eiru_pos/src/store/modules/cart.js

import { 
    SET_CART, 
    PUSH_TO_CART, 
    PULL_FROM_CART, 
    SET_CART_TOTAL,
    SET_ITEM_TO_DISCOUNT,
    SET_ITEM_PRICE
} from '@/constants/mutationTypes'

import { 
    ADD_TO_CART, 
    DECREASE_FROM_CART,
    CHANGE_PRICE,
    APPLY_PRICE,
    REMOVE_FROM_CART, 
    CHANGE_CART_TOTAL, 
    RESET_CART 
} from '@/constants/actionTypes'

const initialState = {
    cartItems: [],
    cartTotal: 0,
    itemToDiscount: null
}

const state = {
    cartItems: initialState.cartItems,
    cartTotal: initialState.cartTotal,
    itemToDiscount: null
}

const getters = {
    /**
     * 
     * @param {*} state 
     */
    cartItems(state) {
        return state.cartItems
    },
    /**
     * 
     * @param {*} state 
     */
    cartTotal(state) {
        return state.cartTotal
    },
    /**
     * 
     * @param {*} state 
     */
    itemToDiscount(state) {
        return state.itemToDiscount
    }
}

const mutations = {
    /**
     * 
     * @param {*} state 
     * @param {*} payload 
     */
    [SET_CART] (state, payload) {
        state.cartItems = payload
    },
    /**
     * 
     * @param {*} state 
     * @param {*} payload 
     */
    [PUSH_TO_CART] (state, payload) {
        let productFound = state.cartItems.find(item => item.id === payload.id)

        if (productFound) {
            if (payload.quantity > 1) {
                if (productFound.quantity === payload.quantity) {
                    productFound.quantity = productFound.quantity + 1    
                } else {
                    productFound.quantity = payload.quantity
                }
            } else {
                productFound.quantity = productFound.quantity + payload.quantity
            }
            return
        }

        state.cartItems = [payload, ...state.cartItems]
    },
    /**
     * 
     * @param {*} state 
     * @param {*} payload 
     */
    [PULL_FROM_CART] (state, payload) {
        let productFoundIndex = state.cartItems.findIndex(item => item.id === payload.item.id)

        if (state.cartItems[productFoundIndex].quantity === 1) {
            payload.mode = 'full'
        }

        if (payload.mode === 'partial') {
            if (payload.item.quantity !== -1) {
                state.cartItems[productFoundIndex].quantity = payload.item.quantity
            } else {
                state.cartItems[productFoundIndex].quantity = state.cartItems[productFoundIndex].quantity - 1
            }
        } else {
            state.cartItems.splice(productFoundIndex, 1)
        }
    },
    /**
     * 
     * @param {*} state 
     * @param {*} payload 
     */
    [SET_CART_TOTAL] (state, payload) {
        state.cartTotal = payload
    },
    /**
     * 
     * @param {*} state 
     * @param {*} payload 
     */
    [SET_ITEM_TO_DISCOUNT] (state, payload) {
        state.itemToDiscount = payload
    },
    /**
     * 
     * @param {*} state 
     * @param {*} payload 
     */
    [SET_ITEM_PRICE] (state, payload) {
        let foundProduct = state.cartItems.find(item => item.id === state.itemToDiscount.id)

        foundProduct.price = payload
    }
}

const actions = {
    /**
     * 
     * @param {*} param0 
     * @param {*} payload 
     */
    [ADD_TO_CART] ({ commit }, payload) {
        commit(PUSH_TO_CART, payload)
    },
    /**
     * 
     * @param {*} param0 
     * @param {*} payload 
     */
    [DECREASE_FROM_CART] ({ commit }, payload) {
        commit(PULL_FROM_CART, {
            item: payload,
            mode: 'partial'
        })
    },
    /**
     * 
     * @param {*} param0 
     * @param {*} payload 
     */
    [CHANGE_PRICE] ({ commit }, payload) {
        commit(SET_ITEM_TO_DISCOUNT, payload)
    },
    /**
     * 
     * @param {*} param0 
     * @param {*} payload 
     */
    [APPLY_PRICE] ({ commit }, payload) {
        if (payload) {
            commit(SET_ITEM_PRICE, payload)
        }

        commit(SET_ITEM_TO_DISCOUNT, null)
    },
    /**
     * 
     * @param {*} param0 
     * @param {*} payload 
     */
    [REMOVE_FROM_CART] ({ commit }, payload) {
        commit(PULL_FROM_CART, {
            item: payload,
            mode: 'full'
        })
    },
    /**
     * 
     * @param {*} param0 
     * @param {*} payload 
     */
    [CHANGE_CART_TOTAL] ({ commit }, payload) {
        commit(SET_CART_TOTAL, payload)
    },
    /**
     * 
     * @param {*} param0 
     * @param {*} payload 
     */
    [RESET_CART] ({ commit }) {
        commit(SET_CART, [])
        commit(SET_CART_TOTAL, 0)
    }
}

export default {
    state,
    getters,
    mutations,
    actions
}