import { Router, Request, Response } from 'express';
import { i18nService } from '../i18n';

export function createI18nRoutes(): Router {
  const router = Router();

  /**
   * Get translations for a specific locale
   * GET /api/i18n/:locale
   */
  router.get('/:locale', (req: Request, res: Response): void => {
    const { locale } = req.params;

    // Validate locale
    if (!i18nService.isLocaleSupported(locale)) {
      res.status(400).json({
        error: 'Unsupported locale',
        supportedLocales: i18nService.getAvailableLocales()
      });
      return;
    }

    // Get translations for the locale
    const translations = i18nService.getTranslations(locale);
    
    if (!translations) {
      res.status(404).json({
        error: 'Translations not found for locale',
        locale
      });
      return;
    }

    // Set appropriate headers for caching
    res.set({
      'Cache-Control': 'public, max-age=3600', // Cache for 1 hour
      'Content-Type': 'application/json'
    });

    res.json(translations);
  });

  /**
   * Get available locales and their display names
   * GET /api/i18n
   */
  router.get('/', (req: Request, res: Response): void => {
    const locales = i18nService.getAvailableLocales().map(locale => ({
      code: locale,
      name: i18nService.getLocaleDisplayName(locale)
    }));

    res.json({
      default: i18nService.getDefaultLocale(),
      available: locales
    });
  });

  /**
   * Detect user's preferred locale based on Accept-Language header
   * GET /api/i18n/detect
   */
  router.get('/detect', (req: Request, res: Response): void => {
    const acceptLanguage = req.get('Accept-Language');
    const detectedLocale = i18nService.detectLocale(acceptLanguage);

    res.json({
      detected: detectedLocale,
      displayName: i18nService.getLocaleDisplayName(detectedLocale)
    });
  });

  return router;
}

export default createI18nRoutes;