'use client';

import { container } from '@/lib/utils';
import { useCart } from 'components/cart/cart-context';
import { useTransition } from 'react';
import { removeItem, updateItemQuantity } from './actions';
import { CartDiscountForm } from './CartDiscountForm';
import { CartSummary } from './CartSummary';
import { EmptyCartMessage } from './EmptyCartMessage';
import { useCartProcessing } from './hooks/useCartProcessing';
import { BoxesSection } from './sections/BoxesSection';
import { CartHeader } from './sections/CartHeader';
import { CartLoading } from './sections/CartLoading';
import { OrderNotes } from './sections/OrderNotes';
import { ProductsSection } from './sections/ProductsSection';

export default function CartPage() {
  const { cart, updateCartItem } = useCart();
  const [isPending, startTransition] = useTransition();
  const { boxes, standaloneProducts, isGroupingComplete, didInitialProcess } = useCartProcessing(cart);

  if (!cart?.lines.length) {
    return <EmptyCartMessage />;
  }

  // Show loading state while processing cart items
  if (!didInitialProcess || !isGroupingComplete) {
    return <CartLoading />;
  }

  const handleUpdateCartItem = (merchandiseId: string, updateType: 'plus' | 'minus' | 'delete', itemId?: string) => {
    // First update the client-side cart state for immediate feedback
    updateCartItem(merchandiseId, updateType, itemId);
    
    // Update lastBoxState in localStorage if this is a box item
    try {
      const boxStateString = localStorage.getItem('lastBoxState');
      if (boxStateString) {
        const boxState = JSON.parse(boxStateString);
        
        // Check if this item belongs to a box
        const cartItem = cart.lines.find(item => {
          if (itemId && item.id) {
            return item.id === itemId;
          }
          return item.merchandise.id === merchandiseId;
        });
        
        if (cartItem) {
          // Check if it's a box item by looking at attributes
          const attrs = cartItem.attributes || [];
          const boxType = attrs.find(attr => attr.key === '_box_type')?.value;
          const boxGroupId = attrs.find(attr => attr.key === '_box_group_id')?.value;
          
          if (boxType && boxGroupId) {
            // Find the corresponding item in the stored state
            if (boxType === 'item' && boxState.productItems) {
              if (updateType === 'delete') {
                // Remove the item from productItems
                boxState.productItems = boxState.productItems.filter((item: { id: string, variantId: string }) => 
                  item.id !== cartItem.merchandise.product.id || 
                  item.variantId !== cartItem.merchandise.id
                );
              } else {
                // Update quantity
                const productItem = boxState.productItems.find((item: { id: string, variantId: string }) => 
                  item.id === cartItem.merchandise.product.id &&
                  item.variantId === cartItem.merchandise.id
                );
                
                if (productItem) {
                  const newQuantity = updateType === 'plus' 
                    ? cartItem.quantity + 1 
                    : Math.max(1, cartItem.quantity - 1);
                  productItem.quantity = newQuantity;
                }
              }
              
              // Save updated state back to localStorage
              localStorage.setItem('lastBoxState', JSON.stringify(boxState));
            }
            else if (boxType === 'container' && boxState.boxItems) {
              if (updateType === 'delete') {
                // Remove the box
                boxState.boxItems = boxState.boxItems.filter((item: { id: string }) => 
                  item.id !== cartItem.merchandise.product.id
                );
              } else {
                // Update quantity
                const boxItem = boxState.boxItems.find((item: { id: string }) => 
                  item.id === cartItem.merchandise.product.id
                );
                
                if (boxItem) {
                  const newQuantity = updateType === 'plus' 
                    ? cartItem.quantity + 1 
                    : Math.max(1, cartItem.quantity - 1);
                  boxItem.quantity = newQuantity;
                }
              }
              
              // Save updated state back to localStorage
              localStorage.setItem('lastBoxState', JSON.stringify(boxState));
            }
          }
        }
      }
    } catch (error) {
      console.error('Error updating box state in localStorage', error);
    }
    
    // Then update the server-side cart
    startTransition(() => {
      if (updateType === 'delete') {
        // Call server action to remove item
        removeItem({}, merchandiseId, itemId);
      } else {
        // Find the specific item to update, using both merchandise ID and item ID if provided
        let item = cart.lines.find((item: { id?: string, merchandise: { id: string } }) => {
          if (itemId && item.id) {
            // If we have item ID, use it for more specific matching
            return item.id === itemId;
          }
          // Fall back to merchandise ID only
          return item.merchandise.id === merchandiseId;
        });
        
        if (item) {
          // Calculate new quantity based on the updateType
          const newQuantity = updateType === 'plus' 
            ? item.quantity + 1 
            : Math.max(1, item.quantity - 1);
          
          // Call server action to update quantity
          updateItemQuantity({}, { merchandiseId, quantity: newQuantity, itemId });
        }
      }
    });
  };

  return (
    <div className={container}>
      <div className="pb-20">
        <div className="flex flex-col lg:flex-row lg:justify-between gap-8">
          {/* Left Side: Cart Items */}
          <div className="lg:w-[62%]">
            <CartHeader totalQuantity={cart.totalQuantity} />
            
            {/* Boxes Section */}
            <BoxesSection 
              boxes={boxes}
              onUpdate={handleUpdateCartItem}
              isPending={isPending}
            />

            {/* Standalone Products Section */}
            <ProductsSection 
              products={standaloneProducts}
              onUpdate={handleUpdateCartItem}
              isPending={isPending}
            />

            {/* Order Notes */}
            <OrderNotes />

            {/* Discount Form */}
            <CartDiscountForm />
          </div>

          {/* Right Side: Order Summary */}
          <div className="lg:w-[30%]">
            <div className="mt-6 lg:mt-[72px]">
              <CartSummary cart={cart} />
            </div>
          </div>
        </div>
      </div>
    </div>
  );
}