import hashlib
import os
from io import BytesIO


def hash_file(f: BytesIO, buffer_size=65536, algo='SH1') -> str:
    """
    Generate the MD5 Hash of the file and return

    f of 
    buffer_size in MB

    """

    algorithm = ['MD5', 'SH1']
    assert algo in algorithm

    if algo == 'MD5':
        algo = hashlib.md5()
    else:
        algo = hashlib.sha1()

    buffer_size = buffer_size * 1024 * 1024

    while True:
        data = f.read(buffer_size)
        if not data:
            break
        algo.update(data)

    algohex = algo.hexdigest()
    f.seek(0)

    return algohex