Refactor quantity input parsing to handle additional units and improve conversion logic across inventory forms and recipe pages

frontend/app/recipes/create/CreateRecipePage.tsx

@@ -144,11 +144,11 @@ export default function CreateRecipePage() {
               style={{ padding: '0.5rem' }}
             >
               <option value={0}>Välj produkt</option>
-              {products.map((product) => (
+              {products.length > 0 ? products.map((product) => (
                 <option key={product.id} value={product.id}>
                   {product.name}
                 </option>
-              ))}
+              )) : <option disabled>Kunde inte ladda produkter</option>}
             </select>
 
             <input

frontend/app/recipes/page.tsx

@@ -36,9 +36,20 @@ function parseQuantityInput(input: string, defaultUnit: string) {
   const match = input.trim().match(/^([\d.,]+)\s*([a-zA-Z]*)$/);
   if (!match) return { quantity: NaN, unit: defaultUnit };
   let [, num, unit] = match;
-  num = num.replace(',', '.');
-  unit = unit || defaultUnit;
-  if (defaultUnit === 'kg' && (unit === 'g' || unit === 'gram')) return { quantity: parseFloat(num) / 1000, unit: 'kg' };
-  if (defaultUnit === 'g' && (unit === 'kg' || unit === 'kilogram')) return { quantity: parseFloat(num) * 1000, unit: 'g' };
-  return { quantity: parseFloat(num), unit };
+    num = num.replace(',', '.');
+    unit = unit.toLowerCase() || defaultUnit;
+    const value = parseFloat(num);
+    // Konvertera alltid till defaultUnit
+    if (defaultUnit === 'kg') {
+      if (unit === 'g' || unit === 'gram') return { quantity: value / 1000, unit: 'kg' };
+      if (unit === 'hg' || unit === 'hektogram') return { quantity: value / 10, unit: 'kg' };
+      if (unit === 'kg' || unit === 'kilogram' || unit === '') return { quantity: value, unit: 'kg' };
+    }
+    if (defaultUnit === 'g') {
+      if (unit === 'kg' || unit === 'kilogram') return { quantity: value * 1000, unit: 'g' };
+      if (unit === 'hg' || unit === 'hektogram') return { quantity: value * 100, unit: 'g' };
+      if (unit === 'g' || unit === 'gram' || unit === '') return { quantity: value, unit: 'g' };
+    }
+    // Lägg till fler konverteringar vid behov
+    return { quantity: value, unit: defaultUnit };
 }