#!/usr/bin/env python

"""MQTT monitoring relay for rtl_433 communication."""

# This program listens on a UDP socket for syslog messages with a json
# payload, and publishes the data via MQTT.  The broker connection is
# kept open (and automatically reconnects on failure).  Each device
# is mapped to its own topic,

# Dependencies:
#   Paho-MQTT; see https://pypi.python.org/pypi/paho-mqtt

#   Optionally: PEP 3143 - Standard daemon process library
#      (on 2.7,  pip install python-daemon)

# To enable daemon support, uncomment the following line and adjust
# run().  Note that print() is still used.
# import daemon

from __future__ import print_function
from __future__ import with_statement

import socket
import json
import paho.mqtt.client as mqtt

import sys
import subprocess

# Syslog socket configuration
UDP_IP = "127.0.0.1"
UDP_PORT = 1433

# MQTT broker configuration
MQTT_HOST = "127.0.0.1"
MQTT_PORT = 1883
MQTT_USERNAME = None
MQTT_PASSWORD = None
MQTT_TLS = False
MQTT_PREFIX = "sensor/rtl_433"

def mqtt_connect(client, userdata, flags, rc):
    """Handle MQTT connection callback."""
    print("MQTT connected: " + mqtt.connack_string(rc))


def mqtt_disconnect(client, userdata, rc):
    """Handle MQTT disconnection callback."""
    print("MQTT disconnected: " + mqtt.connack_string(rc))


# Create listener for incoming json string packets.
sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP)
sock.bind((UDP_IP, UDP_PORT))


# Map characters that will cause problems or be confusing in mqtt
# topics.
def sanitize(text):
    """Sanitize a name for Graphite/MQTT use."""
    return (text
            .replace(" ", "_")
            .replace("/", "_")
            .replace(".", "_")
            .replace("&", ""))

def parse_syslog(line):
    """Try to extract the payload from a syslog line."""
    line = line.decode("ascii")  # also UTF-8 if BOM
    if line.startswith("<"):
        # Fields should be "<PRI>VER", timestamp, hostname, command, pid, mid, sdata, payload.
        # The payload might have spaces, so force split to stop after the sixth space.
        fields = line.split(None, 7)
        line = fields[-1]
    else:
        # Hope that the line was just json without the syslog header.
        pass
    return line

def rtl_433_probe():
    """Run a rtl_433 UDP listener."""

    ## Connect to MQTT
    mqttc = mqtt.Client()
    mqttc.on_connect = mqtt_connect
    mqttc.on_disconnect = mqtt_disconnect
    if MQTT_USERNAME != None:
        mqttc.username_pw_set(MQTT_USERNAME, password=MQTT_PASSWORD)
    if MQTT_TLS:
        mqttc.tls_set()
    mqttc.connect_async(MQTT_HOST, MQTT_PORT, 60)
    mqttc.loop_start()

    ## Receive UDP datagrams, extract json, and publish.
    while True:
        line, addr = sock.recvfrom(1024)
        try:
            line = parse_syslog(line)
            data = json.loads(line)

            if data['model'] == 'Abarth-124Spider':
                process_tires(data)

        except ValueError:
            pass

# initial guesses
#FL = {'id':'c12c86ad','psi':0,'temp':0} test FL at ~35 psi set by hand
#FR = {'id':'c12c86cd','psi':0,'temp':0} test FR at ~30 psi set by hand
#BL = {'id':'c12a5716','psi':0,'temp':0} test BL at ~20 psi set by hand
#BR = {'id':'c12c86dd','psi':0,'temp':0} test BR at ~25 psi set by hand

# final tire mapping
BR = {'id':'c12c86ad','psi':0,'temp':0} # tpms measured 24.4 in test -> BR
FR = {'id':'c12c86cd','psi':0,'temp':0} # tpms measured 27.2 in test -> FR
BL = {'id':'c12a5716','psi':0,'temp':0} # tpms measured 17.8 in test -> BL
FL = {'id':'c12c86dd','psi':0,'temp':0} # tpms measured 30.8 in test -> FL

def process_tires(data):
    global FL, FR, BL, BR

    print(data)

    if (data['id'] == FL['id']):
        FL['psi'] = data['pressure_kPa']*.1450
        FL['temp'] = data['temperature_C']
    elif (data['id'] == FR['id']):
        FR['psi'] = data['pressure_kPa']*.1450
        FR['temp'] = data['temperature_C']
    elif (data['id'] == BL['id']):
        BL['psi'] = data['pressure_kPa']*.1450
        BL['temp'] = data['temperature_C']
    elif (data['id'] == BR['id']):
        BR['psi'] = data['pressure_kPa']*.1450
        BR['temp'] = data['temperature_C']

    print("Front Left:", "{:2.1f}".format(FL['psi']), "PSI /", FL['temp'], "C", "\t","Front Right:", "{:2.1f}".format(FR['psi']), "PSI /", FR['temp'], "C")
    print(" Back Left:", "{:2.1f}".format(BL['psi']), "PSI /", BL['temp'], "C", "\t", " Back Right:", "{:2.1f}".format(BR['psi']), "PSI /", BR['temp'], "C")

if __name__ == "__main__":
    if len(sys.argv) > 1:
        print(sys.argv[1])
        subprocess.Popen(['rtl_433 -R 156 -r '+ sys.argv[1] +' -F syslog:127.0.0.1:1433'],shell=True,stdout=subprocess.DEVNULL)
    else:
        subprocess.Popen(['rtl_433 -f 315000000 -R 156 -F syslog:127.0.0.1:1433'],shell=True,stdout=subprocess.DEVNULL)
    rtl_433_probe()