed().icon_cache.get_filename()

        # Conform to maximum length for MythTV database fields title and subtitle
        maximum_length = 128
        channel_title = it.get_channel_title(True).replace(u'/',u'-')
        if channel_title:
            if len(channel_title) > maximum_length:
                channel_title = channel_title[:maximum_length]
            channel_title = channel_title.replace(u'"', u'')	# These characters mess with filenames
        title = it.get_title().replace(u'/',u'-')
        if title:
            if len(title) > maximum_length:
                title = title[:maximum_length]
            title = title.replace(u'"', u'')	# These characters mess with filenames
            title = title.replace(u"'", u'')	# These characters mess with filenames

        item_dict =  {
            u'feed_id': it.feed_id, u'parent_id': it.parent_id,
            u'isContainerItem': it.is_container_item,
            u'seen': it.get_state(),
            u'autoDownloaded': it.auto_downloaded,
            u'pendingManualDL': it.pending_manual_download,
            u'downloadedTime': it.downloaded_time,
            u'watchedTime': it.watched_time,
            u'pendingReason': it.pending_reason,
            u'title': title,
            u'expired': it.expired,
            u'keep': it.keep, u'videoFilename': it.get_filename(),
            u'eligibleForAutoDownload': it.eligible_for_autodownload,
            u'duration': it.duration,
            u'screenshot': it.screenshot,
            u'resumeTime': it.resume_time,
            u'channelTitle': channel_title,
            u'description': it.get_description(),
            u'size': it.get_size(),
            u'releasedate': it.get_release_date(),
            u'length': it.get_duration_value(),
            u'channel_icon': channel_icon,
            u'item_icon': item_icon_filename,
            u'inetref': u'', u'season': 1, u'episode': 1,
        }

        if not item_dict[u'screenshot']:
            if item_dict[u'item_icon']:
                item_dict[u'screenshot'] = useImageMagick(item_dict[u'item_icon'])

        for key in [u'screenshot', u'channel_icon', u'item_icon']:
            if item_dict[key]:
                item_dict[key] = compatibleGraphics(item_dict[key])
            #if self.verbose:
            #    if item_dict[key]:
            #        print "item (%s - %s) %s (%s)" % (channel_title, title, key, item_dict[key])
            #    else:
            #        print "item (%s - %s) does NOT have a %s" % (channel_title, title, key)

        #print item_dict
        return item_dict

    # Two routines used for Channel title search and matching
    def is_punct_char(self, char):
        '''check if char is punctuation char
        return True if char is punctuation
        return False if char is not punctuation
        '''
        return char in string.punctuation

    def is_not_punct_char(self, char):
        '''check if char is not punctuation char
        return True if char is not punctuation
        return False if chaar is punctuation
        '''
        return not self.is_punct_char(char)

    #######################################################################
    #
    # End of mythbridge specific routines - Part 1
    #
    #######################################################################

    def _print_feeds(self, feeds):
        current_folder = None
        for tab in feeds:
            if isinstance(tab, folder.ChannelFolder):
                current_folder = tab
            elif tab.get_folder() is not current_folder:
                current_folder = None
            if current_folder is None:
                print " * " + tab.get_title()
            elif current_folder is tab:
                print " * [Folder] %s" % tab.get_title()
            else:
                print " * - %s" % tab.get_title()

    @run_in_event_loop
    def do_feeds(self, line):
        """feeds -- Lists all feeds."""
        print "FEEDS"
        self._print_feeds(self.feed_tabs.get_all_tabs())

    @run_in_event_loop
    def do_update(self, line):
        """update -- Updates all the feeds."""
        for mem in self.feed_tabs.get_all_tabs():
            print "telling %s to update" % mem.get_title()
            mem.update()

    @run_in_event_loop
    def do_play(self, line):
        """play <name> -- Plays an item by name in an external player."""
        if self.selection_type is None:
            print "Error: No feed/playlist selected."
            return
        item_ = self._find_item(line)
        if item_ is None:
            print "No item named %r" % line
            return
        if item_.is_downloaded():
            resources.open_file(item_.get_filename())
        else:
            print '%s is not downloaded' % item_.get_title()

