changes and optimisations

src/app/services/seo.service.ts

@@ -1,4 +1,4 @@
-import { Injectable, inject } from '@angular/core';
+import { Injectable, inject, DOCUMENT } from '@angular/core';
 import { Meta, Title } from '@angular/platform-browser';
 import { environment } from '../../environments/environment';
 import { Item } from '../models';
@@ -10,6 +10,7 @@ import { getDiscountedPrice, getMainImage } from '../utils/item.utils';
 export class SeoService {
   private meta = inject(Meta);
   private title = inject(Title);
+  private doc = inject(DOCUMENT);
 
   private readonly siteUrl = `https://${environment.domain}`;
   private readonly siteName = environment.brandFullName;
@@ -25,6 +26,7 @@ export class SeoService {
     const titleText = `${item.name} — ${this.siteName}`;
 
     this.title.setTitle(titleText);
+    this.setCanonical(itemUrl);
 
     this.setOrUpdate([
       // Open Graph
@@ -81,6 +83,7 @@ export class SeoService {
     // Remove product-specific tags
     this.meta.removeTag("property='product:price:amount'");
     this.meta.removeTag("property='product:price:currency'");
+    this.removeCanonical();
   }
 
   private setOrUpdate(tags: Array<{ property?: string; name?: string; content: string }>): void {
@@ -114,4 +117,19 @@ export class SeoService {
     if (!text || text.length <= maxLength) return text || '';
     return text.substring(0, maxLength - 1) + '…';
   }
+
+  private setCanonical(url: string): void {
+    this.removeCanonical();
+    const link = this.doc.createElement('link');
+    link.setAttribute('rel', 'canonical');
+    link.setAttribute('href', url);
+    this.doc.head.appendChild(link);
+  }
+
+  private removeCanonical(): void {
+    const existing = this.doc.head.querySelector('link[rel="canonical"]');
+    if (existing) {
+      this.doc.head.removeChild(existing);
+    }
+  }
 }