"use client";
import { useState, useEffect } from "react";
import { Product } from "@/lib/data";

type CartItem = Product & { quantity: number };

export function useCart() {
  const [cart, setCart] = useState<CartItem[]>([]);

  useEffect(() => {
    const savedCart = localStorage.getItem("cart");
    if (savedCart) setCart(JSON.parse(savedCart));
  }, []);

  const saveCart = (newCart: CartItem[]) => {
    setCart(newCart);
    localStorage.setItem("cart", JSON.stringify(newCart));
  };

  const addToCart = (product: Product) => {
    const existing = cart.find((item) => item.id === product.id);
    if (existing) {
      saveCart(
        cart.map((item) =>
          item.id === product.id ? { ...item, quantity: item.quantity + 1 } : item
        )
      );
    } else {
      saveCart([...cart, { ...product, quantity: 1 }]);
    }
  };

  const removeFromCart = (id: string) => {
    saveCart(cart.filter((item) => item.id !== id));
  };

  const updateQuantity = (id: string, quantity: number) => {
    if (quantity < 1) return removeFromCart(id);
    saveCart(
      cart.map((item) => (item.id === id ? { ...item, quantity } : item))
    );
  };

  const clearCart = () => saveCart([]);

  const total = cart.reduce((sum, item) => sum + item.price * item.quantity, 0);

  return { cart, addToCart, removeFromCart, updateQuantity, clearCart, total };
}