import { defineConfig } from 'vite';
import react from '@vitejs/plugin-react';
import tailwindcss from '@tailwindcss/vite';
import path from 'path';
import { createRequire } from 'module';

const require = createRequire(import.meta.url);

// Fresh, never-cached asset path per build. The public CDN in front of
// ai.qihuyun.com caches the canonical /assets/*.js|css URLs for 30 days. By
// re-writing the assetFileNames / chunkFileNames / entryFileNames to a fresh
// timestamped directory every build we force the CDN to miss-cache and pull
// the real bytes from origin.
const BUILD_STAMP = 'v' + new Date().toISOString().replace(/[-:TZ]/g, '').slice(0, 12);

// Vite emits `<script type="module" crossorigin>` by default. The origin nginx
// does NOT send `Access-Control-Allow-Origin`, so the browser blocks the module
// and the page renders blank. Strip the attribute from the generated index.html.
function stripCrossorigin() {
  return {
    name: 'strip-crossorigin',
    enforce: 'post',
    transformIndexHtml(html: string) {
      return html.replace(/\s+crossorigin(="[^"]*")?/g, '');
    },
  };
}

// Force terser as the minifier. We do NOT rely on Vite 6's
// `minify: 'terser'` string config because that path uses an internal
// requireResolveFromRootWithFallback which, in some workspaces, silently
// falls back to esbuild and re-introduces the react-router
// "o.slice is not a function" runtime crash. We instead spawn a worker that
// calls terser directly, attached as a rollup output plugin so EVERY chunk
// passes through it.
function viteForceTerser() {
  return {
    name: 'vite-force-terser',
    apply: 'build' as const,
    enforce: 'post' as const,
    async generateBundle(_options: unknown, bundle: Record<string, { code?: string; type?: string }>) {
      // TEMP DIAGNOSTIC: do NOT re-minify. We are testing whether the
      // react-router "i.slice is not a function" crash is caused by any
      // minifier (terser or esbuild). If the error disappears with plain
      // (unminified) output, the root cause is minification, not our source.
      return;
    },
  };
}

export default defineConfig({
  plugins: [react(), tailwindcss(), stripCrossorigin(), viteForceTerser()],
  resolve: {
    alias: {
      '@': path.resolve(__dirname, './src'),
    },
    dedupe: ['react', 'react-dom', 'react-router', 'react-router-dom'],
  },
  build: {
    // We bypass Vite's built-in minifier entirely. Our viteForceTerser() plugin
    // re-minifies all chunks after Vite emits them. With esbuild off, the
    // react-router internal Symbol.iterator / slice paths stay intact.
    minify: false,
    assetsDir: `assets/${BUILD_STAMP}`,
    cssMinify: 'lightningcss', // preserves more than esbuild CSS minify
    modulePreload: {
      polyfill: false,
    },
    rollupOptions: {
      output: {
        assetFileNames: `assets/${BUILD_STAMP}/[name]-[hash][extname]`,
        chunkFileNames: `assets/${BUILD_STAMP}/[name]-[hash].js`,
        entryFileNames: `assets/${BUILD_STAMP}/[name]-[hash].js`,
      },
    },
  },
  server: {
    port: 5173,
    proxy: {
      '/api': {
        target: 'http://localhost:8000',
        changeOrigin: true,
      },
    },
  },
});