from .corpus_utils import CheckCorporaMixin
from .job_utils import CheckJobsMixin
from ..import db, socketio
import docker


class TaskRunner(CheckCorporaMixin, CheckJobsMixin):
    def __init__(self):
        self.docker = docker.from_env()
        self._socketio_message_buffer = {}

    def run(self):
        self.check_corpora()
        self.check_jobs()
        db.session.commit()
        self.flush_socketio_messages()

    def buffer_socketio_message(self, event, payload, room,
                                msg_id=None, override_policy='replace'):
        if room not in self._socketio_message_buffer:
            self._socketio_message_buffer[room] = {}
        if event not in self._socketio_message_buffer[room]:
            self._socketio_message_buffer[room][event] = {}
        if msg_id is None:
            msg_id = len(self._socketio_message_buffer[room][event].keys())
        if override_policy == 'append':
            if msg_id in self._socketio_message_buffer[room][event]:
                # If the current message value isn't a list, convert it!
                if not isinstance(self._socketio_message_buffer[room][event][msg_id], list):  # noqa
                    self._socketio_message_buffer[room][event][msg_id] = [self._socketio_message_buffer[room][event][msg_id]]  # noqa
            else:
                self._socketio_message_buffer[room][event][msg_id] = []
            self._socketio_message_buffer[room][event][msg_id].append(payload)
        elif override_policy == 'replace':
            self._socketio_message_buffer[room][event][msg_id] = payload
        else:
            raise Exception('Unknown override policy: {}'.format(override_policy))  # noqa
        return msg_id

    def buffer_user_patch_operation(self, ressource, patch_operation):
        self.buffer_socketio_message('user_{}_patch'.format(ressource.user_id),
                                     patch_operation,
                                     'user_{}'.format(ressource.user_id),
                                     msg_id='_', override_policy='append')

    def clear_socketio_message_buffer(self):
        self._socketio_message_buffer = {}

    def flush_socketio_messages(self):
        for room in self._socketio_message_buffer:
            for event in self._socketio_message_buffer[room]:
                for message in self._socketio_message_buffer[room][event]:
                    socketio.emit(event, self._socketio_message_buffer[room][event][message], room=room)  # noqa
        self.clear_socketio_message_buffer()