import { defineConfig, loadEnv } from 'vite';
import { tanstackStart } from '@tanstack/react-start/plugin/vite';
import react from '@vitejs/plugin-react';
import tailwindcss from '@tailwindcss/vite';
import { fileURLToPath, URL } from 'node:url';

export default defineConfig(async ({ command, mode }) => {
  // OPENROUTER_API_KEY and friends are server-only, so they have no VITE_
  // prefix and Vite would not expose them. Load .env / .env.local into
  // process.env for the server code; variables already set win.
  Object.assign(process.env, loadEnv(mode, process.cwd(), ''));

  return {
    server: { port: 3000 },
    plugins: [
      // Start must come before the React plugin.
      tanstackStart(),
      // Hosting adapter for `vite build`: Nitro packages Start's server for the
      // host (a Vercel Function when building on Vercel, a Node server in
      // .output/ elsewhere). Dev never loads it, so `vite dev` — and the
      // nodesandbox runtime — run plain Vite + TanStack Start + Hono.
      ...(command === 'build'
        ? [
            (await import('nitro/vite')).nitro({
              // Long agent runs stream for minutes (was `maxDuration` on the
              // Next route).
              vercel: { functions: { maxDuration: 300 } },
            }),
          ]
        : []),
      react(),
      tailwindcss(),
    ],
    resolve: {
      alias: {
        '@': fileURLToPath(new URL('./src', import.meta.url)),
      },
    },
  };
});