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

import { Inject, Injectable, OnApplicationShutdown } from '@nestjs/common';
import { Brackets, In, IsNull, ObjectLiteral, SelectQueryBuilder, WhereExpressionBuilder } from 'typeorm';
import * as Redis from 'ioredis';
import { DI } from '@/di-symbols.js';
import { IdService } from '@/core/IdService.js';
import { EmojiEntityService } from '@/core/entities/EmojiEntityService.js';
import { GlobalEventService } from '@/core/GlobalEventService.js';
import type { MiEmoji } from '@/models/Emoji.js';
import type { EmojisRepository, MiRole, MiUser } from '@/models/_.js';
import { bindThis } from '@/decorators.js';
import { MemoryKVCache, RedisSingleCache } from '@/misc/cache.js';
import { UtilityService } from '@/core/UtilityService.js';
import type { Serialized } from '@/types.js';
import { ModerationLogService } from '@/core/ModerationLogService.js';

const parseEmojiStrRegexp = /^([-\w]+)(?:@([\w.-]+))?$/;

export const fetchEmojisHostTypes = [
	'local',
	'remote',
	'all',
] as const;
export type FetchEmojisHostTypes = typeof fetchEmojisHostTypes[number];
export const fetchEmojisSortKeys = [
	'id',
	'updatedAt',
	'name',
	'host',
	'uri',
	'publicUrl',
	'type',
	'aliases',
	'category',
	'license',
	'isSensitive',
	'localOnly',
	'roleIdsThatCanBeUsedThisEmojiAsReaction',
] as const;
export type FetchEmojisSortKeys = typeof fetchEmojisSortKeys[number];
export type FetchEmojisParams = {
	query?: {
		updatedAtFrom?: string;
		updatedAtTo?: string;
		name?: string;
		host?: string;
		uri?: string;
		publicUrl?: string;
		type?: string;
		aliases?: string;
		category?: string;
		license?: string;
		isSensitive?: boolean;
		localOnly?: boolean;
		hostType?: FetchEmojisHostTypes;
		roleIds?: string[];
	},
	sinceId?: string;
	untilId?: string;
	limit?: number;
	page?: number;
	sort?: {
		key: FetchEmojisSortKeys;
		direction: 'ASC' | 'DESC';
	}[]
}

@Injectable()
export class CustomEmojiService implements OnApplicationShutdown {
	private cache: MemoryKVCache<MiEmoji | null>;
	public localEmojisCache: RedisSingleCache<Map<string, MiEmoji>>;

	constructor(
		@Inject(DI.redis)
		private redisClient: Redis.Redis,
		@Inject(DI.emojisRepository)
		private emojisRepository: EmojisRepository,
		private utilityService: UtilityService,
		private idService: IdService,
		private emojiEntityService: EmojiEntityService,
		private moderationLogService: ModerationLogService,
		private globalEventService: GlobalEventService,
	) {
		this.cache = new MemoryKVCache<MiEmoji | null>(1000 * 60 * 60 * 12);

		this.localEmojisCache = new RedisSingleCache<Map<string, MiEmoji>>(this.redisClient, 'localEmojis', {
			lifetime: 1000 * 60 * 30, // 30m
			memoryCacheLifetime: 1000 * 60 * 3, // 3m
			fetcher: () => this.emojisRepository.find({ where: { host: IsNull() } }).then(emojis => new Map(emojis.map(emoji => [emoji.name, emoji]))),
			toRedisConverter: (value) => JSON.stringify(Array.from(value.values())),
			fromRedisConverter: (value) => {
				return new Map(JSON.parse(value).map((x: Serialized<MiEmoji>) => [x.name, {
					...x,
					updatedAt: x.updatedAt ? new Date(x.updatedAt) : null,
				}]));
			},
		});
	}

