Fix edit invoice initialization and routing

The form initialization logic for editing invoices was improved to
handle route changes correctly. The edit link path was fixed and cache
invalidation was added to ensure fresh data on navigation.

src/app/dashboard/invoices/[id]/page.tsx

@@ -131,7 +131,7 @@ function InvoiceViewContent({ invoiceId }: { invoiceId: string }) {
       >
         <PDFDownloadButton invoiceId={invoice.id} variant="outline" />
         <Button asChild variant="default">
-          <Link href={`/dashboard/invoices/${invoice.id}`}>
+          <Link href={`/dashboard/invoices/${invoice.id}/edit`}>
             <Edit className="h-5 w-5" />
             <span>Edit</span>
           </Link>

src/components/forms/invoice-form.tsx

@@ -143,19 +143,26 @@ export default function InvoiceForm({ invoiceId }: InvoiceFormProps) {
     },
   });
 
-  // Single initialization effect - only runs once when data is ready
+  // Reset initialization when invoiceId changes
   useEffect(() => {
-    if (initialized) return;
+    setInitialized(false);
+  }, [invoiceId]);
 
-    const dataReady =
-      !loadingClients &&
-      !loadingBusinesses &&
-      (!invoiceId || invoiceId === "new" || !loadingInvoice);
-    if (!dataReady) return;
-
-    if (invoiceId && invoiceId !== "new" && existingInvoice) {
+  // Initialize form data when invoice data is loaded
+  useEffect(() => {
+    if (invoiceId && invoiceId !== "new" && existingInvoice && !initialized) {
       // Initialize with existing invoice data
-      const formDataToSet = {
+      const mappedItems =
+        existingInvoice.items?.map((item) => ({
+          id: crypto.randomUUID(),
+          date: new Date(item.date),
+          description: item.description,
+          hours: item.hours,
+          rate: item.rate,
+          amount: item.amount,
+        })) || [];
+
+      setFormData({
         invoiceNumber: existingInvoice.invoiceNumber,
         businessId: existingInvoice.businessId ?? "",
         clientId: existingInvoice.clientId,
@@ -166,43 +173,43 @@ export default function InvoiceForm({ invoiceId }: InvoiceFormProps) {
         taxRate: existingInvoice.taxRate,
         defaultHourlyRate: null,
         items:
-          existingInvoice.items?.map((item) => ({
-            id: crypto.randomUUID(),
-            date: new Date(item.date),
-            description: item.description,
-            hours: item.hours,
-            rate: item.rate,
-            amount: item.amount,
-          })) || [],
-      };
-      setFormData(formDataToSet);
-    } else if ((!invoiceId || invoiceId === "new") && businesses) {
+          mappedItems.length > 0
+            ? mappedItems
+            : [
+                {
+                  id: crypto.randomUUID(),
+                  date: new Date(),
+                  description: "",
+                  hours: 1,
+                  rate: 0,
+                  amount: 0,
+                },
+              ],
+      });
+
+      firstItemEditedRef.current = false;
+      setInitialized(true);
+    } else if (
+      (!invoiceId || invoiceId === "new") &&
+      businesses &&
+      !initialized
+    ) {
       // New invoice - set default business
       const defaultBusiness = businesses.find((b) => b.isDefault);
       if (defaultBusiness) {
         setFormData((prev) => ({ ...prev, businessId: defaultBusiness.id }));
       } else if (businesses.length > 0) {
-        // If no default business, use the first one
         setFormData((prev) => ({ ...prev, businessId: businesses[0]!.id }));
       }
+      setInitialized(true);
     }
-
-    // Reset the first item edited flag when initializing
-    firstItemEditedRef.current = false;
-    setInitialized(true);
-  }, [
-    loadingClients,
-    loadingBusinesses,
-    loadingInvoice,
-    existingInvoice,
-    businesses,
-    invoiceId,
-    initialized,
-  ]);
+  }, [invoiceId, existingInvoice, businesses, initialized]);
 
   // Update the first line item when defaultHourlyRate changes (if it hasn't been manually edited)
+  // Only for new invoices, not existing ones being edited
   useEffect(() => {
     if (
+      (!invoiceId || invoiceId === "new") &&
       !firstItemEditedRef.current &&
       formData.items.length === 1 &&
       formData.items[0]?.description === "" &&
@@ -220,7 +227,7 @@ export default function InvoiceForm({ invoiceId }: InvoiceFormProps) {
         ],
       }));
     }
-  }, [formData.defaultHourlyRate, formData.items]);
+  }, [formData.defaultHourlyRate]);
 
   // Update default hourly rate when client changes
   useEffect(() => {
@@ -353,6 +360,10 @@ export default function InvoiceForm({ invoiceId }: InvoiceFormProps) {
     onSuccess: async () => {
       toast.success("Invoice updated successfully");
       await utils.invoices.getAll.invalidate();
+      // Invalidate the specific invoice cache to ensure fresh data on navigation
+      if (invoiceId && invoiceId !== "new") {
+        await utils.invoices.getById.invalidate({ id: invoiceId });
+      }
       // The update mutation returns { success: true }, so we use the current invoiceId
       if (invoiceId && invoiceId !== "new") {
         router.push(`/dashboard/invoices/${invoiceId}`);