from machine import Pin, I2C
import ssd1306
from time import sleep
import dht
import json

# ESP32 Pin assignment 
i2c = I2C(0, scl=Pin(22), sda=Pin(21))
oled_width = 128
oled_height = 64
oled = ssd1306.SSD1306_I2C(oled_width, oled_height, i2c)

#Get Temperature & humidity treshold from sfconfig.json
def get_threshold():
  with open ('sfconfig.json') as f:
    sfconfig = json.load(f)
  f.close
  return sfconfig

#sensor reading function, return temperature and humidity value
def readsensor():
  sensor = dht.DHT22(Pin(14))
  sleep(3)
  sensor.measure()
  temp = sensor.temperature()
  hum = sensor.humidity()
  return temp,hum

#function to send information to oled display  
def showoled(status,msg):
  if status =='init' and msg =='':
    oled.fill(0)
    oled.text('T :', 0,5)
    oled.text('Fan :', 65,5)
    oled.text('H :',0, 20)
    oled.text('Ex :',65,20)

  if status == 'temp':
    oled.text(str(msg), 25,5)
  elif status == 'hum':
    oled.text(str(msg),25,20)
  elif status == 'fan':
    oled.text(str(msg),100,5)
  elif status == 'exhaust': 
    oled.text(str(msg),100,20)
  oled.show()

#function to turning on/off the relay
#two relay introduce to the system : fan relay and exhaust relay
def relaycontrol(rel, command):
  fan_relay = Pin(26, Pin.OUT)
  exhaust_relay = Pin(27, Pin.OUT)
  if rel == 'fan' and command == 'on':
    fan_relay.value(1)
  elif rel == 'fan' and command =='off':
    fan_relay.value(0)
  elif rel == 'exhaust' and command == 'on':
    exhaust_relay.value(1)
  elif rel == 'exhaust' and command =='off':
    exhaust_relay.value(0)

while True:
  config = get_threshold()
  print(config)
  sleep(5)
  
  '''
  showoled('init','')
  print(get_threshold()['temp_th'])
  temperature, humidity = readsensor()
  showoled('temp',temperature)
  showoled('hum',humidity)
  print (temperature,humidity)
  if temperature > get_threshold()['temp_th']:
    relaycontrol('fan','on')
    showoled('fan','On')
    #sleep(5)
  else :
    relaycontrol('fan', 'off')
    showoled('fan','Off')
    #sleep(5)

  if humidity > get_threshold()['hum_th'] :
    relaycontrol('exhaust','on')
    showoled('exhaust', 'On')
    #sleep(5)
  else :
    relaycontrol('exhaust','off')
    showoled('exhaust','Off')
    #sleep(5)
  sleep(5)
  '''