	@bindThis
	public async add(data: {
		originalUrl: string;
		publicUrl: string;
		fileType: string;
		name: string;
		category: string | null;
		aliases: string[];
		host: string | null;
		license: string | null;
		isSensitive: boolean;
		localOnly: boolean;
		roleIdsThatCanBeUsedThisEmojiAsReaction: MiRole['id'][];
	}, moderator?: MiUser): Promise<MiEmoji> {
		const emoji = await this.emojisRepository.insertOne({
			id: this.idService.gen(),
			updatedAt: new Date(),
			name: data.name,
			category: data.category,
			host: data.host,
			aliases: data.aliases,
			originalUrl: data.originalUrl,
			publicUrl: data.publicUrl,
			type: data.fileType,
			license: data.license,
			isSensitive: data.isSensitive,
			localOnly: data.localOnly,
			roleIdsThatCanBeUsedThisEmojiAsReaction: data.roleIdsThatCanBeUsedThisEmojiAsReaction,
		});

		if (data.host == null) {
			this.localEmojisCache.refresh();

			this.globalEventService.publishBroadcastStream('emojiAdded', {
				emoji: await this.emojiEntityService.packDetailed(emoji.id),
			});

			if (moderator) {
				this.moderationLogService.log(moderator, 'addCustomEmoji', {
					emojiId: emoji.id,
					emoji: emoji,
				});
			}
		}

		return emoji;
	}

	@bindThis
	public async update(id: MiEmoji['id'], data: {
		originalUrl?: string;
		publicUrl?: string;
		fileType?: string;
		name?: string;
		category?: string | null;
		aliases?: string[];
		license?: string | null;
		isSensitive?: boolean;
		localOnly?: boolean;
		roleIdsThatCanBeUsedThisEmojiAsReaction?: MiRole['id'][];
	}, moderator?: MiUser): Promise<void> {
		const emoji = await this.emojisRepository.findOneByOrFail({ id: id });
		const sameNameEmoji = await this.emojisRepository.findOneBy({ name: data.name, host: IsNull() });
		if (sameNameEmoji != null && sameNameEmoji.id !== id) throw new Error('name already exists');

		await this.emojisRepository.update(emoji.id, {
			updatedAt: new Date(),
			name: data.name,
			category: data.category,
			aliases: data.aliases,
			license: data.license,
			isSensitive: data.isSensitive,
			localOnly: data.localOnly,
			originalUrl: data.originalUrl,
			publicUrl: data.publicUrl,
			type: data.fileType,
			roleIdsThatCanBeUsedThisEmojiAsReaction: data.roleIdsThatCanBeUsedThisEmojiAsReaction ?? undefined,
		});

		this.localEmojisCache.refresh();

		const packed = await this.emojiEntityService.packDetailed(emoji.id);

		if (emoji.name === data.name) {
			this.globalEventService.publishBroadcastStream('emojiUpdated', {
				emojis: [packed],
			});
		} else {
			this.globalEventService.publishBroadcastStream('emojiDeleted', {
				emojis: [await this.emojiEntityService.packDetailed(emoji)],
			});

			this.globalEventService.publishBroadcastStream('emojiAdded', {
				emoji: packed,
			});
		}

		if (moderator) {
			const updated = await this.emojisRepository.findOneByOrFail({ id: id });
			this.moderationLogService.log(moderator, 'updateCustomEmoji', {
				emojiId: emoji.id,
				before: emoji,
				after: updated,
			});
		}
	}

	@bindThis
	public async addAliasesBulk(ids: MiEmoji['id'][], aliases: string[]) {
		const emojis = await this.emojisRepository.findBy({
			id: In(ids),
		});

		for (const emoji of emojis) {
			await this.emojisRepository.update(emoji.id, {
				updatedAt: new Date(),
				aliases: [...new Set(emoji.aliases.concat(aliases))],
			});
		}

		this.localEmojisCache.refresh();

		this.globalEventService.publishBroadcastStream('emojiUpdated', {
			emojis: await this.emojiEntityService.packDetailedMany(ids),
		});
	}

	@bindThis
	public async setAliasesBulk(ids: MiEmoji['id'][], aliases: string[]) {
		await this.emojisRepository.update({
			id: In(ids),
		}, {
			updatedAt: new Date(),
			aliases: aliases,
		});

		this.localEmojisCache.refresh();

		this.globalEventService.publishBroadcastStream('emojiUpdated', {
			emojis: await this.emojiEntityService.packDetailedMany(ids),
		});
	}

