const fs = require('fs');
const path = require('path');
const { execSync } = require('child_process');

const rootDir = path.join(__dirname, '..');

function readPackageVersion() {
  try {
    const pkg = JSON.parse(fs.readFileSync(path.join(rootDir, 'package.json'), 'utf8'));
    return pkg.version || '0.0.0';
  } catch {
    return '0.0.0';
  }
}

function readGitSha() {
  if (process.env.GIT_SHA) {
    return process.env.GIT_SHA;
  }
  try {
    return execSync('git rev-parse --short HEAD', {
      cwd: rootDir,
      encoding: 'utf8',
      stdio: ['ignore', 'pipe', 'ignore'],
    }).trim();
  } catch {
    return '';
  }
}

function getVersionInfo() {
  const dbName = process.env.DB_NAME || '';
  const appEnv = process.env.APP_ENV || (dbName === 'gallery_prod' ? 'prod' : 'dev');
  const imageTag = process.env.IMAGE_TAG || (appEnv === 'prod' ? 'unknown' : 'dev-local');

  return {
    app_env: appEnv,
    app_version: process.env.APP_VERSION || readPackageVersion(),
    image_tag: imageTag,
    git_sha: readGitSha(),
    built_at: process.env.BUILD_TIME || '',
    db_name: dbName,
    public_url: process.env.PUBLIC_URL || '',
  };
}

module.exports = { getVersionInfo };