porządkowanie kodu i poprawki js

app.py

@@ -1543,7 +1543,7 @@ def handle_disconnect(sid):
 @socketio.on("add_item")
 def handle_add_item(data):
     list_id = data["list_id"]
-    name = data["name"]
+    name = data["name"].strip()
     quantity = data.get("quantity", 1)
 
     try:
@@ -1553,34 +1553,56 @@ def handle_add_item(data):
     except:
         quantity = 1
 
-    new_item = Item(
-        list_id=list_id,
-        name=name,
-        quantity=quantity,
-        added_by=current_user.id if current_user.is_authenticated else None,
-    )
-    db.session.add(new_item)
+    # Szukamy istniejącego itemu w tej liście (ignorując wielkość liter)
+    existing_item = Item.query.filter(
+        Item.list_id == list_id,
+        func.lower(Item.name) == name.lower(),
+        Item.not_purchased == False
+    ).first()
 
-    if not SuggestedProduct.query.filter_by(name=name).first():
-        new_suggestion = SuggestedProduct(name=name)
-        db.session.add(new_suggestion)
+    if existing_item:
+        existing_item.quantity += quantity
+        db.session.commit()
 
-    db.session.commit()
+        emit(
+            "item_edited",
+            {
+                "item_id": existing_item.id,
+                "new_name": existing_item.name,
+                "new_quantity": existing_item.quantity
+            },
+            to=str(list_id),
+        )
+    else:
+        new_item = Item(
+            list_id=list_id,
+            name=name,
+            quantity=quantity,
+            added_by=current_user.id if current_user.is_authenticated else None,
+        )
+        db.session.add(new_item)
 
-    emit(
-        "item_added",
-        {
-            "id": new_item.id,
-            "name": new_item.name,
-            "quantity": new_item.quantity,
-            "added_by": (
-                current_user.username if current_user.is_authenticated else "Gość"
-            ),
-        },
-        to=str(list_id),
-        include_self=True,
-    )
+        if not SuggestedProduct.query.filter(func.lower(SuggestedProduct.name) == name.lower()).first():
+            new_suggestion = SuggestedProduct(name=name)
+            db.session.add(new_suggestion)
 
+        db.session.commit()
+
+        emit(
+            "item_added",
+            {
+                "id": new_item.id,
+                "name": new_item.name,
+                "quantity": new_item.quantity,
+                "added_by": (
+                    current_user.username if current_user.is_authenticated else "Gość"
+                ),
+            },
+            to=str(list_id),
+            include_self=True,
+        )
+
+    # Aktualizacja postępu
     purchased_count, total_count, percent = get_progress(list_id)
 
     emit(