/*
    *    Copyright 2010-2026 the original author or authors.
    *
    *    Licensed under the Apache License, Version 2.0 (the "License");
    *    you may not use this file except in compliance with the License.
    *    You may obtain a copy of the License at
    *
    *       https://www.apache.org/licenses/LICENSE-2.0
    *
   *    Unless required by applicable law or agreed to in writing, software
   *    distributed under the License is distributed on an "AS IS" BASIS,
   *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   *    See the License for the specific language governing permissions and
   *    limitations under the License.
   */
  package org.mybatis.jpetstore.web.controllers;
  
  import java.util.Iterator;
  
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpSession;
  
  import org.mybatis.jpetstore.domain.Cart;
  import org.mybatis.jpetstore.domain.CartItem;
  import org.mybatis.jpetstore.domain.Item;
  import org.mybatis.jpetstore.service.CatalogService;
  import org.springframework.beans.factory.annotation.Autowired;
  import org.springframework.stereotype.Controller;
  import org.springframework.ui.Model;
  import org.springframework.web.bind.annotation.GetMapping;
  import org.springframework.web.bind.annotation.PostMapping;
  import org.springframework.web.bind.annotation.RequestMapping;
  import org.springframework.web.bind.annotation.RequestParam;
  
  /**
   * The Class CartController.
   */
  @Controller
  @RequestMapping("/cart")
  public class CartController {
  
    /** The error view. */
    private static final String ERROR_VIEW = "common/Error";
  
    /** The catalog service. */
    @Autowired
    private CatalogService catalogService;
  
    /**
     * Get cart.
     *
     * @param session
     *          the session
     *
     * @return the cart
     */
    private Cart getCart(HttpSession session) {
      Cart cart = (Cart) session.getAttribute("cart");
      if (cart == null) {
        cart = new Cart();
        session.setAttribute("cart", cart);
      }
      return cart;
    }
  
    /**
     * View cart.
     *
     * @param session
     *          the session
     * @param model
     *          the model
     *
     * @return the string
     */
    @GetMapping({ "", "/" })
    public String viewCart(HttpSession session, Model model) {
      model.addAttribute("cart", getCart(session));
      return "cart/Cart";
    }
  
    /**
     * Add item to cart.
     *
     * @param workingItemId
     *          the working item id
     * @param session
     *          the session
     * @param model
     *          the model
     *
     * @return the string
     */
    @GetMapping("/addItem")
    public String addItemToCart(@RequestParam(value = "workingItemId", required = false) String workingItemId,
        HttpSession session, Model model) {
      if (workingItemId == null || workingItemId.trim().isEmpty()) {
        model.addAttribute("message", "Invalid item ID: cannot add item to cart.");
        return ERROR_VIEW;
     }
     Cart cart = getCart(session);
     if (cart.containsItemId(workingItemId)) {
       cart.incrementQuantityByItemId(workingItemId);
     } else {
       boolean isInStock = catalogService.isItemInStock(workingItemId);
       Item item = catalogService.getItem(workingItemId);
       cart.addItem(item, isInStock);
     }
     model.addAttribute("cart", cart);
     return "cart/Cart";
   }
 
   /**
    * Remove item from cart.
    *
    * @param workingItemId
    *          the working item id
    * @param session
    *          the session
    * @param model
    *          the model
    *
    * @return the string
    */
   @GetMapping("/removeItem")
   public String removeItemFromCart(@RequestParam(value = "workingItemId", required = false) String workingItemId,
       HttpSession session, Model model) {
     if (workingItemId == null || workingItemId.trim().isEmpty()) {
       model.addAttribute("message", "Invalid item ID: cannot remove item from cart.");
       return ERROR_VIEW;
     }
     Cart cart = getCart(session);
     Item item = cart.removeItemById(workingItemId);
     if (item == null) {
       model.addAttribute("message", "Attempted to remove null CartItem from Cart.");
       return ERROR_VIEW;
     }
     model.addAttribute("cart", cart);
     return "cart/Cart";
   }
 
   /**
    * Update cart quantities.
    *
    * @param request
    *          the request
    * @param session
    *          the session
    * @param model
    *          the model
    *
    * @return the string
    */
   @PostMapping("/update")
   public String updateCartQuantities(HttpServletRequest request, HttpSession session, Model model) {
     Cart cart = getCart(session);
     Iterator<CartItem> cartItems = cart.getAllCartItems();
     while (cartItems.hasNext()) {
       CartItem cartItem = cartItems.next();
       String itemId = cartItem.getItem().getItemId();
       try {
         int quantity = Integer.parseInt(request.getParameter(itemId));
         cart.setQuantityByItemId(itemId, quantity);
         if (quantity < 1) {
           cartItems.remove();
         }
       } catch (NumberFormatException e) {
         // ignore invalid numeric input on purpose
       }
     }
     model.addAttribute("cart", cart);
     return "cart/Cart";
   }
 
   /**
    * Check out.
    *
    * @param session
    *          the session
    * @param model
    *          the model
    *
    * @return the string
    */
   @GetMapping("/checkout")
   public String checkOut(HttpSession session, Model model) {
     model.addAttribute("cart", getCart(session));
     return "cart/Checkout";
   }
 
 }