reconstruction of the project

app/Models/InvoiceEvent.php

@@ -7,7 +7,10 @@ use App\Models\BaseModel;
 class InvoiceEvent extends BaseModel
 {
     protected $table = 'invoice_event';
-    protected $primaryKey = 'id';
+
+    // ✅ CI: useTimestamps = true (created_at/updated_at)
+    public $timestamps = true;
+
     protected $fillable = [
         'invoice_id',
         'event_name',
@@ -19,7 +22,21 @@ class InvoiceEvent extends BaseModel
         'created_at',
         'updated_at',
     ];
-    public $timestamps = true;
-    const CREATED_AT = 'created_at';
-    const UPDATED_AT = 'updated_at';
-}
+
+    protected $casts = [
+        'invoice_id'  => 'integer',
+        'amount'      => 'decimal:2', // adjust precision if needed
+        'updated_by'  => 'integer',
+    ];
+
+    /* Optional relationships */
+    public function invoice()
+    {
+        return $this->belongsTo(Invoice::class, 'invoice_id');
+    }
+
+    public function updatedByUser()
+    {
+        return $this->belongsTo(User::class, 'updated_by');
+    }
+}