import { Inject, Injectable } from '@nestjs/common';
import { IsNull } from 'typeorm';
import { DI } from '@/di-symbols.js';
import type { EmojisRepository, BlockingsRepository, NoteReactionsRepository, UsersRepository, NotesRepository } from '@/models/index.js';
import { IdentifiableError } from '@/misc/identifiable-error.js';
import type { IRemoteUser, User } from '@/models/entities/User.js';
import type { Note } from '@/models/entities/Note.js';
import { IdService } from '@/core/IdService.js';
import type { NoteReaction } from '@/models/entities/NoteReaction.js';
import { isDuplicateKeyValueError } from '@/misc/is-duplicate-key-value-error.js';
import { GlobalEventService } from '@/core/GlobalEventService.js';
import { CreateNotificationService } from '@/core/CreateNotificationService.js';
import PerUserReactionsChart from '@/core/chart/charts/per-user-reactions.js';
import { emojiRegex } from '@/misc/emoji-regex.js';
import { ApDeliverManagerService } from '@/core/activitypub/ApDeliverManagerService.js';
import { NoteEntityService } from '@/core/entities/NoteEntityService.js';
import { UserEntityService } from '@/core/entities/UserEntityService.js';
import { ApRendererService } from '@/core/activitypub/ApRendererService.js';
import { MetaService } from '@/core/MetaService.js';
import { UtilityService } from './UtilityService.js';

const legacies: Record<string, string> = {
	'like': '👍',
	'love': '❤', // ここに記述する場合は異体字セレクタを入れない
	'laugh': '😆',
	'hmm': '🤔',
	'surprise': '😮',
	'congrats': '🎉',
	'angry': '💢',
	'confused': '😥',
	'rip': '😇',
	'pudding': '🍮',
	'star': '⭐',
};

type DecodedReaction = {
	/**
	 * リアクション名 (Unicode Emoji or ':name@hostname' or ':name@.')
	 */
	reaction: string;

	/**
	 * name (カスタム絵文字の場合name, Emojiクエリに使う)
	 */
	name?: string;

	/**
	 * host (カスタム絵文字の場合host, Emojiクエリに使う)
	 */
	host?: string | null;
};

@Injectable()
export class ReactionService {
	constructor(
		@Inject(DI.usersRepository)
		private usersRepository: UsersRepository,

		@Inject(DI.blockingsRepository)
		private blockingsRepository: BlockingsRepository,

		@Inject(DI.notesRepository)
		private notesRepository: NotesRepository,

		@Inject(DI.noteReactionsRepository)
		private noteReactionsRepository: NoteReactionsRepository,

		@Inject(DI.emojisRepository)
		private emojisRepository: EmojisRepository,

		private utilityService: UtilityService,
		private metaService: MetaService,
		private userEntityService: UserEntityService,
		private noteEntityService: NoteEntityService,
		private idService: IdService,
		private globalEventServie: GlobalEventService,
		private apRendererService: ApRendererService,
		private apDeliverManagerService: ApDeliverManagerService,
		private createNotificationService: CreateNotificationService,
		private perUserReactionsChart: PerUserReactionsChart,
	) {
	}

	public async create(user: { id: User['id']; host: User['host']; }, note: Note, reaction?: string) {
		// Check blocking
		if (note.userId !== user.id) {
			const block = await this.blockingsRepository.findOneBy({
				blockerId: note.userId,
				blockeeId: user.id,
			});
			if (block) {
				throw new IdentifiableError('e70412a4-7197-4726-8e74-f3e0deb92aa7');
			}
		}
	
		// check visibility
		if (!await this.noteEntityService.isVisibleForMe(note, user.id)) {
			throw new IdentifiableError('68e9d2d1-48bf-42c2-b90a-b20e09fd3d48', 'Note not accessible for you.');
		}
	
		// TODO: cache
		reaction = await this.toDbReaction(reaction, user.host);
	
		const record: NoteReaction = {
			id: this.idService.genId(),
			createdAt: new Date(),
			noteId: note.id,
			userId: user.id,
			reaction,
		};
	
