import subprocess
import paho.mqtt.client as mqtt

import time
import board
import busio
from adafruit_ht16k33 import segments

__TOPIC_BRIGHTNESS__ = "brightness"
__TOPIC_SCROLL_INTERVAL__ = "scroll_interval"
__TOPIC_TEXT__ = ""

class Controller:
    connected = False

    def __init__(self, base_topic, mqtt_host, mqtt_port = 1883):

      self.scroll_interval = 0.25
	  self.text = ""
	  self.poscount = 0
		
      # Create the I2C interface.
      self.i2c = busio.I2C(board.SCL, board.SDA)

      # Create the LED segment class.
      # This creates a 14 segment 4 character display:
      self.display = segments.Seg14x4(self.i2c)

      # Clear the display.
      self.display.fill(0)

      # set brightness, range 0-1.0, 1.0 max brightness
      self.display.brightness = 1.0

      self.mqtt = mqtt.Client()
      self.mqtt.on_connect = self.on_connect
      self.mqtt.on_message = self.on_message
      self.mqtt.on_disconnect = self.on_disconnect
      self.mqtt.connect(mqtt_host, mqtt_port)
      self.topic = base_topic
     

    def on_disconnect(self, client, userdata, rc):
        print("MQTT disconnected")
        self.connected = False

    def on_message(self, client, userdata, message):
        msg = str(message.payload.decode("utf-8"))
        print("msg = " +  msg)

        if message.topic.endswith(__TOPIC_BRIGHTNESS__ + "/set"):
		val = float(msg)
		if val >= 0.0 and val <=1.0:
		  self.display.brightness = val
		  print("changed brightness to ", self.display.brightness)
          self.mqtt.publish(self.topic + "/" + __TOPIC_BRIGHTNESS__, self.display.brightness, 1 )
		else:
		  print("invalid brightness ", val)

        if message.topic.endswith(__TOPIC_SCROLL_INTERVAL__ + "/set"):
		  val = float(msg)
		  if val > 0.0:
			self.scroll_interval = val
			print("changed scroll_interval to ", self.scroll_interval)
            self.mqtt.publish(self.topic + "/" + __TOPIC_SCROLL_INTERVAL__, self.scroll_interval, 1 )
		  else:
			print("error not >0.0: ", val)
			
		  
		  
		  
		if message.topic.endswith(__TOPIC_TEXT__ + "/set"):
          self.text = msg
		  print("changed text to ", self.text)
          self.mqtt.publish(self.topic + "/" + __TOPIC_TEXT__, self.text, 1 )

          

    def on_connect(self, client, userdata, flags, rc):
        print("Connected to MQTT Broker")
        self.mqtt.subscribe(self.topic + "/#")
        self.connected = True


    def loop_forever(self):
      run = True

      while run:
          self.mqtt.loop()

		
          self.display.print(self.text[poscount])
          poscount += 1
		  poscount %= len(self.text)
          time.sleep(self.scroll_interval)