#!/usr/bin/env python

# pylint: disable=line-too-long

import time
from datetime import datetime
import subprocess
import sys
import redis
import paho.mqtt.client as mqtt
import socket
import fcntl
import struct
import logging
import logging.handlers
import atexit
import os
import ConfigParser
import RPi.GPIO as GPIO

from select import select
from gpiozero import Button

# Local files
import lcddriver
import gsmhuaweistatus

# ------------------------------------------------------------------------------------
# Script version
version = '3.0.1'
# ------------------------------------------------------------------------------------


config = ConfigParser.ConfigParser()
config.read('/usr/share/emonPiLCD/emonPiLCD.cfg') 


# ------------------------------------------------------------------------------------
# MQTT Settings
# ------------------------------------------------------------------------------------
mqtt_user = config.get('mqtt','mqtt_user')
mqtt_passwd = config.get('mqtt','mqtt_passwd')
mqtt_host = config.get('mqtt','mqtt_host')
mqtt_port = config.getint('mqtt','mqtt_port')
mqtt_emonpi_topic = config.get('mqtt','mqtt_emonpi_topic') 
mqtt_feed1_topic = config.get('mqtt','mqtt_feed1_topic')
mqtt_feed2_topic = config.get('mqtt','mqtt_feed2_topic')
mqtt_feed1_topic = config.get('mqtt','mqtt_feed3_topic')
mqtt_feed1_topic = config.get('mqtt','mqtt_feed4_topic')


# ------------------------------------------------------------------------------------
# Redis Settings
# ------------------------------------------------------------------------------------
redis_host = config.get('redis', 'redis_host') 
redis_port = config.get('redis', 'redis_port') 
r = redis.Redis(host=redis_host, port=redis_port, db=0)

# ------------------------------------------------------------------------------------
# General Settings
# ------------------------------------------------------------------------------------

# LCD backlight timeout in seconds 0: always on, 300: off after 5 min
backlight_timeout = config.getint('general','backlight_timeout') 
default_page = config.getint('general','default_page') 

#Names to be displayed on power reading page
feed1_name = config.get('general','feed1_name')
feed2_name = config.get('general','feed2_name')
feed3_name = config.get('general','feed3_name')
feed4_name = config.get('general','feed4_name')
feed1_unit = config.get('general','feed1_unit')
feed2_unit = config.get('general','feed2_unit')
feed3_unit = config.get('general','feed3_unit')
feed4_unit = config.get('general','feed4_unit')

#How often the LCD is updated when a button is not pressed
lcd_update_sec = config.getint('general','lcd_update_sec') 
# ------------------------------------------------------------------------------------
# Huawei Hi-Link GSM/3G USB dongle IP address on eth1
# ------------------------------------------------------------------------------------
hilink_device_ip = config.get('huawei', 'hilink_device_ip') 

# ------------------------------------------------------------------------------------
# I2C LCD: each I2C address will be tried in consecutive order until LCD is found
# The first address that matches a device on the I2C bus will be used for the I2C LCD
# ------------------------------------------------------------------------------------
lcd_i2c = ['27', '3f']
current_lcd_i2c = ''
# ------------------------------------------------------------------------------------

# Default Startup Page
max_number_pages = 11
page = default_page

sd_image_version = ''

sshConfirm = False 
shutConfirm = False

# ------------------------------------------------------------------------------------
# Start Logging
# ------------------------------------------------------------------------------------
uselogfile =  config.get('general','uselogfile') 
logger = logging.getLogger("emonPiLCD")

#ssh enable/disable/check commands
ssh_enable = "systemctl enable ssh > /dev/null"
ssh_start = "systemctl start ssh > /dev/null"
ssh_disable = "systemctl disable ssh > /dev/null"
ssh_stop = "systemctl stop ssh > /dev/null"
ssh_status = "systemctl status ssh > /dev/null"





def buttonPressLong():

   logger.info("Mode button LONG press")

   if sshConfirm:

      ret=subprocess.call(ssh_status, shell=True)
      if ret > 0 :
         #ssh not running, enable & start it
         subprocess.call(ssh_enable, shell=True)
         subprocess.call(ssh_start, shell=True)
         logger.info("SSH Enabled")
         lcd[0] = 'SSH Enabled      '
         lcd[1] = 'Change password!'
      else:
         #disable ssh
         subprocess.call(ssh_disable, shell=True)
         subprocess.call(ssh_stop, shell=True)
         logger.info("SSH Disabled")
         lcd[0] = 'SSH Disabled      '
         lcd[1] = '                '
         

   elif shutConfirm:
      logger.info("Shutting down")
      shutdown()
   else:
      lcd.backlight = not lcd.backlight


def buttonPress():
   global page
   global lcd
   global logger

   now = time.time()


   if lcd.backlight:
        page += 1
   if page > max_number_pages:
    page = 0
   buttonPress_time = now
   if not lcd.backlight:
    lcd.backlight = 1
   logger.info("Mode button SHORT press")
   logger.info("Page: " + str(page))
   updateLCD() 


def updateLCD() :

   global page
   global lcd
   global r
   global logger
   global sshConfirm
   global shutConfirm

