<template>
	<view class="clearfix" :class="['qn-page-' + theme]">
		<view class="float_left">
			<scroll-view scroll-y class="left-aside" :style="{ height: 'calc(100vh - 112rpx - ' + (isBang ? '84px' : '50px') + ')' }">
				<view v-for="item in cate_list" :key="item.id" class="f-item b-b ellipsis" :class="{ active: item.id === current_item.id }" @click="tabtap(item)">
					<view v-if="item.id === current_item.id" class="active-line primary-bg"></view>
					{{ item.title }}
				</view>
			</scroll-view>
		</view>
		<view class="float_right">
			<!-- 二级下拉菜单 -->
			<view class="two-cate">
				<scroll-view :scroll-x="true" scroll-with-animation class="two-cate-scroll" :scroll-left="two_cate_scroll">
					<view
						v-for="(item, index) in current_item.children"
						:key="index"
						:class="[tow_current === index ? 'primary-btn-pain' : '']"
						class="cate-two-li"
						@click="twoCateChange(index, item)"
					>
						{{ item.title }}
					</view>
				</scroll-view>
			</view>
			<scroll-view
				scroll-y
				scroll-with-animation
				class="right-aside"
				:style="{ height: 'calc(100vh - 188rpx - ' + (isBang ? '84px' : '50px') + ')' }"
				:scroll-top="scroll_right_top"
				@scroll="rightScroll"
			>
				<view v-for="(titem, tindex) in current_item.children" :key="tindex" class="cate-ul" :id="'item' + tindex">
					<block v-if="titem.children.length">
						<view class="cate-name">{{ titem.title }}</view>
						<view class="clearfix">
							<view
								class="cate-li"
								v-for="(item, index) in titem.children"
								:key="index"
								@click="goPage('/pagesT/productDetail/productDetail?id=' + item.id + '&name=' + item.title)"
							>
								<view class="cate-img-view">
									<image v-if="item.images" :src="item.images" mode="aspectFill" class="cate-img"></image>
									<view class="ibonfont ibonleimupinleifenleileibie cate-img-icon" v-else></view>
								</view>
								<view class="cate-tit ellipsis">{{ item.title }}</view>
							</view>
						</view>
					</block>
				</view>
			</scroll-view>
		</view>
	</view>
</template>

<script>
export default {
	data() {
		return {
			cate_list: [],
			tow_current: 0,
			current_item: {},
			scroll_right_top: 0, // 右边三级分类栏目scroll-view的滚动条高度
			old_scroll_top: 0,
			option_arr: [], // 把3级分类的每一块位置信息存储到数组中
			two_cate_scroll: 0, // 2级分类滚动
			menu_width: 0, // 2级分类菜单的宽度
			menu_item_width: 0, // 2级分类菜单item的宽度
			timer: null, // 定时器
			menu_height: 0 // 3级菜单高度
		};
	},
	computed: {
		isBang() {
			return this.$_utils.modelmes();
		},
		userId() {
			return this.$store.state.userStatus.id;
		}
	},
	created() {
		this.getAllCategory();
	},
	methods: {
		// 分类列表 getAllCategory
		getAllCategory() {
			this.$u.api
				.getAllCategory({
					userCenterId: this.userId || 0
				})
				.then(({ data }) => {
					this.cate_list = data;
					if (data.length) {
						this.current_item = data[0];
					}
					this.getMenuItemTop();
				});
		},
		// 一级分类切换
		tabtap(row) {
			this.current_item = row;
			this.tow_current = 0;
		},
		// 2级分类切换
		async twoCateChange(index, row) {
			if (this.option_arr.length == 0) {
				await this.getMenuItemTop();
			}
			if (row.id == this.two_id) return;
			this.scroll_right_top = this.old_scroll_top;
			this.$nextTick(() => {
				this.scroll_right_top = this.option_arr[index];
				this.tow_current = index;
				this.twoMenuStatus(index, 1);
			});
		},
		// 3级分类列表滚动
		async rightScroll(e) {
			this.old_scroll_top = e.detail.scrollTop;
			// if(this.option_arr.length == 0) {
			// 	await this.getMenuItemTop();
			// }
			// if(this.timer) return ;
			// if(!this.menu_height) {
			// 	await this.getElRect('right-aside', 'menu_height','height');
			// }
			// setTimeout(() => { // 节流
			// 	this.timer = null;
			// 	// scrollHeight为右边菜单垂直中点位置
			// 	let scrollHeight = e.detail.scrollTop + this.menu_height / 2;
			// 	for (let i = 0; i < this.option_arr.length; i++) {
			// 		let height1 = this.option_arr[i];
			// 		let height2 = this.option_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2级菜单为最后一项即可
			// 		if (!height2 || scrollHeight >= height1 && scrollHeight < height2) {
			// 			this.twoMenuStatus(i);
			// 			return ;
			// 		}
			// 	}
			// }, 10)
		},
		// 设置2级分类的滚动状态
		async twoMenuStatus(index) {
			this.tow_current = index;
			// 如果为0，意味着尚未初始化
			if (this.menu_width == 0 || this.menu_item_width == 0) {
				await this.getElRect('two-cate-scroll', 'menu_width', 'width');
				await this.getElRect('cate-two-li', 'menu_item_width', 'width');
			}
			// 将菜单活动item居中
			this.two_cate_scroll = index * this.menu_width + this.menu_item_width / 2 - this.menu_width / 2;
		},
		// 获取3级分类列表菜单每个item到顶部的距离
		getMenuItemTop() {
			new Promise(resolve => {
				let selectorQuery = uni.createSelectorQuery().in(this);
				//添加节点的布局位置的查询请求
				selectorQuery
					.selectAll('.cate-ul')
					.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.option_arr.push(rect.top - rects[0].top);
							resolve();
						});
					})
					.exec();
			});
		},
		// 获取一个目标元素的宽度
		getElRect(elClass, dataVal, option) {
			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, dataVal);
								}, 10);
								return;
							}
							this[dataVal] = res[option];
							resolve();
						}
					)
					.exec();
			});
		}
	}
};
</script>

