play.py

#!/usr/bin/env python3

import os
import time
import traceback

import pychromecast

import RPi.GPIO as GPIO
from mfrc522 import MFRC522

import glog as log

HTTP_SERVER = 'http://192.168.1.236/'
CHROMECAST_NAME = 'Playroom'

log.setLevel('INFO')

def get_chromecast():
    return list(pychromecast.get_listed_chromecasts(friendly_names=[CHROMECAST_NAME])[0])[0]

tracks = {}
def reload_tracks():
    global tracks
    tmtime = os.stat('tracks').st_mtime
    if tracks.get('mtime') != tmtime:
        f = [x.split() for x in open('tracks').read().splitlines()]
        tracks = {int(x): y for x, y in f}
        tracks['mtime'] = tmtime

def stream_pause():
    log.info('pause')
    cc.wait()
    cc.media_controller.pause()

def stream_fastforward():
    log.info('fastforwars')
    cc.wait()
    cc.media_controller.seek(cc.media_controller.status.adjusted_current_time + 60)

def stream_play(uid):
    log.info('play %s', tracks[uid])
    cc.wait()
    cc.media_controller.play_media(HTTP_SERVER + tracks[uid], 'audio/mp3')

reload_tracks()
cc = get_chromecast()
naks = 0
stream = None
last_stream = 0
reader = MFRC522()
try:
    while 1:
        if naks > 3:
            if stream:
                stream_pause()
                stream, last_stream = None, stream
        stat, tt = reader.MFRC522_Request(reader.PICC_REQIDL)
        if stat != reader.MI_OK:
            naks += 1
            time.sleep(.1)
            continue
        stat, uidraw = reader.MFRC522_Anticoll()
        try:
            if stat != reader.MI_OK:
                naks += 1
                log.warn("nak2")
                continue
            naks = 0
            uid = int.from_bytes(uidraw[:4], 'little')
            reload_tracks()
            if uid in tracks:
                if tracks[uid] == "fastforward":
                    stream_fastforward()
                    naks = -30
                    stream = stream or last_stream
                    time.sleep(3)
                    continue
                elif stream != uid:
                    stream_play(uid)
                    stream = uid
            else:
                log.warn('unknown card: %s', uid)
                naks += 1
        except pychromecast.error.NotConnected:
            log.exception('chromecast disconnected')
            cc = get_chromecast()
        except Exception:
            traceback.print_exc()
finally:
        GPIO.cleanup()