# conversation.js

    const _ = require('underscore');
    const { _request } = require('./request');
    const AV = require('./av');

    const serializeMessage = message => {
      if (typeof message === 'string') {
        return message;
      }
      if (typeof message.getPayload === 'function') {
        return JSON.stringify(message.getPayload());
      }
      return JSON.stringify(message);
    };

    /**
     * <p>An AV.Conversation is a local representation of a LeanCloud realtime's
     * conversation. This class is a subclass of AV.Object, and retains the
     * same functionality of an AV.Object, but also extends it with various
     * conversation specific methods, like get members, creators of this conversation.
     * </p>
     *
     * @class AV.Conversation
     * @param {String} name The name of the Role to create.
     * @param {Object} [options]
     * @param {Boolean} [options.isSystem] Set this conversation as system conversation.
     * @param {Boolean} [options.isTransient] Set this conversation as transient conversation.
     */
    module.exports = AV.Object.extend(
      '_Conversation',
      /** @lends AV.Conversation.prototype */ {
        constructor(name, options = {}) {
          AV.Object.prototype.constructor.call(this, null, null);
          this.set('name', name);
          if (options.isSystem !== undefined) {
            this.set('sys', options.isSystem ? true : false);
          }
          if (options.isTransient !== undefined) {
            this.set('tr', options.isTransient ? true : false);
          }
        },
        /**
         * Get current conversation's creator.
         *
         * @return {String}
         */
        getCreator() {
          return this.get('c');
        },

        /**
         * Get the last message's time.
         *
         * @return {Date}
         */
        getLastMessageAt() {
          return this.get('lm');
        },

        /**
         * Get this conversation's members
         *
         * @return {String[]}
         */
        getMembers() {
          return this.get('m');
        },

        /**
         * Add a member to this conversation
         *
         * @param {String} member
         */
        addMember(member) {
          return this.add('m', member);
        },

        /**
         * Get this conversation's members who set this conversation as muted.
         *
         * @return {String[]}
         */
        getMutedMembers() {
          return this.get('mu');
        },

        /**
         * Get this conversation's name field.
         *
         * @return String
         */
        getName() {
          return this.get('name');
        },

        /**
         * Returns true if this conversation is transient conversation.
         *
         * @return {Boolean}
         */
        isTransient() {
          return this.get('tr');
        },

        /**
         * Returns true if this conversation is system conversation.
         *
         * @return {Boolean}
         */
        isSystem() {
          return this.get('sys');
        },

        /**
         * Send realtime message to this conversation, using HTTP request.
         *
         * @param {String} fromClient Sender's client id.
         * @param {String|Object} message The message which will send to conversation.
         *     It could be a raw string, or an object with a `toJSON` method, like a
         *     realtime SDK's Message object. See more: {@link https://leancloud.cn/docs/realtime_guide-js.html#消息}
         * @param {Object} [options]
         * @param {Boolean} [options.transient] Whether send this message as transient message or not.
         * @param {String[]} [options.toClients] Ids of clients to send to. This option can be used only in system conversation.
         * @param {Object} [options.pushData] Push data to this message. See more: {@link https://url.leanapp.cn/pushData 推送消息内容}
         * @param {AuthOptions} [authOptions]
         * @return {Promise}
         */
        send(fromClient, message, options = {}, authOptions = {}) {
          const data = {
            from_peer: fromClient,
            conv_id: this.id,
            transient: false,
            message: serializeMessage(message),
          };
          if (options.toClients !== undefined) {
            data.to_peers = options.toClients;
          }
          if (options.transient !== undefined) {
            data.transient = options.transient ? true : false;
          }
          if (options.pushData !== undefined) {
            data.push_data = options.pushData;
          }
          return _request('rtm', 'messages', null, 'POST', data, authOptions);
        },

        /**
         * Send realtime broadcast message to all clients, via this conversation, using HTTP request.
         *
         * @param {String} fromClient Sender's client id.
         * @param {String|Object} message The message which will send to conversation.
         *     It could be a raw string, or an object with a `toJSON` method, like a
         *     realtime SDK's Message object. See more: {@link https://leancloud.cn/docs/realtime_guide-js.html#消息}.
         * @param {Object} [options]
         * @param {Object} [options.pushData] Push data to this message. See more: {@link https://url.leanapp.cn/pushData 推送消息内容}.
         * @param {Object} [options.validTill] The message will valid till this time.
         * @param {AuthOptions} [authOptions]
         * @return {Promise}
         */
        broadcast(fromClient, message, options = {}, authOptions = {}) {
          const data = {
            from_peer: fromClient,
            conv_id: this.id,
            message: serializeMessage(message),
          };
          if (options.pushData !== undefined) {
            data.push = options.pushData;
          }
          if (options.validTill !== undefined) {
            let ts = options.validTill;
            if (_.isDate(ts)) {
              ts = ts.getTime();
            }
            options.valid_till = ts;
          }
          return _request('rtm', 'broadcast', null, 'POST', data, authOptions);
        },
      }
    );