<template>
	<view class="wrap">
		<view class="menu">
			<scroll-view scroll-y scroll-with-animation class="tab-view menu-scroll-view" :scroll-top="scrollTop"
				:scroll-into-view="itemId">
				<view v-for="(item,index) in category" :key="index" class="tab-item"
					:class="[current == index ? 'tab-item-active' : '']" @tap.stop="swichMenu(index)">
					<text class="hm-line-1">{{item.name}}</text>
				</view>
			</scroll-view>
			<scroll-view :scroll-top="scrollRightTop" scroll-y scroll-with-animation class="right-box"
				@scroll="rightScroll">
				<view class="class-item" :id="'item' + index" v-for="(item , index) in category" :key="index">
					<view class="item-title">{{item.name}}</view>
					<view class="item-goods" v-for="(item1, index1) in item.goods" :key="index1">
						<image :src="item1.image[0].url"></image>
						<div v-if="applet.other.is_stock == 1 && item1.stock < 1" class="tag">
							售罄
						</div>
						<div v-else-if="item1.goods_status.value == 20" class="tag">
							{{item1.goods_status.text}}
						</div>
						<view class="hm-line-1 hm-col-main hm-font-28">{{item1.goods_name}}</view>
						<view class="hm-font-24 hm-col-tips">
							已售：{{item1.goods_sales}}份
						</view>
						<view class="hm-font-24 hm-col-error">
							￥{{item1.spec[0].goods_price}}
						</view>
						<view>
							<view class="hm-dis-block-inline">
								<u-button @click="del(item1.goods_id)" type="error" size="mini" text="删除"></u-button>
							</view>
							<view class="hm-m-l-10 hm-dis-block-inline">
								<u-button @click="goTo('user/goods/edit?id='+item1.goods_id)" type="primary" size="mini" text="删除">修改</u-button>
							</view>
							<view class="hm-m-l-10 hm-dis-block-inline">
								<u-button @click="status(item1.goods_status.value,item1.goods_id)" :type="item1.goods_status.value == 10 ? 'success':'warning'" size="mini" :text="item1.goods_status.text"></u-button>
							</view>
						</view>
					</view>
				</view>
			</scroll-view>
		</view>
		<view class="hm-footer-fixed">
			<view class="hm-p-lr-b25 hm-w-b100 hm-bg-f">
				<view class="hm-p-t-10">
					<u-button @click="goTo('user/goods/add')" type="success" text="添加商品"></u-button>
				</view>
			</view>
		</view>
	</view>
</template>

<script>
	var App = getApp();
	export default {
		data() {
			return {
				applet:{},
				scrollTop: 0, //tab标题的滚动条位置
				oldScrollTop: 0,
				current: 0, // 预设当前项的值
				menuHeight: 0, // 左边菜单的高度
				menuItemHeight: 0, // 左边菜单item的高度
				itemId: '', // 栏目右边scroll-view用于滚动的id
				arr: [],
				scrollRightTop: 0, // 右边栏目scroll-view的滚动条高度
				timer: null, // 定时器
				category: {}, //分类+商品列表
			};
		},
		components: {},
		props: {},
		onLoad(options) {
			let _this = this;
			_this.applet = App.getApplet();
		},
		/**
		 * 生命周期函数--监听页面显示
		 */
		onShow() {
			let _this = this;
			_this.getList(); //获取商品和分类
		},

		methods: {
			/**
			 * 获取商品列表
			 */
			getList: function() {
				let _this = this;
				App._get('goods/lists', {}, function(result) {
					_this.setData(result.data);
				});
			},
			
			/**
			 * 删除商品
			 */
			del: function(goods_id) {
				let _this = this;
				uni.showModal({
					title: "提示",
					content: "确定要删除该商品？",
					success: function(o) {
						if (o.confirm) {
							App._get('goods/delete', {
								id: goods_id
							}, function(result) {
								App.showSuccess(result.msg, function() {
									_this.getList();
								});
							});
						}
					}
				});
			},
			