   # Create object for getting IP addresses of interfaces
   ipaddress = IPAddress()

   if not page == 9:
       sshConfirm = False
   if not page == 11:
       shutConfirm = False


   # Now display the appropriate LCD page
   if page == 0:
    # Update ethernet
        eth0ip = ipaddress.get_ip_address('eth0')
        r.set("eth:active", bool(eth0ip))
        r.set("eth:ip", eth0ip)

        wlan0ip = ipaddress.get_ip_address('wlan0')
        r.set("wlan:active", bool(wlan0ip))

        if eval(r.get("eth:active")):
            lcd[0] = "Ethernet: YES"
            lcd[1] = r.get("eth:ip")
        elif eval(r.get("wlan:active")) or eval(r.get("gsm:active")):
            page += 1
        else:
            lcd[0] = "Ethernet:"
            lcd[1] = "NOT CONNECTED"

   if page == 1:
   # Update wifi
        wlan0ip = ipaddress.get_ip_address('wlan0')

        r.set("wlan:active", bool(wlan0ip))
        r.set("wlan:ip", wlan0ip)

        signallevel = 0
        if wlan0ip:
            # wlan link status
            with open('/proc/net/wireless', 'r') as f:
                wireless = f.readlines()
                signals = [x.split()[3] for x in wireless if x.strip().startswith('wlan0')]
            if signals:
                signallevel = signals[0].partition('.')[0]
            if signallevel.startswith('-'): # Detect the alternate signal strength reporting via dBm
                signallevel = 2 * ( int(signallevel) + 100 ) # Convert to percent
            r.set("wlan:signallevel", signallevel)


        if eval(r.get("wlan:active")):
            if int(r.get("wlan:signallevel")) > 0:
               lcd[0] = "WiFi: YES  " + r.get("wlan:signallevel") + "%"
            else:
               if r.get("wlan:ip") == "192.168.42.1":
                  lcd[0] = "WiFi: AP MODE"
               else:
                  lcd[0] = "WiFi: YES  "

            lcd[1] = r.get("wlan:ip")
        elif eval(r.get("gsm:active")) or eval(r.get("eth:active")):
            page += 1
        else:
            lcd[0] = "WiFi:"
            lcd[1] = "NOT CONNECTED"

   if page == 2:
    # Update Hi-Link 3G Dongle - connects on eth1
        if ipaddress.get_ip_address("eth1") and gsmhuaweistatus.is_hilink(hilink_device_ip):
            gsm_connection_status = gsmhuaweistatus.return_gsm_connection_status(hilink_device_ip)
            r.set("gsm:connection", gsm_connection_status[0])
            r.set("gsm:signal", gsm_connection_status[1])
            r.set("gsm:active", 1)
        else:
            r.set("gsm:active", 0)


        if eval(r.get("gsm:active")):
            lcd[0] = r.get("gsm:connection")
            lcd[1] = r.get("gsm:signal")
        elif eval(r.get("eth:active")) or eval(r.get("wlan:active")):
            page += 1
        else:
            lcd[0] = "GSM:"
            lcd[1] = "NO DEVICE"

   if page == 3:
        if r.get("feed1") is not None:
            lcd[0] = feed1_name + ':'  + r.get("feed1") + feed1_unit 
        else:
            lcd[0] = feed1_name + ':'  + "---"

        if r.get("feed2") is not None:
            lcd[1] = feed2_name + ':'  + r.get("feed2") + feed2_unit 
        else:
            lcd[1] = feed2_name + ':'  + "---"

        if r.get("feed3") is not None:
            lcd[2] = feed3_name + ':'  + r.get("feed3") + feed3_unit 
        else:
            lcd[2] = feed3_name + ':'  + "---"

        if r.get("feed4") is not None:
            lcd[3] = feed4_name + ':'  + r.get("feed4") + feed4_unit 
        else:
            lcd[3] = feed4_name + ':'  + "---"

   elif page == 4:
        basedata = r.get("basedata")
        if basedata is not None:
            basedata = basedata.split(",")
            lcd[0] = 'VRMS: ' + basedata[3] + "V"
	    lcd[1] = 'Pulse: ' + basedata[10] + "p"
        else:
            lcd[0] = 'Connecting...'
            lcd[1] = 'Please Wait'
            page +=1

