<template>
	<view class="uni-numbox">
		<!-- -部分 -->
		<view class="uni-numbox-minus" @click="_calcValue('subtract')">
			<text :class="minDisabled?'uni-numbox-disabled': ''">-</text>
		</view>
		<!-- 中间输入数值部分 -->
		<input class="uni-numbox-value" type="number" :disabled="disabled" :value="inputValue" @blur="_onBlur">
		<!-- + 部分 -->
		<view class="uni-numbox-plus" @click="_calcValue('add')">
			<text :class="maxDisabled?'uni-numbox-disabled': ''">+</text>
		</view>
	</view>
</template>
<script>
	export default {
		name: 'uni-number-box',
		props: {
			// isMax  是否有上限设置
			isMax: {
				type: Boolean,
				default: false
			},
			// isMin  是否有下限设置
			isMin: {
				type: Boolean,
				default: false
			},
			// index 唯一值，如果一个页面有多个数量增减组件时，起到唯一的作用
			index: {
				type: String,
				default: 0
			},
			// value 是数值
			value: {
				type: Number,
				default: 0
			},
			// min 最小值
			min: {
				type: Number,
				default: -Infinity
			},
			// max 最大值
			max: {
				type: Number,
				default: Infinity
			},
			// step  步长
			step: {
				type: Number,
				default: 1
			},
			// disabled 是否禁用
			disabled: {
				type: Boolean,
				default: false
			}
		},
		data() {
			return {
				inputValue: this.value,
				minDisabled: false,
				maxDisabled: false
			}
		},
		created() {
			this.maxDisabled = this.isMax;
			this.minDisabled = this.isMin;
		},
		computed: {

		},
		watch: {
			inputValue(number) {
				const data = {
					number: number,
					index: this.index
				}
				this.$emit('eventChange', data);
			}
		},
		methods: {
			_calcValue(type) {
				const scale = this._getDecimalScale();
				let value = this.inputValue * scale;
				let newValue = 0;
				let step = this.step * scale;

				if (type === 'subtract') {
					newValue = value - step;
					if (newValue <= this.min) {
						this.minDisabled = true;
					}
					if (newValue < this.min) {
						newValue = this.min
					}
					if (newValue < this.max && this.maxDisabled === true) {
						this.maxDisabled = false;
					}
				} else if (type === 'add') {
					newValue = value + step;
					if (newValue >= this.max) {
						this.maxDisabled = true;
					}
					if (newValue > this.max) {
						newValue = this.max
					}
					if (newValue > this.min && this.minDisabled === true) {
						this.minDisabled = false;
					}
				}
				if (newValue === value) {
					return;
				}
				this.inputValue = newValue / scale;
				this.$emit('increment',this.inputValue)
			},
			_getDecimalScale() {
				let scale = 1;
				// 浮点型
				if (~~this.step !== this.step) {
					scale = Math.pow(10, (this.step + '').split('.')[1].length);
				}
				return scale;
			},
			_onBlur(event) {
				let value = event.detail.value;
				if (!value) {
					this.inputValue = 0;
					return
				}
				value = +value;
				if (value > this.max) {
					value = this.max;
				} else if (value < this.min) {
					value = this.min
				}

				this.inputValue = value
			}
		}
	}
</script>
<style>
	.uni-numbox {
		/* position:absolute; */
		/* left: 30upx;
		bottom: 0; */
		display: flex;
		justify-content: flex-start;
		align-items: center;
		width: 200upx;
		height: 50upx;
		/* background:#f5f5f5; */
	}

	.uni-numbox-minus {
		background: #EEEEEE !important;

		color: #909399 !important;
	}

	.uni-numbox-minus,
	.uni-numbox-plus {
		margin: 0;
		width: 53rpx;
		height: 53rpx;
		background-color: #F84221;
		opacity: 1;
		line-height: 53rpx;
		text-align: center;
		position: relative;
		color: #fff;
		font-size: 40upx;
	}

	.uni-numbox-minus .yticon,
	.uni-numbox-plus .yticon {
		font-size: 36upx;
		color: #555;
	}

	.uni-numbox-minus {
		/* 	border-right: none;
		border-top-left-radius: 6upx;
		border-bottom-left-radius: 6upx; */
	}

	.uni-numbox-plus {
		/* border-left: none;
		border-top-right-radius: 6upx;
		border-bottom-right-radius: 6upx; */
	}

	.uni-numbox-value {
		position: relative;
		/* background-color: #f5f5f5; */
		width: 90upx;
		height: 50upx;
		text-align: center;
		padding: 0;
		font-size: 30upx;
	}

	.uni-numbox-disabled.yticon {
		color: #d6d6d6;
	}
</style>