const models = require('../models');
import * as api from '../../client/src/api';
import { EndpointError, EndpointHandler, catchUnhandledErrors } from './types';
const { Op } = require("sequelize");

export const CreateAlbumEndpointHandler: EndpointHandler = async (req: any, res: any) => {
  if (!api.checkCreateAlbumRequest(req)) {
    const e: EndpointError = {
      internalMessage: 'Invalid CreateAlbum request: ' + JSON.stringify(req.body),
      httpStatus: 400
    };
    throw e;
  }
  const reqObject: api.CreateAlbumRequest = req.body;

  // Start retrieving the artist instances to link the album to.
  var artistInstancesPromise = reqObject.artistIds && models.Artist.findAll({
    where: {
      id: {
        [Op.in]: reqObject.artistIds
      }
    }
  });

  // Start retrieving the tag instances to link the album to.
  var tagInstancesPromise = reqObject.tagIds && models.Tag.findAll({
    where: {
      id: {
        [Op.in]: reqObject.tagIds
      }
    }
  });

  // Upon finish retrieving artists and tags, create the album and associate it.
  await Promise.all([artistInstancesPromise, tagInstancesPromise])
    .then((values: any) => {
      var [artists, tags] = values;

      if ((reqObject.artistIds && artists.length !== reqObject.artistIds.length) ||
        (reqObject.tagIds && tags.length !== reqObject.tagIds.length)) {
        const e: EndpointError = {
          internalMessage: 'Not all albums and/or artists and/or tags exist for CreateAlbum request: ' + JSON.stringify(req.body),
          httpStatus: 400
        };
        throw e;
      }

      var album = models.Album.build({
        name: reqObject.name,
        storeLinks: reqObject.storeLinks || [],
      });
      artists && album.addArtists(artists);
      tags && album.addTags(tags);
      return album.save();
    })
    .then((album: any) => {
      const responseObject: api.CreateSongResponse = {
        id: album.id
      };
      res.status(200).send(responseObject);
    })
    .catch(catchUnhandledErrors);
}