ForestAdmin/forest-express

const _ = require('lodash');
const JSONAPISerializer = require('jsonapi-serializer').Serializer;

function serializeConversations(conversations, collectionName, meta) {
  function mapConversation(conversation) {
    // jshint camelcase: false
    conversation.id = conversation.id.replace('layer:///conversations/', '');
    conversation.createdAt = conversation.created_at;

    if (conversation.last_message) {
      conversation.lastMessage = {
        id: conversation.last_message.id.replace('layer:///messages/', ''),
        sentAt: conversation.last_message.sent_at,
        content: conversation.last_message.parts[0].body,
        mimeType: conversation.last_message.parts[0].mime_type,
        sender: conversation.last_message.sender.display_name,
      };
    }

    if (_.isArray(conversation.participants) && conversation.participants.length) {
      conversation.title = conversation.participants.map((participant) => participant.display_name).join(', ');
    }

    return conversation;
  }

  const type = `${collectionName}_layer_conversations`;
  let data = null;

  if (_.isArray(conversations)) {
    data = conversations.map((conversation) => mapConversation(conversation));
  } else {
    data = mapConversation(conversations);
  }

  return new JSONAPISerializer(type, data, {
    attributes: ['title', 'createdAt', 'messages', 'lastMessage'],
    messages: {
      ref: 'id',
      ignoreRelationshipData: true,
      included: false,
      nullIfMissing: true,
      relationshipLinks: {
        related(dataSet) {
          return {
            href: `/forest/${collectionName}_layer_conversations/${dataSet.id
            }/relationships/messages`,
          };
        },
      },
    },
    lastMessage: {
      ref: 'id',
      attributes: ['sender', 'sentAt', 'content', 'mimeType'],
    },
    keyForAttribute(key) { return key; },
    typeForAttribute(attribute) {
      if (attribute === 'lastMessage') {
        return `${collectionName}_layer_messages`;
      }

      return undefined;
    },
    meta,
  });
}

module.exports = serializeConversations;