# Copyright 2014 The LUCI Authors. All rights reserved.
# Use of this source code is governed under the Apache License, Version 2.0
# that can be found in the LICENSE file.

"""Toolset to run multiple Swarming tasks in parallel."""

import json
import os
import optparse
import subprocess
import sys
import tempfile
import time

CLIENT_DIR = os.path.dirname(os.path.dirname(os.path.abspath(
    __file__.decode(sys.getfilesystemencoding()))))
sys.path.insert(0, CLIENT_DIR)

from utils import tools
tools.force_local_third_party()

# pylint: disable=ungrouped-imports
import auth
import isolateserver
from utils import logging_utils
from utils import threading_utils
from utils import tools


def task_to_name(name, dimensions, isolated_hash):
  """Returns a task name the same way swarming.py generates them."""
  return '%s/%s/%s' % (
      name,
      '_'.join('%s=%s' % (k, v) for k, v in sorted(dimensions.iteritems())),
      isolated_hash[:8])


def capture(cmd):
  assert all(isinstance(i, basestring) for i in cmd), cmd
  start = time.time()
  p = subprocess.Popen(
      [sys.executable] + cmd, cwd=CLIENT_DIR, stdout=subprocess.PIPE)
  out = p.communicate()[0]
  return p.returncode, out, time.time() - start


def trigger(swarming_server, isolate_server, task_name, isolated_hash, args):
  """Triggers a specified .isolated file."""
  fd, jsonfile = tempfile.mkstemp(prefix=u'swarming')
  os.close(fd)
  try:
    cmd = [
      'swarming.py', 'trigger',
      '--swarming', swarming_server,
      '--isolate-server', isolate_server,
      '--task-name', task_name,
      '--dump-json', jsonfile,
      '-s', isolated_hash,
    ]
    returncode, out, duration = capture(cmd + args)
    with open(jsonfile) as f:
      data = json.load(f)
    task_id = str(data['tasks'][task_name]['task_id'])
    return returncode, out, duration, task_id
  finally:
    os.remove(jsonfile)


def collect(swarming_server, task_id):
  """Collects results of a swarming task."""
  cmd = ['swarming.py', 'collect', '--swarming', swarming_server, task_id]
  return capture(cmd)


class Runner(object):
  """Runners runs tasks in parallel on Swarming."""
  def __init__(
      self, swarming_server, isolate_server, add_task, progress,
      extra_trigger_args):
    self.swarming_server = swarming_server
    self.isolate_server = isolate_server
    self.add_task = add_task
    self.progress = progress
    self.extra_trigger_args = extra_trigger_args

  def trigger(self, task_name, isolated_hash, dimensions, env):
    args = sum((['--dimension', k, v] for k, v in dimensions.iteritems()), [])
    args.extend(sum((['--env', k, v] for k, v in env), []))
    returncode, stdout, duration, task_id = trigger(
        self.swarming_server,
        self.isolate_server,
        task_name,
        isolated_hash,
        args + self.extra_trigger_args)
    step_name = '%s (%3.2fs)' % (task_name, duration)
    if returncode:
      line = 'Failed to trigger %s\n%s' % (step_name, stdout)
      self.progress.update_item(line, index=1)
      return
    self.progress.update_item('Triggered %s' % step_name, index=1)
    self.add_task(0, self.collect, task_name, task_id, dimensions)

  def collect(self, task_name, task_id, dimensions):
    returncode, stdout, duration = collect(self.swarming_server, task_id)
    step_name = '%s (%3.2fs)' % (task_name, duration)
    if returncode:
      # Only print the output for failures, successes are unexciting.
      self.progress.update_item(
          'Failed %s:\n%s' % (step_name, stdout), index=1)
      return (task_name, dimensions, stdout)
    self.progress.update_item('Passed %s' % step_name, index=1)
    return None, None, None


def run_swarming_tasks_parallel(
    swarming_server, isolate_server, extra_trigger_args, tasks):
  """Triggers swarming tasks in parallel and gets results.

  This is done by using one thread per task and shelling out swarming.py.

  Arguments:
    extra_trigger_args: list of additional flags to pass down to
        'swarming.py trigger'
    tasks: list of tuple(task_name, isolated_hash, dimensions) where dimension
        are --dimension flags to provide when triggering the task.

  Yields:
    tuple(name, dimensions, stdout) for the tasks that failed.
  """
  runs = len(tasks)
  # triger + collect
  total = 2 * runs
  failed_tasks = []
  progress = threading_utils.Progress([('index', 0), ('size', total)])
  progress.use_cr_only = False
  start = time.time()
  with threading_utils.ThreadPoolWithProgress(
      progress, runs, runs, total) as pool:
    runner = Runner(
        swarming_server, isolate_server, pool.add_task, progress,
        extra_trigger_args)

    for task_name, isolated_hash, dimensions, env in tasks:
      pool.add_task(
          0, runner.trigger, task_name, isolated_hash, dimensions, env)

    # Runner.collect() only return task failures.
    for failed_task in pool.iter_results():
      task_name, dimensions, stdout = failed_task
      yield task_name, dimensions, stdout
      failed_tasks.append(task_name)

  duration = time.time() - start
  print('\nCompleted in %3.2fs' % duration)
  if failed_tasks:
    print('Detected the following failures:')
    for task in sorted(failed_tasks):
      print('  %s' % task)


class OptionParser(logging_utils.OptionParserWithLogging):
  def __init__(self, **kwargs):
    logging_utils.OptionParserWithLogging.__init__(self, **kwargs)
    self.server_group = optparse.OptionGroup(self, 'Server')
    self.server_group.add_option(
        '-S', '--swarming',
        metavar='URL', default=os.environ.get('SWARMING_SERVER', ''),
        help='Swarming server to use')
    isolateserver.add_isolate_server_options(self.server_group)
    self.add_option_group(self.server_group)
    auth.add_auth_options(self)
    self.add_option(
        '-d', '--dimension', default=[], action='append', nargs=2,
        dest='dimensions', metavar='FOO bar',
        help='dimension to filter on')
    self.add_option(
        '--priority', type='int',
        help='The lower value, the more important the task is. It may be '
            'important to specify a higher priority since the default value '
            'will make the task to be triggered only when the bots are idle.')
    self.add_option(
        '--deadline', type='int', default=6*60*60,
        help='Seconds to allow the task to be pending for a bot to run before '
            'this task request expires.')
    self.add_option(
        '--env', default=[], action='append', nargs=2,
        metavar='ENV VAL', help='environment variables')

  def parse_args(self, *args, **kwargs):
    options, args = logging_utils.OptionParserWithLogging.parse_args(
        self, *args, **kwargs)
    options.swarming = options.swarming.rstrip('/')
    if not options.swarming:
      self.error('--swarming is required.')
    auth.process_auth_options(self, options)
    isolateserver.process_isolate_server_options(self, options, False, True)
    options.dimensions = dict(options.dimensions)
    return options, args

  def format_description(self, _):
    return self.description