# Copyright 2014 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 collections

from telemetry.web_perf.metrics import timeline_based_metric
from telemetry.value import scalar


class LoadTimesTimelineMetric(timeline_based_metric.TimelineBasedMetric):
  def __init__(self):
    super(LoadTimesTimelineMetric, self).__init__()
    self.report_main_thread_only = True

  def AddResults(self, model, renderer_thread, interaction_records, results):
    assert model
    assert len(interaction_records) == 1, (
      'LoadTimesTimelineMetric cannot compute metrics for more than 1 time '
      'range.')
    interaction_record = interaction_records[0]
    if self.report_main_thread_only:
      thread_filter = 'CrRendererMain'
    else:
      thread_filter = None

    events_by_name = collections.defaultdict(list)
    renderer_process = renderer_thread.parent

    for thread in renderer_process.threads.itervalues():

      if thread_filter and not thread.name in thread_filter:
        continue

      thread_name = thread.name.replace('/','_')
      for e in thread.IterAllSlicesInRange(interaction_record.start,
                                           interaction_record.end):
        events_by_name[e.name].append(e)

      for event_name, event_group in events_by_name.iteritems():
        times = [event.self_time for event in event_group]
        total = sum(times)
        biggest_jank = max(times)

        # Results objects cannot contain the '.' character, so remove that here.
        sanitized_event_name = event_name.replace('.', '_')

        full_name = thread_name + '|' + sanitized_event_name
        results.AddValue(scalar.ScalarValue(
            results.current_page, full_name, 'ms', total))
        results.AddValue(scalar.ScalarValue(
            results.current_page, full_name + '_max', 'ms', biggest_jank))
        results.AddValue(scalar.ScalarValue(
            results.current_page, full_name + '_avg', 'ms', total / len(times)))

    for counter_name, counter in renderer_process.counters.iteritems():
      total = sum(counter.totals)

      # Results objects cannot contain the '.' character, so remove that here.
      sanitized_counter_name = counter_name.replace('.', '_')

      results.AddValue(scalar.ScalarValue(
          results.current_page, sanitized_counter_name, 'count', total))
      results.AddValue(scalar.ScalarValue(
          results.current_page, sanitized_counter_name + '_avg', 'count',
          total / float(len(counter.totals))))

# We want to generate a consistant picture of our thread usage, despite
# having several process configurations (in-proc-gpu/single-proc).
# Since we can't isolate renderer threads in single-process mode, we
# always sum renderer-process threads' times. We also sum all io-threads
# for simplicity.
TimelineThreadCategories =  {
  "Chrome_InProcGpuThread": "GPU",
  "CrGpuMain"             : "GPU",
  "AsyncTransferThread"   : "GPU_transfer",
  "CrBrowserMain"         : "browser",
  "Browser Compositor"    : "browser",
  "CrRendererMain"        : "renderer_main",
  "Compositor"            : "renderer_compositor",
  "IOThread"              : "IO",
  "CompositorRasterWorker": "raster",
  "DummyThreadName1"      : "other",
  "DummyThreadName2"      : "total_fast_path",
  "DummyThreadName3"      : "total_all"
}

_MatchBySubString = ["IOThread", "CompositorRasterWorker"]

AllThreads = TimelineThreadCategories.values()
NoThreads = []
FastPathThreads = ["GPU", "renderer_compositor", "browser", "IO"]

ReportMainThreadOnly = ["renderer_main"]
ReportFastPathResults = AllThreads
ReportFastPathDetails = NoThreads
ReportSilkResults = ["renderer_main", "total_all"]
ReportSilkDetails = ["renderer_main"]

# TODO(epenner): Thread names above are likely fairly stable but trace names
# could change. We should formalize these traces to keep this robust.
OverheadTraceCategory = "trace_event_overhead"
OverheadTraceName = "overhead"
FrameTraceName = "::SwapBuffers"
FrameTraceThreadName = "renderer_compositor"


def ClockOverheadForEvent(event):
  if (event.category == OverheadTraceCategory and
      event.name == OverheadTraceName):
    return event.duration
  else:
    return 0

def CpuOverheadForEvent(event):
  if (event.category == OverheadTraceCategory and
      event.thread_duration):
    return event.thread_duration
  else:
    return 0

def ThreadCategoryName(thread_name):
  thread_category = "other"
  for substring, category in TimelineThreadCategories.iteritems():
    if substring in _MatchBySubString and substring in thread_name:
      thread_category = category
  if thread_name in TimelineThreadCategories:
    thread_category = TimelineThreadCategories[thread_name]
  return thread_category

def ThreadTimeResultName(thread_category):
  return "thread_" + thread_category + "_clock_time_per_frame"

def ThreadCpuTimeResultName(thread_category):
  return "thread_" + thread_category + "_cpu_time_per_frame"

def ThreadDetailResultName(thread_category, detail):
  detail_sanitized = detail.replace('.','_')
  return "thread_" + thread_category + "|" + detail_sanitized


class ResultsForThread(object):
  def __init__(self, model, record_ranges, name):
    self.model = model
    self.toplevel_slices = []
    self.all_slices = []
    self.name = name
    self.record_ranges = record_ranges

