#!/usr/bin/env python
# Copyright 2017 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.

from os import path as os_path
import platform
import subprocess
import sys
import os

def which(cmd):
    pathenv = os.getenv('PATH')
    for p in pathenv.split(os_path.pathsep):
        p = os_path.join(p, cmd)
        if os_path.exists(p) and os.access(p, os.X_OK):
            return p
    return None

def GetBinaryPath():
  if sys.platform == 'win32':
    nodejs = which('node.exe')
    if nodejs:
      return nodejs
  else:
    nodejs = which('nodejs')
    if nodejs:
      return nodejs
    nodejs = which('node')
    if nodejs:
      return nodejs

  return os_path.join(os_path.dirname(__file__), *{
    'Darwin': ('mac', 'node-darwin-x64', 'bin', 'node'),
    'Linux': ('linux', 'node-linux-x64', 'bin', 'node'),
    'Windows': ('win', 'node.exe'),
  }[platform.system()])


def RunNode(cmd_parts, stdout=None):
  cmd = [GetBinaryPath()] + cmd_parts
  process = subprocess.Popen(
      cmd, cwd=os.getcwd(), stdout=subprocess.PIPE, stderr=subprocess.PIPE)
  stdout, stderr = process.communicate()

  # TODO(crbug.com/1098074): Properly handle the returncode of
  # process defined above. Right now, if the process would exit
  # with a return code of non-zero, but the stderr is empty,
  # we would still pass.
  #
  # However, we can't make this change here yet, as there are
  # various presubmit scripts that rely on the runtime error
  # and are unable to handle a `os.exit` call in this branch.
  # These presubmit scripts need to spawn `subprocesses`
  # themselves to handle the exitcode, before we can make the
  # change here.
  if stderr:
    raise RuntimeError('%s failed: %s' % (cmd, stderr))

  return stdout

if __name__ == '__main__':
  RunNode(sys.argv[1:])