# Copyright (c) 2020, the Dart 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.

import re

from contextlib import contextmanager
from recipe_engine import recipe_api

class BuildApi(recipe_api.RecipeApi):
  """Recipe module for building the Dart SDK with and without goma."""

  def __init__(self, properties, *args, **kwargs):
    super(BuildApi, self).__init__(*args, **kwargs)
    self._timeout = properties.timeout or 50 * 60  # 50 minutes

    self._goma_enabled = not properties.disable_goma
    # No need to download goma if it's disabled.
    self._goma_ensured = properties.disable_goma

  def build(self, name='build dart', args=None):
    """Builds dart using the specified args"""
    if not args:  # pragma: no cover
      args = []
    with self.m.depot_tools.on_path(), self.m.context(
        cwd=self.m.path['checkout']):
      if self._goma_enabled:
        self._build_with_goma(name, args)
      else:
        if '--no-goma' not in args:
          args = args + ['--no-goma']
        self._run_build_py(name, args)

  def gn(self, name='gn', args=None):
    """Runs gn.py using the specified args"""
    with self.m.context(env=self._build_env):
      if not self._goma_enabled and '--no-goma' not in args:
        args = args + ['--no-goma']
      gn_py = self.m.path['checkout'].join('tools', 'gn.py')
      self.m.step(name, ['python3', '-u', gn_py] + args)

  @contextmanager
  def goma(self):
    self._ensure_goma()
    with self.m.context(env=self._build_env):
      try:
        self._goma('restart')
        try:
          yield
        finally:
          self._goma('stat')
      finally:
        self._goma('stop')

  @property
  def _build_env(self):
    if not self._goma_enabled:
      return {}
    self._ensure_goma()
    return {
        'GOMA_DIR': self._goma_dir,
    }

  @property
  def _goma_env(self):
    env = {
        'GOMA_DIR':
            self._goma_dir,
        'GOMA_CACHE_DIR':
            self._goma_cache,
        'GOMACTL_CRASH_REPORT_ID_FILE':
            self.m.path['cleanup'].join('crash_report_id'),
        'GOMA_DUMP_STATS_FILE':
            self.m.path['cleanup'].join('goma_stats'),
        'GOMA_HERMETIC':
            'error',
        'GOMA_SERVER_HOST':
            'goma.chromium.org',
    }
    if self.m.platform.is_linux:
      env['GOMA_ARBITRARY_TOOLCHAIN_SUPPORT'] = 'true'
    return env

  def _run_build_py(self, name, args):
    with self.m.context(infra_steps=False):
      build_py = self.m.path['checkout'].join('tools', 'build.py')
      self.m.step(
          name, ['python3', '-u', build_py] + args, timeout=self._timeout)

  def _build_with_goma(self, name, args):
    with self.goma():
      args = args + ['--no-start-goma', '-j200']
      self._run_build_py(name, args)

  def _ensure_goma(self):
    if not self._goma_ensured:
      self._goma_root = self.m.path['cache'].join('goma')
      self._goma_dir = self._goma_root.join('client')
      self._goma_ctl = self._goma_dir.join('goma_ctl.py')
      safe_buildername = re.sub(r'[^a-zA-Z0-9]', '_',
                                self.m.buildbucket.builder_name)
      self._goma_cache = self._goma_root.join('data', safe_buildername)
      self.m.file.ensure_directory('goma cache directory', self._goma_cache)
      goma_package = r'infra_internal/goma/client/${platform}'
      ensure_file = self.m.cipd.EnsureFile().add_package(
          goma_package, 'release')
      self.m.cipd.ensure(self._goma_dir, ensure_file)
      self._goma_ensured = True

  def _goma(self, cmd):
    with self.m.context(env=self._goma_env):
      self.m.step(
          name='goma %s' % cmd,
          cmd=['python3', self._goma_ctl, cmd],
          infra_step=True)