		// Create reaction
		try {
			await this.noteReactionsRepository.insert(record);
		} catch (e) {
			if (isDuplicateKeyValueError(e)) {
				const exists = await this.noteReactionsRepository.findOneByOrFail({
					noteId: note.id,
					userId: user.id,
				});
	
				if (exists.reaction !== reaction) {
					// 別のリアクションがすでにされていたら置き換える
					await this.delete(user, note);
					await this.noteReactionsRepository.insert(record);
				} else {
					// 同じリアクションがすでにされていたらエラー
					throw new IdentifiableError('51c42bb4-931a-456b-bff7-e5a8a70dd298');
				}
			} else {
				throw e;
			}
		}
	
		// Increment reactions count
		const sql = `jsonb_set("reactions", '{${reaction}}', (COALESCE("reactions"->>'${reaction}', '0')::int + 1)::text::jsonb)`;
		await this.notesRepository.createQueryBuilder().update()
			.set({
				reactions: () => sql,
				score: () => '"score" + 1',
			})
			.where('id = :id', { id: note.id })
			.execute();
	
		this.perUserReactionsChart.update(user, note);
	
		// カスタム絵文字リアクションだったら絵文字情報も送る
		const decodedReaction = this.decodeReaction(reaction);
	
		const emoji = await this.emojisRepository.findOne({
			where: {
				name: decodedReaction.name,
				host: decodedReaction.host ?? IsNull(),
			},
			select: ['name', 'host', 'originalUrl', 'publicUrl'],
		});
	
		this.globalEventServie.publishNoteStream(note.id, 'reacted', {
			reaction: decodedReaction.reaction,
			emoji: emoji != null ? {
				name: emoji.host ? `${emoji.name}@${emoji.host}` : `${emoji.name}@.`,
				url: emoji.publicUrl ?? emoji.originalUrl, // || emoji.originalUrl してるのは後方互換性のため
			} : null,
			userId: user.id,
		});
	
		// リアクションされたユーザーがローカルユーザーなら通知を作成
		if (note.userHost === null) {
			this.createNotificationService.createNotification(note.userId, 'reaction', {
				notifierId: user.id,
				noteId: note.id,
				reaction: reaction,
			});
		}
	
		//#region 配信
		if (this.userEntityService.isLocalUser(user) && !note.localOnly) {
			const content = this.apRendererService.renderActivity(await this.apRendererService.renderLike(record, note));
			const dm = this.apDeliverManagerService.createDeliverManager(user, content);
			if (note.userHost !== null) {
				const reactee = await this.usersRepository.findOneBy({ id: note.userId });
				dm.addDirectRecipe(reactee as IRemoteUser);
			}
	
			if (['public', 'home', 'followers'].includes(note.visibility)) {
				dm.addFollowersRecipe();
			} else if (note.visibility === 'specified') {
				const visibleUsers = await Promise.all(note.visibleUserIds.map(id => this.usersRepository.findOneBy({ id })));
				for (const u of visibleUsers.filter(u => u && this.userEntityService.isRemoteUser(u))) {
					dm.addDirectRecipe(u as IRemoteUser);
				}
			}
	
			dm.execute();
		}
		//#endregion
	}

	public async delete(user: { id: User['id']; host: User['host']; }, note: Note) {
		// if already unreacted
		const exist = await this.noteReactionsRepository.findOneBy({
			noteId: note.id,
			userId: user.id,
		});
	
		if (exist == null) {
			throw new IdentifiableError('60527ec9-b4cb-4a88-a6bd-32d3ad26817d', 'not reacted');
		}
	
		// Delete reaction
		const result = await this.noteReactionsRepository.delete(exist.id);
	
		if (result.affected !== 1) {
			throw new IdentifiableError('60527ec9-b4cb-4a88-a6bd-32d3ad26817d', 'not reacted');
		}
	
