import time
import threading
from typing import Callable

import RPi.GPIO as GPIO

class SoundReader:

    _pin :int
    _running :bool
    _thread :threading.Thread | None
    _subscriber :Callable[[str], None]

    def __init__(self, pin):
        self._pin = pin
        self._running = False
        self._thread = None

        GPIO.setmode(GPIO.BCM)
        GPIO.setup(self._pin, GPIO.IN)

    def start(self):
        if not self._running:
            self._running = True
            self._thread = threading.Thread(target=self._read, daemon=True)
            self._thread.start()

    def stop(self):
        self._running = False
        if self._thread:
            self._thread.join()
        GPIO.cleanup()

    def subscribe(self, handler:Callable[[str], None]):
        self._subscriber = handler

    def _notify(self, data : str):
        if self._subscriber:
            self._subscriber(data)

    def _read(self):
        measure_iteration = 100
        level = 0
        i = 0
        while self._running:
            if GPIO.input(self._pin):
                level += 1
            if i == measure_iteration:
                self._notify(f'{{"soundSensorValue": {level}}}')
                i = 0
                level = 0
            i += 1
            time.sleep(0.02)

if __name__ == "__main__":
    sensor = SoundReader(pin=17)
    sensor.start()

    try:
        while True:
            print(f"Approx. Sound Level: {sensor.get_level()}")
            time.sleep(0.2)
    except KeyboardInterrupt:
        print("Exiting...")
    finally:
        sensor.stop()