import { NextResponse } from "next/server";
import { auth } from "@/app/(auth)/auth";

export const runtime = "nodejs";
export const maxDuration = 60;

function isAllowedModelHost(hostname: string) {
  const normalized = hostname.toLowerCase();
  return (
    normalized === "tripo3d.com" ||
    normalized.endsWith(".tripo3d.com")
  );
}

export async function GET(request: Request) {
  try {
    const session = await auth();
    if (!session?.user?.id) {
      return NextResponse.json({ success: false, error: "未登录" }, { status: 401 });
    }

    const { searchParams } = new URL(request.url);
    const rawUrl = String(searchParams.get("url") || "").trim();
    if (!rawUrl) {
      return NextResponse.json({ success: false, error: "缺少 url 参数" }, { status: 400 });
    }

    let targetUrl: URL;
    try {
      targetUrl = new URL(rawUrl);
    } catch {
      return NextResponse.json({ success: false, error: "url 参数无效" }, { status: 400 });
    }

    if (targetUrl.protocol !== "https:") {
      return NextResponse.json({ success: false, error: "仅支持 https 模型地址" }, { status: 400 });
    }

    if (!isAllowedModelHost(targetUrl.hostname)) {
      return NextResponse.json({ success: false, error: "不允许的模型地址域名" }, { status: 403 });
    }

    const forwardedHeaders = new Headers();
    const range = request.headers.get("range");
    if (range) {
      forwardedHeaders.set("range", range);
    }

    const upstream = await fetch(targetUrl.toString(), {
      method: "GET",
      headers: forwardedHeaders,
      cache: "no-store",
    });

    if (!upstream.ok && upstream.status !== 206) {
      const upstreamText = await upstream.text().catch(() => "");
      return NextResponse.json(
        {
          success: false,
          error: upstreamText || `模型拉取失败（HTTP ${upstream.status}）`,
        },
        { status: upstream.status || 502 }
      );
    }

    const responseHeaders = new Headers();
    const contentType = upstream.headers.get("content-type") || "application/octet-stream";
    responseHeaders.set("content-type", contentType);

    const contentLength = upstream.headers.get("content-length");
    if (contentLength) responseHeaders.set("content-length", contentLength);

    const contentRange = upstream.headers.get("content-range");
    if (contentRange) responseHeaders.set("content-range", contentRange);

    const acceptRanges = upstream.headers.get("accept-ranges");
    if (acceptRanges) responseHeaders.set("accept-ranges", acceptRanges);

    responseHeaders.set("cache-control", "private, no-store");

    return new NextResponse(upstream.body, {
      status: upstream.status,
      headers: responseHeaders,
    });
  } catch (error) {
    return NextResponse.json(
      {
        success: false,
        error: error instanceof Error ? error.message : "代理拉取 3D 模型失败",
      },
      { status: 500 }
    );
  }
}