import { createContext, useContext, useState, useEffect } from 'react';
import { toast } from 'sonner';

const CartContext = createContext();

export const CartProvider = ({ children }) => {
  const [items, setItems] = useState([]);
  const [total, setTotal] = useState(0);

  // Load cart from localStorage on initial load
  useEffect(() => {
    if (typeof window !== 'undefined') {
      const savedCart = localStorage.getItem('cart');
      if (savedCart) {
        try {
          const parsedCart = JSON.parse(savedCart);
          setItems(parsedCart);
          calculateTotal(parsedCart);
        } catch (error) {
          console.error('Failed to parse cart from localStorage:', error);
        }
      }
    }
  }, []);

  // Save cart to localStorage whenever it changes
  useEffect(() => {
    if (typeof window !== 'undefined') {
      localStorage.setItem('cart', JSON.stringify(items));
      calculateTotal(items);
    }
  }, [items]);

  // Calculate total price
  const calculateTotal = (cartItems) => {
    const sum = cartItems.reduce((acc, item) => acc + item.price * item.quantity, 0);
    setTotal(sum);
  };

  // Add item to cart
  const addItem = (item) => {
    setItems((prevItems) => {
      // Check if item already exists in cart
      const existingItemIndex = prevItems.findIndex((i) => i.id === item.id);

      if (existingItemIndex !== -1) {
        // Item exists, update quantity
        const updatedItems = [...prevItems];
        updatedItems[existingItemIndex] = {
          ...updatedItems[existingItemIndex],
          quantity: updatedItems[existingItemIndex].quantity + 1,
        };
        toast.success(`Added another ${item.name} to your cart`);
        return updatedItems;
      } else {
        // Item doesn't exist, add new item
        toast.success(`Added ${item.name} to your cart`);
        return [...prevItems, { ...item, quantity: 1 }];
      }
    });
  };

  // Remove item from cart
  const removeItem = (itemId) => {
    setItems((prevItems) => {
      const itemToRemove = prevItems.find((item) => item.id === itemId);
      if (itemToRemove) {
        toast.success(`Removed ${itemToRemove.name} from your cart`);
      }
      return prevItems.filter((item) => item.id !== itemId);
    });
  };

  // Update item quantity
  const updateQuantity = (itemId, quantity) => {
    if (quantity < 1) return;

    setItems((prevItems) =>
      prevItems.map((item) =>
        item.id === itemId ? { ...item, quantity } : item
      )
    );
  };

  // Clear cart
  const clearCart = () => {
    setItems([]);
    toast.success('Cart cleared');
  };

  // Get cart item count
  const getItemCount = () => {
    return items.reduce((count, item) => count + item.quantity, 0);
  };

  return (
    <CartContext.Provider
      value={{
        items,
        total,
        addItem,
        removeItem,
        updateQuantity,
        clearCart,
        getItemCount,
      }}
    >
      {children}
    </CartContext.Provider>
  );
};

// Custom hook to use cart context
export const useCart = () => {
  const context = useContext(CartContext);
  if (!context) {
    throw new Error('useCart must be used within a CartProvider');
  }
  return context;
};