#!/usr/bin/env python3

import atexit
import argparse
import datetime
import http.server
import os
import shutil
import socketserver
import subprocess
import sys
import time
import webbrowser

ROOT_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))

# This is not required. It's only used as a fallback if no adb is found on the
# PATH. It's fine if it doesn't exist so this script can be copied elsewhere.
HERMETIC_ADB_PATH = ROOT_DIR + '/buildtools/android_sdk/platform-tools/adb'

devnull = open(os.devnull, 'rb')
adb_path = None
procs = []


class ANSI:
  END = '\033[0m'
  BOLD = '\033[1m'
  RED = '\033[91m'
  BLACK = '\033[30m'
  BLUE = '\033[94m'
  BG_YELLOW = '\033[43m'
  BG_BLUE = '\033[44m'


# HTTP Server used to open the trace in the browser.
class HttpHandler(http.server.SimpleHTTPRequestHandler):

  def end_headers(self):
    self.send_header('Access-Control-Allow-Origin', '*')
    return super().end_headers()

  def do_GET(self):
    self.server.last_request = self.path
    return super().do_GET()

  def do_POST(self):
    self.send_error(404, "File not found")


def main():
  atexit.register(kill_all_subprocs_on_exit)
  default_out_dir_str = '~/traces/'
  default_out_dir = os.path.expanduser(default_out_dir_str)

  examples = '\n'.join([
      ANSI.BOLD + 'Examples' + ANSI.END, '  -t 10s -b 32mb sched gfx wm',
      '  -t 5s sched/sched_switch raw_syscalls/sys_enter raw_syscalls/sys_exit',
      '  -c /path/to/full-textual-trace.config', '',
      ANSI.BOLD + 'Long traces' + ANSI.END,
      'If you want to record a hours long trace and stream it into a file ',
      'you need to pass a full trace config and set write_into_file = true.',
      'See https://perfetto.dev/docs/concepts/config#long-traces .'
  ])
  parser = argparse.ArgumentParser(
      epilog=examples, formatter_class=argparse.RawTextHelpFormatter)

  help = 'Output file or directory (default: %s)' % default_out_dir_str
  parser.add_argument('-o', '--out', default=default_out_dir, help=help)

  help = 'Don\'t open in the browser'
  parser.add_argument('-n', '--no-open', action='store_true', help=help)

  grp = parser.add_argument_group(
      'Short options: (only when not using -c/--config)')

  help = 'Trace duration N[s,m,h] (default: trace until stopped)'
  grp.add_argument('-t', '--time', default='0s', help=help)

  help = 'Ring buffer size N[mb,gb] (default: 32mb)'
  grp.add_argument('-b', '--buffer', default='32mb', help=help)

  help = 'Android (atrace) app names (can be specified multiple times)'
  grp.add_argument(
      '-a',
      '--app',
      metavar='Atrace apps',
      action='append',
      default=[],
      help=help)

  help = 'sched, gfx, am, wm (see --list)'
  grp.add_argument('events', metavar='Atrace events', nargs='*', help=help)

  help = 'sched/sched_switch kmem/kmem (see --list-ftrace)'
  grp.add_argument('_', metavar='Ftrace events', nargs='*', help=help)

  help = 'Lists all the categories available'
  grp.add_argument('--list', action='store_true', help=help)

  help = 'Lists all the ftrace events available'
  grp.add_argument('--list-ftrace', action='store_true', help=help)

  section = ('Full trace config (only when not using short options)')
  grp = parser.add_argument_group(section)

  help = 'Can be generated with https://ui.perfetto.dev/#!/record'
  grp.add_argument('-c', '--config', default=None, help=help)
  args = parser.parse_args()

  tstamp = datetime.datetime.now().strftime('%Y-%m-%d_%H-%M')
  fname = '%s.pftrace' % tstamp
  device_file = '/data/misc/perfetto-traces/' + fname

  find_adb()

  if args.list:
    adb('shell', 'atrace', '--list_categories').wait()
    sys.exit(0)

  if args.list_ftrace:
    adb('shell', 'cat /d/tracing/available_events | tr : /').wait()
    sys.exit(0)

  if args.config is not None and not os.path.exists(args.config):
    prt('Config file not found: %s' % args.config, ANSI.RED)
    sys.exit(1)

  if len(args.events) == 0 and args.config is None:
    prt('Must either pass short options (e.g. -t 10s sched) or a --config file',
        ANSI.RED)
    parser.print_help()
    sys.exit(1)

  if args.config is None and args.events and os.path.exists(args.events[0]):
    prt(('The passed event name "%s" is a local file. ' % args.events[0] +
         'Did you mean to pass -c / --config ?'), ANSI.RED)
    sys.exit(1)

  cmd = ['perfetto', '--background', '--txt', '-o', device_file]
  if args.config is not None:
    cmd += ['-c', '-']
  else:
    cmd += ['-t', args.time, '-b', args.buffer]
    for app in args.app:
      cmd += ['--app', app]
    cmd += args.events

  # Perfetto will error out with a proper message if both a config file and
  # short options are specified. No need to replicate that logic.

