const fs = require('fs');
const path = require('path');

const distDir = path.resolve(__dirname, '..', 'dist');

function walk(dir) {
  if (!fs.existsSync(dir)) {
    return [];
  }

  return fs.readdirSync(dir, { withFileTypes: true }).flatMap((entry) => {
    const fullPath = path.join(dir, entry.name);
    if (entry.isDirectory()) {
      return walk(fullPath);
    }
    return fullPath.endsWith('.js') ? [fullPath] : [];
  });
}

function toRequirePath(fromFile, srcImport) {
  const target = path.join(distDir, srcImport.replace(/^src[\\/]/, ''));
  let relative = path.relative(path.dirname(fromFile), target).replace(/\\/g, '/');

  if (!relative.startsWith('.')) {
    relative = `./${relative}`;
  }

  return relative;
}

for (const file of walk(distDir)) {
  const source = fs.readFileSync(file, 'utf8');
  const rewritten = source.replace(/require\((['"])src\/([^'"]+)\1\)/g, (_match, quote, importPath) => {
    return `require(${quote}${toRequirePath(file, `src/${importPath}`)}${quote})`;
  });

  if (rewritten !== source) {
    fs.writeFileSync(file, rewritten);
  }
}