ログイン状態の出品者でも、売却済みの商品に対しては「編集・削除ボタン」を表示しない

ruby
1  <% if user_signed_in? %>
2    <% if current_user.id == @item.user_id %>
3      <%= link_to '商品の編集', edit_item_path, method: :get, class: "item-red-btn" %>
4      <p class='or-text'>or</p>
5      <%= link_to '削除', item_path(@item.id), method: :delete, class:'item-destroy' %>
6    <% elsif @item.purchase.blank? %>
7
8      <%= link_to '購入画面に進む', item_purchases_path(@item.id), class:"item-red-btn"%>
9    <% end %>
10  <% end %>

class ItemsController < ApplicationController
  before_action :authenticate_user!, except: [:index, :show]
  before_action :set_item, only: [:show, :edit, :update, :destroy]
  def index
    @item = Item.all
  end

  def new
    @item = Item.new
  end

  def create
    @item = Item.new(item_params)
    if @item.save
      redirect_to root_path
    else
      render :new
    end    
  end

  def show
  end

  def edit
    unless current_user == @item.user
      redirect_to root_path
    end  
  end

  def update
    if @item.update(item_params)
      redirect_to item_path(@item)
    else
      render :edit
    end
  end

  def destroy
    if current_user == @item.user
      @item.destroy
    end
      redirect_to root_path
  end
  
  def set_item
    @item = Item.find(params[:id])
  end


  private

  def item_params
    params.require(:item).permit(:name, :price, :category_id, :condition_id, :postage_id, :region_id, :shipping_date_id, :description, :image).merge(user_id: current_user.id)
  end
  
end