misskey/packages/backend/src/server/api/endpoints/notes/translate.ts

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

import { URLSearchParams } from 'node:url';
import { TextDecoder } from 'node:util';
import { Inject, Injectable } from '@nestjs/common';
import { Endpoint } from '@/server/api/endpoint-base.js';
import { NoteEntityService } from '@/core/entities/NoteEntityService.js';
import { HttpRequestService } from '@/core/HttpRequestService.js';
import { GetterService } from '@/server/api/GetterService.js';
import { RoleService } from '@/core/RoleService.js';
import { MiMeta } from '@/models/_.js';
import { DI } from '@/di-symbols.js';
import { ApiError } from '../../error.js';

export const meta = {
	tags: ['notes'],

	requireCredential: true,
	kind: 'read:account',

	res: {
		type: 'object',
		optional: true, nullable: false,
		properties: {
			sourceLang: { type: 'string' },
			text: { type: 'string' },
		},
	},

	errors: {
		unavailable: {
			message: 'Translate of notes unavailable.',
			code: 'UNAVAILABLE',
			id: '50a70314-2d8a-431b-b433-efa5cc56444c',
		},
		noSuchNote: {
			message: 'No such note.',
			code: 'NO_SUCH_NOTE',
			id: 'bea9b03f-36e0-49c5-a4db-627a029f8971',
		},
		cannotTranslateInvisibleNote: {
			message: 'Cannot translate invisible note.',
			code: 'CANNOT_TRANSLATE_INVISIBLE_NOTE',
			id: 'ea29f2ca-c368-43b3-aaf1-5ac3e74bbe5d',
		},
	},
} as const;

export const paramDef = {
	type: 'object',
	properties: {
		noteId: { type: 'string', format: 'misskey:id' },
		targetLang: { type: 'string' },
	},
	required: ['noteId', 'targetLang'],
} as const;

@Injectable()
export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-disable-line import/no-default-export
	constructor(
		@Inject(DI.meta)
		private serverSettings: MiMeta,

		private noteEntityService: NoteEntityService,
		private getterService: GetterService,
		private httpRequestService: HttpRequestService,
		private roleService: RoleService,
	) {
		super(meta, paramDef, async (ps, me) => {
			const policies = await this.roleService.getUserPolicies(me.id);
			if (!policies.canUseTranslator) {
				throw new ApiError(meta.errors.unavailable);
			}

			const note = await this.getterService.getNote(ps.noteId).catch(err => {
				if (err.id === '9725d0ce-ba28-4dde-95a7-2cbb2c15de24') throw new ApiError(meta.errors.noSuchNote);
				throw err;
			});

			if (!(await this.noteEntityService.isVisibleForMe(note, me.id))) {
				throw new ApiError(meta.errors.cannotTranslateInvisibleNote);
			}

			if (note.text == null) {
				return;
			}

			if (this.serverSettings.deeplAuthKey == null) {
				throw new ApiError(meta.errors.unavailable);
			}

			let targetLang = ps.targetLang;
			if (targetLang.includes('-')) targetLang = targetLang.split('-')[0];

			const systemPrompt = this.serverSettings.deeplAuthKey;

			const userPrompt = `pls translate to ${targetLang} ${note.text}`;

			const endpoint = this.serverSettings.deeplIsPro ? 'https://chatapi.neko.ci/api/qwen/chat' : 'https://chatapi.neko.ci/api/mthreads/chat';

			const body = {
				prompt: [systemPrompt, userPrompt],
				temperature: 0.6,
				top_p: 0.8,
				max_tokens: 3000,
			};

			const res = await this.httpRequestService.send(endpoint, {
				method: 'POST',
				headers: {
					'Content-Type': 'application/json',
					Accept: '*/*',
				},
				body: JSON.stringify(body),
				timeout: 120_000,
			});

			let translatedText = '';

			if (res.body) {
				const decoder = new TextDecoder();
				let buffer = '';
				try {
					outer: for await (const chunk of res.body) {
						buffer += decoder.decode(chunk, { stream: true });
						const messages = buffer.split('\n\n');
						buffer = messages.pop() || '';

						for (const msg of messages) {
							if (msg.includes('event: complete')) {
								const dataLine = msg.split('\n').find(line => line.startsWith('data:'));
								if (dataLine) {
									try {
										const data = JSON.parse(dataLine.substring(6));
										if (Array.isArray(data) && data.length > 0) {
											translatedText = data[0];
											res.body.destroy();
											break outer;
										}
									} catch { }
								}
							}
						}
					}
				} catch { }
			}

			const fullToHalfMap: { [key: string]: string } = {
				'，': ',', '。': '.', '！': '!', '？': '?', '：': ':', '；': ';',
				'（': '(', '）': ')', '“': '"', '”': '"', '‘': '\'', '’': '\'',
				'【': '[', '】': ']', '、': ',', '　': ' ',
			};

			let processedText = translatedText.replace(/[，。！？：；（）“”‘’【】、　]/g, m => fullToHalfMap[m]);
			if (processedText.trim().length > 0) {
				processedText = '\u200B\n\u200B' + processedText;
			}

			return {
				sourceLang: 'AI',
				text: processedText,
			};
		});
	}
}