create filters for messageCount

apps/meteor/client/views/admin/import/useMessagesCount.ts

@@ -1,5 +1,20 @@
-const useMessagesCount = () => {
-	return 'messageCount';
+import { useMemo } from 'react';
+
+const useMessagesCount = (users, channels, messages, setMessageCount) => {
+	useMemo(() => {
+		let messageCount = 0;
+
+		const selectedUsers = new Set(users.map((user) => user._id));
+		const selectedChannels = new Set(users.map((channel) => channel._id));
+
+		for (const message of messages) {
+			if (selectedUsers.has(message.u._id) || selectedChannels.has(message.rid)) {
+				messageCount++;
+			}
+		}
+
+		setMessageCount(messageCount);
+	}, [users, setMessageCount, messages]);
 };
 
 export default useMessagesCount;

packages/core-typings/src/import/IImportFileData.ts

@@ -1,8 +1,10 @@
 import type { IImportChannel } from './IImportChannel';
+import type { IImportMessage } from './IImportMessage';
 import type { IImportUser } from './IImportUser';
 
 export interface IImportFileData {
 	users: Array<IImportUser>;
 	channels: Array<IImportChannel>;
+	messages: Array<Pick<IImportMessage, '_id' | 'rid' | 'u'>>;
 	message_count: number;
 }