  # Work out the output file or directory.
  if args.out.endswith('/') or os.path.isdir(args.out):
    host_dir = args.out
    host_file = os.path.join(args.out, fname)
  else:
    host_file = args.out
    host_dir = os.path.dirname(host_file)
    if host_dir == '':
      host_dir = '.'
      host_file = './' + host_file
  if not os.path.exists(host_dir):
    shutil.os.makedirs(host_dir)

  with open(args.config or os.devnull, 'rb') as f:
    print('Running ' + ' '.join(cmd))
    proc = adb('shell', *cmd, stdin=f, stdout=subprocess.PIPE)
    bg_pid = proc.communicate()[0].decode().strip()
    exit_code = proc.wait()

  if exit_code != 0:
    prt('Perfetto invocation failed', ANSI.RED)
    sys.exit(1)

  prt('Trace started. Press CTRL+C to stop', ANSI.BLACK + ANSI.BG_BLUE)
  logcat = adb('logcat', '-v', 'brief', '-s', 'perfetto', '-b', 'main', '-T',
               '1')

  ctrl_c_count = 0
  while ctrl_c_count < 2:
    try:
      poll = adb('shell', 'test -d /proc/' + bg_pid)
      if poll.wait() != 0:
        break
      time.sleep(0.5)
    except KeyboardInterrupt:
      sig = 'TERM' if ctrl_c_count == 0 else 'KILL'
      ctrl_c_count += 1
      prt('Stopping the trace (SIG%s)' % sig, ANSI.BLACK + ANSI.BG_YELLOW)
      res = adb('shell', 'kill -%s %s' % (sig, bg_pid)).wait()

  logcat.kill()
  logcat.wait()

  prt('\n')
  prt('Pulling into %s' % host_file, ANSI.BOLD)
  adb('pull', device_file, host_file).wait()

  if not args.no_open:
    prt('\n')
    prt('Opening the trace (%s) in the browser' % host_file)
    open_trace_in_browser(host_file)


def prt(msg, colors=ANSI.END):
  print(colors + msg + ANSI.END)


def find_adb():
  """ Locate the "right" adb path

  If adb is in the PATH use that (likely what the user wants) otherwise use the
  hermetic one in our SDK copy.
  """
  global adb_path
  for path in ['adb', HERMETIC_ADB_PATH]:
    try:
      subprocess.call([path, '--version'], stdout=devnull, stderr=devnull)
      adb_path = path
      break
    except OSError:
      continue
  if adb_path is None:
    sdk_url = 'https://developer.android.com/studio/releases/platform-tools'
    prt('Could not find a suitable adb binary in the PATH. ', ANSI.RED)
    prt('You can download adb from %s' % sdk_url, ANSI.RED)
    sys.exit(1)


def open_trace_in_browser(path):
  # We reuse the HTTP+RPC port because it's the only one allowed by the CSP.
  PORT = 9001
  os.chdir(os.path.dirname(path))
  fname = os.path.basename(path)
  socketserver.TCPServer.allow_reuse_address = True
  with socketserver.TCPServer(('127.0.0.1', PORT), HttpHandler) as httpd:
    webbrowser.open_new_tab(
            'https://ui.perfetto.dev/#!/?url=http://127.0.0.1:%d/%s' %
        (PORT, fname))
    while httpd.__dict__.get('last_request') != '/' + fname:
      httpd.handle_request()


def adb(*args, stdin=devnull, stdout=None):
  cmd = [adb_path, *args]
  setpgrp = None
  if os.name != 'nt':
    # On Linux/Mac, start a new process group so all child processes are killed
    # on exit. Unsupported on Windows.
    setpgrp = lambda: os.setpgrp()
  proc = subprocess.Popen(cmd, stdin=stdin, stdout=stdout, preexec_fn=setpgrp)
  procs.append(proc)
  return proc


def kill_all_subprocs_on_exit():
  for p in [p for p in procs if p.poll() is None]:
    p.kill()


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