#!/usr/bin/python
# Copyright (c) 2009 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 os
import re
import subprocess
import sys

# Find depot_tools in PATH, append it to sys.path so we can import.
paths = os.environ.get("PATH")
for path in paths.split(':'):
  if not path.endswith("depot_tools"):
    continue
  sys.path.append(path)
  break

import gclient_scm
import presubmit_support

def Backquote(cmd, cwd=None):
  """Like running `cmd` in a shell script."""
  return subprocess.Popen(cmd,
                          cwd=cwd,
                          stdout=subprocess.PIPE).communicate()[0].strip()


class ChangeOptions:
  def __init__(self, commit=None, upstream_branch=None):
    self.commit = commit
    self.verbose = None
    self.default_presubmit = None
    self.may_prompt = None

    root = os.path.abspath(Backquote(['git', 'rev-parse', '--show-cdup']))
    if not root:
      raise Exception("Could not get root directory.")
    log = Backquote(['git', 'show', '--name-only',
                     '--pretty=format:%H%n%s%n%n%b'])
    m = re.match(r'^(\w+)\n(.*)$', log, re.MULTILINE|re.DOTALL)
    if not m:
      raise Exception("Could not parse log message: %s" % log)
    name = m.group(1)
    description = m.group(2)
    files = gclient_scm.CaptureGitStatus([root], upstream_branch)
    issue = Backquote(['git', 'cl', 'status', '--field=id'])
    patchset = None
    self.change = presubmit_support.GitChange(name, description, root, files,
                                              issue, patchset)


# Ensure we were called with the necessary number of arguments.
program_name = os.path.basename(sys.argv[0])
if len(sys.argv) < 2:
  raise Exception("usage: %s [upstream branch]" % program_name)

# Get arguments from how we were called.
commit = (program_name == 'pre-cl-dcommit')
upstream_branch = sys.argv[1]

# Create our options based on the command-line args and the current checkout.
options = ChangeOptions(commit=commit, upstream_branch=upstream_branch)

# Run the presubmit checks.
if presubmit_support.DoPresubmitChecks(options.change,
                                       options.commit,
                                       options.verbose,
                                       sys.stdout,
                                       sys.stdin,
                                       options.default_presubmit,
                                       options.may_prompt):
  sys.exit(0)
else:
  sys.exit(1)