next.config.ts

import type { NextConfig } from "next";

const isServerless = process.env.NEXT_PUBLIC_LEETPROOF_SERVERLESS === "true";
const isFirebase = process.env.NEXT_PUBLIC_DB_PROVIDER === "firebase";

const nextConfig: NextConfig = {
  // In serverless mode, produce a fully static site in the `out/` directory.
  ...(isServerless && {
    output: "export",
    // GitHub Pages project sites are served from /<repo-name>/.
    // Set NEXT_PUBLIC_BASE_PATH=/leetproof (or your repo name) when deploying.
    basePath: process.env.NEXT_PUBLIC_BASE_PATH || "",
  }),

  // Turbopack (Next.js 16 default bundler)
  turbopack: {
    // When firebase provider is NOT selected, alias firebase packages to an
    // empty stub so the build doesn't fail if firebase isn't installed.
    resolveAlias: {
      ...(isFirebase
        ? {}
        : {
            "firebase/app": "@/lib/db/firebase-stub",
            "firebase/firestore": "@/lib/db/firebase-stub",
            "firebase/auth": "@/lib/db/firebase-stub",
          }),
      // lean4monaco uses Node.js modules in browser (same as vite-plugin-node-polyfills)
      path: "path-browserify",
      fs: "memfs",
      perf_hooks: "./src/lib/perf-hooks-stub.ts",
    },
  },

  // lean4monaco / monaco-editor need transpilation for proper bundling
  transpilePackages: ["lean4monaco"],

  // Webpack fallback (used with --webpack flag)
  webpack: (config) => {
    if (!isFirebase) {
      config.resolve.alias = {
        ...config.resolve.alias,
        "firebase/app": false,
        "firebase/firestore": false,
        "firebase/auth": false,
      };
    }
    // lean4monaco uses Node.js `path` module in browser
    config.resolve.fallback = {
      ...config.resolve.fallback,
      path: require("path-browserify"),
    };
    return config;
  },
};

export default nextConfig;