session-desktop/ts/util/readReceipts.ts

import _ from 'lodash';
import { MessageCollection } from '../models/message';

import * as Data from '../data/data';
import { getConversationController } from '../session/conversations';

async function getTargetMessage(reader: string, messages: MessageCollection) {
  if (messages.length === 0) {
    return null;
  }
  const message = messages.find(msg => msg.isOutgoing() && reader === msg.get('conversationId'));
  if (message) {
    return message;
  }

  // we do not support read messages for groups
  return null;
}

async function onReadReceipt(receipt: { source: string; timestamp: number; readAt: number }) {
  try {
    const messages = await Data.getMessagesBySentAt(receipt.timestamp);

    const message = await getTargetMessage(receipt.source, messages);

    if (!message) {
      window.log.info('No message for read receipt', receipt.source, receipt.timestamp);
      return;
    }

    const readBy = message.get('read_by') || [];
    const expirationStartTimestamp = message.get('expirationStartTimestamp');

    if (!readBy.includes(receipt.source)) {
      readBy.push(receipt.source);
    }
    message.set({
      read_by: readBy,
      expirationStartTimestamp: expirationStartTimestamp || Date.now(),
      sent: true,
    });

    if (message.isExpiring() && !expirationStartTimestamp) {
      // This will save the message for us while starting the timer
      await message.setToExpire();
    } else {
      await message.commit();
    }

    // notify frontend listeners
    const conversation = getConversationController().get(message.get('conversationId'));
    if (conversation) {
      conversation.updateLastMessage();
    }
  } catch (error) {
    window.log.error('ReadReceipts.onReceipt error:', error && error.stack ? error.stack : error);
  }
}

export const ReadReceipts = { onReadReceipt };