import type {PayloadAction} from '@reduxjs/toolkit';
import type {CartItem, CartProduct, CartState} from '@/types/domain';
import type {RootState} from './store';
import {createSlice} from '@reduxjs/toolkit';

const initialState: CartState = {
    items: [], // { id, name, priceNumeric, priceLabel, qty, image }
};

const cartSlice = createSlice({
    name: 'cart',
    initialState,
    reducers: {
        restoreCart: (state, action: PayloadAction<CartItem[]>) => {
            state.items = action.payload;
        },
        addToCart: (state, action: PayloadAction<CartProduct>) => {
            const product = action.payload;
            const existing = state.items.find(item => item.id === product.id);
            if (existing) {
                existing.qty += 1;
            } else {
                state.items.push({...product, qty: 1});
            }
        },
        removeFromCart: (state, action: PayloadAction<string>) => {
            state.items = state.items.filter(item => item.id !== action.payload);
        },
        setQuantity: (state, action: PayloadAction<{id: string; qty: number}>) => {
            const {id, qty} = action.payload;
            if (!Number.isSafeInteger(qty) || qty < 1) return;
            const item = state.items.find(item => item.id === id);
            if (item) item.qty = qty;
        },
        incrementQty: (state, action: PayloadAction<string>) => {
            const item = state.items.find(item => item.id === action.payload);
            if (item) item.qty += 1;
        },
        decrementQty: (state, action: PayloadAction<string>) => {
            const item = state.items.find(item => item.id === action.payload);
            if (item && item.qty > 1) {
                item.qty -= 1;
            } else if (item) {
                state.items = state.items.filter(i => i.id !== action.payload);
            }
        },
        clearCart: state => {
            state.items = [];
        },
    },
});

export const {restoreCart, addToCart, removeFromCart, setQuantity, incrementQty, decrementQty, clearCart} =
    cartSlice.actions;

// Selectors
export const selectCartItems = (state: RootState) => state.cart.items;
export const selectCartCount = (state: RootState) => state.cart.items.reduce((sum, item) => sum + item.qty, 0);
export const selectCartTotal = (state: RootState) =>
    state.cart.items.reduce((sum, item) => sum + item.qty * item.priceNumeric, 0);

export default cartSlice.reducer;