    @run_in_event_loop
    def do_playlists(self, line):
        """playlists -- Lists all playlists."""
        for tab in self.playlistTabs.getView():
            print tab.obj.get_title()

    @run_in_event_loop
    def do_playlist(self, line):
        """playlist <name> -- Selects a playlist."""
        for tab in self.playlistTabs.getView():
            if tab.obj.get_title() == line:
                self.tab = tab
                self.tab_changed()
                return
        print "Error: %s not found." % line

    @run_in_event_loop
    def do_items(self, line):
        """items -- Lists the items in the feed/playlist/tab selected."""
        if self.selection_type is None:
            print "Error: No tab/feed/playlist selected."
            return
        elif self.selection_type == 'feed':
            feed = self.tab
            view = feed.items
            self.printout_item_list(view)
        elif self.selection_type == 'playlist':
            playlist = self.tab.obj
            self.printout_item_list(playlist.getView())
        elif self.selection_type == 'downloads':
            self.printout_item_list(item.Item.downloading_view(),
                                    item.Item.paused_view())
        elif self.selection_type == 'channel-folder':
            folder = self.tab.obj
            allItems = views.items.filterWithIndex(
                    indexes.itemsByChannelFolder, folder)
            allItemsSorted = allItems.sort(folder.itemSort.sort)
            self.printout_item_list(allItemsSorted)
            allItemsSorted.unlink()
        else:
            raise ValueError("Unknown tab type")

    @run_in_event_loop
    def do_downloads(self, line):
        """downloads -- Selects the downloads tab."""
        self.tab = FakeTab("statictab", "downloadtab")
        self.tab_changed()

    def printout_item_list(self, *views):
        totalItems = 0
        for view in views:
            totalItems += view.count()
        if totalItems > 0:
            print "%-20s %-10s %s" % ("State", "Size", "Name")
            print "-" * 70
            for view in views:
                for item in view:
                    state = item.get_state()
                    if state == 'downloading':
                        state += ' (%0.0f%%)' % item.download_progress()
                    print "%-20s %-10s %s" % (state,
                                              item.get_size_for_display(),
                                              item.get_title())
            print
        else:
            print "No items"

    def _get_item_view(self):
        if self.selection_type == 'feed':
            return item.Item.visible_feed_view(self.tab.id)
        elif self.selection_type == 'playlist':
            return item.Item.playlist_view(self.tab.id)
        elif self.selection_type == 'downloads':
            return item.Item.downloading_view()
        elif self.selection_type == 'channel-folder':
            folder = self.tab
            return item.Item.visible_folder_view(folder.id)
        else:
            raise ValueError("Unknown selection type")

    def _find_item(self, line):
        line = line.lower()
        for item in self._get_item_view():
            if item.get_title().lower() == line:
                return item

    @run_in_event_loop
    def do_stop(self, line):
        """stop <name> -- Stops download by name."""
        if self.selection_type is None:
            print "Error: No feed/playlist selected."
            return
        item = self._find_item(line)
        if item is None:
            print "No item named %r" % line
            return
        if item.get_state() in ('downloading', 'paused'):
            item.expire()
        else:
            print '%s is not being downloaded' % item.get_title()

    @run_in_event_loop
    def complete_stop(self, text, line, begidx, endidx):
        return self.handle_item_complete(text, self._get_item_view(),
                lambda i: i.get_state() in ('downloading', 'paused'))

    @run_in_event_loop
    def do_download(self, line):
        """download <name> -- Downloads an item by name in the feed/playlist
        selected.
        """
        if self.selection_type is None:
            print "Error: No feed/playlist selected."
            return
        item = self._find_item(line)
        if item is None:
            print "No item named %r" % line
            return
        if item.get_state() == 'downloading':
            print '%s is currently being downloaded' % item.get_title()
        elif item.is_downloaded():
            print '%s is already downloaded' % item.get_title()
        else:
            item.download()

