from pyA20.gpio import gpio as GPIO
import threading
import time


class OrangePwm(threading.Thread):
    def __init__(self, frequency, gpioPin, gpioScheme=0):
        """
        Init the OrangePwm instance. Expected parameters are :
        - frequency : the frequency in Hz for the PWM pattern. A correct value may be 100.
        - gpioPin : the gpio.port which will act as PWM ouput
        - gpioScheme : saved for compatibility with PiZyPWM code
        """
        super().__init__()

        self.baseTime = 1.0 / frequency
        self.maxCycle = 100.0
        self.sliceTime = self.baseTime / self.maxCycle
        self.gpioPin = gpioPin
        self.terminated = False
        self.toTerminate = False
        # GPIO.setmode(gpioScheme)

    def start(self, dutyCycle):
        """
        Start PWM output. Expected parameter is :
        - dutyCycle : percentage of a single pattern to set HIGH output on the GPIO pin

        Example : with a frequency of 1 Hz, and a duty cycle set to 25, GPIO pin will
        stay HIGH for 1*(25/100) seconds on HIGH output, and 1*(75/100) seconds on LOW output.
        """
        self.dutyCycle = dutyCycle
        GPIO.setcfg(self.gpioPin, GPIO.OUTPUT)
        self.thread = threading.Thread(None, self.run, None, (), {})
        self.thread.start()

    def run(self):
        """
        Run the PWM pattern into a background thread. This function should not be called outside of this class.
        """
        while self.toTerminate == False:
            if self.dutyCycle > 0:
                GPIO.output(self.gpioPin, GPIO.HIGH)
                time.sleep(self.dutyCycle * self.sliceTime)

            if self.dutyCycle < self.maxCycle:
                GPIO.output(self.gpioPin, GPIO.LOW)
                time.sleep((self.maxCycle - self.dutyCycle) * self.sliceTime)

        self.terminated = True

    def changeDutyCycle(self, dutyCycle):
        """
        Change the duration of HIGH output of the pattern. Expected parameter is :
        - dutyCycle : percentage of a single pattern to set HIGH output on the GPIO pin

        Example : with a frequency of 1 Hz, and a duty cycle set to 25, GPIO pin will
        stay HIGH for 1*(25/100) seconds on HIGH output, and 1*(75/100) seconds on LOW output.
        """
        self.dutyCycle = dutyCycle

    def changeFrequency(self, frequency):
        """
        Change the frequency of the PWM pattern. Expected parameter is :
        - frequency : the frequency in Hz for the PWM pattern. A correct value may be 100.

        Example : with a frequency of 1 Hz, and a duty cycle set to 25, GPIO pin will
        stay HIGH for 1*(25/100) seconds on HIGH output, and 1*(75/100) seconds on LOW output.
        """
        self.baseTime = 1.0 / frequency
        self.sliceTime = self.baseTime / self.maxCycle

    def stop(self):
        """
        Stops PWM output.
        """
        self.toTerminate = True
        while self.terminated == False:
            # Just wait
            time.sleep(0.01)

        GPIO.output(self.gpioPin, GPIO.LOW)
        GPIO.setcfg(self.gpioPin, GPIO.INPUT)