#!/usr/bin/python3
#
# Copyright 2018 Jonathan McDowell <noodles@earth.li>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

import glob
import time
import sys

import hid
import paho.mqtt.client as mqtt

debug = False
Broker = 'mqtt.host'
prefix = 'relay-{}/cmnd/#'
auth = {
    'username': 'mqttuser',
    'password': 'mqttpass',
}


def control_relay(device, relay=0, power=False):
    cmnd = [0] * 8
    if power:
        cmnd[1] = 0xFF
    else:
        cmnd[1] = 0xFD
    cmnd[2] = relay
    device.write(cmnd)
    time.sleep(1)


def mqtt_message(client, device, message):
    if debug:
        print("message received :", str(message.payload.decode("utf-8")))
        print("           topic :", message.topic)

    relay = int(message.topic[-1])

    cmnd = message.payload.decode("utf-8").lower()
    if cmnd in ["on", "1", "true"]:
        state = True
    elif cmnd in ["off", "0", "false"]:
        state = False
    else:
        print("Unknown command value: %s" % cmnd)
        return

    control_relay(device, relay, state)


relay = None
for dev in hid.enumerate(0x16c0, 0x05df):
    if dev['manufacturer_string'] == 'www.dcttech.com':
        relay = hid.device()
        relay.open_path(dev['path'])
        break

if relay is None:
    raise ValueError('Relay device not found')

relay.set_nonblocking(1)
serno = relay.get_feature_report(1, 9)
serno_str = bytes(serno[0:5]).decode('ascii')

client = mqtt.Client("P1Client")
client.tls_set(ca_certs='/etc/ssl/certs/ca-certificates.crt')
client.username_pw_set(auth['username'], auth['password'])
client.user_data_set(relay)
client.on_message = mqtt_message
client.connect(Broker, port=8883)
print("Subscribing to %s" % prefix.format(serno_str))
client.subscribe(prefix.format(serno_str))
client.loop_start()

while True:
    time.sleep(60)