import datetime
import logging

from redis import RedisError
from trollius import From, Return, coroutine

from data.database import BUILD_PHASE
from data import model
from buildman.asyncutil import AsyncWrapper


logger = logging.getLogger(__name__)


class StatusHandler(object):
  """ Context wrapper for writing status to build logs. """

  def __init__(self, build_logs, repository_build_uuid):
    self._current_phase = None
    self._current_command = None
    self._uuid = repository_build_uuid
    self._build_logs = AsyncWrapper(build_logs)
    self._sync_build_logs = build_logs
    self._build_model = AsyncWrapper(model.build)

    self._status = {
      'total_commands': 0,
      'current_command': None,
      'push_completion': 0.0,
      'pull_completion': 0.0,
    }

    # Write the initial status.
    self.__exit__(None, None, None)

  @coroutine
  def _append_log_message(self, log_message, log_type=None, log_data=None):
    log_data = log_data or {}
    log_data['datetime'] = str(datetime.datetime.now())

    try:
      yield From(self._build_logs.append_log_message(self._uuid, log_message, log_type, log_data))
    except RedisError:
      logger.exception('Could not save build log for build %s: %s', self._uuid, log_message)

  @coroutine
  def append_log(self, log_message, extra_data=None):
    if log_message is None:
      return

    yield From(self._append_log_message(log_message, log_data=extra_data))

  @coroutine
  def set_command(self, command, extra_data=None):
    if self._current_command == command:
      raise Return()

    self._current_command = command
    yield From(self._append_log_message(command, self._build_logs.COMMAND, extra_data))

  @coroutine
  def set_error(self, error_message, extra_data=None, internal_error=False, requeued=False):
    error_phase = BUILD_PHASE.INTERNAL_ERROR if internal_error and requeued else BUILD_PHASE.ERROR
    yield From(self.set_phase(error_phase))

    extra_data = extra_data or {}
    extra_data['internal_error'] = internal_error
    yield From(self._append_log_message(error_message, self._build_logs.ERROR, extra_data))

  @coroutine
  def set_phase(self, phase, extra_data=None):
    if phase == self._current_phase:
      raise Return(False)

    self._current_phase = phase
    yield From(self._append_log_message(phase, self._build_logs.PHASE, extra_data))

    # Update the repository build with the new phase
    raise Return(self._build_model.update_phase_then_close(self._uuid, phase))

  def __enter__(self):
    return self._status

  def __exit__(self, exc_type, value, traceback):
    try:
      self._sync_build_logs.set_status(self._uuid, self._status)
    except RedisError:
      logger.exception('Could not set status of build %s to %s', self._uuid, self._status)