import * as path from 'node:path';
import { watch } from 'node:fs';
import { readFile, writeFile } from 'node:fs/promises';
import { fileURLToPath } from 'node:url';
import { globby } from 'globby';
import { minify } from 'terser';

const currentDirectory = fileURLToPath(new URL('.', import.meta.url));

const preamble = [
  '// This file is autogenerated. Do not edit it directly.',
  '// To update it, modify the corresponding source file and run `pnpm inline-scripts`.',
].join('\n');

async function buildFile(sourceFile: string) {
  const sourceContent = await readFile(sourceFile, 'utf8');
  const { code: minifiedCode } = await minify(sourceContent, { ecma: 2020 });
  const escapedCode = minifiedCode!.replace(/'/g, "\\'");
  const output = [
    preamble,
    '',
    '// prettier-ignore',
    `export const script = '${escapedCode}';\n`,
  ].join('\n');
  const outputFilename = sourceFile.replace('.template.js', '.min.ts');
  await writeFile(outputFilename, output);
}

/**
 * Finds files with the `.template.js` extension in the `react` package, minifies them, and writes
 * the code to a new file with the `.min.ts` extension.
 * The minified code is then exported as a string literal.
 */
async function run() {
  const files = await globby('**/*.template.js', {
    absolute: true,
    cwd: path.resolve(currentDirectory, '../packages/react/src'),
  });
  await Promise.all(files.map(buildFile));
  return files;
}

const files = await run();

if (process.argv.includes('--watch') || process.argv.includes('-w')) {
  // eslint-disable-next-line no-console
  console.log('Processing *.template.js files in watch mode...');

  files.forEach((file) => {
    watch(file, (eventType) => {
      if (eventType === 'change') {
        buildFile(file);
      }
    });
  });
}