#!/usr/bin/python

import dbus
from dbus.mainloop.glib import DBusGMainLoop
DBusGMainLoop(set_as_default=True)
import logging
import sys
import xapian

from gi.repository import GObject

from softwarecenter.db.database import StoreDatabase
from softwarecenter.backend import get_install_backend
import softwarecenter.paths

LOG = logging.getLogger("update-software-center-channels")

def compare_channels_in_db_to_cache(db):
    # the operation get_origins can take some time (~60s?)
    cache_origins = set(db._aptcache.get_all_origins())
    db_origins = set(db.get_origins_from_db())
    # origins
    LOG.debug("cache_origins: %s" % cache_origins)
    LOG.debug("db_origins: %s" % db_origins)
    # the db_origins will contain origins from the s-c-agent, so
    # we don't need to rebuild if the db has more origins then
    # the cache, but we need to rebuild if the cache has origins
    # that a-x-i does not have
    if not cache_origins.issubset(db_origins):
        return True
    return False

def trigger_axi_update_and_wait():
    def _axi_finished(res):
        main.quit()
    context = GObject.main_context_default()
    main = GObject.MainLoop(context)
    system_bus = dbus.SystemBus()
    try:
        axi = dbus.Interface(
            system_bus.get_object("org.debian.AptXapianIndex","/"),
            "org.debian.AptXapianIndex")
        axi.connect_to_signal("UpdateFinished", _axi_finished)
        # first arg is force, second update_only
        axi.update_async(True, False)
        main.run()
    except Exception as e:
        print e
        LOG.warning("could not update axi")

def check_for_channel_updates_and_trigger_axi():
    db = StoreDatabase()
    db._aptcache.open()
    db.open()
    if compare_channels_in_db_to_cache(db):
        trigger_axi_update_and_wait()
        return True
    return False

if __name__ == "__main__":
    # poor mans argparse
    if "--debug" in sys.argv:
        logging.basicConfig(level=logging.DEBUG)

    # do it
    try:
        res = check_for_channel_updates_and_trigger_axi()
        # return "1" means xapian got updated
        if res:
            sys.exit(1)
    except xapian.DatabaseOpeningError as e:
        # this can happen if there is no a-x-i DB yet and we can ignore it
        LOG.info("failed to open xapian db: '%s'" % e)
    # return "0" nothing was done
    sys.exit(0)