import json

from contextlib import contextmanager

from app import app, notification_queue
from data import model
from auth.auth_context import get_authenticated_user, get_validated_oauth_token

DEFAULT_BATCH_SIZE = 1000


def build_repository_event_data(namespace_name, repo_name, extra_data=None, subpage=None):
  """ Builds the basic repository data for an event, including the repository's name, Docker URL
      and homepage. If extra_data is specified, it is appended to the dictionary before it is
      returned.
  """
  repo_string = '%s/%s' % (namespace_name, repo_name)
  homepage = '%s://%s/repository/%s' % (app.config['PREFERRED_URL_SCHEME'],
                                        app.config['SERVER_HOSTNAME'], repo_string)

  if subpage:
    if not subpage.startswith('/'):
      subpage = '/' + subpage

    homepage = homepage + subpage

  event_data = {
    'repository': repo_string,
    'namespace': namespace_name,
    'name': repo_name,
    'docker_url': '%s/%s' % (app.config['SERVER_HOSTNAME'], repo_string),
    'homepage': homepage,
  }

  event_data.update(extra_data or {})
  return event_data


def build_notification_data(notification, event_data, performer_data=None):
  if not performer_data:
    performer_data = {}

    oauth_token = get_validated_oauth_token()
    if oauth_token:
      performer_data['oauth_token_id'] = oauth_token.id
      performer_data['oauth_token_application_id'] = oauth_token.application.client_id
      performer_data['oauth_token_application'] = oauth_token.application.name

    performer_user = get_authenticated_user()
    if performer_user:
      performer_data['entity_id'] = performer_user.id
      performer_data['entity_name'] = performer_user.username

  return {
    'notification_uuid': notification.uuid,
    'event_data': event_data,
    'performer_data': performer_data,
  }


@contextmanager
def notification_batch(batch_size=DEFAULT_BATCH_SIZE):
  """
  Context manager implementation which returns a target callable with the same signature
  as spawn_notification. When the the context block exits the notifications generated by
  the callable will be bulk inserted into the queue with the specified batch size.
  """
  with notification_queue.batch_insert(batch_size) as queue_put:

    def spawn_notification_batch(repo, event_name, extra_data=None, subpage=None, pathargs=None,
                                 performer_data=None):
      event_data = build_repository_event_data(repo.namespace_name, repo.name,
                                               extra_data=extra_data, subpage=subpage)

      notifications = model.notification.list_repo_notifications(repo.namespace_name, repo.name,
                                                                 event_name=event_name)
      path = [repo.namespace_name, repo.name, event_name] + (pathargs or [])
      for notification in list(notifications):
        notification_data = build_notification_data(notification, event_data, performer_data)
        queue_put(path, json.dumps(notification_data))

    yield spawn_notification_batch


def spawn_notification(repo, event_name, extra_data=None, subpage=None, pathargs=None,
                       performer_data=None):
  with notification_batch(1) as batch_spawn:
    batch_spawn(repo, event_name, extra_data, subpage, pathargs, performer_data)