#!/usr/bin/env python
from __future__ import print_function, unicode_literals
import argparse
import cchardet


def read_chunks(f, chunk_size):
    chunk = f.read(chunk_size)
    while chunk:
        yield chunk
        chunk = f.read(chunk_size)


def main():
    parser = argparse.ArgumentParser()
    parser.add_argument('files', nargs='+', help="Files to detect encoding of", type=argparse.FileType('r'))
    parser.add_argument('--chunk-size', type=int, default=(256 * 1024))
    args = parser.parse_args()

    for f in args.files:
        detector = cchardet.UniversalDetector()
        for chunk in read_chunks(f, args.chunk_size):
            detector.feed(chunk)
        detector.close()
        print('{file.name}: {result[encoding]} with confidence {result[confidence]}'.format(
            file=f,
            result=detector.result
        ))


if __name__ == '__main__':
    main()