/**
 * App-specific i18n request configuration.
 * Loads translation messages from the app's messages directory.
 *
 * Supports two loading strategies:
 * 1. Single file: messages/${locale}.json (all namespaces in one file)
 * 2. Multiple files: messages/${locale}/*.json (namespaces in separate files for lazy loading)
 *
 */
import { getRequestConfig } from 'next-intl/server';

import { routing } from '@kit/i18n/routing';

// Define the namespaces to load
const namespaces = [
  'common',
  'auth',
  'account',
  'teams',
  'billing',
  'marketing',
  'cms',
  'verband',
  'members',
  'fischerei',
  'meetings',
  'courses',
  'finance',
  'newsletter',
  'siteBuilder',
  'events',
  'documents',
  'bookings',
  'portal',
] as const;

const isDevelopment = process.env.NODE_ENV === 'development';

export default getRequestConfig(async ({ requestLocale }) => {
  // Get the locale from the request (provided by middleware)
  let locale = await requestLocale;

  // Validate that the locale is supported, fallback to default if not
  if (!locale || !routing.locales.includes(locale as never)) {
    locale = routing.defaultLocale;
  }

  // Load all namespace files and merge them
  const messages = await loadMessages(locale);

  return {
    locale,
    messages,
    timeZone: 'UTC',
    onError(error) {
      if (isDevelopment) {
        // Missing translations are expected and should only log an error
        console.warn(`[Dev Only] i18n error: ${error.message}`);
      }
    },
    getMessageFallback(info) {
      return info.key;
    },
  };
});

/**
 * Loads translation messages for all namespaces.
 * Each namespace is loaded from a separate file for better code splitting.
 */
async function loadMessages(locale: string) {
  const loadedMessages: Record<string, unknown> = {};

  // Load each namespace file
  await Promise.all(
    namespaces.map(async (namespace) => {
      try {
        const namespaceMessages = await import(
          `./messages/${locale}/${namespace}.json`
        );

        loadedMessages[namespace] = namespaceMessages.default;
      } catch (error) {
        console.warn(
          `Failed to load namespace "${namespace}" for locale "${locale}":`,
          error,
        );
        // Set empty object as fallback
        loadedMessages[namespace] = {};
      }
    }),
  );

  return loadedMessages;
}