import array
import sys
import usb.core
import usb.util
import paho.mqtt.client as mqtt
import time
from threading import Event, Thread

def sdsAnalyzer(sds011_thread_Event, client):
    global th_abort
    VID =0x1a86
    PID = 0x7523
    DATA_SIZE = 4
    
    device = usb.core.find(idVendor = VID, idProduct = PID)
    if device is None:
        sys.exit("Could not find sds011 Sensor.")
    
    if device.is_kernel_driver_active(0):
        try:
            device.detach_kernel_driver(0)
        except usb.core.USBError as e:
            sys.exit("Could not detatch kernel driver: %s" % str(e))
    
    try:
        device.reset()
        device.set_configuration()
    except usb.core.USBError as e:
        sys.exit("Could not set configuration: %s" % str(e))
    
    endpoint = device[0][(0,0)][0]
    print(endpoint.wMaxPacketSize)

    data = array.array('B',(0,)*4)
    while data[0] != 3 and th_abort == False:
        try:
            data = device.read(endpoint.bEndpointAddress, endpoint.wMaxPacketSize)
            print(data)
            result, mid = client.publish("sds011/data", str(data), 0)
        except usb.core.USBError as e:
            if e.args == ('Operation timed out',):
                print("timeout)")
                continue

    #print("work!")    

    print('sdsAnalyzer stopped...')
    exit()


def on_connect(client, obj, flags, rc):
    client.subscribe("sds011/#", 0)


def on_subscribe(client, userdata, mid, granted_qos):
    print ('Subscribed:', userdata, mid, granted_qos)
    print ('We are here, waiting...')


def on_message(mosq, obj, msg):
    global th_abort
    if "Are you alive?" in msg.payload.decode("utf-8"):
        result, mid = client.publish("sds011/heartbeat_response", "alive", 0)
    if "abort" in msg.payload.decode("utf-8"):
        th_abort = True


th_abort = False
client = mqtt.Mosquitto()
client.on_connect = on_connect
client.on_message = on_message
client.on_subscribe = on_subscribe
resp = client.connect('127.0.0.1', 1883, 60)

sds011_thread_Event = Event()
sds011_thread = Thread(target=sdsAnalyzer, args=(sds011_thread_Event,client,))
sds011_thread.start()  # start the child thread

client.loop_start()
while not th_abort:
    time.sleep(0.1)
client.loop_stop()
client.disconnect()
print ("sds011 script stopped...")
exit()