#!/usr/bin/env python3

import wave


class WaveLoader:
	def __init__(self, filename):
		self.soundfile = wave.open(filename, 'rb')

		self.channels = self.soundfile.getnchannels()
		self.sampleWidth = self.soundfile.getsampwidth()
		self.frameCount = self.soundfile.getnframes()
		self.frameRate = self.soundfile.getframerate()
		self.filename = filename
		self.amplitudeMax = 2 ** (self.sampleWidth * 8)
		self.levelData = {}
		self.amplitudeData = {}

	def __del__(self):
		self.soundfile.close()

	def getCurrentLevelRealtime(self, seconds):
		frameIndex = int(round(seconds * self.frameRate))

		if frameIndex >= self.frameCount:
			return 0

		self.soundfile.setpos(frameIndex)

		level = int.from_bytes(self.soundfile.readframes(1)[0:self.sampleWidth], 'little')

		if level > self.amplitudeMax * 0.5:
			level -= self.amplitudeMax

		return abs(level) / (self.amplitudeMax * 0.5)

	def getLevel(self, channel = 0):
		if channel < self.channels:
			return self.levelData[channel].copy()

	def getAmplitude(self, channel = 0):
		if channel < self.channels:
			return self.amplitudeData[channel].copy()

	def getLevelSum(self):
		if self.channels == 1:
			return self.levelData[0].copy()

		levelSum = []

		for f in range(self.frameCount):
			amplitudeSum = 0

			for c in range(self.channels):
				amplitudeSum += self.levelData[c][f]

			levelSum.append(amplitudeSum / self.channels)

		return levelSum

	def getCurrentLevel(self, seconds):
		frameIndex = int(round(seconds * self.frameRate))

		if frameIndex >= self.frameCount:
			return 0

		level = self.levelData[0][frameIndex]
		return level

		level = 0

		for c in range(self.channels):
			level += self.levelData[c][frameIndex]
		
		return level / self.channels

	def loadData(self):
		self.levelReset()
		self.amplitudeReset()
		soundfile = wave.open(self.filename, 'rb')

		for f in range(self.frameCount):
			frame = soundfile.readframes(1)

			for c in range(self.channels):
				byteOffset = c * self.sampleWidth
				amplitude = int.from_bytes(frame[byteOffset:byteOffset + self.sampleWidth], 'little')
				
				if amplitude > self.amplitudeMax * 0.5:
					amplitude -= self.amplitudeMax

				self.amplitudeData[c].append(amplitude / (self.amplitudeMax * 0.5))
				self.levelData[c].append(abs(amplitude) / (self.amplitudeMax * 0.5))

		soundfile.close()

	def levelReset(self):
		self.levelData = {}

		for c in range(self.channels):
			self.levelData[c] = []

	def amplitudeReset(self):
		self.amplitudeData = {}

		for c in range(self.channels):
			self.amplitudeData[c] = []