@jsxc/jsxc/src/plugins/LastMessageCorrectionPlugin.ts

Real-time XMPP chat application with video calls, file transfer and encrypted communication

import { AbstractPlugin, IMetaData } from '../plugin/AbstractPlugin';
import PluginAPI from '../plugin/PluginAPI';
import Translation from '@util/Translation';
import * as Namespace from '@connection/xmpp/namespace';
import { IContact } from '@src/Contact.interface';
import { IMessage } from '@src/Message.interface';
import Message from '@src/Message';

/**
 * XEP-0308: Last Message Correction
 *
 * @version: 1.2.0
 * @see: https://xmpp.org/extensions/xep-0308.html
 *
 */

const CORRECTION_CMD = '/fix';
const LMC = 'urn:xmpp:message-correct:0';

const MIN_VERSION = '4.3.0';
const MAX_VERSION = '99.0.0';

Namespace.register('LAST_MSG_CORRECTION', LMC);

export default class LastMessageCorrectionPlugin extends AbstractPlugin {
   public static getId(): string {
      return 'lmc';
   }

   public static getName(): string {
      return 'Last Message Correction';
   }

   public static getMetaData(): IMetaData {
      return {
         description: Translation.t('setting-lmc-enable'),
         xeps: [
            {
               id: 'XEP-0308',
               name: 'Last Message Correction',
               version: '1.2.0',
            },
         ],
      };
   }

   private correctionRequests: { [contactUid: string]: IMessage } = {};

   constructor(pluginAPI: PluginAPI) {
      super(MIN_VERSION, MAX_VERSION, pluginAPI);

      pluginAPI.registerCommand(CORRECTION_CMD, this.commandHandler, 'cmd_correction');

      pluginAPI.addPreSendMessageStanzaProcessor(this.addReplaceElementToStanza, 90);

      pluginAPI.addAfterReceiveMessageProcessor(this.checkMessageCorrection, 90);

      pluginAPI.registerChatMessageMenuItem({
         generate: this.generateCorrectMessageMenuItem,
      });
   }

   private commandHandler = async (args: string[], contact: IContact, messageString: string) => {
      const originalMessage = contact.getTranscript().getFirstOutgoingMessage();

      this.correctionRequests[contact.getUid()] = originalMessage;

      if (!originalMessage || !contact.isChat()) {
         return false;
      }

      const chatWindow = contact.getChatWindow();
      const message = new Message({
         peer: contact.getJid(),
         direction: Message.DIRECTION.OUT,
         type: contact.getType(),
         plaintextMessage: messageString.replace(/^\/fix /, ''),
         attachment: chatWindow.getAttachment(),
         unread: false,
         original: originalMessage.getUid(),
      });

      contact.getTranscript().pushMessage(message);

      chatWindow.clearAttachment();

      let pipe = contact.getAccount().getPipe('preSendMessage');

      return pipe
         .run(contact, message)
         .then(([contact, message]) => {
            originalMessage.getLastVersion().setReplacedBy(message);

            contact.getAccount().getConnection().sendMessage(message);

            return true;
         })
         .catch(err => {
            this.pluginAPI.Log.warn('Error during preSendMessage pipe', err);

            return false;
         });
   };

   private addReplaceElementToStanza = async (
      message: IMessage,
      xmlMsg: Strophe.Builder
   ): Promise<[IMessage, Strophe.Builder]> => {
      const contact = this.pluginAPI.getContact(message.getPeer());
      const originalMessage = this.correctionRequests[contact.getUid()];

      if (!originalMessage || originalMessage.getLastVersion().getUid() !== message.getUid()) {
         return [message, xmlMsg];
      }

      delete this.correctionRequests[contact.getUid()];

      xmlMsg
         .c('replace', {
            xmlns: LMC,
            id: originalMessage.getAttrId(),
         })
         .up();

      return [message, xmlMsg];
   };

   private checkMessageCorrection = async (
      contact: IContact,
      message: IMessage,
      stanza: Element
   ): Promise<[IContact, IMessage, Element]> => {
      const replaceElement = $(stanza).find(`>replace[xmlns="${LMC}"]`);

      if (replaceElement.length === 0) {
         return [contact, message, stanza];
      }

      const attrIdToBeReplaced = replaceElement.attr('id');

      if (!attrIdToBeReplaced) {
         return [contact, message, stanza];
      }

      const firstIncomingMessage = contact.getTranscript().getFirstIncomingMessage();

      if (firstIncomingMessage && firstIncomingMessage.getAttrId() === attrIdToBeReplaced) {
         message.setOriginal(firstIncomingMessage);

         firstIncomingMessage.getLastVersion().setReplacedBy(message);
      }

      return [contact, message, stanza];
   };

   private generateCorrectMessageMenuItem = (contact: IContact, message: IMessage) => {
      if (message.isOutgoing()) {
         const lastOutgoingMessage = contact.getTranscript().getFirstOutgoingMessage().getLastVersion();

         if (lastOutgoingMessage.getUid() === message.getUid()) {
            const chatWindow = contact.getChatWindow();

            return {
               id: 'lmc-edit',
               label: '',
               icon: 'edit',
               handler: () => {
                  let plaintextMessage = message.getPlaintextMessage();

                  if (message.hasAttachment()) {
                     const attachment = message.getAttachment();

                     chatWindow.setAttachment(attachment);
                     plaintextMessage = plaintextMessage.replace(attachment.getData() + '\n', '');
                  }

                  chatWindow.setInput(CORRECTION_CMD + ' ' + plaintextMessage);
               },
            };
         }
      }

      return false;
   };
}