nove-b/無料の翻訳API、みんなの自動翻訳を使ってみた

import { NextResponse } from "next/server";

export async function POST(req: Request) {
  try {
    const body = await req.json();
    if (!body || !body.text) {
      return NextResponse.json(
        { error: "Text is required for translation" },
        { status: 400 },
      );
    }

    const { text } = body;
    const url = "https://mt-auto-minhon-mlt.ucri.jgn-x.jp";
    const key = "xxxxxxxxxxxxxxxxxx";
    const secret = "xxxxxxxxxxxxxxxxxx";
    const name = "xxxxxxxxxxxxxxxxxx";
    const api_name = "mt";
    const api_param = "generalNT_en_ja";

    let access_token = null;

    // アクセストークン取得
    const tokenResponse = await fetch(`${url}/oauth2/token.php`, {
      method: "POST",
      body: new URLSearchParams({
        grant_type: "client_credentials",
        client_id: key,
        client_secret: secret,
      }),
    });

    if (!tokenResponse.ok) {
      throw new Error("Failed to fetch access token");
    }

    const tokenData = await tokenResponse.json();
    access_token = tokenData.access_token;

    if (!access_token) {
      return NextResponse.json(
        { error: "Access token not found" },
        { status: 400 },
      );
    }

    // APIリクエストの形式を修正
    const apiResponse = await fetch(`${url}/api/`, {
      method: "POST",
      headers: {
        "Content-Type": "application/x-www-form-urlencoded",
      },
      body: new URLSearchParams({
        access_token: access_token,
        key: key, // API Key
        api_name: api_name,
        api_param: api_param,
        name: name, // ログインID
        type: "json", // レスポンスタイプ
        text: text, // 翻訳テキスト
      }),
    });

    if (!apiResponse.ok) {
      throw new Error("API request failed");
    }

    const apiData = await apiResponse.json();

    const response = NextResponse.json(apiData);
    response.headers.set("Access-Control-Allow-Origin", "*");
    response.headers.set("Access-Control-Allow-Methods", "GET, POST, OPTIONS");
    response.headers.set(
      "Access-Control-Allow-Headers",
      "Content-Type, Authorization",
    );
    return response;
  } catch (error: unknown) {
    // エラーがオブジェクトかどうかをチェック
    if (error instanceof Error) {
      const response = NextResponse.json(
        { error: `Error: ${error.message}` },
        { status: 500 },
      );
      response.headers.set("Access-Control-Allow-Origin", "*");
      return response;
    } else {
      const response = NextResponse.json(
        { error: "Unknown error occurred" },
        { status: 500 },
      );
      response.headers.set("Access-Control-Allow-Origin", "*");
      return response;
    }
  }
}

// OPTIONS メソッド対応
export async function OPTIONS() {
  const response = new NextResponse(null, { status: 204 });
  response.headers.set("Access-Control-Allow-Origin", "*");
  response.headers.set("Access-Control-Allow-Methods", "GET, POST, OPTIONS");
  response.headers.set(
    "Access-Control-Allow-Headers",
    "Content-Type, Authorization",
  );
  return response;
}