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

export interface CartItem {
  menuItemId: string
  name: string
  price: number
  quantity: number
  specialRequest?: string
}

interface CartStore {
  restaurantId: string | null
  restaurantName: string | null
  restaurantSlug: string | null
  items: CartItem[]

  addItem: (restaurantId: string, restaurantName: string, restaurantSlug: string, item: Omit<CartItem, 'quantity'>) => void
  removeItem: (menuItemId: string) => void
  updateQuantity: (menuItemId: string, quantity: number) => void
  clearCart: () => void

  // Computed
  subtotal: () => number
  itemCount: () => number
  deliveryFee: number
}

export const useCart = create<CartStore>()(
  persist(
    (set, get) => ({
      restaurantId: null,
      restaurantName: null,
      restaurantSlug: null,
      items: [],
      deliveryFee: 5.00,

      addItem: (restaurantId, restaurantName, restaurantSlug, item) => {
        // Coerce price to number (PostgreSQL returns DECIMAL as string)
        item = { ...item, price: Number(item.price) }
        const { restaurantId: currentRestId, items } = get()

        // Switching restaurant — clear cart first
        if (currentRestId && currentRestId !== restaurantId) {
          set({ restaurantId, restaurantName, restaurantSlug, items: [{ ...item, quantity: 1 }] })
          return
        }

        const existing = items.find((i) => i.menuItemId === item.menuItemId)
        if (existing) {
          set({
            items: items.map((i) =>
              i.menuItemId === item.menuItemId ? { ...i, quantity: i.quantity + 1 } : i,
            ),
          })
        } else {
          set({
            restaurantId,
            restaurantName,
            restaurantSlug,
            items: [...items, { ...item, quantity: 1 }],
          })
        }
      },

      removeItem: (menuItemId) =>
        set({ items: get().items.filter((i) => i.menuItemId !== menuItemId) }),

      updateQuantity: (menuItemId, quantity) => {
        if (quantity <= 0) {
          get().removeItem(menuItemId)
          return
        }
        set({ items: get().items.map((i) => (i.menuItemId === menuItemId ? { ...i, quantity } : i)) })
      },

      clearCart: () => set({ restaurantId: null, restaurantName: null, restaurantSlug: null, items: [] }),

      subtotal: () => get().items.reduce((sum, i) => sum + Number(i.price) * i.quantity, 0),
      itemCount: () => get().items.reduce((sum, i) => sum + i.quantity, 0),
    }),
    { name: 'vibe-cart' },
  ),
)