initial commit

fluxer_api/src/channel/services/DMPermissionValidator.ts

@@ -0,0 +1,122 @@
+/*
+ * Copyright (C) 2026 Fluxer Contributors
+ *
+ * This file is part of Fluxer.
+ *
+ * Fluxer is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Fluxer is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with Fluxer. If not, see <https://www.gnu.org/licenses/>.
+ */
+
+import type {UserID} from '~/BrandedTypes';
+import {RelationshipTypes, UserFlags} from '~/Constants';
+import {CannotSendMessagesToUserError, UnclaimedAccountRestrictedError} from '~/Errors';
+import type {IGuildRepository} from '~/guild/IGuildRepository';
+import type {User} from '~/Models';
+import type {IUserRepository} from '~/user/IUserRepository';
+import {checkGuildVerificationWithGuildModel} from '~/utils/GuildVerificationUtils';
+
+interface DMPermissionValidatorDeps {
+	userRepository: IUserRepository;
+	guildRepository: IGuildRepository;
+}
+
+export class DMPermissionValidator {
+	constructor(private deps: DMPermissionValidatorDeps) {}
+
+	async validate({recipients, userId}: {recipients: Array<User>; userId: UserID}): Promise<void> {
+		const senderUser = await this.deps.userRepository.findUnique(userId);
+		if (senderUser && !senderUser.passwordHash && !senderUser.isBot) {
+			throw new UnclaimedAccountRestrictedError('send direct messages');
+		}
+
+		const targetUser = recipients.find((recipient) => recipient.id !== userId);
+		if (!targetUser) return;
+
+		if (!targetUser.passwordHash && !targetUser.isBot) {
+			throw new UnclaimedAccountRestrictedError('receive direct messages');
+		}
+
+		const senderBlockedTarget = await this.deps.userRepository.getRelationship(
+			userId,
+			targetUser.id,
+			RelationshipTypes.BLOCKED,
+		);
+		if (senderBlockedTarget) {
+			throw new CannotSendMessagesToUserError();
+		}
+
+		const targetBlockedSender = await this.deps.userRepository.getRelationship(
+			targetUser.id,
+			userId,
+			RelationshipTypes.BLOCKED,
+		);
+		if (targetBlockedSender) {
+			throw new CannotSendMessagesToUserError();
+		}
+
+		const friendship = await this.deps.userRepository.getRelationship(userId, targetUser.id, RelationshipTypes.FRIEND);
+		if (friendship) return;
+
+		if (targetUser.flags & UserFlags.APP_STORE_REVIEWER) {
+			throw new CannotSendMessagesToUserError();
+		}
+
+		const targetSettings = await this.deps.userRepository.findSettings(targetUser.id);
+		if (!targetSettings) return;
+
+		const dmRestrictionsEnabled = targetSettings.defaultGuildsRestricted || targetSettings.restrictedGuilds.size > 0;
+		if (!dmRestrictionsEnabled) {
+			return;
+		}
+
+		const [userGuilds, targetGuilds] = await Promise.all([
+			this.deps.guildRepository.listUserGuilds(userId),
+			this.deps.guildRepository.listUserGuilds(targetUser.id),
+		]);
+
+		if (!senderUser) {
+			throw new CannotSendMessagesToUserError();
+		}
+
+		const userGuildIds = new Set(userGuilds.map((guild) => guild.id));
+		const mutualGuilds = targetGuilds.filter((guild) => userGuildIds.has(guild.id));
+
+		if (mutualGuilds.length === 0) {
+			throw new CannotSendMessagesToUserError();
+		}
+
+		const restrictedGuildIds = targetSettings.restrictedGuilds;
+
+		let hasValidMutualGuild = false;
+		for (const guild of mutualGuilds) {
+			if (restrictedGuildIds.has(guild.id)) {
+				continue;
+			}
+
+			const member = await this.deps.guildRepository.getMember(guild.id, userId);
+			if (!member) {
+				continue;
+			}
+
+			try {
+				checkGuildVerificationWithGuildModel({user: senderUser, guild, member});
+				hasValidMutualGuild = true;
+				break;
+			} catch {}
+		}
+
+		if (!hasValidMutualGuild) {
+			throw new CannotSendMessagesToUserError();
+		}
+	}
+}