import { config as dotenvConfig } from 'dotenv';
// Load .env.local first (takes precedence), then .env as fallback
dotenvConfig({ path: '../../.env.local', override: false });
dotenvConfig({ path: '../../.env', override: false });

function require(name: string): string {
  const val = process.env[name];
  if (!val) throw new Error(`Missing required env var: ${name}`);
  return val;
}

function optional(name: string, fallback: string): string {
  return process.env[name] ?? fallback;
}

export const config = {
  PORT: parseInt(optional('PORT', '3001'), 10),
  NODE_ENV: optional('NODE_ENV', 'development'),
  DATABASE_PATH: optional('DATABASE_PATH', './data/oo.db'),

  SESSION_SECRET: require('SESSION_SECRET'),

  GOOGLE_CLIENT_ID: require('GOOGLE_CLIENT_ID'),
  GOOGLE_CLIENT_SECRET: require('GOOGLE_CLIENT_SECRET'),

  TODOIST_CLIENT_ID: require('TODOIST_CLIENT_ID'),
  TODOIST_CLIENT_SECRET: require('TODOIST_CLIENT_SECRET'),

  /** Absolute base URL of this API, e.g. http://localhost:3001 */
  API_BASE_URL: optional('API_BASE_URL', 'http://localhost:3001'),
  /** Absolute base URL of the web app, e.g. http://localhost:3000 */
  WEB_BASE_URL: optional('WEB_BASE_URL', 'http://localhost:3000'),

  ML_SERVING_URL: optional('ML_SERVING_URL', 'http://localhost:8000'),
  LITELLM_URL: optional('LITELLM_URL', 'http://localhost:4000'),

  VAPID_PUBLIC_KEY: optional('VAPID_PUBLIC_KEY', ''),
  VAPID_PRIVATE_KEY: optional('VAPID_PRIVATE_KEY', ''),
  VAPID_SUBJECT: optional('VAPID_SUBJECT', 'mailto:admin@localhost'),
};