feat: add SEO configuration with dynamic robots.txt and sitemap.xml generation

utils/sitemap.js

@@ -0,0 +1,45 @@
+// Utility functions for sitemap generation
+export const DOMAIN_CONFIG = {
+    MAIN_DOMAIN: 'nobat724.com',
+    MAX_SPECIALTY_COMBINATIONS: 20, // Limit specialty combinations to prevent too many URLs
+    MAIN_CITIES: ['108', '104', '111', '117', '113'], // Tehran, Isfahan, Mashhad, Shiraz, Ahvaz
+};
+
+export function isMainDomain(domain) {
+    return domain === DOMAIN_CONFIG.MAIN_DOMAIN;
+}
+
+export function encodeUrlParam(param) {
+    return encodeURIComponent(param || '');
+}
+
+export function createSitemapUrl(baseUrl, path, params = {}) {
+    let url = `${baseUrl}${path}`;
+    const searchParams = new URLSearchParams();
+
+    Object.entries(params).forEach(([key, value]) => {
+        if (value) {
+            searchParams.append(key, value);
+        }
+    });
+
+    const queryString = searchParams.toString();
+    return queryString ? `${url}?${queryString}` : url;
+}
+
+export function createSitemapEntry(url, priority = 0.8, changeFrequency = 'weekly') {
+    return {
+        url,
+        lastModified: new Date(),
+        changeFrequency,
+        priority,
+    };
+}
+
+export function limitArray(array, limit) {
+    return limit > 0 ? array.slice(0, limit) : array;
+}
+
+export function getBaseUrl(domain) {
+    return `https://${domain}`;
+}