#!/usr/bin/env vpython3
# Copyright 2019 The Chromium Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

from __future__ import print_function

import argparse
import json
import logging
import os
import sys

# TODO(crbug.com/40102479): Adding tools/perf to path. We can remove this when
# we have a wrapper script under tools/perf that sets up import paths more
# nicely.
sys.path.append(os.path.join(os.path.dirname(__file__), '..', '..'))

from core import path_util

path_util.AddPyUtilsToPath()
path_util.AddTracingToPath()

from core.tbmv3 import trace_processor


_CHROMIUM_SRC_PATH = os.path.join(
  os.path.dirname(__file__), '..', '..', '..', '..'
)


def _WriteHistogramSetToFile(histograms, outfile):
  with open(outfile, 'w') as f:
    json.dump(
      histograms.AsDicts(), f, indent=2, sort_keys=True, separators=(',', ': ')
    )
    f.write("\n")


def Main(cli_args):
  parser = argparse.ArgumentParser(
    description='[Experimental] Runs TBMv3 metrics on local traces and '
    'produces histogram json.'
  )
  parser.add_argument(
    '--trace', required=True, help='Trace file you want to compute metric on'
  )
  parser.add_argument(
    '--metric', required=True, help=('Name of the metric you want to run')
  )
  parser.add_argument(
    '--trace-processor-path',
    help='Path to trace processor shell. '
    'Default: Binary downloaded from cloud storage.',
  )
  parser.add_argument(
    '--outfile',
    default='results.json',
    help='Path to output file. Default: %(default)s',
  )
  args = parser.parse_args(cli_args)

  histograms = trace_processor.RunMetric(
    args.trace_processor_path, args.trace, args.metric
  )
  _WriteHistogramSetToFile(histograms, args.outfile)
  logging.info('JSON result created in file://%s' % (args.outfile))


if __name__ == '__main__':
  sys.exit(Main(sys.argv[1:]))