#!/usr/bin/env node
import { createHash } from 'node:crypto';
import { readFileSync, writeFileSync } from 'node:fs';
import { dirname, resolve } from 'node:path';
import { fileURLToPath } from 'node:url';

const repositoryRoot = resolve(dirname(fileURLToPath(import.meta.url)), '..');
const sourceFiles = Object.freeze([
  'src/runtime/constants.js',
  'src/runtime/diagnostics.js',
  'src/runtime/rng.js',
  'src/runtime/types.js',
  'src/runtime/values.js',
  'src/runtime/audio-contract.js',
  'src/runtime/audio-graph.js',
  'src/runtime/validator.js',
  'src/runtime/persistence.js',
  'src/runtime/library.js',
  'src/runtime/resolution.js',
  'src/runtime/actions.js',
  'src/runtime/performance.js',
  'src/runtime/activation.js',
  'src/runtime/audio-engine.js',
  'src/runtime/app.js'
]);

function normalized(path) {
  return readFileSync(resolve(repositoryRoot, path), 'utf8').replace(/\r\n/g, '\n');
}

function bundleModule(source, path) {
  const withoutImports = source.replace(/^import\s+[\s\S]*?\s+from\s+['"][^'"]+['"];\s*$/gm, '');
  const withoutExports = withoutImports.replace(/\bexport\s+/g, '');
  return `\n/* ${path} */\n${withoutExports.trim()}\n`;
}

export function buildStandalone(outputPath = resolve(repositoryRoot, 'XZBT.html')) {
  const template = normalized('src/XZBT.template.html');
  const styles = normalized('src/styles.css').trim();
  const script = `'use strict';\n(() => {\n${sourceFiles.map((path) => bundleModule(normalized(path), path)).join('')}\n})();`;
  if (!template.includes('/*__XZBT_STYLES__*/') || !template.includes('/*__XZBT_SCRIPT__*/')) {
    throw new Error('Standalone template is missing a build placeholder.');
  }
  const artifact = template
    .replace('/*__XZBT_STYLES__*/', () => styles)
    .replace('/*__XZBT_SCRIPT__*/', () => script)
    .replace(/\r\n/g, '\n');
  writeFileSync(outputPath, artifact, 'utf8');
  return { outputPath, bytes: Buffer.byteLength(artifact), sha256: createHash('sha256').update(artifact).digest('hex') };
}

if (process.argv[1] && resolve(process.argv[1]) === fileURLToPath(import.meta.url)) {
  const outputIndex = process.argv.indexOf('--output');
  const outputPath = outputIndex >= 0 ? resolve(process.argv[outputIndex + 1]) : resolve(repositoryRoot, 'XZBT.html');
  const result = buildStandalone(outputPath);
  console.log(`Built ${result.outputPath}`);
  console.log(`SHA-256 ${result.sha256} (${result.bytes} bytes)`);
}