#!/usr/bin/python
# -*- coding: utf-8 -*-
"""A small filter that converts between various byte-encodings of Unicode text.

Default behavior translates Unicode-escaped text ("\u2603") to UTF-8 ("☃") to
better read Python repr() output.
"""
from __future__ import unicode_literals

import io
import optparse
import sys

def getopt():
	parser = optparse.OptionParser(__doc__)
	parser.add_option(
		'-i',
		'--input',
		dest='input_encoding',
		default='utf-8',
		help='Input encoding.  [default: %default]',
	)
	parser.add_option(
		'-o',
		'--output',
		dest='output_encoding',
		default='utf-8',
		help='Output encoding.  [default: %default]',
	)
	options, args = parser.parse_args()

	if not args:
		args = ['/dev/stdin']
	
	return args, options

def show_unicode(infiles, input_encoding='utf-8', output_encoding='utf-8'):
	output = io.open(sys.stdout.fileno(), 'w', encoding=output_encoding)
	for arg in infiles:
		input = io.open(arg, 'r', encoding=input_encoding)
		for line in input:
			line = line.encode('ascii', 'backslashreplace')
			line = line.decode('unicode_escape')
			output.write(line)
	output.flush()

def main():
	args, options = getopt()
	return show_unicode(args, **vars(options))

if __name__ == '__main__':
	exit(main())