#!/usr/bin/env python
# Copyright 2015 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.

"""Runner for Mojo application benchmarks."""

import argparse
import logging
import sys

from devtoolslib import shell_arguments
from devtoolslib import shell_config


_DESCRIPTION = """Runner for Mojo application benchmarks.

|benchmark_list_file| has to be a valid Python program that sets a |benchmarks|
global variable, containing entries of the following form:

  {
    'name': '<name of the benchmark>',
    'app': '<url of the app to benchmark>',
    'shell-args': [],
    'duration': <duration in seconds>,

    # List of measurements to make.
    'measurements': [
      '<measurement type>/<event category>/<event name>',
    ]
  }

Available measurement types are:

  - 'time_until' - time until the first occurence of the targeted event
  - 'avg_duration' - average duration of the targeted event

|benchmark_list_file| may reference the |target_os| global that will be any of
['android', 'linux'], indicating the system on which the benchmarks are to be
run.
"""

_logger = logging.getLogger()

_BENCHMARK_APP = 'https://core.mojoapps.io/benchmark.mojo'
_CACHE_SERVICE_URL = 'mojo:url_response_disk_cache'

# Additional time in seconds allocated per shell run to accommodate start-up.
# The shell should terminate before hitting this time out, it is an error if it
# doesn't.
_EXTRA_TIMEOUT = 20


def _run_benchmark(shell, shell_args, name, app, duration_seconds, measurements,
                   cold_start, verbose):
  """Runs `benchmark.mojo` in shell with correct arguments, parses and
  presents the benchmark results.
  """
  timeout = duration_seconds + _EXTRA_TIMEOUT
  benchmark_args = []
  benchmark_args.append('--app=' + app)
  benchmark_args.append('--duration=' + str(duration_seconds))
  for measurement in measurements:
    benchmark_args.append(measurement)

  shell_args = list(shell_args)
  shell_args.append(_BENCHMARK_APP)
  shell_args.append('--args-for=%s %s' % (_BENCHMARK_APP,
                                          ' '.join(benchmark_args)))

  if cold_start:
    shell_args.append('--args-for=%s %s' % (_CACHE_SERVICE_URL, '--clear'))

  if verbose:
    print 'shell arguments: ' + str(shell_args)
  print '[ %s ] %s' % (name, 'cold start' if cold_start else 'warm start')
  return_code, output, did_time_out = shell.run_and_get_output(
      shell_args, timeout=timeout)
  output_lines = [line.strip() for line in output.split('\n')]

  if return_code or did_time_out or 'benchmark succeeded' not in output_lines:
    print 'timed out' if did_time_out else 'failed'
    if return_code:
      print 'Return code: ' + str(return_code)
    print 'Output: '
    print output
    print '-' * 72
    return False

  # Echo measurement results.
  for line in output_lines:
    if line.strip().startswith('measurement:'):
      print line
  return True


def main():
  parser = argparse.ArgumentParser(
      formatter_class=argparse.RawDescriptionHelpFormatter,
      description=_DESCRIPTION)
  parser.add_argument('benchmark_list_file', type=file,
                      help='a file listing benchmarks to run')

  # Common shell configuration arguments.
  shell_config.add_shell_arguments(parser)
  script_args = parser.parse_args()
  config = shell_config.get_shell_config(script_args)

  try:
    shell, common_shell_args = shell_arguments.get_shell(config, [])
  except shell_arguments.ShellConfigurationException as e:
    print e
    return 1

  target_os = 'android' if script_args.android else 'linux'
  benchmark_list_params = {"target_os": target_os}
  exec script_args.benchmark_list_file in benchmark_list_params
  benchmark_list = benchmark_list_params['benchmarks']

  succeeded = True
  for benchmark_spec in benchmark_list:
    name = benchmark_spec['name']
    app = benchmark_spec['app']
    duration = benchmark_spec['duration']
    shell_args = benchmark_spec.get('shell-args', []) + common_shell_args
    measurements = benchmark_spec['measurements']
    _run_benchmark(shell, shell_args, name, app, duration, measurements,
                   cold_start=True, verbose=script_args.verbose)
    _run_benchmark(shell, shell_args, name, app, duration, measurements,
                   cold_start=False, verbose=script_args.verbose)

  return 0 if succeeded else 1

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