	@bindThis
	public async removeAliasesBulk(ids: MiEmoji['id'][], aliases: string[]) {
		const emojis = await this.emojisRepository.findBy({
			id: In(ids),
		});

		for (const emoji of emojis) {
			await this.emojisRepository.update(emoji.id, {
				updatedAt: new Date(),
				aliases: emoji.aliases.filter(x => !aliases.includes(x)),
			});
		}

		this.localEmojisCache.refresh();

		this.globalEventService.publishBroadcastStream('emojiUpdated', {
			emojis: await this.emojiEntityService.packDetailedMany(ids),
		});
	}

	@bindThis
	public async setCategoryBulk(ids: MiEmoji['id'][], category: string | null) {
		await this.emojisRepository.update({
			id: In(ids),
		}, {
			updatedAt: new Date(),
			category: category,
		});

		this.localEmojisCache.refresh();

		this.globalEventService.publishBroadcastStream('emojiUpdated', {
			emojis: await this.emojiEntityService.packDetailedMany(ids),
		});
	}

	@bindThis
	public async setLicenseBulk(ids: MiEmoji['id'][], license: string | null) {
		await this.emojisRepository.update({
			id: In(ids),
		}, {
			updatedAt: new Date(),
			license: license,
		});

		this.localEmojisCache.refresh();

		this.globalEventService.publishBroadcastStream('emojiUpdated', {
			emojis: await this.emojiEntityService.packDetailedMany(ids),
		});
	}

	@bindThis
	public async delete(id: MiEmoji['id'], moderator?: MiUser) {
		const emoji = await this.emojisRepository.findOneByOrFail({ id: id });

		await this.emojisRepository.delete(emoji.id);

		this.localEmojisCache.refresh();

		this.globalEventService.publishBroadcastStream('emojiDeleted', {
			emojis: [await this.emojiEntityService.packDetailed(emoji)],
		});

		if (moderator) {
			this.moderationLogService.log(moderator, 'deleteCustomEmoji', {
				emojiId: emoji.id,
				emoji: emoji,
			});
		}
	}

	@bindThis
	public async deleteBulk(ids: MiEmoji['id'][], moderator?: MiUser) {
		const emojis = await this.emojisRepository.findBy({
			id: In(ids),
		});

		for (const emoji of emojis) {
			await this.emojisRepository.delete(emoji.id);

			if (moderator) {
				this.moderationLogService.log(moderator, 'deleteCustomEmoji', {
					emojiId: emoji.id,
					emoji: emoji,
				});
			}
		}

		this.localEmojisCache.refresh();

		this.globalEventService.publishBroadcastStream('emojiDeleted', {
			emojis: await this.emojiEntityService.packDetailedMany(emojis),
		});
	}

	@bindThis
	private normalizeHost(src: string | undefined, noteUserHost: string | null): string | null {
		// クエリに使うホスト
		let host = src === '.' ? null	// .はローカルホスト (ここがマッチするのはリアクションのみ)
			: src === undefined ? noteUserHost	// ノートなどでホスト省略表記の場合はローカルホスト (ここがリアクションにマッチすることはない)
			: this.utilityService.isSelfHost(src) ? null	// 自ホスト指定
			: (src || noteUserHost);	// 指定されたホスト || ノートなどの所有者のホスト (こっちがリアクションにマッチすることはない)

		host = this.utilityService.toPunyNullable(host);

		return host;
	}

	@bindThis
	public parseEmojiStr(emojiName: string, noteUserHost: string | null) {
		const match = emojiName.match(parseEmojiStrRegexp);
		if (!match) return { name: null, host: null };

		const name = match[1];

		// ホスト正規化
		const host = this.utilityService.toPunyNullable(this.normalizeHost(match[2], noteUserHost));

		return { name, host };
	}

	/**
	 * 添付用(リモート)カスタム絵文字URLを解決する
	 * @param emojiName ノートやユーザープロフィールに添付された、またはリアクションのカスタム絵文字名 (:は含めない, リアクションでローカルホストの場合は@.を付ける (これはdecodeReactionで可能))
	 * @param noteUserHost ノートやユーザープロフィールの所有者のホスト
	 * @returns URL, nullは未マッチを意味する
	 */
	@bindThis
	public async populateEmoji(emojiName: string, noteUserHost: string | null): Promise<string | null> {
		const { name, host } = this.parseEmojiStr(emojiName, noteUserHost);
		if (name == null) return null;
		if (host == null) return null;

		const queryOrNull = async () => (await this.emojisRepository.findOneBy({
			name,
			host,
		})) ?? null;

		const emoji = await this.cache.fetch(`${name} ${host}`, queryOrNull);

		if (emoji == null) return null;
		return emoji.publicUrl || emoji.originalUrl; // || emoji.originalUrl してるのは後方互換性のため（publicUrlはstringなので??はだめ）
	}

