import {spawnSync} from 'node:child_process';
import {mkdtempSync, readFileSync, rmSync, writeFileSync} from 'node:fs';
import {tmpdir} from 'node:os';
import {dirname, join, resolve} from 'node:path';
import {fileURLToPath} from 'node:url';

const patchDir = resolve(dirname(fileURLToPath(import.meta.url)), '../patches');
const source = resolve(process.argv[2] || 'fluxer-src');
const names = readFileSync(resolve(patchDir, 'series'), 'utf8')
  .replace(/^\uFEFF/, '').split(/\r?\n/).filter(Boolean);
if (!names.length) throw new Error('The patch series is empty');
for (const name of names) {
  if (!/^[0-9]{4}-[a-z0-9-]+\.patch$/.test(name)) throw new Error(`Invalid patch name: ${name}`);
}

// Windows checkout or an editor may supply CRLF despite .gitattributes.
// Normalize copies, retaining the original patch files and meaningful whitespace.
const temporaryDir = mkdtempSync(join(tmpdir(), 'gscord-patches-'));
try {
  const patches = names.map((name) => {
    const text = readFileSync(resolve(patchDir, name), 'utf8')
      .replace(/^\uFEFF/, '').replace(/\r\n/g, '\n');
    const target = join(temporaryDir, name);
    writeFileSync(target, text, 'utf8');
    return target;
  });
  function apply(...options) {
    const result = spawnSync('git', ['-C', source, 'apply', '--whitespace=error-all', ...options, ...patches], {
      stdio: 'inherit',
    });
    if (result.error) throw result.error;
    if (result.status !== 0) throw new Error(`git apply ${options.join(' ')} failed (${result.status})`);
  }
  apply('--check');
  if (!process.argv.includes('--check')) apply();
  console.log(`Validated ${patches.length} GSCORD patches${process.argv.includes('--check') ? '' : ' and applied them'}.`);
} finally {
  rmSync(temporaryDir, {recursive: true, force: true});
}