import path from 'path';
import chokidar from 'chokidar';
import { exec } from 'child_process';
import { writeFile, copyFile, makeDir, copyDir, cleanDir } from './lib/fs';
import pkg from '../package.json';
import { format } from './run';

/**
 * Copies static files such as robots.txt, favicon.ico to the
 * output (build) folder.
 */
async function copy() {
  await makeDir('build');
  await Promise.all([
    writeFile('build/package.json', JSON.stringify({
      private: true,
      engines: pkg.engines,
      dependencies: pkg.dependencies,
      scripts: {
        start: 'node server.js',
      },
    }, null, 2)),
    copyFile('LICENSE.txt', 'build/LICENSE.txt'),
    copyDir('src/content', 'build/content'),
    copyDir('public', 'build/public'),
  ]);
  await exec('git log -n 1 --pretty=format:"%H"', (err, stdout) => {
    if (stdout) {
      writeFile('build/public/config.json', JSON.stringify({
        build: {
          hash: stdout,
          time: new Date(),
        },
      }, null, 2));
    }
  });
  if (process.argv.includes('--watch')) {
    const watcher = chokidar.watch([
      'src/content/**/*',
      'public/**/*',
    ], { ignoreInitial: true });

    watcher.on('all', async (event, filePath) => {
      const start = new Date();
      const src = path.relative('./', filePath);
      const dist = path.join('build/', src.startsWith('src') ? path.relative('src', src) : src);
      switch (event) {
        case 'add':
        case 'change':
          await makeDir(path.dirname(dist));
          await copyFile(filePath, dist);
          break;
        case 'unlink':
        case 'unlinkDir':
          cleanDir(dist, { nosort: true, dot: true });
          break;
        default:
          return;
      }
      const end = new Date();
      const time = end.getTime() - start.getTime();
      console.log(`[${format(end)}] ${event} '${dist}' after ${time} ms`);
    });
  }
}

export default copy;