	/**
	 * 複数の添付用(リモート)カスタム絵文字URLを解決する (キャシュ付き, 存在しないものは結果から除外される)
	 */
	@bindThis
	public async populateEmojis(emojiNames: string[], noteUserHost: string | null): Promise<Record<string, string>> {
		const emojis = await Promise.all(emojiNames.map(x => this.populateEmoji(x, noteUserHost)));
		const res = {} as Record<string, string>;
		for (let i = 0; i < emojiNames.length; i++) {
			const resolvedEmoji = emojis[i];
			if (resolvedEmoji != null) {
				res[emojiNames[i]] = resolvedEmoji;
			}
		}
		return res;
	}

	/**
	 * 与えられた絵文字のリストをデータベースから取得し、キャッシュに追加します
	 */
	@bindThis
	public async prefetchEmojis(emojis: { name: string; host: string | null; }[]): Promise<void> {
		const notCachedEmojis = emojis.filter(emoji => this.cache.get(`${emoji.name} ${emoji.host}`) == null);
		const emojisQuery: any[] = [];
		const hosts = new Set(notCachedEmojis.map(e => e.host));
		for (const host of hosts) {
			if (host == null) continue;
			emojisQuery.push({
				name: In(notCachedEmojis.filter(e => e.host === host).map(e => e.name)),
				host: host,
			});
		}
		const _emojis = emojisQuery.length > 0 ? await this.emojisRepository.find({
			where: emojisQuery,
			select: ['name', 'host', 'originalUrl', 'publicUrl'],
		}) : [];
		for (const emoji of _emojis) {
			this.cache.set(`${emoji.name} ${emoji.host}`, emoji);
		}
	}

	/**
	 * ローカル内の絵文字に重複がないかチェックします
	 * @param name 絵文字名
	 */
	@bindThis
	public checkDuplicate(name: string): Promise<boolean> {
		return this.emojisRepository.exists({ where: { name, host: IsNull() } });
	}

	@bindThis
	public getEmojiById(id: string): Promise<MiEmoji | null> {
		return this.emojisRepository.findOneBy({ id });
	}

	@bindThis
	public getEmojiByName(name: string): Promise<MiEmoji | null> {
		return this.emojisRepository.findOneBy({ name, host: IsNull() });
	}

	@bindThis
	public async fetchEmojis(params?: FetchEmojisParams) {
		function multipleWordsToQuery<T extends ObjectLiteral>(
			query: string,
			builder: SelectQueryBuilder<T>,
			action: (qb: WhereExpressionBuilder, idx: number, word: string) => void,
		) {
			const words = query.split(/\s/);
			builder.andWhere(new Brackets((qb => {
				for (const [idx, word] of words.entries()) {
					action(qb, idx, word);
				}
			})));
		}

		const builder = this.emojisRepository.createQueryBuilder('emoji');
		if (params?.query) {
			const q = params.query;
			if (q.updatedAtFrom) {
				// noIndexScan
				builder.andWhere('CAST(emoji.updatedAt AS DATE) >= :updateAtFrom', { updateAtFrom: q.updatedAtFrom });
			}
			if (q.updatedAtTo) {
				// noIndexScan
				builder.andWhere('CAST(emoji.updatedAt AS DATE) <= :updateAtTo', { updateAtTo: q.updatedAtTo });
			}
			if (q.name) {
				multipleWordsToQuery(q.name, builder, (qb, idx, word) => {
					qb.orWhere(`emoji.name LIKE :name${idx}`, Object.fromEntries([[`name${idx}`, `%${word}%`]]));
				});
			}