  @property
  def clock_time(self):
    clock_duration = sum([x.duration for x in self.toplevel_slices])
    clock_overhead = sum([ClockOverheadForEvent(x) for x in self.all_slices])
    return clock_duration - clock_overhead

  @property
  def cpu_time(self):
    cpu_duration = 0
    cpu_overhead = sum([CpuOverheadForEvent(x) for x in self.all_slices])
    for x in self.toplevel_slices:
      # Only report thread-duration if we have it for all events.
      #
      # A thread_duration of 0 is valid, so this only returns 0 if it is None.
      if x.thread_duration == None:
        if not x.duration:
          continue
        else:
          return 0
      else:
        cpu_duration += x.thread_duration
    return cpu_duration - cpu_overhead

  def SlicesInActions(self, slices):
    slices_in_actions = []
    for event in slices:
      for record_range in self.record_ranges:
        if record_range.ContainsInterval(event.start, event.end):
          slices_in_actions.append(event)
          break
    return slices_in_actions

  def AppendThreadSlices(self, thread):
    self.all_slices.extend(self.SlicesInActions(thread.all_slices))
    self.toplevel_slices.extend(self.SlicesInActions(thread.toplevel_slices))

  def AddResults(self, num_frames, results):
    cpu_per_frame = (float(self.cpu_time) / num_frames) if num_frames else 0
    results.AddValue(scalar.ScalarValue(
        results.current_page, ThreadCpuTimeResultName(self.name),
        'ms', cpu_per_frame))

  def AddDetailedResults(self, num_frames, results):
    slices_by_category = collections.defaultdict(list)
    for s in self.all_slices:
      slices_by_category[s.category].append(s)
    all_self_times = []
    for category, slices_in_category in slices_by_category.iteritems():
      self_time = sum([x.self_time for x in slices_in_category])
      all_self_times.append(self_time)
      self_time_result = (float(self_time) / num_frames) if num_frames else 0
      results.AddValue(scalar.ScalarValue(
          results.current_page, ThreadDetailResultName(self.name, category),
          'ms', self_time_result))
    all_measured_time = sum(all_self_times)
    all_action_time = \
        sum([record_range.bounds for record_range in self.record_ranges])
    idle_time = max(0, all_action_time - all_measured_time)
    idle_time_result = (float(idle_time) / num_frames) if num_frames else 0
    results.AddValue(scalar.ScalarValue(
        results.current_page, ThreadDetailResultName(self.name, "idle"),
        'ms', idle_time_result))


class ThreadTimesTimelineMetric(timeline_based_metric.TimelineBasedMetric):
  def __init__(self):
    super(ThreadTimesTimelineMetric, self).__init__()
    # Minimal traces, for minimum noise in CPU-time measurements.
    self.results_to_report = AllThreads
    self.details_to_report = NoThreads

  def CountSlices(self, slices, substring):
    count = 0
    for event in slices:
      if substring in event.name:
        count += 1
    return count

  def AddResults(self, model, _, interaction_records, results):
    # Set up each thread category for consistant results.
    thread_category_results = {}
    for name in TimelineThreadCategories.values():
      thread_category_results[name] = ResultsForThread(
        model, [r.GetBounds() for r in interaction_records], name)

    # Group the slices by their thread category.
    for thread in model.GetAllThreads():
      thread_category = ThreadCategoryName(thread.name)
      thread_category_results[thread_category].AppendThreadSlices(thread)

    # Group all threads.
    for thread in model.GetAllThreads():
      thread_category_results['total_all'].AppendThreadSlices(thread)

    # Also group fast-path threads.
    for thread in model.GetAllThreads():
      if ThreadCategoryName(thread.name) in FastPathThreads:
        thread_category_results['total_fast_path'].AppendThreadSlices(thread)

    # Calculate the number of frames.
    frame_slices = thread_category_results[FrameTraceThreadName].all_slices
    num_frames = self.CountSlices(frame_slices, FrameTraceName)

    # Report the desired results and details.
    for thread_results in thread_category_results.values():
      if thread_results.name in self.results_to_report:
        thread_results.AddResults(num_frames, results)
      # TOOD(nduca): When generic results objects are done, this special case
      # can be replaced with a generic UI feature.
      if thread_results.name in self.details_to_report:
        thread_results.AddDetailedResults(num_frames, results)