import { NextResponse } from "next/server";
import { AdminAuthorizationError, requireAdminSession } from "@/lib/admin/auth";
import { adminErrorResponse } from "@/lib/admin/http";
import { epaySubmitUrl, readEpayConfig } from "@/lib/epay/config";
import { assertPublicGatewayUrl } from "@/lib/epay/gateway-policy";

export const runtime = "nodejs";

function reachableStatus(status: number) {
  return status >= 200 && status < 500;
}

export async function POST() {
  try {
    await requireAdminSession("write");
    const config = await readEpayConfig();
    const submitUrl = epaySubmitUrl(config.gatewayUrl);
    await assertPublicGatewayUrl(submitUrl);
    const startedAt = performance.now();
    let response = await fetch(submitUrl, {
      method: "HEAD",
      redirect: "manual",
      signal: AbortSignal.timeout(8_000),
    });
    if (response.status === 405 || response.status === 501) {
      response = await fetch(submitUrl, {
        method: "GET",
        redirect: "manual",
        signal: AbortSignal.timeout(8_000),
      });
    }
    const available = reachableStatus(response.status);
    return NextResponse.json({
      available,
      message: available ? "当前已保存的易支付配置可访问" : "当前已保存的易支付配置暂不可用",
      latencyMs: Math.round(performance.now() - startedAt),
      status: response.status,
    });
  } catch (error) {
    if (error instanceof AdminAuthorizationError) return adminErrorResponse(error);
    return NextResponse.json({
      available: false,
      message: "当前已保存的易支付配置暂不可用",
    });
  }
}