		// Decrement reactions count
		const sql = `jsonb_set("reactions", '{${exist.reaction}}', (COALESCE("reactions"->>'${exist.reaction}', '0')::int - 1)::text::jsonb)`;
		await this.notesRepository.createQueryBuilder().update()
			.set({
				reactions: () => sql,
			})
			.where('id = :id', { id: note.id })
			.execute();
	
		this.notesRepository.decrement({ id: note.id }, 'score', 1);
	
		this.globalEventServie.publishNoteStream(note.id, 'unreacted', {
			reaction: this.decodeReaction(exist.reaction).reaction,
			userId: user.id,
		});
	
		//#region 配信
		if (this.userEntityService.isLocalUser(user) && !note.localOnly) {
			const content = this.apRendererService.renderActivity(this.apRendererService.renderUndo(await this.apRendererService.renderLike(exist, note), user));
			const dm = this.apDeliverManagerService.createDeliverManager(user, content);
			if (note.userHost !== null) {
				const reactee = await this.usersRepository.findOneBy({ id: note.userId });
				dm.addDirectRecipe(reactee as IRemoteUser);
			}
			dm.addFollowersRecipe();
			dm.execute();
		}
		//#endregion
	}
	
	public async getFallbackReaction(): Promise<string> {
		const meta = await this.metaService.fetch();
		return meta.useStarForReactionFallback ? '⭐' : '👍';
	}

	public convertLegacyReactions(reactions: Record<string, number>) {
		const _reactions = {} as Record<string, number>;

		for (const reaction of Object.keys(reactions)) {
			if (reactions[reaction] <= 0) continue;

			if (Object.keys(legacies).includes(reaction)) {
				if (_reactions[legacies[reaction]]) {
					_reactions[legacies[reaction]] += reactions[reaction];
				} else {
					_reactions[legacies[reaction]] = reactions[reaction];
				}
			} else {
				if (_reactions[reaction]) {
					_reactions[reaction] += reactions[reaction];
				} else {
					_reactions[reaction] = reactions[reaction];
				}
			}
		}

		const _reactions2 = {} as Record<string, number>;

		for (const reaction of Object.keys(_reactions)) {
			_reactions2[this.decodeReaction(reaction).reaction] = _reactions[reaction];
		}

		return _reactions2;
	}

	public async toDbReaction(reaction?: string | null, reacterHost?: string | null): Promise<string> {
		if (reaction == null) return await this.getFallbackReaction();

		reacterHost = this.utilityService.toPunyNullable(reacterHost);

		// 文字列タイプのリアクションを絵文字に変換
		if (Object.keys(legacies).includes(reaction)) return legacies[reaction];

		// Unicode絵文字
		const match = emojiRegex.exec(reaction);
		if (match) {
		// 合字を含む1つの絵文字
			const unicode = match[0];

			// 異体字セレクタ除去
			return unicode.match('\u200d') ? unicode : unicode.replace(/\ufe0f/g, '');
		}

		const custom = reaction.match(/^:([\w+-]+)(?:@\.)?:$/);
		if (custom) {
			const name = custom[1];
			const emoji = await this.emojisRepository.findOneBy({
				host: reacterHost ?? IsNull(),
				name,
			});

			if (emoji) return reacterHost ? `:${name}@${reacterHost}:` : `:${name}:`;
		}

		return await this.getFallbackReaction();
	}

	public decodeReaction(str: string): DecodedReaction {
		const custom = str.match(/^:([\w+-]+)(?:@([\w.-]+))?:$/);

		if (custom) {
			const name = custom[1];
			const host = custom[2] ?? null;

			return {
				reaction: `:${name}@${host ?? '.'}:`,	// ローカル分は@以降を省略するのではなく.にする
				name,
				host,
			};
		}

		return {
			reaction: str,
			name: undefined,
			host: undefined,
		};
	}

	public convertLegacyReaction(reaction: string): string {
		reaction = this.decodeReaction(reaction).reaction;
		if (Object.keys(legacies).includes(reaction)) return legacies[reaction];
		return reaction;
	}
}