trimet.py

import os
import requests
import time
import datetime
import sys
import signal

from papirus import PapirusComposite

screen = PapirusComposite(False)
screen.RemoveText("Status")

def parseTime(num):
    return datetime.datetime.fromtimestamp(round(num / 1000))

def minutesDiff(sched, est):
    if est:
        return ((parseTime(est) - datetime.datetime.now()).total_seconds()) / 60
    else:
        return ((parseTime(sched) - datetime.datetime.now()).total_seconds()) / 60




def get_next_stops(stop=3940):
  url = "https://developer.trimet.org/ws/v2/arrivals/locIDs/%s/appID/%s" % (stop, os.environ['APP_ID'])
  while True:
    resp = requests.get(url)
    yield resp.json().get('resultSet').get('arrival')

def displayArrivals(display, displayed=dict(), arrivals=[]):
  height = 20
  for i,arrival in enumerate(arrivals):
    minutes, name = arrival['minsAway'], arrival['name']
    if displayed.get(str(i)):
      display.UpdateText(str(i), '%s | %s' % (minutes, name))
    else:
      display.AddText('%s | %s' % (minutes, name), 0, height * i, Id=str(i))
      displayed[str(i)] = True
  display.WriteAll()

def update_display_func(display):
  store = dict()
  displayed = dict()
  def update_display(arrivals): 
    changed = False;
    for arrival in arrivals:
      id, name, scheduled, estimated = arrival.get('id'), arrival.get('shortSign'), arrival.get('scheduled'), arrival.get('estimated')
      minsAway = round(minutesDiff(scheduled, estimated))
      arrivalInfo = {
        'id': id,
        'name': name,
        'estimated': estimated,
        'scheduled': scheduled,
        'minsAway': minsAway,
      }
      if store.get(arrivalInfo['id']):
        storedArrival = store.get(arrivalInfo['id'])
        if minsAway != storedArrival['minsAway']:
          # trigger update if time estimate
          changed = True
      else:
        # trigger update if new arrival
        changed = True
      store[arrivalInfo['id']] = arrivalInfo
    arrivalList = list(map(lambda i: store.get(i.get('id')), arrivals))
    if (changed):
      displayArrivals(display, displayed, arrivalList)
  return update_display

def set_offline_func(display):
  def set_offline(*args):
    display.AddText("X", 5 * 20, 5 * 20, Id="Status")
    display.WriteAll()
    sys.exit()
  return set_offline
exiter = set_offline_func(screen)
signal.signal(signal.SIGTERM, exiter)

# update_display = update_display_func('')
update_display = update_display_func(screen)
for arrivals in get_next_stops(3940):
  update_display(arrivals)
  time.sleep(30)