<style lang="scss">
.left-aside {
	width: 200upx;
	background-color: #f5f6f7;
	/* #ifdef H5||MP */
	height: calc(100vh - 130upx);
	/*#endif*/
	/* #ifdef APP-PLUS */
	height: 100vh;
	/*#endif*/
	.f-item {
		-webkit-line-clamp: 1;
		width: 100%;
		height: 80upx;
		line-height: 80rpx;
		padding-left: 48rpx;
		margin-bottom: 10rpx;
		font-size: 26upx;
		color: #4b4b4b;
		position: relative;

		&.active {
			color: #000000;
			font-size: 32upx;
			font-weight: bold;
			background-color: #ffffff;
			border-radius: 100rpx 0 0 100rpx;
		}
		.active-line {
			position: absolute;
			left: 28rpx;
			top: 50%;
			transform: translateY(-50%);
			height: 24upx;
			width: 4upx;
			border-radius: 4rpx;
		}
	}
}
.two-cate {
	.two-cate-scroll {
		width: 550upx;
		padding: 14rpx 0;
		white-space: nowrap;
		.cate-two-li {
			padding: 0 32rpx;
			display: inline-block;
			font-size: 24rpx;
			margin-left: 16rpx;
			border: 1px solid #f5f6f7;
			background-color: #f5f6f7;
			border-radius: 50rpx;
			height: 48rpx;
			line-height: 48rpx;
			&:last-child {
				margin-right: 40rpx;
			}
			&:first-child {
				margin-left: 40rpx;
			}
		}
	}
}
.right-aside {
	/* #ifdef H5||MP */
	height: calc(100vh - 140upx);
	/*#endif*/
	/* #ifdef APP-PLUS */
	height: 100vh;
	/*#endif*/
	width: 550upx;
	.cate-name {
		padding-top: 20rpx;
		padding-left: 40rpx;
		font-size: 26rpx;
		font-weight: 600;
		color: #000000;
	}
	.cate-li {
		float: left;
		width: 130upx;
		text-align: center;
		margin: 20upx 0 20rpx 40rpx;
		.cate-img-view {
			width: 130rpx;
			height: 104rpx;
			background: #f5f7f7;
			border-radius: 8px;
			margin-bottom: 24rpx;
			.cate-img {
				width: 84upx;
				height: 84upx;
				border-radius: 8upx;
				display: block;
				margin: 0 auto;
				transform: translateY(10rpx);
			}
			.cate-img-icon {
				font-size: 80upx;
				width: 84upx;
				line-height: 84upx;
				color: #eeeeee;
				height: 84upx;
				border-radius: 8upx;
				margin: 0 auto;
				transform: translateY(10rpx);
			}
		}

		.cate-tit {
			font-size: 24upx;
			font-weight: 400;
			color: #3a3a3a;
			width: 100%;
			-webkit-line-clamp: 1;
		}
	}
}
</style>