<template>
	<view class="uni-combox" :class="border ? '' : 'uni-combox__no-border'">
		<view v-if="label" class="uni-combox__label" :style="labelStyle">
			<text>{{label}}</text>
		</view>
		<view class="uni-combox__input-box">
			<input class="uni-combox__input" type="text" :placeholder="placeholder" 
			placeholder-class="uni-combox__input-plac" v-model="inputVal" @input="onInput" @focus="onFocus" 
@blur="onBlur" />
			<uni-icons :type="showSelector? 'top' : 'bottom'" size="14" color="#999" @click="toggleSelector">
			</uni-icons>
		</view>
		<view class="uni-combox__selector" v-if="showSelector">
			<view class="uni-popper__arrow"></view>
			<scroll-view scroll-y="true" class="uni-combox__selector-scroll">
				<view class="uni-combox__selector-empty" v-if="filterCandidatesLength === 0">
					<text>{{emptyTips}}</text>
				</view>
				<view class="uni-combox__selector-item" v-for="(item,index) in filterCandidates" :key="index" 
				@click="onSelectorClick(index)">
					<text>{{item}}</text>
				</view>
			</scroll-view>
		</view>
	</view>
</template>

<script>
	/**
	 * Combox 组合输入框
	 * @description 组合输入框一般用于既可以输入也可以选择的场景
	 * @tutorial https://ext.dcloud.net.cn/plugin?id=1261
	 * @property {String} label 左侧文字
	 * @property {String} labelWidth 左侧内容宽度
	 * @property {String} placeholder 输入框占位符
	 * @property {Array} candidates 候选项列表
	 * @property {String} emptyTips 筛选结果为空时显示的文字
	 * @property {String} value 组合框的值
	 */
	export default {
		name: 'uniCombox',
		emits: ['input', 'update:modelValue'],
		props: {
			border: {
				type: Boolean,
				default: true
			},
			label: {
				type: String,
				default: ''
			},
			labelWidth: {
				type: String,
				default: 'auto'
			},
			placeholder: {
				type: String,
				default: ''
			},
			candidates: {
				type: Array,
				default () {
					return []
				}
			},
			emptyTips: {
				type: String,
				default: '无匹配项'
			},
			// #ifndef VUE3
			value: {
				type: [String, Number],
				default: ''
			},
			// #endif
			// #ifdef VUE3
			modelValue: {
				type: [String, Number],
				default: ''
			},
			// #endif
		},
		data() {
			return {
				showSelector: false,
				inputVal: ''
			}
		},
		computed: {
			labelStyle() {
				if (this.labelWidth === 'auto') {
					return ""
				}
				return `width: ${this.labelWidth}`
			},
			filterCandidates() {
				return this.candidates.filter((item) => {
					return item.toString().indexOf(this.inputVal) > -1
				})
			},
			filterCandidatesLength() {
				return this.filterCandidates.length
			}
		},
		watch: {
			// #ifndef VUE3
			value: {
				handler(newVal) {
					this.inputVal = newVal
				},
				immediate: true
			},
			// #endif
			// #ifdef VUE3
			modelValue: {
				handler(newVal) {
					this.inputVal = newVal
				},
				immediate: true
			},
			// #endif
		},
		methods: {
			toggleSelector() {
				this.showSelector = !this.showSelector
			},
			onFocus() {
				this.showSelector = true
			},
			onBlur() {
				setTimeout(() => {
					this.showSelector = false
				}, 153)
			},
			onSelectorClick(index) {
				this.inputVal = this.filterCandidates[index]
				this.showSelector = false
				this.$emit('input', this.inputVal)
				this.$emit('update:modelValue', this.inputVal)
			},
			onInput() {
				setTimeout(() => {
					this.$emit('input', this.inputVal)
					this.$emit('update:modelValue', this.inputVal)
				})
			}
		}
	}
</script>

<style lang="scss" scoped>
	.uni-combox {
		font-size: 14px;
		border: 1px solid #DCDFE6;
		border-radius: 4px;
		padding: 10px 10px;
		position: relative;
		/* #ifndef APP-NVUE */
		display: flex;
		/* #endif */
		// height: 40px;
		flex-direction: row;
		align-items: center;
		// border-bottom: solid 1px #DDDDDD;
	}

	.uni-combox__label {
		font-size: 16px;
		line-height: 22px;
		padding-right: 10px;
		color: #999999;
	}

	.uni-combox__input-box {
		position: relative;
		/* #ifndef APP-NVUE */
		display: flex;
		/* #endif */
		flex: 1;
		flex-direction: row;
		align-items: center;
	}

	.uni-combox__input {
		flex: 1;
		font-size: 14px;
		height: 22px;
		line-height: 22px;
	}

	.uni-combox__input-plac {
		font-size: 14px;
		color: #999;
	}

	.uni-combox__selector {
		/* #ifndef APP-NVUE */
		box-sizing: border-box;
		/* #endif */
		position: absolute;
		top: calc(100% + 12px);
		left: 0;
		width: 100%;
		background-color: #FFFFFF;
		border: 1px solid #EBEEF5;
		border-radius: 6px;
		box-shadow: 0 2px 12px 0 rgba(0, 0, 0, 0.1);
		z-index: 2;
		padding: 4px 0;
	}

	.uni-combox__selector-scroll {
		/* #ifndef APP-NVUE */
		max-height: 200px;
		box-sizing: border-box;
		/* #endif */
	}

	.uni-combox__selector-empty,
	.uni-combox__selector-item {
		/* #ifndef APP-NVUE */
		display: flex;
		cursor: pointer;
		/* #endif */
		line-height: 36px;
		font-size: 14px;
		text-align: center;
		// border-bottom: solid 1px #DDDDDD;
		padding: 0px 10px;
	}

	.uni-combox__selector-item:hover {
		background-color: #f9f9f9;
	}

	.uni-combox__selector-empty:last-child,
	.uni-combox__selector-item:last-child {
		/* #ifndef APP-NVUE */
		border-bottom: none;
		/* #endif */
	}

	// picker 弹出层通用的指示小三角
	.uni-popper__arrow,
	.uni-popper__arrow::after {
		position: absolute;
		display: block;
		width: 0;
		height: 0;
		border-color: transparent;
		border-style: solid;
		border-width: 6px;
	}

	.uni-popper__arrow {
		filter: drop-shadow(0 2px 12px rgba(0, 0, 0, 0.03));
		top: -6px;
		left: 10%;
		margin-right: 3px;
		border-top-width: 0;
		border-bottom-color: #EBEEF5;
	}

	.uni-popper__arrow::after {
		content: " ";
		top: 1px;
		margin-left: -6px;
		border-top-width: 0;
		border-bottom-color: #fff;
	}

	.uni-combox__no-border {
		border: none;
	}
</style>