   elif page == 5:
        basedata = r.get("basedata")
        if basedata is not None:
            basedata = basedata.split(",")
            lcd[0] = 'Temp 1: ' + basedata[4] + "C"
            lcd[1] = 'Temp 2: ' + basedata[5] + "C"
        else:
            lcd[0] = 'Connecting...'
            lcd[1] = 'Please Wait'
            page +=1

   elif page == 6:
    # Get uptime
        with open('/proc/uptime', 'r') as f:
            seconds = float(f.readline().split()[0])
        r.set('uptime', seconds)

        lcd[0] = datetime.now().strftime('%b %d %H:%M')
        lcd[1] = 'Uptime %.2f days' % (seconds / 86400)

   elif page == 7:
        lcd[0] = "emonPi Build:"
        lcd[1] = sd_image_version

   elif page == 8:
        ret=subprocess.call(ssh_status, shell=True)
        if ret > 0 : 
          #ssh not running
          lcd[0] = "SSH Enable?"
        else:
          #ssh not running
          lcd[0] = "SSH Disable?"

        lcd[1] = "Y press & hold"
	sshConfirm = False

   elif page == 9:
        sshConfirm = True

   elif page == 10:
        lcd[0] = "Shutdown?"
        lcd[1] = "Y press & hold"
	shutConfirm = False
   elif page == 11:
        lcd[0] = "Shutdown?"
	shutConfirm = True



class IPAddress(object):
    def __init__(self):
        self.sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)

    def get_ip_address(self, ifname):
        try:
            return socket.inet_ntoa(fcntl.ioctl(
                self.sock.fileno(),
                0x8915,  # SIOCGIFADDR
                struct.pack('256s', ifname[:15])
            )[20:24])
        except Exception:
            return 0

def preShutdown():
    lcd[0] = "Shutdown?"
    lcd[1] = "Hold 5 secs"

def shutdown():

    global lcd
    lcd.backlight = 1
    lcd[0] = "emonPi Shutdown"
    lcd[1] = "SHUTDOWN NOW!"
    time.sleep(2)
    lcd.lcd_clear()
    lcd[0] = "Wait 30s..."
    lcd[1] = "Before Unplug!"
    time.sleep(4)
    # backlight zero must be the last call to the LCD to keep the backlight off
    lcd.backlight = 0
    subprocess.call('halt', shell=False)
    sys.exit(0)  # end script


class LCD(object):
    def __init__(self, logger):
        # Scan I2C bus for LCD I2C addresses as defined in led_i2c, we have a couple of models of LCD which have different adreses that are shipped with emonPi. First I2C device to match address is used.
        self.logger = logger
        for i2c_address in lcd_i2c:
          lcd_status = subprocess.check_output(["/home/pi/emonpi/lcd/emonPiLCD_detect.sh", "%s" % i2c_address])
          if lcd_status.rstrip() == 'True':
            print "I2C LCD DETECTED Ox%s" % i2c_address
            logger.info("I2C LCD DETECTED 0x%s" % i2c_address)
            current_lcd_i2c = "0x%s" % i2c_address
            # add file to identify device as emonpi
            open('/home/pi/data/emonpi', 'a').close()
            break

        if lcd_status.rstrip() == 'False':
          print ("I2C LCD NOT DETECTED on either 0x" + str(lcd_i2c) + " ...exiting LCD script")
          logger.error("I2C LCD NOT DETECTED on either 0x" + str(lcd_i2c) + " ...exiting LCD script")
          # add file to identify device as emonbase
          open('/home/pi/data/emonbase', 'a').close()
          sys.exit(1)

        # Init LCD using detected I2C address with 16 characters
        self.lcd = lcddriver.lcd(int(current_lcd_i2c, 16))
        self._display = ['', '']

    def __setitem__(self, line, string):
        if not 0 <= line <= 1:
            raise IndexError("line number out of range")
        # Format string to exactly the width of LCD
        string = '{0!s:<16.16}'.format(string)
        if string != self._display[line]:
            self._display[line] = string
            self.logger.debug("LCD line {0}: {1}".format(line, string))
            self.lcd.lcd_display_string(string, line + 1)

    @property
    def backlight(self):
        return self.lcd.backlight

    @backlight.setter
    def backlight(self, state):
        if not 0 <= state <= 1:
            raise IndexError("backlight state out of range")
        self.logger.debug("LCD backlight: " + repr(state))
        self.lcd.backlight = state

    def lcd_clear(self):
        self.lcd.lcd_clear()

def main():
    global page
    global sd_image_version
    global r

    # Initialise some redis variables
    r.set("gsm:active", 0)
    r.set("wlan:active", 0)
    r.set("eth:active", 0)

    # First set up logging
    atexit.register(logging.shutdown)
    if not uselogfile:
        loghandler = logging.StreamHandler()
    else:
        logfile = "/var/log/emonpilcd/emonpilcd.log"
        print "emonPiLCD logging to: "+logfile
        loghandler = logging.handlers.RotatingFileHandler(logfile,
                                                          mode='a',
                                                          maxBytes=1000 * 1024,
                                                          backupCount=1,
                                                         )

    loghandler.setFormatter(logging.Formatter('%(asctime)s %(levelname)s %(message)s'))
    logger.addHandler(loghandler)
    logger.setLevel(logging.INFO)

    logger.info("Starting emonPiLCD V" + version)

