#!/usr/bin/env python2

import alsaaudio
import numpy
import random
import time
import sys


WIDTH = 6
HEIGHT = 8
AUDIO_RATE = 4000 # sampling rate in Hz
WINDOW_SIZE = 8 # average fft over WINDOW_SIZE audio frames

BOX_MAP = [
			[357,  18, 369, 186, 249, 228,  51],
			[279,   9,  57, 159, 300, 108, 204],
			[261,  42, 183, 201, 273, 246,  15],
			[306, 168,  24, 138, 309, 165,  39],
			[258, 222,  87, 363, 291, 231, 243],
			[252, 114, 180,  75, 282, 141,  33],
			[264, 288, 120, 135, 255,  99, 105],
			[285, 207, 102,  45, 297, 216,  63],
		]

COLORS = [
			[50, 255, 50], [50, 255, 120], [50, 251, 255], [50, 120, 255],
			[50, 50, 255], [180, 50, 255], [255, 50, 137], [255, 50, 50]
		]


channels = {}

def set_box(x,y,r,g,b):
	if x >= 0 and y >= 0 and x < WIDTH and y < HEIGHT:
		base_address = BOX_MAP[y][x]
		channels[base_address] = r
		channels[base_address + 1] = g
		channels[base_address + 2] = b


def output_channels():
	for channel, value in channels.items():
		print("%d : %d" % (channel, value))
	print("")
	sys.stdout.flush()


class Background:
	"""clear the light wall to a pseudorandomly changing/fading solid color"""

	def __init__(self):
		self._current_bg_color = [ 0, 0, 0 ]
		self._target_bg_color = [ 128, 128, 128 ]
		self._bg_time = 0


	def clear(self):
		for i in range(3):
			if self._current_bg_color[i] < self._target_bg_color[i]:
				self._current_bg_color[i] = self._current_bg_color[i] + 1
			elif self._current_bg_color[i] > self._target_bg_color[i]:
				self._current_bg_color[i] = self._current_bg_color[i] - 1

			if self._current_bg_color[i] > 128:
				self._current_bg_color[i] = 128
			elif self._current_bg_color[i] < 0:
				self._current_bg_color[i] = 0

		self._bg_time = self._bg_time + 1
		if self._bg_time == 64:
			for i in range(3):
				self._target_bg_color[i] = random.randint(0, 128)
			self._bg_time = 0

		for x in range(0, WIDTH):
			for y in range(0, HEIGHT):
				set_box(x, y, self._current_bg_color[0], self._current_bg_color[1], self._current_bg_color[2])


def audio_from_raw(raw):
	"""convert bytewise signed 16bit little endian to int list"""
	out = []
	high = False
	current = 0
	for value in raw:
		value = ord(value[0])
		if high:
			sign = value & 0x80
			current = current + 256 * (value & 0x7F)
			if sign:
				current =  -((~current & 0x7FFF) + 1)
			out.append(current)
			high = False
		else:
			current = value
			high = True
	return out


class Fft_output:
	"""aggregate several fft'ed samples, does postprocessing to make it look nice and outputs
	the aggregated result"""


	def __init__(self, width, height, windowsize):
		self._background = Background()
		self._width = width
		self._height = height
		self._windowsize = windowsize

		self._count = 0
		self._data = []
		for _ in range(width):
			self._data.append(0)


	def add(self, data):
		"""add a set of fft data to the internal store, output the result if enough data is
			available"""
		abss = numpy.absolute(data[1:self._width+1])

		for i in range(self._width):
			self._data[i] = self._data[i] + abss[i]

		self._count = self._count + 1
		if (self._count == self._windowsize):
			self.output_twinkl()
			self._count = 0
			for i in range(self._width):
				self._data[i] = 0


	def output_twinkl(self):
		"""output graph to twinkl client"""
		# correct for disproportionately large first and second column
		self._data[0] = self._data[0] / 2.5
		self._data[1] = self._data[1] / 1.5

		abss = numpy.absolute(self._data)

		self._background.clear()
		for col in range(self._width):
			normalized = min(int(abss[col] / (self._height * self._windowsize * 1000)), self._height)
			color = COLORS[normalized-1]
			for row in range(self._height - normalized, self._height):
				set_box(col, row, color[0], color[1], color[2])
		output_channels()


def init_audio(rate):
	"""init sound input to 16bit little endian and user defined sampling rate"""
	ain = alsaaudio.PCM(alsaaudio.PCM_CAPTURE, alsaaudio.PCM_NORMAL)
	ain.setformat(alsaaudio.PCM_FORMAT_S16_LE)
	ain.setrate(rate)

	return ain


def main():
	ain = init_audio(AUDIO_RATE)
	fft_out = Fft_output(WIDTH, HEIGHT, WINDOW_SIZE)

	while True:
		data = ain.read();
		audio = audio_from_raw(data[1])
		fft = numpy.fft.fft(audio)
		fft_out.add(fft)

main()