amount update

app/Models/Invoice.php

@@ -92,5 +92,20 @@ class Invoice extends Model
     return $this->hasMany(InvoiceInstallment::class);
 }
 
+// App\Models\Invoice.php
+
+public function totalPaid()
+{
+    return $this->installments()->sum('amount');
+}
+
+public function remainingAmount()
+{
+    return max(
+        ($this->final_amount_with_gst ?? 0) - $this->totalPaid(),
+        0
+    );
+}
+
 
 }