#!/usr/bin/python2.5
 
# Copyright (C) 2007 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.
 
 
"""Filter the unused stops out of a transit feed file."""
 
import optparse
import sys
import transitfeed
 
 
def main():
  parser = optparse.OptionParser(
      usage="usage: %prog [options] input_feed output_feed",
      version="%prog "+transitfeed.__version__)
  parser.add_option("-l", "--list_removed", dest="list_removed",
                    default=False,
                    action="store_true",
                    help="Print removed stops to stdout")
  (options, args) = parser.parse_args()
  if len(args) != 2:
    print >>sys.stderr, parser.format_help()
    print >>sys.stderr, "\n\nYou must provide input_feed and output_feed\n\n"
    sys.exit(2)
  input_path = args[0]
  output_path = args[1]
 
  loader = transitfeed.Loader(input_path)
  schedule = loader.Load()
 
  print "Removing unused stops..."
  removed = 0
  for stop_id, stop in schedule.stops.items():
    if not stop.GetTrips(schedule):
      removed += 1
      del schedule.stops[stop_id]
      if options.list_removed:
        print "Removing %s (%s)" % (stop_id, stop.stop_name)
  if removed == 0:
    print "No unused stops."
  elif removed == 1:
    print "Removed 1 stop"
  else:
    print "Removed %d stops" % removed
 
  schedule.WriteGoogleTransitFeed(output_path)
 
if __name__ == "__main__":
  main()