import pyaudio
import math
import struct
import wave
import time
import os
import threading

#modify this param for decibels
ThresholdStart = 250
ThresholdEnd = 100

# lenght of sound
#current interval can detect dog bark
SOUND_LENGTH_MIN = 0.25
SOUND_LENGTH_MAX = 0.35
#modify this param for timeout after sound
TIMEOUT_LENGTH = 0.05
#modify this for how many time to replay
Replay = 1


# Audio settings
SHORT_NORMALIZE = (1.0/32768.0)
chunk = 512
FORMAT = pyaudio.paInt16
CHANNELS = 1
RATE = 16000
swidth = 2

#audio heard will be stored here
rec = []


# this will compute the power of the sound
def rms(frame):
	count = len(frame) / swidth
	format = "%dh" % (count)
	shorts = struct.unpack(format, frame)

	sum_squares = 0.0
	for sample in shorts:
		n = sample * SHORT_NORMALIZE
		sum_squares += n * n
	rms = math.pow(sum_squares / count, 0.5)

	return rms * 1000





# this will record after detection
def record(data):
	print('Sound detected, recording beginning')
	lrec = [data]
	start = current = time.time()
	end = time.time() + TIMEOUT_LENGTH


	while current <= end:

		data = stream.read(chunk)
		myrms = rms(data)

		if myrms >= ThresholdEnd: end = time.time() + TIMEOUT_LENGTH

		current = time.time()
		lrec.append(data)

	if SOUND_LENGTH_MIN <= current - start  <= SOUND_LENGTH_MAX :
		print('Sound added')
		rec.append(lrec)

	print ("time ", time.time() - start)


	print('End sound')




#this will play the detected sound
def play(playevent):

	while True:
		# wait until there is something to play
		playevent.wait()
		playevent.clear()
		while rec :
			lrec = rec.pop(0)
			for i in range(Replay):
				for f in lrec:
					stream.write(f)




#start the player thread
playevent = threading.Event()
threading.Thread(target=play, args=[playevent],daemon=True).start()



# init pyaudio
p = pyaudio.PyAudio()
stream = p.open(format=FORMAT,
			  channels=CHANNELS,
			  rate=RATE,
			  input=True,
			  output=True,
			  frames_per_buffer=chunk)


print('Listening beginning')
while True:
	# get sound
	input = stream.read(chunk)
	# compute power
	rms_val = rms(input)
	# then start recording if we met our power we want
	if rms_val > ThresholdStart:
		record(input)
		playevent.set()