import type { NextConfig } from "next";

/** 构建期兜底代理。请求期以 API_PROXY_TARGET 为准，见 src/lib/api/upstream-proxy.ts。 */
const apiProxyTarget = (process.env.API_PROXY_TARGET || "").replace(/\/$/, "");
const appEnv = process.env.APP_ENV;

const nextConfig: NextConfig = {
  output: "standalone",
  // 仅在显式 APP_ENV=test|development 时分目录；未设置 / production 仍用 .next
  distDir:
    appEnv === "test" ? ".next-test" : appEnv === "development" ? ".next-dev" : ".next",
  poweredByHeader: false,
  cacheComponents: true,
  partialPrefetching: true,
  // 本机用 127.0.0.1 打开时，允许跨源访问 Next 开发资源
  allowedDevOrigins: ["127.0.0.1"],
  turbopack: {
    rules: {
      "*.css": {
        loaders: ["@tailwindcss/turbopack"],
        as: "*.css",
      },
    },
  },
  async rewrites() {
    if (!apiProxyTarget) return [];
    // fallback：动态 Route Handler（upstream-proxy）优先；避免 afterFiles 抢走
    // /api/[...path] 后走 Next httpxy（本机 IPv6 不通时 AggregateError → 500）。
    // /h5/m3u8、/enkey、/newenkey 由 route handler（lib/media/proxy）代理，密钥地址不带尾斜杠
    const proxy = [
      {
        source: "/api/:path*",
        destination: `${apiProxyTarget}/api/:path*`,
      },
    ];
    return { fallback: proxy };
  },
};

export default nextConfig;