#!/usr/bin/env python

# Copyright 2017 The LUCI Authors. All rights reserved.
# Use of this source code is governed under the Apache License, Version 2.0
# that can be found in the LICENSE file.

"""Bootstrap script to clone and forward to the recipe engine tool.

*******************
** DO NOT MODIFY **
*******************

This is a copy of https://github.com/luci/recipes-py/blob/master/doc/recipes.py.
To fix bugs, fix in the github repo then run the autoroller.
"""

import os

#### PER-REPO CONFIGURATION (editable) ####
# The root of the repository relative to the directory of this file.
REPO_ROOT = os.path.join(os.pardir, os.pardir)
# The path of the recipes.cfg file relative to the root of the repository.
RECIPES_CFG = os.path.join('infra', 'config', 'recipes.cfg')
#### END PER-REPO CONFIGURATION ####

import argparse
import json
import logging
import random
import subprocess
import sys
import time
import urlparse

from collections import namedtuple

from cStringIO import StringIO

# The dependency entry for the recipe_engine in the client repo's recipes.cfg
#
# url (str) - the url to the engine repo we want to use.
# revision (str) - the git revision for the engine to get.
# path_override (str) - the subdirectory in the engine repo we should use to
#   find it's recipes.py entrypoint. This is here for completeness, but will
#   essentially always be empty. It would be used if the recipes-py repo was
#   merged as a subdirectory of some other repo and you depended on that
#   subdirectory.
# branch (str) - the branch to fetch for the engine as an absolute ref (e.g.
#   refs/heads/master)
# repo_type ("GIT"|"GITILES") - An ignored enum which will be removed soon.
EngineDep = namedtuple('EngineDep',
                       'url revision path_override branch repo_type')


class MalformedRecipesCfg(Exception):
  def __init__(self, msg, path):
    super(MalformedRecipesCfg, self).__init__('malformed recipes.cfg: %s: %r'
                                              % (msg, path))


def parse(repo_root, recipes_cfg_path):
  """Parse is a lightweight a recipes.cfg file parser.

  Args:
    repo_root (str) - native path to the root of the repo we're trying to run
      recipes for.
    recipes_cfg_path (str) - native path to the recipes.cfg file to process.

  Returns (as tuple):
    engine_dep (EngineDep): The recipe_engine dependency.
    recipes_path (str) - native path to where the recipes live inside of the
      current repo (i.e. the folder containing `recipes/` and/or
      `recipe_modules`)
  """
  with open(recipes_cfg_path, 'rU') as fh:
    pb = json.load(fh)

  try:
    if pb['api_version'] != 2:
      raise MalformedRecipesCfg('unknown version %d' % pb['api_version'],
                                recipes_cfg_path)

    engine = pb['deps']['recipe_engine']

    if 'url' not in engine:
      raise MalformedRecipesCfg(
        'Required field "url" in dependency "recipe_engine" not found',
        recipes_cfg_path)

    engine.setdefault('revision', '')
    engine.setdefault('path_override', '')
    engine.setdefault('branch', 'refs/heads/master')
    recipes_path = pb.get('recipes_path', '')

    # TODO(iannucci): only support absolute refs
    if not engine['branch'].startswith('refs/'):
      engine['branch'] = 'refs/heads/' + engine['branch']

    engine.setdefault('repo_type', 'GIT')
    if engine['repo_type'] not in ('GIT', 'GITILES'):
      raise MalformedRecipesCfg(
        'Unsupported "repo_type" value in dependency "recipe_engine"',
        recipes_cfg_path)

    recipes_path = os.path.join(
      repo_root, recipes_path.replace('/', os.path.sep))
    return EngineDep(**engine), recipes_path
  except KeyError as ex:
    raise MalformedRecipesCfg(ex.message, recipes_cfg_path)


GIT = 'git.bat' if sys.platform.startswith(('win', 'cygwin')) else 'git'


def _subprocess_call(argv, **kwargs):
  logging.info('Running %r', argv)
  return subprocess.call(argv, **kwargs)


def _git_check_call(argv, **kwargs):
  argv = [GIT]+argv
  logging.info('Running %r', argv)
  subprocess.check_call(argv, **kwargs)


def _git_output(argv, **kwargs):
  argv = [GIT]+argv
  logging.info('Running %r', argv)
  return subprocess.check_output(argv, **kwargs)


def parse_args(argv):
  """This extracts a subset of the arguments that this bootstrap script cares
  about. Currently this consists of:
    * an override for the recipe engine in the form of `-O recipe_engin=/path`
    * the --package option.
  """
  PREFIX = 'recipe_engine='

  p = argparse.ArgumentParser(add_help=False)
  p.add_argument('-O', '--project-override', action='append')
  p.add_argument('--package', type=os.path.abspath)
  args, _ = p.parse_known_args(argv)
  for override in args.project_override or ():
    if override.startswith(PREFIX):
      return override[len(PREFIX):], args.package
  return None, args.package


def checkout_engine(engine_path, repo_root, recipes_cfg_path):
  dep, recipes_path = parse(repo_root, recipes_cfg_path)

  url = dep.url

  if not engine_path and url.startswith('file://'):
    engine_path = urlparse.urlparse(url).path

  if not engine_path:
    revision = dep.revision
    subpath = dep.path_override
    branch = dep.branch

    # Ensure that we have the recipe engine cloned.
    engine = os.path.join(recipes_path, '.recipe_deps', 'recipe_engine')
    engine_path = os.path.join(engine, subpath)

    with open(os.devnull, 'w') as NUL:
      # Note: this logic mirrors the logic in recipe_engine/fetch.py
      _git_check_call(['init', engine], stdout=NUL)

      try:
        _git_check_call(['rev-parse', '--verify', '%s^{commit}' % revision],
                        cwd=engine, stdout=NUL, stderr=NUL)
      except subprocess.CalledProcessError:
        _git_check_call(['fetch', url, branch], cwd=engine, stdout=NUL,
                        stderr=NUL)

    try:
      _git_check_call(['diff', '--quiet', revision], cwd=engine)
    except subprocess.CalledProcessError:
      _git_check_call(['reset', '-q', '--hard', revision], cwd=engine)

  return engine_path


def main():
  if '--verbose' in sys.argv:
    logging.getLogger().setLevel(logging.INFO)

  args = sys.argv[1:]
  engine_override, recipes_cfg_path = parse_args(args)

  if recipes_cfg_path:
    # calculate repo_root from recipes_cfg_path
    repo_root = os.path.dirname(
      os.path.dirname(
        os.path.dirname(recipes_cfg_path)))
  else:
    # find repo_root with git and calculate recipes_cfg_path
    repo_root = (_git_output(
      ['rev-parse', '--show-toplevel'],
      cwd=os.path.abspath(os.path.dirname(__file__))).strip())
    repo_root = os.path.abspath(repo_root)
    recipes_cfg_path = os.path.join(repo_root, 'infra', 'config', 'recipes.cfg')
    args = ['--package', recipes_cfg_path] + args

  engine_path = checkout_engine(engine_override, repo_root, recipes_cfg_path)

  return _subprocess_call([
      sys.executable, '-u',
      os.path.join(engine_path, 'recipes.py')] + args)


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