import type { NextRequest } from "next/server";

export const runtime = "nodejs";
export const maxDuration = 300;

type RouteContext = {
  params: Promise<{ path: string[] }>;
};

function proxyHeaders(request: NextRequest) {
  const headers = new Headers(request.headers);
  headers.delete("host");
  headers.delete("content-length");
  headers.delete("connection");
  return headers;
}

function responseHeaders(response: Response) {
  const headers = new Headers(response.headers);
  headers.delete("content-length");
  headers.delete("content-encoding");
  headers.delete("transfer-encoding");
  return headers;
}

async function proxy(request: NextRequest, context: RouteContext) {
  const { path } = await context.params;
  const apiBaseUrl = process.env.API_BASE_URL || "http://127.0.0.1:8080";
  const target = `${apiBaseUrl.replace(/\/$/, "")}/api/${path.map(encodeURIComponent).join("/")}${request.nextUrl.search}`;
  const hasBody = request.method !== "GET" && request.method !== "HEAD";

  try {
    const response = await fetch(target, {
      method: request.method,
      headers: proxyHeaders(request),
      body: hasBody ? request.body : undefined,
      duplex: hasBody ? "half" : undefined,
    } as RequestInit & { duplex?: "half" });

    return new Response(response.body, {
      status: response.status,
      statusText: response.statusText,
      headers: responseHeaders(response),
    });
  } catch (error) {
    console.error("Failed to proxy", target, error);
    return Response.json({ code: 1, data: null, msg: "接口连接失败，请确认后端服务已启动" }, { status: 502 });
  }
}

export const GET = proxy;
export const HEAD = proxy;
export const POST = proxy;
export const PUT = proxy;
export const PATCH = proxy;
export const DELETE = proxy;
export const OPTIONS = proxy;