#!/usr/bin/env python
# Copyright 2014 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

import argparse
import os
import subprocess
import sys
import tempfile
import zipfile

BINARY_FOR_PLATFORM = {
    "linux-x64" : "dart_snapshotter",
    "mac-x64": "dart_snapshotter",
}

CURRENT_PATH = os.path.dirname(os.path.realpath(__file__))
sys.path.insert(0, os.path.join(CURRENT_PATH, "pylib"))
import gs

PREBUILT_FILE_PATH = os.path.join(CURRENT_PATH, "prebuilt", "dart_snapshotter")


def download(tools_directory, version_file):
  stamp_path = os.path.join(PREBUILT_FILE_PATH, "VERSION")

  version_path = os.path.join(CURRENT_PATH, version_file)
  with open(version_path) as version_file:
    version = version_file.read().strip()

  try:
    with open(stamp_path) as stamp_file:
      current_version = stamp_file.read().strip()
      if current_version == version:
        return 0  # Already have the right version.
  except IOError:
    pass  # If the stamp file does not exist we need to download new binaries.

  if sys.platform.startswith("linux"):
    platforms = ["linux-x64"]
  elif sys.platform.startswith("darwin"):
    platforms = ["mac-x64"]
  else:
    print "No prebuilt dart_snapshotter available for %s" % sys.platform
    return 0

  for platform in platforms:
    download_version_for_platform(version, platform, tools_directory)

  with open(stamp_path, 'w') as stamp_file:
    stamp_file.write(version)
  return 0

def download_version_for_platform(version, platform, tools_directory):
  find_depot_tools_path = os.path.join(CURRENT_PATH, tools_directory)
  sys.path.insert(0, find_depot_tools_path)
  # pylint: disable=F0401
  import find_depot_tools
  depot_tools_path = find_depot_tools.add_depot_tools_to_path()

  basename = platform + ".zip"
  gs_path = "gs://mojo/dart_snapshotter/" + version + "/" + basename

  with tempfile.NamedTemporaryFile() as temp_zip_file:
    gs.download_from_public_bucket(gs_path, temp_zip_file.name,
                                   depot_tools_path)
    binary_name = BINARY_FOR_PLATFORM[platform]
    output_dir = os.path.join(PREBUILT_FILE_PATH, platform)
    with zipfile.ZipFile(temp_zip_file.name) as z:
      zi = z.getinfo(binary_name)
      mode = zi.external_attr >> 16
      z.extract(zi, output_dir)
      os.chmod(os.path.join(output_dir, binary_name), mode)


def main():
  parser = argparse.ArgumentParser(
      description="Download dart_snapshotter binaries from google storage")
  parser.add_argument("--tools-directory",
                      dest="tools_directory",
                      metavar="<tools-directory>",
                      type=str,
                      required=True,
                      help="Path to the directory containing "
                           "find_depot_tools.py, specified as a relative path "
                           "from the location of this file.")
  parser.add_argument("--version-file",
                      dest="version_file",
                      metavar="<version-file>",
                      type=str,
                      default="../VERSION",
                      help="Path to the file containing the version of the "
                           "dart_snapshotter to be fetched, specified as a"
                           "relative path from the location of this file "
                           "(default: %(default)s).")
  args = parser.parse_args()
  return download(args.tools_directory, args.version_file)

if __name__ == "__main__":
  sys.exit(main())