import { NextRequest, NextResponse } from "next/server";
import { getApiSettings } from "@/lib/api-settings";

export async function GET(
  request: NextRequest,
  { params }: { params: Promise<{ path: string[] }> },
) {
  const { path } = await params;
  return handleRequest(request, "GET", path);
}

export async function POST(
  request: NextRequest,
  { params }: { params: Promise<{ path: string[] }> },
) {
  const { path } = await params;
  return handleRequest(request, "POST", path);
}

export async function PUT(
  request: NextRequest,
  { params }: { params: Promise<{ path: string[] }> },
) {
  const { path } = await params;
  return handleRequest(request, "PUT", path);
}

export async function DELETE(
  request: NextRequest,
  { params }: { params: Promise<{ path: string[] }> },
) {
  const { path } = await params;
  return handleRequest(request, "DELETE", path);
}

function getClientInfo(request: NextRequest) {
  const ip =
    request.headers.get("CF-Connecting-IP") ||
    request.headers.get("X-Forwarded-For")?.split(",")[0]?.trim() ||
    request.headers.get("X-Real-IP") ||
    "unknown";
  const country = request.headers.get("CF-IPCountry") || "-";
  const ua = request.headers.get("User-Agent")?.slice(0, 80) || "unknown";
  return { ip, country, ua };
}

async function handleRequest(request: NextRequest, method: string, path: string[]) {
  const startTime = Date.now();
  const client = getClientInfo(request);

  try {
    // Get dynamic settings
    const settings = await getApiSettings();
    const BACKEND_URL = settings.backendUrl;
    const API_KEY = settings.apiKey;

    const url = new URL(request.url);
    const searchParams = url.searchParams.toString();
    const targetUrl = `${BACKEND_URL}/${path.join("/")}${searchParams ? `?${searchParams}` : ""}`;
    const hasAuth = Boolean(request.headers.get("authorization"));

    console.log(
      `[PROXY] ip=${client.ip} | country=${client.country} | method=${method} | path=/${path.join("/")} | backend=${BACKEND_URL} | auth=${hasAuth ? "present" : "none"}`,
    );

    const headers: HeadersInit = {
      ...(request.headers.get("accept") ? { Accept: request.headers.get("accept") as string } : {}),
    };

    const incomingContentType = request.headers.get("content-type");
    if (incomingContentType) headers["Content-Type"] = incomingContentType;

    // Prefer per-user Authorization header passed from the browser; fallback to configured API key.
    const incomingAuth = request.headers.get("authorization");
    if (incomingAuth) {
      headers["Authorization"] = incomingAuth;
    } else if (API_KEY) {
      headers["Authorization"] = `Bearer ${API_KEY}`;
    }

    const body = method !== "GET" && method !== "DELETE" ? await request.text() : undefined;

    const response = await fetch(targetUrl, {
      method,
      headers,
      body,
    });

    const contentType = response.headers.get("content-type") || "application/json";

    if (contentType.includes("text/event-stream") && response.body) {
      return new NextResponse(response.body, {
        status: response.status,
        headers: {
          "Content-Type": contentType,
          "Cache-Control": response.headers.get("cache-control") || "no-cache",
        },
      });
    }

    const data = await response.text();
    return new NextResponse(data, {
      status: response.status,
      headers: { "Content-Type": contentType },
    });
  } catch (error) {
    const duration = Date.now() - startTime;
    console.error(
      `[PROXY ERROR] ip=${client.ip} | country=${client.country} | method=${method} | path=/${path.join("/")} | duration=${duration}ms | error=${String(error)}`,
    );
    return NextResponse.json(
      { error: "Internal server error", details: String(error) },
      { status: 500 },
    );
  }
}