#!/usr/bin/env python
# Copyright (C) 2017 The Android Open Source Project
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# Generates proto definitions from ftrace format files.
# Arguments:
#   path to ftrace_proto_gen
#   path to input directory full of format files
#   path to output directory for proto definitions files
#   Either:
#    --whitelist PATH : path to a list of events to generate
#    --event EVENT : a single event to generate
#
# Example:
# ./tools/update_protos.py
#    out/linux/ftrace_proto_gen
#   libftrace/test/data/android_seed_N2F62_3.10.49
#   protos/ftrace
#   --whitelist tools/ftrace_proto_gen/event_whitelist


from __future__ import print_function
import argparse
import os
import subprocess
import sys
import tempfile


def command(*args):
  subprocess.check_call(args, stdout=sys.stdout, stderr=sys.stderr)


def get_whitelisted_events(single_event, whitelist_path):
  if single_event:
    return [single_event]

  if whitelist_path:
    with open(whitelist_path) as f:
      s = f.read()
    lines = s.split('\n')
    lines = [line for line in lines if line and not line.startswith('#')]
    return lines

  return []


def main():
  parser = argparse.ArgumentParser(description='Generate protos.')
  parser.add_argument('ftrace_proto_gen',
                      help='an ftrace_proto_gen binary')
  parser.add_argument('input_dir',
                      help='input directory')
  parser.add_argument('output_dir',
                      help='output directory')
  parser.add_argument('--whitelist', dest='whitelist_path',
                      default=None,
                      help='path to whitelist of events')
  parser.add_argument('--event', dest='event',
                      default=None,
                      help='output directory')
  args = parser.parse_args()

  gen_path = args.ftrace_proto_gen
  input_dir = args.input_dir
  output_dir = args.output_dir
  whitelist_path = args.whitelist_path
  single_event = args.event

  if whitelist_path is not None and not os.path.isfile(whitelist_path):
    parser.error('Whitelist file {} does not exist.'.format(whitelist_path))

  if bool(whitelist_path) == bool(single_event):
    parser.error('Exactly one of --whitelist and --event required.')

  if not os.path.isdir(input_dir):
    parser.error('Input directory {} does not exist.'.format(input_dir))
  if not os.path.isdir(output_dir):
    parser.error('Output directory {} does not exist.'.format(output_dir))

  events = get_whitelisted_events(single_event, whitelist_path)

  for event in events:
    proto_file_name = event.split('/')[1] + '.proto'
    input_path = os.path.join(input_dir, event, 'format')
    output_path = os.path.join(output_dir, proto_file_name)
    command(gen_path, input_path, output_path)


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