# Copyright 2018 The Chromium Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

import os

from page_sets.rendering import rendering_shared_state as shared_state
from page_sets.rendering import rendering_story
from page_sets.rendering import story_tags
from page_sets.system_health import platforms

from telemetry import story

from py_utils import discover


class RenderingStorySet(story.StorySet):
  """Stories related to rendering."""

  def __init__(self,
               platform,
               scroll_forever=False,
               disable_tracing=False,
               os_name=None):
    super(RenderingStorySet, self).__init__(
        archive_data_file=('../data/rendering_%s.json' % platform),
        cloud_storage_bucket=story.PARTNER_BUCKET)

    assert platform in platforms.ALL_PLATFORMS
    self._platform = platform

    if platform == platforms.MOBILE:
      shared_page_state_class = shared_state.MobileRenderingSharedState
    elif platform == platforms.DESKTOP:
      shared_page_state_class = shared_state.DesktopRenderingSharedState
    else:
      shared_page_state_class = shared_state.RenderingSharedState

    self.scroll_forever = scroll_forever

    # For pinch zoom page sets, set default to desktop scale factor
    self.target_scale_factor = 4.0

    for story_class in _IterAllRenderingStoryClasses():
      if (story_class.ABSTRACT_STORY or not _IsSupportedPlatform(
          platform, story_class.SUPPORTED_PLATFORMS, os_name)
          or story_class.DISABLE_TRACING != disable_tracing):
        continue

      required_args = []
      if story_class.EXTRA_BROWSER_ARGUMENTS:
        required_args += story_class.EXTRA_BROWSER_ARGUMENTS

      name_suffix = ''
      if (story_class.TAGS and
          story_tags.USE_FAKE_CAMERA_DEVICE in story_class.TAGS):
        required_args += [
            # Use a fake camera showing a placeholder video.
            '--use-fake-device-for-media-stream',
            # Don't prompt for camera access. (Conveniently,
            # this takes precedent over --deny-permission-prompts.)
            '--use-fake-ui-for-media-stream',
        ]

      if story_class.TAGS and story_tags.BACKDROP_FILTER in story_class.TAGS:
        # Experimental web platform features must be enabled in order for the
        # 'backdrop-filter' CSS property to work.
        required_args.append('--enable-experimental-web-platform-features')

      # TODO(crbug.com/40629637): We must run without out-of-process
      # rasterization until that branch is implemented for YUV decoding.
      if (story_class.TAGS and story_tags.IMAGE_DECODING in story_class.TAGS
          and story_tags.GPU_RASTERIZATION in story_class.TAGS):
        required_args += ['--enable-gpu-rasterization']
        # Run RGB decoding with GPU rasterization (to be most comparable to YUV)
        self.AddStory(story_class(
            page_set=self,
            extra_browser_args=required_args +
                ['--disable-yuv-image-decoding'],
            shared_page_state_class=shared_page_state_class,
            name_suffix='_rgb_and_gpu_rasterization'))
        # Also run YUV decoding story with GPU rasterization.
        name_suffix = '_yuv_and_gpu_rasterization'

      self.AddStory(story_class(
          page_set=self,
          extra_browser_args=required_args,
          shared_page_state_class=shared_page_state_class,
          name_suffix=name_suffix))

  def GetAbridgedStorySetTagFilter(self):
    if self._platform == platforms.DESKTOP:
      if os.name == 'nt':
        return 'representative_win_desktop'
      # There is no specific tag for linux, cros, etc,
      # so just use mac's.
      return 'representative_mac_desktop'
    if self._platform == platforms.MOBILE:
      return 'representative_mobile'
    raise RuntimeError('Platform {} is not in the list of expected platforms.')


class DesktopRenderingStorySet(RenderingStorySet):
  """Desktop stories related to rendering.

  Note: This story set is only intended to be used for recording stories via
  tools/perf/record_wpr. If you would like to use it in a benchmark, please use
  the generic RenderingStorySet class instead (you'll need to override the
  CreateStorySet method of your benchmark).
  """
  def __init__(self):
    super(DesktopRenderingStorySet, self).__init__(platform='desktop')


def _IterAllRenderingStoryClasses():
  start_dir = os.path.dirname(os.path.abspath(__file__))
  # Sort the classes by their names so that their order is stable and
  # deterministic.
  for _, cls in sorted(discover.DiscoverClasses(
      start_dir=start_dir,
      top_level_dir=os.path.dirname(start_dir),
      base_class=rendering_story.RenderingStory).items()):
    yield cls


# Checks that the OS is within the SUPPORTED_PLATFORMS for the story, as while
# the top-level benchmark supports multiple platforms, individual stories may
# only support a sub-set of OSes for those platforms.
def _IsSupportedPlatform(platform, story_supported_platforms, os_name):
  if platform in story_supported_platforms:
    return True

  if platform == platforms.DESKTOP and os_name is not None:
    # TODO(jonross): port all rendering benchmarks to use stories.exceptions
    if story_supported_platforms in (platforms.MOBILE, platforms.MOBILE_ONLY,
                                     platforms.NO_PLATFORMS):
      return False
    # Stories can have multiple separate `_TestConditionByPlatformList` set as
    # expectations, check in each. For details see
    # third_party/catapult/telemetry/telemetry/story/expectations.py
    for supported_platform in story_supported_platforms:
      if os_name in supported_platform.GetSupportedPlatformNames():
        return True
  return False