import logging

from random import SystemRandom
from loremipsum import get_sentence
from functools import wraps
from copy import deepcopy

from data.buildlogs import BuildLogs


logger = logging.getLogger(__name__)
random = SystemRandom()


def maybe_advance_script(is_get_status=False):
  def inner_advance(func):
    @wraps(func)
    def wrapper(self, *args, **kwargs):
      advance_units = random.randint(1, 500)
      logger.debug('Advancing script %s units', advance_units)
      while advance_units > 0 and self.remaining_script:
        units = self.remaining_script[0][0]

        if advance_units > units:
          advance_units -= units
          self.advance_script(is_get_status)
        else:
          break

      return func(self, *args, **kwargs)
    return wrapper
  return inner_advance


class TestBuildLogs(BuildLogs):
  COMMAND_TYPES = ['FROM', 'MAINTAINER', 'RUN', 'CMD', 'EXPOSE', 'ENV', 'ADD', 
                   'ENTRYPOINT', 'VOLUME', 'USER', 'WORKDIR']
  STATUS_TEMPLATE = {
    'total_commands': None,
    'current_command': None,
    'push_completion': 0.0,
    'image_completion': {},
  }

  def __init__(self, redis_host, namespace, repository, test_build_id):
    super(TestBuildLogs, self).__init__(redis_host)
    self.namespace = namespace
    self.repository = repository
    self.test_build_id = test_build_id
    self.remaining_script = self._generate_script()
    logger.debug('Total script size: %s', len(self.remaining_script))
    self._logs = []

    self._status = {}
    self._last_status = {}

  def advance_script(self, is_get_status):
    (_, log, status_wrapper) = self.remaining_script.pop(0)
    if log is not None:
      self._logs.append(log)

    if status_wrapper is not None:
      (phase, status) = status_wrapper

      from data import model
      build_obj = model.get_repository_build(self.namespace, self.repository,
                                             self.test_build_id)
      build_obj.phase = phase
      build_obj.save()

      self._status = status
      if not is_get_status:
        self._last_status = status

  def _generate_script(self):
    script = []

    # generate the init phase
    script.append(self._generate_phase(400, 'initializing'))
    script.extend(self._generate_logs(random.randint(1, 3)))

    # move to the building phase
    script.append(self._generate_phase(400, 'building'))
    total_commands = random.randint(5, 20)
    for command_num in range(1, total_commands + 1):
      command_weight = random.randint(50, 100)
      script.append(self._generate_command(command_num, total_commands,
                                           command_weight))

      # we want 0 logs some percent of the time
      num_logs = max(0, random.randint(-50, 400))
      script.extend(self._generate_logs(num_logs))

    # move to the pushing phase
    script.append(self._generate_phase(400, 'pushing'))
    script.extend(self._generate_push_statuses(total_commands))

    # move to the error or complete phase
    if random.randint(0, 1) == 0:
      script.append(self._generate_phase(400, 'complete'))
    else:
      script.append(self._generate_phase(400, 'error'))
      script.append((1, {'message': 'Something bad happened! Oh noes!',
                         'type': self.ERROR}, None))

    return script

  def _generate_phase(self, start_weight, phase_name):
    return (start_weight, {'message': phase_name, 'type': self.PHASE},
            (phase_name, deepcopy(self.STATUS_TEMPLATE)))

  def _generate_command(self, command_num, total_commands, command_weight):
    sentence = get_sentence()
    command = random.choice(self.COMMAND_TYPES)
    if command == 'FROM':
      sentence = random.choice(['ubuntu', 'lopter/raring-base',
                                'quay.io/devtable/simple',
                                'quay.io/buynlarge/orgrepo',
                                'stackbrew/ubuntu:precise'])

    msg = {
      'message': 'Step %s: %s %s' % (command_num, command, sentence),
      'type': self.COMMAND,
    }
    status = deepcopy(self.STATUS_TEMPLATE)
    status['total_commands'] = total_commands
    status['current_command'] = command_num
    return (command_weight, msg, ('building', status))

  @staticmethod
  def _generate_logs(count):
    return [(1, {'message': get_sentence()}, None) for _ in range(count)]

  @staticmethod
  def _compute_total_completion(statuses, total_images):
    percentage_with_sizes = float(len(statuses.values()))/total_images
    sent_bytes = sum([status[u'current'] for status in statuses.values()])
    total_bytes = sum([status[u'total'] for status in statuses.values()])
    return float(sent_bytes)/total_bytes*percentage_with_sizes

  @staticmethod
  def _generate_push_statuses(total_commands):
    push_status_template = deepcopy(TestBuildLogs.STATUS_TEMPLATE)
    push_status_template['current_command'] = total_commands
    push_status_template['total_commands'] = total_commands

    push_statuses = []

    one_mb = 1 * 1024 * 1024

    num_images = random.randint(2, 7)
    sizes = [random.randint(one_mb, one_mb * 5) for _ in range(num_images)]

    image_completion = {}
    for image_num, image_size in enumerate(sizes):
      image_id = 'image_id_%s' % image_num

      image_completion[image_id] = {
        'current': 0,
        'total': image_size,
      }

      for i in range(one_mb, image_size, one_mb):
        image_completion[image_id]['current'] = i
        new_status = deepcopy(push_status_template)
        new_status['image_completion'] = deepcopy(image_completion)

        completion = TestBuildLogs._compute_total_completion(image_completion,
                                                             num_images)
        new_status['push_completion'] = completion
        push_statuses.append((250, None, ('pushing', new_status)))

    return push_statuses

  @maybe_advance_script()
  def get_log_entries(self, build_id, start_index):
    if build_id == self.test_build_id:
      return (len(self._logs), self._logs[start_index:])
    else:
      return super(TestBuildLogs, self).get_log_entries(build_id, start_index)

  @maybe_advance_script(True)
  def get_status(self, build_id):
    if build_id == self.test_build_id:
      returnable_status = self._last_status
      self._last_status = self._status
      return returnable_status
    else:
      return super(TestBuildLogs, self).get_status(build_id)