    # Now check the LCD and initialise the object
    global lcd 
    lcd = LCD(logger)
    lcd.backlight = 1

    # ------------------------------------------------------------------------------------
    # Discover & display emonPi SD card image version
    # ------------------------------------------------------------------------------------

    sd_card_image = subprocess.call("ls /boot | grep emonSD", shell=True)
    if not sd_card_image:  # if emonSD file exists
        sd_image_version = subprocess.check_output("ls /boot | grep emonSD", shell=True)
    else:
        sd_card_image = subprocess.call("ls /boot | grep emonpi", shell=True)
        if not sd_card_image:
            sd_image_version = subprocess.check_output("ls /boot | grep emonpi", shell=True)
        else:
            sd_image_version = "N/A "
    sd_image_version = sd_image_version.rstrip()

    lcd[0] = "emonPi Build:"
    lcd[1] = sd_image_version
    logger.info("SD card image build version: " + sd_image_version)

    # Set up the buttons and install handlers

    # emonPi LCD push button Pin 16 GPIO 23
    # Uses gpiozero library to handle short and long press https://gpiozero.readthedocs.io/en/stable/api_input.html?highlight=button
    # push_btn = Button(23, pull_up=False, hold_time=5, bounce_time=0.1)
    # No bounce time increases responce time but may result in switch bouncing...
    logger.info("Attaching push button interrupt...")
    try:
       push_btn = Button(12, pull_up=False, hold_time=5)
       push_btn.when_pressed = buttonPress
       push_btn.when_held = buttonPressLong
    except: 
       logger.error("Failed to attach LCD push button interrupt...")

    logger.info("Attaching shutdown button interrupt...")
    try:
       shut_btn = Button(26, pull_up=False, hold_time=5)
       shut_btn.when_pressed = preShutdown
       shut_btn.when_held = shutdown 
    except: 
       logger.error("Failed to attach shutdown button interrupt...")


    logger.info("Connecting to redis server...")
    # We wait here until redis has successfully started up
    while True:
        try:
            r.client_list()
            break
        except redis.ConnectionError:
            logger.error("waiting for redis-server to start...")
            time.sleep(1.0)
    logger.info("Connected to redis")

    logger.info("Connecting to MQTT Server: " + mqtt_host + " on port: " + str(mqtt_port) + " with user: " + mqtt_user)

    def on_message(client, userdata, msg):
        topic_parts = msg.topic.split("/")

        if mqtt_feed1_topic in msg.topic: 
            r.set("feed1" , msg.payload)

        if mqtt_feed2_topic in msg.topic:
            r.set("feed2" , msg.payload)

        if mqtt_feed3_topic in msg.topic:
            r.set("feed3" , msg.payload)

        if mqtt_feed4_topic in msg.topic:
            r.set("feed4" , msg.payload)

        if mqtt_emonpi_topic in msg.topic:
            r.set("basedata", msg.payload)


    def on_connect(client, userdata, flags, rc):
        if (rc==0):
            mqttc.subscribe(mqtt_emonpi_topic)
            mqttc.subscribe(mqtt_feed1_topic)
            mqttc.subscribe(mqtt_feed2_topic)
            mqttc.subscribe(mqtt_feed3_topic)
            mqttc.subscribe(mqtt_feed4_topic)

    mqttc = mqtt.Client()
    mqttc.on_message = on_message
    mqttc.on_connect = on_connect

    try:
        mqttc.username_pw_set(mqtt_user, mqtt_passwd)
        mqttc.reconnect_delay_set(min_delay=1, max_delay=120)
        mqttc.connect_async(mqtt_host, mqtt_port, 60)
        # Run MQTT background thread which handles reconnects
        mqttc.loop_start()
    except Exception:
        logger.error("Could not connect to MQTT")
    else:
        logger.info("Connected to MQTT")

    # time to show Build version
    time.sleep(2)

    buttonPress_time = time.time()


    if not backlight_timeout: 
      lcd.backlight = 1

    page = default_page

    # Enter main loop
    while True:

        # turn backight off after backlight_timeout seconds
        now = time.time()
        if (backlight_timeout) and now - buttonPress_time > backlight_timeout and lcd.backlight:
            lcd.backlight = 0
        
        #Update LCD in case it is left at a screen where values can change (e.g uptime etc)
        updateLCD() ;
        time.sleep(lcd_update_sec) 

if __name__ == '__main__':
    main()