import { defineConfig } from 'vite';
import vue from '@vitejs/plugin-vue';
import path from 'node:path';
import fs from 'node:fs';
import { fileURLToPath } from 'node:url';

const here = path.dirname(fileURLToPath(import.meta.url));

// pdf.js needs font data to draw pdfs which do not embed their fonts (and CMaps for
// Korean/Chinese/Japanese text). Without it rendering such a pdf takes very long.
// The files are only fetched when a pdf is selected, and only the ones that are needed.
const pdfAssets = () => ({
  name: 'pdfjs-assets',
  apply: 'build',
  closeBundle() {
    const out = path.resolve(here, '../public/app');
    for (const dir of ['standard_fonts', 'cmaps']) {
      fs.cpSync(path.resolve(here, 'node_modules/pdfjs-dist', dir), path.join(out, dir), { recursive: true });
    }
  },
});

// The server renders a thin html shell (public/pug/page.pug) which loads
// app/main.js and app/main.css. Fixed file names keep that shell independent
// of the build; heavy parts (pdf.js) are separate chunks loaded on demand.
export default defineConfig({
  base: './',
  plugins: [vue(), pdfAssets()],
  build: {
    outDir: path.resolve(here, '../public/app'),
    emptyOutDir: true,
    cssCodeSplit: false,
    target: 'es2022',
    rollupOptions: {
      input: path.resolve(here, 'src/main.js'),
      output: {
        entryFileNames: 'main.js',
        chunkFileNames: 'chunks/[name]-[hash].js',
        assetFileNames: (info) => {
          const name = (info.names && info.names[0]) || info.name || '';
          return name.endsWith('.css') ? 'main.css' : 'assets/[name]-[hash][extname]';
        },
      },
    },
    chunkSizeWarningLimit: 1500,
  },
});