# -*- coding: utf-8 -*-
import hashlib
import argparse

def parse_args():
    parser = argparse.ArgumentParser(description='py_split_hash')
    parser.add_argument('input', help='Input file path')
    parser.add_argument('--algo', help='Input algorithm (md5, sha1, sha224, sha256, sha384, sha512)', default = 'sha1')
    parser.add_argument('--size', help='Split size (1,048,576 10,485,760 104,857,600 1,073,741,824 byte)', default = 1048576)
    return parser.parse_args()

def main():
    args = parse_args()
    inputFile = args.input
    algo = args.algo
    splitSize = int(args.size)
    readBytes = 0
    
    hash = getattr(hashlib, algo)()
    
    with open(inputFile, 'rb') as f:
        while True:
            chunk = f.read(splitSize)
            
            if len(chunk) == 0:
                break
    
            splitDigest = getattr(hashlib, algo)(chunk).hexdigest()
            print(f'{algo}({readBytes}): {splitDigest}')
            hash.update(chunk)
            
            readBytes += splitSize
    
    digest = hash.hexdigest()
    print(f'{algo}: {digest}')

if __name__ == "__main__":
    main()