#!/usr/bin/env python                                                                                                                                                                            
# Copyright (C) The Arvados Authors. All rights reserved.
#
# SPDX-License-Identifier: Apache-2.0

import arvados
import hashlib
import os

arvados.job_setup.one_task_per_input_file(if_sequence=0, and_end_task=True, input_as_path=True)

this_job = arvados.current_job()
this_task = arvados.current_task()

if 'algorithm' in this_job['script_parameters']:
    alg = this_job['script_parameters']['algorithm']
else:
    alg = 'md5'
digestor = hashlib.new(alg)

input_file = arvados.get_task_param_mount('input')

with open(input_file) as f:
    while True:
        buf = f.read(2**20)
        if len(buf) == 0:
            break
        digestor.update(buf)

hexdigest = digestor.hexdigest()

file_name = '/'.join(this_task['parameters']['input'].split('/')[1:])

out = arvados.CollectionWriter()
out.set_current_file_name("md5sum.txt")
out.write("%s %s\n" % (hexdigest, file_name))
this_task.set_output(out.finish())