eiru_pos/src/store/modules/cart.js

const state = {
    cart: [],
    total: 0,
    productToDiscount: null
}

const getters = {
    cartItems(state) {
        return state.cart
    },
    total(state) {
        return state.total
    },
    cartIsEmpty(state) {
        return state.cart.length !== 0
    },
    productToDiscount(state) {
        return state.productToDiscount
    }
}

const mutations = {
    addToCart(state, payload) {
        let finded = state.cart.find(item => item.id == payload.product.id)

        if (finded) {
            payload.product.qty = payload.product.qty + 1
        } else {
            state.cart = [payload.product, ...state.cart]
        }
    },
    subtractFromCart(state, payload) {
        let finded = state.cart.find(item => item.id == payload.product.id)
        finded.qty = finded.qty - 1
    },
    discountFromCart(state, payload) {
        state.productToDiscount = payload
    },
    applyDiscount(state, payload) {
        let finded = state.cart.find(item => item.id == state.productToDiscount.id)
        finded.price = state.productToDiscount.discount
    },
    removeFromCart(state, payload) {
        let findedIndex = state.cart.findIndex(item => item.id == payload.product.id)
        state.cart.splice(findedIndex, 1)
    },
    calculateTotal(state) {
        let sum = 0

        state.cart.forEach(item => {
            sum = sum + ((item.price || item.list_price) * (item.qty || 1))
        })

        state.total = sum
    }
}

const actions = {
    addToCart({ commit, dispatch }, payload) {
        commit('addToCart', {
            product: payload
        })
        
        commit('calculateTotal')

        // dispatch('setSelectedProduct', {
        //     product: null
        // })
    },
    subtractFromCart({ commit, dispatch }, payload) {
        if (payload.qty > 1) {
            commit('subtractFromCart', {
                product: payload
            })
        } else {
            commit('removeFromCart', {
                product: payload
            })     
        }
        
        commit('calculateTotal')
    },
    discountFromCart({ commit, dispatch }, payload) {
        if (payload && !payload.minimum_price && !payload.maximum_price) {
            dispatch('notify', 'No hay descuento para este producto')
            return
        }

        commit('discountFromCart', payload)
    },
    applyDiscount({ getters, commit, dispatch  }, payload) {
        if(payload.apply) {
            let product = getters.productToDiscount

            if (product.priceApply < product.minimum_price || product.priceApply > product.maximum_price) {
                dispatch('notify', 'No se puede aplicar este descuento')
                return
            }

            commit('applyDiscount', product.id)
            commit('calculateTotal')
        }

        dispatch('discountFromCart', null)
    },
    removeFromCart({ commit, dispatch }, payload) {
        commit('removeFromCart', {
            product: payload
        })
        
        commit('calculateTotal')
    }
}

export default {
    state,
    getters,
    mutations,
    actions
}