import * as esbuild from 'esbuild';
import { mkdir, rm, writeFile } from 'node:fs/promises';
import path from 'node:path';

export const outdir = 'dist/assets';

export function buildOptions({ dev = false } = {}) {
  return {
    entryPoints: [
      { in: 'client/js/main.js', out: 'app' },
      { in: 'client/css/main.css', out: 'app' },
    ],
    outdir,
    bundle: true,
    format: 'esm',
    minify: !dev,
    sourcemap: dev ? 'linked' : false,
    metafile: true,
    entryNames: '[name]-[hash]',
    assetNames: '[name]-[hash]',
    loader: { '.woff2': 'file', '.woff': 'file' },
    // Old enough that esbuild lowers CSS nesting for Safari 15/16
    target: ['chrome109', 'firefox115', 'safari15.4'],
    logLevel: 'info',
  };
}

// Maps "app.js" -> "/assets/app-HASH.js" so templates don't need to know the hash.
export async function writeManifest(metafile) {
  const manifest = {};
  for (const [file, output] of Object.entries(metafile.outputs)) {
    if (!output.entryPoint) continue;
    const base = path.basename(file);
    const key = base.replace(/-[A-Z0-9]{8}(\.\w+)$/, '$1');
    manifest[key] = '/assets/' + base;
  }
  await writeFile('dist/manifest.json', JSON.stringify(manifest, null, 2));
}

if (import.meta.url === `file://${process.argv[1]}`) {
  await rm('dist', { recursive: true, force: true });
  await mkdir(outdir, { recursive: true });
  const result = await esbuild.build(buildOptions());
  await writeManifest(result.metafile);
}