DONE: generate letter after the membership-application is completed

be/Modules/MembershipApplication/Entities/MembershipApplication.php

@@ -2,11 +2,13 @@
 
 namespace Modules\MembershipApplication\Entities;
 
+use App\Models\Document;
 use App\Traits\HasDocuments;
 use Illuminate\Database\Eloquent\Concerns\HasUuids;
 use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Eloquent\Relations\HasMany;
 use Illuminate\Database\Eloquent\Relations\HasOne;
+use Illuminate\Database\Eloquent\Relations\MorphOne;
 use Modules\Auth\Entities\User;
 use Modules\MembershipApplication\Enums\ApplicationStatus;
 
@@ -14,6 +16,12 @@ class MembershipApplication extends Model
 {
     use HasDocuments, HasUuids;
 
+    public const RESULT_LETTER_DOCUMENT_TYPE = 'result_letter';
+
+    public const MINIMUM_SHARE_CAPITAL = 500;
+
+    public const SHARE_INSTALLMENT_MONTHS = 6;
+
     protected $table = 'membership_applications';
 
     /**
@@ -65,4 +73,10 @@ class MembershipApplication extends Model
     {
         return $this->belongsTo(User::class);
     }
+
+    public function resultLetterDocument(): MorphOne
+    {
+        return $this->morphOne(Document::class, 'documentable')
+            ->where('type', self::RESULT_LETTER_DOCUMENT_TYPE);
+    }
 }