export default {
	fmtDate(obj) {
		let date =obj? new Date(obj) : new Date();
		let y = 1900+date.getYear();
		let m = "0"+(date.getMonth()+1);
		let d = "0"+date.getDate();
		return y+"-"+m.substring(m.length-2,m.length)+"-"+d.substring(d.length-2,d.length);
	},
	judgeDate(obj) { //判断学期
		let date = obj ? new Date(obj) : new Date();
		let y = 1900 + date.getYear();
		let m = date.getMonth() + 1;
		if(m >= 2) {
			if(m < 7) {
				return (y - 1) + '-' + y + '学年第二学期'
			} else {
				return y + '-' + (y + 1) + '学年第一学期'
			}
		}else{
			return (y - 1) + '-' + y + '学年第一学期'
		}
	},
	oneDayTime () {
		return 24 * 60 * 60 * 1000  //一天时间
	},
	weekday(obj) { //根据今天得到周一与周日的时间
		var now = obj? new Date(obj):new Date(); 
		var nowTime = now.getTime(); 
		var day = now.getDay();
		//显示周一
		var MondayTime = nowTime - (day - 1) * this.oneDayTime() ; 
		//显示周日
		var SundayTime =  nowTime + (7 - day) * this.oneDayTime() ; 
		return {
			MondayTime: MondayTime,
			Monday: this.fmtDate(MondayTime),
			SundayTime: SundayTime,
			Sunday: this.fmtDate(SundayTime)
		}
	},
	compare (key) {
	  return (obj1, obj2) => {
	    let value1 = obj1[key]
	    let value2 = obj2[key]
	    if (value1 < value2) {
	      return -1;
	    } else if (value1 > value2) {
	      return 1;
	    } else {
	      return 0
	    }
	  }
	}
}