import type { ILivechatAgent, ILivechatVisitor, IMessage, IRoom, IUser, IAuditLog } from '@rocket.chat/core-typings';
import { LivechatRooms, Messages, Rooms, Users, AuditLog } from '@rocket.chat/models';
import { escapeRegExp, isTruthy } from '@rocket.chat/tools';
import { Meteor } from 'meteor/meteor';
import type { Filter } from 'mongodb';

import { hasPermissionAsync } from '../../../../server/lib/authorization/hasPermission';
import { callbacks } from '../../../../server/lib/callbacks';
import { i18n } from '../../../../server/lib/i18n';
import { updateCounter } from '../../../../server/lib/statistics';

const getValue = (room: IRoom | null) => room && { rids: [room._id], name: room.name };

const getUsersIdFromUserName = async (usernames: IUser['username'][]) => {
	const users = usernames ? await Users.findByUsernames(usernames.filter(isTruthy)).toArray() : undefined;

	return users?.filter(isTruthy).map((userId) => userId._id);
};

const getRoomInfoByAuditParams = async ({
	type,
	roomId: rid,
	users: usernames,
	visitor,
	agent,
	userId,
}: {
	type: string;
	roomId: IRoom['_id'];
	users: NonNullable<IUser['username']>[];
	visitor: ILivechatVisitor['_id'];
	agent: ILivechatAgent['_id'];
	userId: string;
}) => {
	if (rid) {
		return getValue(await Rooms.findOne({ _id: rid, abacAttributes: { $exists: false } }));
	}

	if (type === 'd') {
		return getValue(await Rooms.findDirectRoomContainingAllUsernames(usernames));
	}

	if (type === 'l') {
		const extraQuery = await callbacks.run('livechat.applyRoomRestrictions', {}, { userId });
		const rooms = await LivechatRooms.findByVisitorIdAndAgentId(
			visitor,
			agent,
			{
				projection: { _id: 1 },
			},
			extraQuery,
		).toArray();
		return rooms?.length ? { rids: rooms.map(({ _id }) => _id), name: i18n.t('Omnichannel') } : undefined;
	}
};

const requireAuditor = async (userId: string | null): Promise<IUser> => {
	if (!userId) {
		throw new Meteor.Error('Not allowed');
	}

	const user = await Users.findOneById(userId);
	if (!user || !(await hasPermissionAsync(user._id, 'can-audit'))) {
		throw new Meteor.Error('Not allowed');
	}
	return user;
};

type AuditMessagesParams = {
	rid?: IRoom['_id'];
	startDate: Date;
	endDate: Date;
	users: NonNullable<IUser['username']>[];
	msg: IMessage['msg'];
	type: string;
	visitor?: ILivechatVisitor['_id'];
	agent?: ILivechatAgent['_id'];
};

export const auditGetMessagesMethod = async (userId: string | null, params: AuditMessagesParams): Promise<IMessage[]> => {
	const { rid, startDate, endDate, users: usernames, msg, type, visitor, agent } = params;

	const user = await requireAuditor(userId);

	const userFields = {
		_id: user._id,
		username: user.username,
		...(user.name && { name: user.name }),
		...(user.avatarETag && { avatarETag: user.avatarETag }),
	};

	let rids;
	let name;

	const query: Filter<IMessage> = {
		ts: {
			$gt: startDate,
			$lt: endDate,
		},
	};

	if (type === 'u') {
		const usersId = await getUsersIdFromUserName(usernames);
		query['u._id'] = { $in: usersId };

		const abacRooms = await Rooms.findAllPrivateRoomsWithAbacAttributes({ projection: { _id: 1 } })
			.map((doc) => doc._id)
			.toArray();

		query.rid = { $nin: abacRooms };
	} else {
		const roomInfo = await getRoomInfoByAuditParams({
			type,
			roomId: rid ?? '',
			users: usernames,
			visitor: visitor ?? '',
			agent: agent ?? '',
			userId: user._id,
		});
		if (!roomInfo) {
			throw new Meteor.Error(`Room doesn't exist`);
		}

		rids = roomInfo.rids;
		name = roomInfo.name;
		query.rid = { $in: rids };
	}

	if (msg) {
		const regex = new RegExp(escapeRegExp(msg).trim(), 'i');
		query.msg = regex;
	}

	const messages = await Messages.find(query).toArray();

	await AuditLog.insertOne(
		{
			ts: new Date(),
			results: messages.length,
			u: userFields,
			fields: { msg, users: usernames, rids, room: name, startDate, endDate, type, visitor, agent },
		},
		{ ignoreUndefined: true },
	);

	updateCounter({ settingsId: 'Message_Auditing_Panel_Load_Count' });

	return messages;
};

type AuditOmnichannelMessagesParams = {
	startDate: Date;
	endDate: Date;
	users: NonNullable<IUser['username']>[];
	msg: IMessage['msg'];
	type: string;
	visitor?: ILivechatVisitor['_id'];
	agent?: ILivechatAgent['_id'];
};

export const auditGetOmnichannelMessagesMethod = async (
	userId: string | null,
	params: AuditOmnichannelMessagesParams,
): Promise<IMessage[]> => {
	const { startDate, endDate, users: usernames, msg, type, visitor, agent } = params;

	const user = await requireAuditor(userId);

	const userFields = {
		_id: user._id,
		username: user.username,
		...(user.name && { name: user.name }),
		...(user.avatarETag && { avatarETag: user.avatarETag }),
	};

	// No livechat.applyRoomRestrictions here (unlike the type 'l' path in getRoomInfoByAuditParams): this
	// mirrors the original DDP auditGetOmnichannelMessages. Access is gated by the can-audit permission and
	// audit is intended to span all omnichannel rooms, so unit/visibility restrictions are not applied.
	const rooms = await LivechatRooms.findByVisitorIdAndAgentId(visitor, agent, {
		projection: { _id: 1 },
	}).toArray();
	// keep rids an array — `$in: undefined` throws "$in needs an array" when no rooms match
	const rids = rooms.map(({ _id }) => _id);
	const name = i18n.t('Omnichannel');

	const query: Filter<IMessage> = {
		rid: { $in: rids },
		ts: {
			$gt: startDate,
			$lt: endDate,
		},
	};

	if (msg) {
		const regex = new RegExp(escapeRegExp(msg).trim(), 'i');
		query.msg = regex;
	}

	const messages = await Messages.find(query).toArray();

	await AuditLog.insertOne(
		{
			ts: new Date(),
			results: messages.length,
			u: userFields,
			fields: { msg, users: usernames, rids, room: name, startDate, endDate, type, visitor, agent },
		},
		{ ignoreUndefined: true },
	);

	return messages;
};

export const auditGetAuditionsMethod = async (userId: string | null, startDate: Date, endDate: Date): Promise<IAuditLog[]> => {
	if (!userId || !(await hasPermissionAsync(userId, 'can-audit-log'))) {
		throw new Meteor.Error('Not allowed');
	}
	return AuditLog.find(
		{
			ts: {
				$gt: startDate,
				$lt: endDate,
			},
		},
		{
			projection: {
				'u.services': 0,
				'u.roles': 0,
				'u.lastLogin': 0,
				'u.statusConnection': 0,
				'u.emails': 0,
			},
		},
	).toArray();
};