/*
 * SPDX-FileCopyrightText: syuilo and misskey-project
 * SPDX-License-Identifier: AGPL-3.0-only
 */

import { Inject, Injectable } from '@nestjs/common';
import { Not, IsNull, DataSource } from 'typeorm';
import type { FollowingsRepository, FollowRequestsRepository, UsersRepository } from '@/models/_.js';
import { MiUser } from '@/models/User.js';
import { QueueService } from '@/core/QueueService.js';
import { GlobalEventService } from '@/core/GlobalEventService.js';
import { DI } from '@/di-symbols.js';
import { ApRendererService } from '@/core/activitypub/ApRendererService.js';
import { UserEntityService } from '@/core/entities/UserEntityService.js';
import { bindThis } from '@/decorators.js';
import { RelationshipJobData } from '@/queue/types.js';
import { ModerationLogService } from '@/core/ModerationLogService.js';
import { isSystemAccount } from '@/misc/is-system-account.js';
import { CacheService } from '@/core/CacheService.js';
import { LoggerService } from '@/core/LoggerService.js';
import type Logger from '@/logger.js';
import { renderInlineError } from '@/misc/render-inline-error.js';
import { trackPromise } from '@/misc/promise-tracker.js';
import { InternalEventService } from '@/core/InternalEventService.js';

@Injectable()
export class UserSuspendService {
	private readonly logger: Logger;

	constructor(
		@Inject(DI.usersRepository)
		private usersRepository: UsersRepository,

		@Inject(DI.followingsRepository)
		private followingsRepository: FollowingsRepository,

		@Inject(DI.followRequestsRepository)
		private followRequestsRepository: FollowRequestsRepository,

		@Inject(DI.db)
		private db: DataSource,

		private userEntityService: UserEntityService,
		private queueService: QueueService,
		private globalEventService: GlobalEventService,
		private apRendererService: ApRendererService,
		private moderationLogService: ModerationLogService,
		private readonly cacheService: CacheService,
		private readonly internalEventService: InternalEventService,

		loggerService: LoggerService,
	) {
		this.logger = loggerService.getLogger('user-suspend');
	}

	@bindThis
	public async suspend(user: MiUser, moderator: MiUser): Promise<void> {
		if (isSystemAccount(user)) throw new Error('cannot suspend a system account');

		await this.usersRepository.update(user.id, {
			isSuspended: true,
		});

		await this.internalEventService.emit(user.host == null ? 'localUserUpdated' : 'remoteUserUpdated', { id: user.id });

		await this.moderationLogService.log(moderator, 'suspend', {
			userId: user.id,
			userUsername: user.username,
			userHost: user.host,
		});

		trackPromise((async () => {
			await this.postSuspend(user);
			await this.freezeAll(user);
		})().catch(e => this.logger.error(`Error suspending user ${user.id}: ${renderInlineError(e)}`)));
	}

	@bindThis
	public async unsuspend(user: MiUser, moderator: MiUser): Promise<void> {
		await this.usersRepository.update(user.id, {
			isSuspended: false,
		});

		await this.internalEventService.emit(user.host == null ? 'localUserUpdated' : 'remoteUserUpdated', { id: user.id });

		await this.moderationLogService.log(moderator, 'unsuspend', {
			userId: user.id,
			userUsername: user.username,
			userHost: user.host,
		});

		trackPromise((async () => {
			await this.postUnsuspend(user);
			await this.unFreezeAll(user);
		})().catch(e => this.logger.error(`Error un-suspending for user ${user.id}: ${renderInlineError(e)}`)));
	}

	@bindThis
	private async postSuspend(user: { id: MiUser['id']; host: MiUser['host'] }): Promise<void> {
		this.globalEventService.publishInternalEvent('userChangeSuspendedState', { id: user.id, isSuspended: true });

		/*
		this.followRequestsRepository.delete({
			followeeId: user.id,
		});
		this.followRequestsRepository.delete({
			followerId: user.id,
		});
		*/

		if (this.userEntityService.isLocalUser(user)) {
			// 知り得る全SharedInboxにDelete配信
			const content = this.apRendererService.addContext(this.apRendererService.renderDelete(this.userEntityService.genLocalUserUri(user.id), user));

			const queue = new Map<string, boolean>();

			const followings = await this.followingsRepository.find({
				where: [
					{ followerSharedInbox: Not(IsNull()) },
					{ followeeSharedInbox: Not(IsNull()) },
				],
				select: ['followerSharedInbox', 'followeeSharedInbox'],
			});

			const inboxes = followings.map(x => x.followerSharedInbox ?? x.followeeSharedInbox);

			for (const inbox of inboxes) {
				if (inbox != null) {
					queue.set(inbox, true);
				}
			}

			await this.queueService.deliverMany(user, content, queue);
		}
	}

	@bindThis
	private async postUnsuspend(user: MiUser): Promise<void> {
		this.globalEventService.publishInternalEvent('userChangeSuspendedState', { id: user.id, isSuspended: false });

		if (this.userEntityService.isLocalUser(user)) {
			// 知り得る全SharedInboxにUndo Delete配信
			const content = this.apRendererService.addContext(this.apRendererService.renderUndo(this.apRendererService.renderDelete(this.userEntityService.genLocalUserUri(user.id), user), user));

			const queue = new Map<string, boolean>();

			const followings = await this.followingsRepository.find({
				where: [
					{ followerSharedInbox: Not(IsNull()) },
					{ followeeSharedInbox: Not(IsNull()) },
				],
				select: ['followerSharedInbox', 'followeeSharedInbox'],
			});

			const inboxes = followings.map(x => x.followerSharedInbox ?? x.followeeSharedInbox);

			for (const inbox of inboxes) {
				if (inbox != null) {
					queue.set(inbox, true);
				}
			}

			await this.queueService.deliverMany(user, content, queue);
		}
	}

	@bindThis
	private async unFollowAll(follower: MiUser) {
		const followings = await this.cacheService.userFollowingsCache.fetch(follower.id)
			.then(fs => Array.from(fs.values()).filter(f => f.followeeHost != null));

		const jobs: RelationshipJobData[] = [];
		for (const following of followings) {
			if (following.followeeId && following.followerId) {
				jobs.push({
					from: { id: following.followerId },
					to: { id: following.followeeId },
					silent: true,
				});
			}
		}
		this.queueService.createUnfollowJob(jobs);
	}

	@bindThis
	private async freezeAll(user: MiUser): Promise<void> {
		// Freeze follow relations with all remote users
		await this.followingsRepository
			.createQueryBuilder('following')
			.update({
				isFollowerHibernated: true,
			})
			.where({
				followeeId: user.id,
				followerHost: Not(IsNull()),
			})
			.execute();
	}

	@bindThis
	private async unFreezeAll(user: MiUser): Promise<void> {
		// Restore follow relations with all remote users

		// TypeORM does not support UPDATE with JOIN: https://github.com/typeorm/typeorm/issues/564#issuecomment-310331468
		await this.db.query(`
			UPDATE "following"
				SET "isFollowerHibernated" = false
			FROM "user"
			WHERE "user"."id" = "following"."followerId"
				AND "user"."isHibernated" = false -- Don't unfreeze if the follower is *actually* frozen
				AND "followeeId" = $1
				AND "followeeHost" IS NOT NULL
		`, [user.id]);
	}
}