refactor: update models relations

app/Models/Airline.php

@@ -15,12 +15,13 @@ use Illuminate\Database\Eloquent\Model;
  * 
  * @property int $id
  * @property string $name
- * @property string $country
+ * @property int $country_id
  * @property string $phone
  * @property int $status
  * @property Carbon $created_at
  * @property Carbon $updated_at
  * 
+ * @property Country $country
  * @property Collection|Flight[] $flights
  *
  * @package App\Models
@@ -31,16 +32,22 @@ class Airline extends Model
 	public static $snakeAttributes = false;
 
 	protected $casts = [
+		'country_id' => 'int',
 		'status' => 'int'
 	];
 
 	protected $fillable = [
 		'name',
-		'country',
+		'country_id',
 		'phone',
 		'status'
 	];
 
+	public function country()
+	{
+		return $this->belongsTo(Country::class);
+	}
+
 	public function flights()
 	{
 		return $this->hasMany(Flight::class);