upstream-rocketchat/apps/meteor/server/lib/notifications/message/index.ts

import type { IMessage, IUser } from '@rocket.chat/core-typings';
import { isFileAttachment, isFileImageAttachment } from '@rocket.chat/core-typings';
import { escapeRegExp } from '@rocket.chat/tools';

import { settings } from '../../../settings';
import { callbacks } from '../../callbacks';
import { i18n } from '../../i18n';

/**
 * This function returns a string ready to be shown in the notification
 *
 * @param {object} message the message to be parsed
 */
export async function parseMessageTextPerUser(
	messageText: string,
	message: Pick<IMessage, 'u' | 'msg' | 't' | 'attachments'>,
	receiver: Pick<IUser, 'language'>,
): Promise<string> {
	const lng = receiver.language || settings.get('Language') || 'en';

	const firstAttachment = message.attachments?.[0];
	if (!message.msg && firstAttachment && isFileAttachment(firstAttachment) && isFileImageAttachment(firstAttachment)) {
		return firstAttachment.image_type ? i18n.t('User_uploaded_image', { lng }) : i18n.t('User_uploaded_file', { lng });
	}

	if (message.msg && message.t === 'e2e') {
		return i18n.t('Encrypted_message', { lng });
	}

	// perform processing required before sending message as notification such as markdown filtering
	return callbacks.run('renderNotification', messageText);
}

/**
 * Replaces @username with full name
 *
 * @param {string} message The message to replace
 * @param {object[]} mentions Array of mentions used to make replacements
 *
 * @returns {string}
 */
export function replaceMentionedUsernamesWithFullNames(message: string, mentions: NonNullable<IMessage['mentions']>): string {
	mentions.forEach((mention) => {
		if (mention.name) {
			message = message.replace(new RegExp(escapeRegExp(`@${mention.username}`), 'g'), mention.name);
		}
	});
	return message;
}