import datetime as dt
import RPi.GPIO as GPIO
import Adafruit_DHT as Adafruit_DHT

class CoolingSchedule:

    def __init__(self):

        self.temp_s = None
        self.temp_p = None

        self.humid_s = None
        self.humid_p = None

        self.status = False

        self.lcd = None

        self.log_file = "logs/log_cooling.txt"

    def setup(self, lcd):

        # cooling
        GPIO.setup(26, GPIO.OUT)

        # initialize to 0
        GPIO.output(26, GPIO.HIGH)

        # initialize lcd for cooling
        self.lcd = lcd

        # log system startup
        self.log("SYS START: COOLING")

        # display startup on lcd
        cur_time = dt.datetime.now()
        dsp_time = cur_time.strftime("%H:%M:%S")

        msg_top = "SYS START:    AC\n"
        msg_btm = "{:8}".format(dsp_time)

    def teardown(self):
        # clear GPIO on program failure
        GPIO.output(26, GPIO.HIGH)

    def log(self, msg):

        # get time
        cur_time = dt.datetime.now()
        cur_time = cur_time.strftime("%Y/%m/%d %H:%M:%S")

        # get variables
        status = self.status
        temp = self.temp_s
        humid = self.humid_s

        # log
        pin_26 = "0" if GPIO.input(26) else "1"

        log_msg = "[ {:>22} ] : [ {} ] Status: {:1}, Temp: {}, Humid: {}%".format(msg, cur_time, status, temp, humid)
        log_msg += "[ {:>22} ] : [ {:2} {:1} ]\n".format("Pin", 26, pin_26)

        log_file = open(self.log_file, "a")
        log_file.write(log_msg)
        log_file.close()

        # display on LCD
        dsp_status = "ON" if status else "OFF"
        msg_top = "TEMP:     {:5}\n".format(self.temp_s)
        msg_btm = "AC:          {:3}".format(dsp_status)

        self.lcd.showMessage(msg_top, msg_btm)

        # use these for debugging
        #print "[ {:>22} ] : [ {} ] Status: {:1}, Temp: {}, Humid: {}%".format(msg, cur_time, status, temp, humid)
        #print "[ {:>22} ] : [ {:2} {:1} ]".format("PIN", 26, pin_26)

    def start(self):

        # set status
        self.status = True

        # set relay on
        GPIO.output(26, GPIO.LOW)

        # call log
        self.log("COOLING ON")

    def stop(self):

        # set status
        self.status = False

        # set relay off
        GPIO.output(26, GPIO.HIGH)

        # call log
        self.log("COOLING OFF")

    def update(self):

        # get temperature and humidity
        humid, temp = Adafruit_DHT.read_retry(Adafruit_DHT.AM2302, 17)

        # check value exists
        if temp is not None and humid is not None:

            # calculate farenheit
            temp = temp * 9 / 5.0 + 32

            # check if temp has been saved
            if self.temp_p == None or self.humid_p == None:

                # set initial value
                self.temp_s = "{:.2f}".format(temp)
                self.temp_p = temp

                self.humid_s = "{:.2f}".format(humid)
                self.humid_p = humid

                # saved initial value, skip the rest
                return

            # at this point, temp has been checked more than once
            # check margin (faulty reading), within 3 degrees
            margin = abs(self.temp_p - temp)
            if margin < 5:

                # check status
                if not self.status and temp > 77:

                    # start
                    self.start()

                elif self.status and temp < 73:

                    # stop
                    self.stop()

                else:

                    # log
                    self.log("COOLING LOG")

            self.temp_s = "{:.2f}".format(temp)
            self.temp_p = temp

            self.humid_s = "{:.2f}".format(humid)
            self.humid_p = humid