import { writeFileSync, mkdirSync } from 'node:fs';
import { execSync } from 'node:child_process';
import { resolve } from 'node:path';

function safe(cmd, fallback = '') {
  try {
    return execSync(cmd, { stdio: ['ignore', 'pipe', 'ignore'] })
      .toString()
      .trim();
  } catch {
    return fallback;
  }
}

const now = new Date().toISOString();
const commit = safe('git rev-parse --short HEAD', 'local');
const branch = safe('git rev-parse --abbrev-ref HEAD', '');
const buildId = `${now.replace(/[-:TZ.]/g, '').slice(0, 14)}.${commit}`;

const payload = {
  version: now,   // 比對用（每次 build 都不同）
  commit,
  branch,
  buildId
};

mkdirSync(resolve('public'), { recursive: true });
writeFileSync(resolve('public/version.json'), JSON.stringify(payload, null, 2), 'utf-8');
console.log('[write-version] public/version.json ->', payload);