snapshot of https://github.com/RocketChat/Rocket.Chat.git (develop, 2026-09-16; blobs > 131072B omitted)

apps/meteor/server/lib/messages/loadMessageHistory.ts

@@ -0,0 +1,94 @@
+import type { IMessage, IRoom, MessageTypesValues } from '@rocket.chat/core-typings';
+import { Messages, Rooms } from '@rocket.chat/models';
+import type { FindOptions } from 'mongodb';
+
+import { settings } from '../../settings/cached';
+import { getHiddenSystemMessages } from '../messaging/getHiddenSystemMessages';
+import { normalizeMessagesForUser } from '../utils/lib/normalizeMessagesForUser';
+
+export async function loadMessageHistory({
+	userId,
+	rid,
+	end,
+	limit = 20,
+	ls,
+	showThreadMessages = true,
+	offset = 0,
+	room: providedRoom,
+}: {
+	// userId is undefined if user is reading anonymously
+	userId?: string;
+	rid: string;
+	end: Date | undefined;
+	limit?: number;
+	ls?: string | Date;
+	showThreadMessages?: boolean;
+	offset?: number;
+	room?: IRoom;
+}) {
+	const room = providedRoom ?? (await Rooms.findOneById(rid, { projection: { sysMes: 1 } }));
+
+	if (!room) {
+		throw new Error('error-invalid-room');
+	}
+
+	const hiddenSystemMessages = settings.get<MessageTypesValues[]>('Hide_System_Messages');
+
+	const hiddenMessageTypes = getHiddenSystemMessages(room, hiddenSystemMessages);
+
+	const options: FindOptions<IMessage> = {
+		sort: {
+			ts: -1,
+		},
+		limit,
+		skip: offset,
+	};
+
+	const records = end
+		? await Messages.findVisibleByRoomIdBeforeTimestampNotContainingTypes(
+				rid,
+				end,
+				hiddenMessageTypes,
+				options,
+				showThreadMessages,
+			).toArray()
+		: await Messages.findVisibleByRoomIdNotContainingTypes(rid, hiddenMessageTypes, options, showThreadMessages).toArray();
+
+	const firstMessage = records[records.length - 1];
+	const lastSeen = ls ? new Date(ls) : undefined;
+	const hasValidLastSeen = lastSeen !== undefined && !Number.isNaN(lastSeen.getTime());
+
+	const computeUnread = async (): Promise<{ firstUnread: IMessage | undefined; unreadNotLoaded: number }> => {
+		if (!hasValidLastSeen || !lastSeen || !firstMessage || !(new Date(firstMessage.ts) > lastSeen)) {
+			return { firstUnread: undefined, unreadNotLoaded: 0 };
+		}
+
+		const [firstUnreadRecords, unreadNotLoaded] = await Promise.all([
+			Messages.findVisibleByRoomIdBetweenTimestampsNotContainingTypes(
+				rid,
+				lastSeen,
+				firstMessage.ts,
+				hiddenMessageTypes,
+				{ limit: 1, sort: { ts: 1 } },
+				showThreadMessages,
+			).toArray(),
+			Messages.countVisibleByRoomIdBetweenTimestampsNotContainingTypes(
+				rid,
+				lastSeen,
+				firstMessage.ts,
+				hiddenMessageTypes,
+				showThreadMessages,
+			),
+		]);
+
+		return { firstUnread: firstUnreadRecords[0], unreadNotLoaded };
+	};
+
+	const [messages, unread] = await Promise.all([normalizeMessagesForUser(records, userId), computeUnread()]);
+
+	return {
+		messages,
+		firstUnread: unread.firstUnread,
+		unreadNotLoaded: unread.unreadNotLoaded,
+	};
+}