			switch (true) {
				case q.hostType === 'local': {
					builder.andWhere('emoji.host IS NULL');
					break;
				}
				case q.hostType === 'remote': {
					if (q.host) {
						// noIndexScan
						multipleWordsToQuery(q.host, builder, (qb, idx, word) => {
							qb.orWhere(`emoji.host LIKE :host${idx}`, Object.fromEntries([[`host${idx}`, `%${word}%`]]));
						});
					} else {
						builder.andWhere('emoji.host IS NOT NULL');
					}
					break;
				}
			}

			if (q.uri) {
				// noIndexScan
				multipleWordsToQuery(q.uri, builder, (qb, idx, word) => {
					qb.orWhere(`emoji.uri LIKE :uri${idx}`, Object.fromEntries([[`uri${idx}`, `%${word}%`]]));
				});
			}
			if (q.publicUrl) {
				// noIndexScan
				multipleWordsToQuery(q.publicUrl, builder, (qb, idx, word) => {
					qb.orWhere(`emoji.publicUrl LIKE :publicUrl${idx}`, Object.fromEntries([[`publicUrl${idx}`, `%${word}%`]]));
				});
			}
			if (q.type) {
				// noIndexScan
				multipleWordsToQuery(q.type, builder, (qb, idx, word) => {
					qb.orWhere(`emoji.type LIKE :type${idx}`, Object.fromEntries([[`type${idx}`, `%${word}%`]]));
				});
			}
			if (q.aliases) {
				// noIndexScan
				const subQueryBuilder = builder.subQuery()
					.select('COUNT(0)', 'count')
					.from(
						sq2 => sq2
							.select('unnest(subEmoji.aliases)', 'alias')
							.addSelect('subEmoji.id', 'id')
							.from('emoji', 'subEmoji'),
						'aliasTable',
					)
					.where('"emoji"."id" = "aliasTable"."id"');
				multipleWordsToQuery(q.aliases, subQueryBuilder, (qb, idx, word) => {
					qb.orWhere(`"aliasTable"."alias" LIKE :aliases${idx}`, Object.fromEntries([[`aliases${idx}`, `%${word}%`]]));
				});

				builder.andWhere(`(${subQueryBuilder.getQuery()}) > 0`);
			}
			if (q.category) {
				multipleWordsToQuery(q.category, builder, (qb, idx, word) => {
					qb.orWhere(`emoji.category LIKE :category${idx}`, Object.fromEntries([[`category${idx}`, `%${word}%`]]));
				});
			}
			if (q.license) {
				// noIndexScan
				multipleWordsToQuery(q.license, builder, (qb, idx, word) => {
					qb.orWhere(`emoji.license LIKE :license${idx}`, Object.fromEntries([[`license${idx}`, `%${word}%`]]));
				});
			}
			if (q.isSensitive != null) {
				// noIndexScan
				builder.andWhere('emoji.isSensitive = :isSensitive', { isSensitive: q.isSensitive });
			}
			if (q.localOnly != null) {
				// noIndexScan
				builder.andWhere('emoji.localOnly = :localOnly', { localOnly: q.localOnly });
			}
			if (q.roleIds && q.roleIds.length > 0) {
				builder.andWhere('emoji.roleIdsThatCanBeUsedThisEmojiAsReaction @> :roleIds', { roleIds: q.roleIds });
			}
		}

		if (params?.sinceId) {
			builder.andWhere('emoji.id > :sinceId', { sinceId: params.sinceId });
		}
		if (params?.untilId) {
			builder.andWhere('emoji.id < :untilId', { untilId: params.untilId });
		}

		if (params?.sort && params.sort.length > 0) {
			for (const sort of params.sort) {
				builder.addOrderBy(`emoji.${sort.key}`, sort.direction);
			}
		} else {
			builder.addOrderBy('emoji.id', 'DESC');
		}

		const limit = params?.limit ?? 10;
		if (params?.page) {
			builder.skip((params.page - 1) * limit);
		}

		builder.take(limit);

		const [emojis, count] = await builder.getManyAndCount();

		return {
			emojis,
			count: (count > limit ? emojis.length : count),
			allCount: count,
			allPages: Math.ceil(count / limit),
		};
	}

	@bindThis
	public dispose(): void {
		this.cache.dispose();
	}

	@bindThis
	public onApplicationShutdown(signal?: string | undefined): void {
		this.dispose();
	}
}