import sys
import os
import time

startTime = time.time()

NUMBER_OF_CHANNELS = 16
SAMPLE_LENGTH = NUMBER_OF_CHANNELS // 8
IO_BUFFER_SIZE = 1042*1024

try:
	if len(sys.argv) < 2:
		raise ValueError('Too few input arguments.')

	sampleCounter = 0
	inputFileName = sys.argv[1]
	outputDirName = os.path.splitext(inputFileName)[0]

	inputFileSize = os.path.getsize(inputFileName)
	if inputFileSize % SAMPLE_LENGTH != 0:
		raise ValueError('Input file has wrong length.')

	try:
		inputFile = open(inputFileName, 'rb')
		outputFiles = []

		if not os.path.exists(outputDirName):
			os.mkdir(outputDirName)

		for channel in range(0, NUMBER_OF_CHANNELS):
			outputFiles.append(open(outputDirName + "/" + str(channel) + ".dat", 'wb', IO_BUFFER_SIZE))

		while True:
			multiChannelSample = inputFile.read(SAMPLE_LENGTH)
			if multiChannelSample == b'':
				break

			for channel in range(0, NUMBER_OF_CHANNELS):
				bit = (multiChannelSample[channel // 8] >> (channel % 8)) & 1
				outputFiles[channel].write(b'+1\n' if (bit) else b'-1\n')

			sampleCounter += 1

	finally:
		inputFile.close()
		for channel in range(0, NUMBER_OF_CHANNELS):
			outputFiles[channel].close()

	print(str(sampleCounter), " samples were processed.\n")
	print("--- %s seconds ---" % (time.time() - startTime))

except IOError as error:
    print(error, "\n")

except ValueError as error:
	print(error, "\n")

#input("Press ENTER to quit.")