Added customer composite key

app/models/reservation.rb

@@ -1,11 +1,28 @@
 class Reservation < ApplicationRecord
   belongs_to :company
-  belongs_to :customer
+  belongs_to :customer,
+             primary_key: %i[first_name surname original_phone],
+             query_constraints: %i[customer_first_name customer_surname customer_original_phone]
   belongs_to :team
 
   validates :company_id, presence: true
-  validates :customer_id, presence: true
   validates :team_id, presence: true
+
+  # Remove customer_id validation since we're using composite key
+  validates :customer_first_name, :customer_surname, :customer_original_phone, presence: true
+
+  # Add validation to ensure customer exists
+  validate :customer_must_exist
+
+  private
+
+  def customer_must_exist
+    unless Customer.exists?(first_name: customer_first_name,
+                            surname: customer_surname,
+                            original_phone: customer_original_phone)
+      errors.add(:base, "Selected customer does not exist")
+    end
+  end
 end
 
 class ReservationSerializer < ActiveModel::Serializer