    @run_in_event_loop
    def complete_download(self, text, line, begidx, endidx):
        return self.handle_item_complete(text, self._get_item_view(),
                lambda i: i.is_downloadable())

    @run_in_event_loop
    def do_pause(self, line):
        """pause <name> -- Pauses a download by name."""
        if self.selection_type is None:
            print "Error: No feed/playlist selected."
            return
        item = self._find_item(line)
        if item is None:
            print "No item named %r" % line
            return
        if item.get_state() == 'downloading':
            item.pause()
        else:
            print '%s is not being downloaded' % item.get_title()

    @run_in_event_loop
    def complete_pause(self, text, line, begidx, endidx):
        return self.handle_item_complete(text, self._get_item_view(),
                lambda i: i.get_state() == 'downloading')

    @run_in_event_loop
    def do_resume(self, line):
        """resume <name> -- Resumes a download by name."""
        if self.selection_type is None:
            print "Error: No feed/playlist selected."
            return
        item = self._find_item(line)
        if item is None:
            print "No item named %r" % line
            return
        if item.get_state() == 'paused':
            item.resume()
        else:
            print '%s is not a paused download' % item.get_title()

    @run_in_event_loop
    def complete_resume(self, text, line, begidx, endidx):
        return self.handle_item_complete(text, self._get_item_view(),
                lambda i: i.get_state() == 'paused')

    @run_in_event_loop
    def do_rm(self, line):
        """rm <name> -- Removes an item by name in the feed/playlist selected.
        """
        if self.selection_type is None:
            print "Error: No feed/playlist selected."
            return
        item = self._find_item(line)
        if item is None:
            print "No item named %r" % line
            return
        if item.is_downloaded():
            item.expire()
        else:
            print '%s is not downloaded' % item.get_title()

    @run_in_event_loop
    def complete_rm(self, text, line, begidx, endidx):
        return self.handle_item_complete(text, self._get_item_view(),
                lambda i: i.is_downloaded())

    @run_in_event_loop
    def do_testdialog(self, line):
        """testdialog -- Tests the cli dialog system."""
        d = dialogs.ChoiceDialog("Hello", "I am a test dialog",
                dialogs.BUTTON_OK, dialogs.BUTTON_CANCEL)
        def callback(dialog):
            print "TEST CHOICE: %s" % dialog.choice
        d.run(callback)

    #######################################################################
    #
    # Start of mirobridge specific routines - Part 2
    #
    #######################################################################
@eventloop.idle_iterator
def clear_icon_cache_orphans():
    # delete icon_cache rows from the database with no associated
    # item/feed/guide.
    removed_objs = []
    for ic in iconcache.IconCache.orphaned_view():
        logging.warn("No object for IconCache: %s.  Discarding", ic)
        ic.remove()
        removed_objs.append(str(ic.url))
    if removed_objs:
        databaselog.info("Removed IconCache objects without an associated "
                "db object: %s", ','.join(removed_objs))
    yield None

    # delete files in the icon cache directory that don't belong to IconCache
    # objects.

    cachedir = fileutil.expand_filename(app.config.get(
        prefs.ICON_CACHE_DIRECTORY))
    if not os.path.isdir(cachedir):
        return

    existingFiles = [os.path.normcase(os.path.join(cachedir, f))
            for f in os.listdir(cachedir)]
    yield None

    knownIcons = iconcache.IconCache.all_filenames()
    yield None

    knownIcons = [ os.path.normcase(fileutil.expand_filename(path)) for path in
            knownIcons]
    yield None

    for filename in existingFiles:
        if (os.path.exists(filename)
                and os.path.basename(filename)[0] != '.'
                and os.path.basename(filename) != 'extracted'
                and not filename in knownIcons):
            try:
                os.remove(filename)
            except OSError:
                pass
        yield None
    #####################################################################
    #
    # End of mirobridge specific routines - Part 2
    #
    #####################################################################