<template>
 <div id="app">
 <h3>Shopping Cart Demo</h3>
 <hr>
 <h4>Products:</h4>
 <ProductList />
 <hr>
 <h4>My Cart</h4>
 <ShoppingCart />
 </div>
</template>
<script>
import ProductList from '@/components/ProductList';
import ShoppingCart from '@/components/ShoppingCart';
 
export default {
 components: {
 ProductList,
 ShoppingCart
 }
}
</script>

<template>
 <div>
  <ul v-for="item in products" :key="item.id">
  <li>
   {{ item.title }} - {{ item.price }} &nbsp;&nbsp; 库存： {{ item.inventory }}<br>
   <button :disabled="!item.inventory" @click="addToCart(item)">add to cart</button> 
  </li>
  </ul>
 </div>
 
</template>
 
<script>
import { mapGetters, mapActions } from 'vuex';
export default {
 computed: {
 // ...mapGetters('products',{
 // products: 'allProducts'
 // })
 ...mapGetters({
  products: 'products/allProducts'
 })
 },
 methods: {
 ...mapActions('cart',['addToCart'])
 },
 created() {
 this.$store.dispatch('products/getAllProducts');
 }
 
}
</script>

<template>
 <div>
 <ul v-for="item in products" :key="item.id">
  <li>{{ item.title }} *{{ item.quantity }}</li>
 </ul>
 <div>total: {{ total }}</div>
 </div>
</template>
<script>
import { mapGetters } from 'vuex';
export default {
 computed: {
 ...mapGetters('cart', {
  products: 'cartProducts',
  total: 'cartTotalPrice'
 })
 }
}
</script>

import api from '../../api';
 
const state = {
 all: []
}
 
const getters = {
 allProducts: state => state.all
}
 
const actions = {
 // 获取初始商品数据
 getAllProducts({ commit }) {
 api.getProducts(products => commit('setProducts', products));
 }
}
 
const mutations = {
 setProducts(state, products) {
 state.all = products;
 },
 // 减少该商品库存
 decreamentInventory(state, { id }) {
 let productItem = state.all.find(item => item.id === id);
 productItem.inventory --;
 }
}
 
export default {
 namespaced: true,
 state,
 getters,
 actions,
 mutations
}

const state = {
 addedList: []
}
 
const getters = {
 cartProducts(state, getters, rootState) {
 return state.addedList.map((item, index) => {
  let productItem = rootState.products.all.find(product => product.id === item.id);
  return {
  title: productItem.title,
  price: productItem.price,
  quantity: item.quantity
  }
 })
 },
 cartTotalPrice(state, getters) {
 return getters.cartProducts.reduce((total, product) => {
  return total + (product.price * product.quantity);
 }, 0);
 }
}
 
const actions = {
 addToCart({ state, commit }, product) {
 if (product.inventory > 0) {
  let productItem = state.addedList.find(item => item.id === product.id);
  if (productItem) {
  commit('increamentItemQuantity', productItem);
  } else {
  commit('pushItemToCart', product);
  }
  commit('products/decreamentInventory', product, { root: true });
 }
 }
}
 
const mutations = {
 // 增加购物车中同等商品的数量
 increamentItemQuantity(state, { id }) {
 let productItem = state.addedList.find(item => item.id === id);
 productItem.quantity ++;
 },
 // 将商品加入购物车
 pushItemToCart(state, { id }) {
 state.addedList.push({
  id,
  quantity: 1
 })
 },
 
}
 
export default {
 namespaced: true,
 state,
 getters,
 actions,
 mutations
}

import Vue from 'vue';
import Vuex from 'vuex';
import cart from './modules/cart';
import products from './modules/products';
 
Vue.use(Vuex);
 
export default new Vuex.Store({
 modules: {
 cart,
 products
 }
});

import Vue from "vue";
import App from "@/components/App.vue";
import store from "@/store";
 
Vue.config.productionTip = false;
 
new Vue({
 store,
 render: h => h(App)
}).$mount("#app");