#!/usr/bin/env python
# Copyright (c) 2016, the R8 project authors. Please see the AUTHORS file
# for details. All rights reserved. Use of this source code is governed by a
# BSD-style license that can be found in the LICENSE file.

# Script for downloading from x20 a dependency in the same way we use cloud
# storage.

import optparse
import os
import shutil
import subprocess
import sys
import tarfile
import utils

GMSCORE_DEPS = '/google/data/ro/teams/gmscore-size/deps'

def parse_options():
  return optparse.OptionParser().parse_args()

def extract_dir(filename):
  return filename[0:len(filename) - len('.tar.gz')]

def unpack_archive(filename):
  dest_dir = extract_dir(filename)
  if os.path.exists(dest_dir):
    print 'Deleting existing dir %s' % dest_dir
    shutil.rmtree(dest_dir)
  dirname = os.path.dirname(os.path.abspath(filename))
  with tarfile.open(filename, 'r:gz') as tar:
    tar.extractall(path=dirname)

def Main():
  (options, args) = parse_options()
  assert len(args) == 1
  sha1_file = args[0]
  dest = sha1_file[:-5]
  print 'Ensuring %s' % dest
  with open(sha1_file, 'r') as input_sha:
    sha1 = input_sha.readline()
  if os.path.exists(dest) and utils.get_sha1(dest) == sha1:
    print 'sha1 matches, not downloading'
    dest_dir = extract_dir(dest)
    if os.path.exists(dest_dir):
      print 'destination directory exists, no extraction'
    else:
      unpack_archive(dest)
    return
  src = os.path.join(GMSCORE_DEPS, sha1)
  if not os.path.exists(src):
    print 'File (%s) does not exist on x20' % src
  print 'Downloading %s to %s' % (src, dest)
  shutil.copyfile(src, dest)
  unpack_archive(dest)

if __name__ == '__main__':
  sys.exit(Main())