<template>
	<!-- 横向滚动容器：恢复scroll-into-view，绑定动态变量targetScrollId，移除ref -->
	<scroll-view class="tabs-scroll-container" scroll-x="true" scroll-with-animation :show-scrollbar="false" :scroll-into-view="targetScrollId">
		<view class="tabs-wrapper" :style="{ display: noScroll ? 'flex' : 'inline-block' }">
			<!-- 遍历tab列表：保留tab-${index}的id，用于scroll-into-view定位 -->
			<!-- 核心：与scroll-into-view绑定的id -->
			<view v-for="(item, index) in list" :key="index" :id="`tab-${index}`" hover-class="none" active-class="none" :style="{ flex: noScroll ? '1' : '' }" :class="['tab-item', `tab-item-${index}`, { active: activeIndex === index }]" @click="handleTabClick(index)">
				<span class="tab-text" :style="getTabTextStyle(index)">{{ item.name }}</span>
				<view class="tab-active-line" v-show="activeIndex === index" :style="getActiveLineStyle()"></view>
			</view>
		</view>
	</scroll-view>
</template>

<script>
export default {
	name: "ScrollableTabs",
	props: {
		list: { type: Array, default: () => [] },
		noScroll: { type: Boolean, default: true },
		current: { type: Number, default: 0 },
		activeColor: { type: String, default: "" },
		fontSize: { type: [String, Number], default: 32 },
		activeFontWeight: { type: [String, Number], default: 600 },
		normalColor: { type: String, default: "#333333" },
		bgColor: { type: String, default: "#ffffff" },
	},
	data() {
		return {
			targetScrollId: `tab-${this.current}`,
			currentActiveColor: this.activeColor || getApp().globalData.themeColor,
		};
	},
	created() {
		uni.$on('themeChanged', (color) => {
			if (!this.activeColor) {
				this.currentActiveColor = color;
			}
		});
	},
	beforeDestroy() {
		uni.$off('themeChanged');
	},
	watch: {
		activeColor(newVal) {
			if (newVal) {
				this.currentActiveColor = newVal;
			}
		},
	},
	computed: {
		activeIndex() {
			return this.current;
		},
	},
	methods: {
		// 点击tab切换（核心：通过变量赋值控制滚动）
		handleTabClick(index) {
			if (this.activeIndex === index) return;
			this.activeIndex = index;
			this.$emit("change", index);
      console.log();
			// 计算要滚动到的目标id，让相邻tab显示到可视区
			this.calcTargetScrollId(index);
		},

		/**
		 * 计算scroll-into-view的目标id（完全基于索引，无节点查询）
		 * @param {Number} currentIndex - 点击的tab索引
		 */
		calcTargetScrollId(currentIndex) {
			const listLen = this.list.length;
			if (listLen <= 1) return;

			let targetIndex = currentIndex;
			// 情况1：点击第一个tab → 滚动到第一个，确保第二个显示
			if (currentIndex === 0) {
				targetIndex = 0;
			}
			// 情况2：点击最后一个tab → 滚动到倒数第二个，确保倒数第二个显示
			else if (currentIndex === listLen - 1) {
				targetIndex = listLen - 2;
			}
			// 情况3：点击中间tab → 滚动到当前tab的前一个，确保上一个和下一个都显示
			else {
				// 优先滚动到当前tab的前一个，让当前+下一个都在可视区
				targetIndex = currentIndex - 1;
				// 兜底：确保目标索引不越界
				targetIndex = Math.max(0, Math.min(targetIndex, listLen - 1));
			}

			// 变量赋值：控制scroll-into-view滚动到目标tab
			this.targetScrollId = `tab-${targetIndex}`;
		},

		// 动态生成tab文字样式
		getTabTextStyle(index) {
			const baseStyle = {
				fontSize: `${this.fontSize}rpx`,
				fontWeight: 400,
				transition: "all 0.2s ease",
			};
			return this.activeIndex === index ? { ...baseStyle, color: this.currentActiveColor, fontWeight: this.activeFontWeight } : { ...baseStyle, color: this.normalColor };
		},

		// 动态生成active底部横条样式
		getActiveLineStyle() {
			return {
				backgroundColor: this.currentActiveColor,
				transition: "all 0.2s ease",
			};
		},
	},
};
</script>

<style lang="scss" scoped>
/* 滚动容器：保留原有样式，仅移除无用注释 */
.tabs-scroll-container {
	width: 100%;
	white-space: nowrap;
	height: 88rpx;
	box-sizing: border-box;
	background-color: v-bind(bgColor);
}

.tabs-wrapper {
	width: 100%;
	padding: 0;
}

.tab-item {
	display: inline-block;
	position: relative;
	padding: 0 20rpx;
	height: 88rpx;
	line-height: 88rpx;
	text-align: center;
	box-sizing: border-box;
	cursor: default;
	-webkit-tap-highlight-color: transparent;
	tap-highlight-color: transparent;
	user-select: none;
}

.tab-text {
	display: inline-block;
}

.tab-active-line {
	position: absolute;
	bottom: 5px;
	left: 50%;
	transform: translateX(-50%);
	width: 40rpx;
	height: 6rpx;
	border-radius: 3rpx;
}

::-webkit-scrollbar {
	display: none;
}
</style>
