import { NextRequest, NextResponse } from 'next/server';
import { getLocalizedMessage } from '@/lib/i18n-loader';
import enMessages from '@/messages/en.json';
import deMessages from '@/messages/de.json';

// Cache für 5 Minuten
export const revalidate = 300;

const messagesMap = { en: enMessages, de: deMessages };

/**
 * GET /api/messages?locale=en
 * Lädt ALLE Messages aus Directus + JSON Fallback
 * Wird von next-intl als messages source verwendet
 */
export async function GET(req: NextRequest) {
  const locale = req.nextUrl.searchParams.get('locale') || 'en';

  // Normalize locale (de-DE -> de)
  const normalizedLocale = locale.startsWith('de') ? 'de' : 'en';

  try {
    // Starte mit JSON als Basis
    const jsonMessages = messagesMap[normalizedLocale as 'en' | 'de'];
    
    // Clone das Objekt
    const messages = JSON.parse(JSON.stringify(jsonMessages));

    // Flatten alle Keys
    const allKeys = getAllKeys(messages);

    // Lade jeden Key aus Directus (überschreibt JSON wenn vorhanden)
    await Promise.all(
      allKeys.map(async (key) => {
        try {
          const value = await getLocalizedMessage(key, locale);
          if (value && value !== key) {
            // Überschreibe den Wert im messages Objekt
            setNestedValue(messages, key, value);
          }
        } catch (error) {
          // Fallback auf JSON Wert (schon vorhanden)
        }
      })
    );

    return NextResponse.json(messages, {
      headers: {
        'Cache-Control': 'public, s-maxage=300, stale-while-revalidate=600',
      },
    });
  } catch (error) {
    console.error('Messages API error:', error);
    // Fallback: Return nur JSON messages
    return NextResponse.json(messagesMap[normalizedLocale as 'en' | 'de'], {
      headers: {
        'Cache-Control': 'public, s-maxage=60',
      },
    });
  }
}

// Helper: Sammle alle Keys aus verschachteltem Objekt
function getAllKeys(obj: any, prefix = ''): string[] {
  const keys: string[] = [];

  for (const [key, value] of Object.entries(obj)) {
    const fullKey = prefix ? `${prefix}.${key}` : key;
    
    if (value && typeof value === 'object' && !Array.isArray(value)) {
      keys.push(...getAllKeys(value, fullKey));
    } else {
      keys.push(fullKey);
    }
  }

  return keys;
}

// Helper: Setze Wert in verschachteltem Objekt
function setNestedValue(obj: any, path: string, value: any) {
  const keys = path.split('.');
  const lastKey = keys.pop()!;
  
  let current = obj;
  for (const key of keys) {
    if (!(key in current)) {
      current[key] = {};
    }
    current = current[key];
  }
  
  current[lastKey] = value;
}