/**
 * Simple ESM-compatible configuration loader
 * Loads JSON files: base.json -> environment.json -> secrets.json
 */

import { readFileSync, existsSync } from 'fs';
import { join, dirname } from 'path';
import { fileURLToPath } from 'url';

const __dirname = dirname(fileURLToPath(import.meta.url));

function deepMerge(target, source) {
  const result = { ...target };
  for (const key of Object.keys(source)) {
    if (source[key] && typeof source[key] === 'object' && !Array.isArray(source[key])) {
      result[key] = deepMerge(result[key] || {}, source[key]);
    } else {
      result[key] = source[key];
    }
  }
  return result;
}

function loadJsonFile(filename) {
  const path = join(__dirname, '..', 'conf', filename);
  if (!existsSync(path)) return {};
  try {
    return JSON.parse(readFileSync(path, 'utf-8'));
  } catch (err) {
    console.warn(`Warning: Failed to load ${filename}:`, err.message);
    return {};
  }
}

// Load configuration
const environment = process.env.NODE_ENV || 'development';

const base = loadJsonFile('base.json');
const envConfig = loadJsonFile(`${environment}.json`);
const secrets = loadJsonFile('secrets.json');

// Merge all configs
const config = deepMerge(deepMerge(base, envConfig), secrets);

// Add environment info
config.environment = environment;

// Allow env var overrides for critical settings
if (process.env.PORT) {
  config.server = config.server || {};
  config.server.port = parseInt(process.env.PORT);
}

if (process.env.OPENCLAW_GATEWAY) {
  config.gateway = config.gateway || {};
  config.gateway.url = process.env.OPENCLAW_GATEWAY;
}

if (process.env.OPENCLAW_TOKEN) {
  config.gateway = config.gateway || {};
  config.gateway.token = process.env.OPENCLAW_TOKEN;
}

if (process.env.SESSION_SECRET) {
  config.session = config.session || {};
  config.session.secret = process.env.SESSION_SECRET;
}

if (process.env.LDAP_ENABLED === 'true') {
  config.auth = config.auth || {};
  config.auth.ldap = config.auth.ldap || {};
  config.auth.ldap.enabled = true;
}

export default config;