refactor: implement optimistic updates for chicken inventory and simplify transaction handling

Author: Hopertz

src/hooks/use-chicken-inventory.ts

@@ -84,6 +84,7 @@ export function useChickenInventory() {
     }
 
     try {
+      // First fetch the current chicken data to get the correct IDs
       const response = await fetch(`${API_BASE_URL}/auth/chickens`, {
         headers: { 'Authorization': `Bearer ${user.token}` }
       });
@@ -105,6 +106,10 @@ export function useChickenInventory() {
 
       // Only send the update if there's an actual change
       if (quantityChange !== 0) {
+        // Update local state optimistically
+        setCounts(prev => ({ ...prev, [type]: newQuantity }));
+        
+        // Send the update to the server with the correct ID
         const updateResponse = await fetch(`${API_BASE_URL}/auth/chickens/${chickenToUpdate.id}`, {
           method: 'PUT',
           headers: {
@@ -115,21 +120,17 @@ export function useChickenInventory() {
         });
 
         if (!updateResponse.ok) {
+          // If update fails, revert the local state
+          setCounts(prev => ({ ...prev, [type]: currentQuantity }));
           throw new Error(`Failed to update chicken inventory: ${updateResponse.status}`);
         }
       }
-      
-      // Update local state with the new quantity
-      setCounts(prev => ({ ...prev, [type]: newQuantity }));
-      
-      // Refetch the inventory to ensure consistency
-      await fetchChickenInventory();
     } catch (err) {
       setError(err instanceof Error ? err.message : 'An unknown error occurred');
     } finally {
       setLoading(false);
     }
-  }, [user?.token, API_BASE_URL]); // End of updateChickenInventory
+  }, [user?.token, API_BASE_URL]);
 
   const fetchChickenHistory = useCallback(async (type?: ChickenType, reason?: string) => {
     setHistoryLoading(true);

src/pages/Index.tsx

@@ -239,37 +239,11 @@ const Index = () => {
         id: crypto.randomUUID(),
       };
 
+      // Since the backend already handles chicken inventory updates when posting transactions,
+      // we only need to fetch the updated data once after the transaction is complete
       if (transaction.category === 'chicken') {
-        const isIncrease = transaction.type === 'expense';
-        const reason = isIncrease ? 'purchase' : 'sale';
-        const updatePromises: Promise<void>[] = [];
-
-        if (transaction.bulkQuantities) {
-          const { hen: henCount, cock: cockCount, chicks: chicksCount } = transaction.bulkQuantities;
-          if (henCount > 0) {
-            const current = hookChickenCounts.hen;
-            const newQty = isIncrease ? current + henCount : Math.max(0, current - henCount);
-            updatePromises.push(hookUpdateChickenInventory('hen' as HookChickenType, newQty, reason));
-          }
-          if (cockCount > 0) {
-            const current = hookChickenCounts.cock;
-            const newQty = isIncrease ? current + cockCount : Math.max(0, current - cockCount);
-            updatePromises.push(hookUpdateChickenInventory('cock' as HookChickenType, newQty, reason));
-          }
-          if (chicksCount > 0) {
-            const current = hookChickenCounts.chicks;
-            const newQty = isIncrease ? current + chicksCount : Math.max(0, current - chicksCount);
-            updatePromises.push(hookUpdateChickenInventory('chicks' as HookChickenType, newQty, reason));
-          }
-        } else if (transaction.chickenType && typeof transaction.quantity === 'number') {
-          const current = hookChickenCounts[transaction.chickenType as HookChickenType];
-          const newQty = isIncrease ? current + transaction.quantity : Math.max(0, current - transaction.quantity);
-          updatePromises.push(hookUpdateChickenInventory(transaction.chickenType as HookChickenType, newQty, reason));
-        }
-
-        // Wait for all chicken inventory updates to complete
-        // The updateChickenInventory function already refetches the inventory data
-        await Promise.all(updatePromises);
+        // Fetch the updated chicken inventory data
+        await hookFetchChickenInventory();
 
         // Only fetch history if we're on the history tab
         if (activeInventoryTab === 'history') {