// Centralized env loader with required-value enforcement.
// Loaded once at startup; throws if anything mandatory is missing.
import { z } from 'zod';

const envSchema = z.object({
  NODE_ENV: z.enum(['development', 'production', 'test']).default('development'),
  PORT: z.coerce.number().int().positive().default(3010),
  DATABASE_URL: z.string().url(),
  REDIS_URL: z.string().url(),
  SESSION_SECRET: z.string().min(32, 'SESSION_SECRET must be at least 32 chars'),
  COOKIE_DOMAIN: z.string().default(''),
  UPLOAD_DIR: z.string().default('./uploads'),
  CORS_ORIGINS: z.string().default('http://localhost:3009'),
  LOG_LEVEL: z.enum(['trace', 'debug', 'info', 'warn', 'error', 'fatal']).default('info'),
  // OAuth — optional; providers without credentials are simply not offered.
  OAUTH_CALLBACK_BASE: z.string().default(''),
  GOOGLE_CLIENT_ID: z.string().default(''),
  GOOGLE_CLIENT_SECRET: z.string().default(''),
  GITHUB_CLIENT_ID: z.string().default(''),
  GITHUB_CLIENT_SECRET: z.string().default(''),
  SMTP_HOST: z.string().default(''),
  SMTP_PORT: z.coerce.number().int().positive().default(587),
  SMTP_USER: z.string().default(''),
  SMTP_PASS: z.string().default(''),
  SMTP_FROM: z.string().default('no-reply@teknav.ir'),
  SMS_PROVIDER: z.string().default(''),
  SMS_API_KEY: z.string().default(''),
  SMS_SENDER: z.string().default(''),
});

const parsed = envSchema.safeParse(process.env);
if (!parsed.success) {
  console.error('Invalid environment variables:');
  console.error(parsed.error.flatten().fieldErrors);
  process.exit(1);
}

export const config = {
  ...parsed.data,
  corsOrigins: parsed.data.CORS_ORIGINS.split(',').map((s) => s.trim()).filter(Boolean),
  isProd: parsed.data.NODE_ENV === 'production',
};