import { create } from 'zustand';
import { persist } from 'zustand/middleware';

export interface CartItem {
  id: string;
  slug: string;
  name: string;
  brand: string;
  image: string;
  price: number;
  quantity: number;
}

interface CartState {
  items: CartItem[];
  addItem: (item: Omit<CartItem, 'id' | 'quantity'>) => void;
  removeItem: (id: string) => void;
  updateQuantity: (id: string, quantity: number) => void;
  clearCart: () => void;
  getTotal: () => number;
  getCount: () => number;
}

export const useCartStore = create<CartState>()(
  persist(
    (set, get) => ({
      items: [],

      addItem: (newItem) => {
        set((state) => {
          const id = newItem.slug;
          const existing = state.items.find((i) => i.id === id);
          if (existing) {
            return {
              items: state.items.map((i) =>
                i.id === id ? { ...i, quantity: i.quantity + 1 } : i
              ),
            };
          }
          return { items: [...state.items, { ...newItem, id, quantity: 1 }] };
        });
      },

      removeItem: (id) =>
        set((state) => ({ items: state.items.filter((i) => i.id !== id) })),

      updateQuantity: (id, quantity) => {
        if (quantity < 1) return;
        set((state) => ({
          items: state.items.map((i) => (i.id === id ? { ...i, quantity } : i)),
        }));
      },

      clearCart: () => set({ items: [] }),

      getTotal: () => {
        const { items } = get();
        return items.reduce((sum, i) => sum + i.price * i.quantity, 0);
      },

      getCount: () => {
        const { items } = get();
        return items.reduce((sum, i) => sum + i.quantity, 0);
      },
    }),
    { name: 'thermcool-cart' }
  )
);