			/**
			 * 商品上/下架
			 */
			status: function(value,goods_id) {
				let _this = this;
				let msg = value == 10 ? "下架" : "上架";
				uni.showModal({
					title: "提示",
					content: "确定要" + msg + "该商品？",
					success: function(o) {
						if (o.confirm) {
							App._get('goods/status', {
								id: goods_id
							}, function(result) {
								App.showSuccess(result.msg, function() {
									_this.getList();
								});
							});
						}
					}
				});
			},
			// 点击左边的栏目切换
			async swichMenu(index) {
				if (this.arr.length == 0) {
					await this.getMenuItemTop();
				}
				if (index == this.current) return;
				this.scrollRightTop = this.oldScrollTop;
				this.$nextTick(function() {
					this.scrollRightTop = this.arr[index];
					this.current = index;
					this.leftMenuStatus(index);
				})
			},
			// 获取一个目标元素的高度
			getElRect(elClass, dataVal) {
				new Promise((resolve, reject) => {
					const query = uni.createSelectorQuery().in(this);
					query.select('.' + elClass).fields({
						size: true
					}, res => {
						// 如果节点尚未生成，res值为null，循环调用执行
						if (!res) {
							setTimeout(() => {
								this.getElRect(elClass);
							}, 10);
							return;
						}
						this[dataVal] = res.height;
						resolve();
					}).exec();
				})
			},
			// 观测元素相交状态
			async observer() {
				this.tabbar.map((val, index) => {
					let observer = uni.createIntersectionObserver(this);
					// 检测右边scroll-view的id为itemxx的元素与right-box的相交状态
					// 如果跟.right-box底部相交，就动态设置左边栏目的活动状态
					observer.relativeTo('.right-box', {
						top: 0
					}).observe('#item' + index, res => {
						if (res.intersectionRatio > 0) {
							let id = res.id.substring(4);
							this.leftMenuStatus(id);
						}
					})
				})
			},
			// 设置左边菜单的滚动状态
			async leftMenuStatus(index) {
				this.current = index;
				// 如果为0，意味着尚未初始化
				if (this.menuHeight == 0 || this.menuItemHeight == 0) {
					await this.getElRect('menu-scroll-view', 'menuHeight');
					await this.getElRect('tab-item', 'menuItemHeight');
				}
				// 将菜单活动item垂直居中
				this.scrollTop = index * this.menuItemHeight + this.menuItemHeight / 2 - this.menuHeight / 2;
			},
			// 获取右边菜单每个item到顶部的距离
			getMenuItemTop() {
				new Promise(resolve => {
					let selectorQuery = uni.createSelectorQuery();
					selectorQuery.selectAll('.class-item').boundingClientRect((rects) => {
						// 如果节点尚未生成，rects值为[](因为用selectAll，所以返回的是数组)，循环调用执行
						if (!rects.length) {
							setTimeout(() => {
								this.getMenuItemTop();
							}, 10);
							return;
						}
						rects.forEach((rect) => {
							// 这里减去rects[0].top，是因为第一项顶部可能不是贴到导航栏(比如有个搜索框的情况)
							this.arr.push(rect.top - rects[0].top);
							resolve();
						})
					}).exec()
				})
			},
			// 右边菜单滚动
			async rightScroll(e) {
				this.oldScrollTop = e.detail.scrollTop;
				if (this.arr.length == 0) {
					await this.getMenuItemTop();
				}
				if (this.timer) return;
				if (!this.menuHeight) {
					await this.getElRect('menu-scroll-view', 'menuHeight');
				}
				setTimeout(() => { // 节流
					this.timer = null;
					// scrollHeight为右边菜单垂直中点位置
					let scrollHeight = e.detail.scrollTop + this.menuHeight / 2;
					for (let i = 0; i < this.arr.length; i++) {
						let height1 = this.arr[i];
						let height2 = this.arr[i + 1];
						// 如果不存在height2，意味着数据循环已经到了最后一个，设置左边菜单为最后一项即可
						if (!height2 || scrollHeight >= height1 && scrollHeight < height2) {
							this.leftMenuStatus(i);
							return;
						}
					}
				}, 10)
			},
			/**
			 * 跳转
			 */
			goTo: function(url) {
				App.goTo(url);
			}
		}
	};
</script>
<style lang="scss" scoped>
	.wrap {
		height: calc(100vh - 100rpx);
		/* #ifdef H5 */
		height: calc(100vh - 100rpx - var(--window-top));
		/* #endif */
		display: flex;
		flex-direction: column;
		.menu {
			flex: 1;
			display: flex;
			overflow: hidden;
			.tab-view {
				width: 220rpx;
				height: 100%;
				background-color: #FFFFFF;
				.tab-item {
					height: 110rpx;
					background: #FFFFFF;
					box-sizing: border-box;
					display: flex;
					align-items: center;
					justify-content: center;
					font-size: 26rpx;
					color: #444;
					font-weight: 400;
					line-height: 1;
					border-bottom: 1rpx solid #f3f4f6;
				}
				
				.tab-item-active {
					position: relative;
					color: #000;
					font-size: 30rpx;
					font-weight: 600;
					background: #f3f4f6;
				}
				
				.tab-item-active::before {
					content: "";
					position: absolute;
					border-left: 4px solid #fa3534;
					height: 32rpx;
					left: 0;
					top: 39rpx;
				}
			}
			.right-box {
				background-color: #f3f4f6;
				.class-item {
					padding: 16rpx;
					.item-title {
						font-size: 28rpx;
						color: #999;
						background-color: #FFF;
						padding: 15rpx 20rpx;
						border-bottom: 1rpx solid #f3f4f6;
					}
					.item-goods {
						padding: 15rpx;
						background-color: #FFF;
						height: 150rpx;
						position:relative;
						image {
							width: 150rpx;
							height: 150rpx;
							border-radius: 8rpx;
							float: left;
							margin-right: 20rpx;
						}
						.tag{
							display: inline-block;
							z-index: 1;
							position: absolute;
							top: 15rpx;
							left: 15rpx;
							width: 150rpx;
							height: 150rpx;
							border-radius: 8rpx;
							background: rgba(0, 0, 0, 0.5);
							color: #fff;
							line-height: 150rpx;
							text-align: center;
							font-size: 26rpx;
						}
					}
				}
			}
		}
	}
</style>