<template>
	<view class="calendar__wrap">
		<view class="header">
			<view class="current-date">{{ currentDate }}</view>
		</view>
		<view class="body">
			<view class="weeks">
				<view class="week__item" v-for="week in weeks" :key="week">{{ week }}</view>
			</view>
			<view class="day__list">
				<view class="day__item" v-for="(item, index) in dateData" :key="index">
					<view class="checked-box" :class="[checksClass]" v-if="item === 'checked'">
						<text class="checked iconfont iconfavor" v-if="!checksIcon"></text>
						<image v-else :src="checksIcon" mode="aspectFit"></image>
						<view class="check_text" v-if="checkTextShow">{{ dayLoad(index) }}</view>
					</view>
					<text class="current-box" :class="[item === day ? (actionClass ? actionClass : 'current') : '']" v-else>{{ item }}</text>
				</view>
			</view>
		</view>
	</view>
</template>

<script>
export default {
	props: {
		//选中的日期数据
		checks: {
			type: Array,
			default() {
				// 例子[1,2,3,4],表示本月1,2,3,4号4天被选中
				return [];
			}
		},
		// 选中物品的样式类
		checksClass: {
			type: String,
			default: ''
		},
		// 选中时图标
		checksIcon: {
			type: String
		},
		// 选中时是否显示文字
		checkTextShow: {
			type: Boolean, 
			default: false
		},
		// 表示当前日期的样式
		actionClass: {
			type: String,
			default: ''
		}
	},
	data() {
		const { year, month, day } = this.getDate();
		const dateData = this.getDateData(year, month);
		const noDay = ( new Date(year,month-1,1)).getDay();
		return {
			year,
			month,
			day,
			dateData,
			noDay,//本月1号是星期几
			weeks: ['日', '一', '二', '三', '四', '五', '六'],
		};
	},
	computed: {
		// 获取当前日期
		currentDate() {
			return `${this.year}-${this.format(this.month)}`;
		}
	},
	watch: {
		checks(val) {
			const { year, month } = this.getDate();
			const dateData = this.getDateData(year, month);
			// 保存当前月份信息
			this.dateData = dateData;
		},
	},
	methods: {
		// 重新计算时间
		dayLoad: function(value) {
			return value + 1 - this.noDay;
		},
		// 获取当前日期
		getDate(current) {
			console.log(current);
			const date = current ? new Date(current) : new Date();
			const year = date.getFullYear();
			// 月份值默认从0开始
			const month = date.getMonth() + 1;
			const day = date.getDate();
			return {
				year,
				month,
				day
			};
		},
		// 日期处理
		getDateData(year, month) {
			// 新增月份时需要减少1个月
			const date = new Date(year,month-1,1);
			const firstDayWeek = date.getDay();
			const data = [...this.getEmptys(firstDayWeek), ...this.getDays(firstDayWeek)];
			return data;
		},
		// 查询日期列表有几个空格
		getEmptys(count) {
			let arr = [];
			if (count) {
				for (let i = 0; i < count; i++) {
					arr.push('');
				}
			}
			return arr;
		},
		getLastDay() {
			let { year, month } = this.getDate();
			month += 1;
			if (month > 11) {
				year += 1;
				month = 1;
			}
			let firstDayTimeStamp = new Date(`${year}/${month}/1`).getTime();
			let oneDayTimeStamp = 24 * 60 * 60 * 1000;
			let lastDay = new Date(firstDayTimeStamp - oneDayTimeStamp).getDate();
			return lastDay;
		},
		getDays() {
			const lastDay = this.getLastDay();
			const days = [];
			for (let i = 1; i <= lastDay; i++) {
				days.push(this.checks.includes(i) ? 'checked' : i);
			}
			return days;
		},
		format(num) {
			return num < 10 ? `0${num}` : num;
		}
	}
};
</script>

<style lang="scss" scoped>
.calendar__wrap {
	background-color: #fff;
	color: $uni-text-color;
	.header {
		padding: 0 24rpx;
		.current-date {
			text-align: center;
			font-size: $font-lg + 2rpx;
			// border-bottom: 2rpx solid #eee;
			padding: 32rpx 0;
		}
	}
	.body {
		.weeks {
			display: flex;
			font-size: $font-lg;
			padding: 10rpx 0;
			background-color: #f4f7ff;
			.week__item {
				flex: 1;
				text-align: center;
			}
		}
		.day__list {
			display: flex;
			flex-wrap: wrap;
			.day__item {
				display: flex;
				justify-content: center;
				width: 14.285%;
				text-align: center;
				padding: 30rpx 0;
				font-size: 34rpx;
				color: $font-color-light;
				.checked-box,
				.current-box {
					display: flex;
					align-items: center;
					justify-content: center;
					border-radius: 100%;
					box-sizing: border-box;
					position: relative;
				}
				image,
				.checked-box,
				.current-box,
				.check_text {
					width: 56rpx;
					height: 56rpx;
					line-height: 56rpx;
				}
				image,
				.check_text {
					position: absolute;
					top: 0;
					left: 0;
				}
				.checked {
					font-size: 40rpx;
					background-color: #3f9dff;
					color: #fff;
				}
				.current {
					padding: 12rpx;
					background-color: $background-color;
					color: #fff;
					font-size: 28rpx;
				}
			}
		}
	}
}
</style>
