var monthday=[31,28,31,30,31,30,31,31,30,31,30,31];
var weekarea=new Array(7);
var nowdate=new Date();
var weekName=['日','六','五','四','三','二','一'];
var timeinterval={
    //闰年判断
    getRunnian(yy){
        if(yy % 4 == 0 && yy % 100 !== 0 || yy % 400 == 0){
            monthday[1]=29;
        }else{
            monthday[1]=28;
        }
    },
    /*
        几种情况：
        1.当月第一天是星期一
        2.当月最后一天是星期日
        3.同时满足 1,2  必是平年28天  4行
    */
    //获取月份区间
    getMonthArea(yy=nowdate.getFullYear(),mm=nowdate.getMonth()+1,dd=nowdate.getDate()){
        this.getRunnian(yy);
        mm--;
        var showday=monthday[mm];
        var d1=new Date(yy,mm,1);
        var firstday=d1.getDay();
        var d2=new Date(yy,mm,monthday[mm]);
        var lastday=d2.getDay();
        if(lastday==0)
            lastday=7;
        if(firstday==0){
            firstday=7;
        }
        if(firstday!=1){
            showday+=firstday-1;
        }
        if(lastday!=7){
            showday+=7-lastday;
        }
        var hangshu=showday/7;
        var montharea=new Array(7*hangshu);
        for(var i=0;i<7*hangshu;i++){
            var sm=mm,sd=dd,sy=yy;
            //上个月尾部几天
            if(firstday-1>i){
                sm--;
                if(sm<0){
                    sm=11;
                    sy--;
                }
                sd=monthday[sm]-(firstday-2-i);
            }
            if(i>=firstday-1&&i<monthday[sm]+firstday-1){
                sd=i-(firstday-2);
            }
            if(i>=monthday[sm]+firstday-1){
                sd=i-(monthday[sm]+firstday-1)+1;
                sm++;
                if(sm>11){
                    sm=0;
                    sy++;
                }
            }
            montharea[i]={yy:sy,mm:sm+1,dd:sd,xx:new Date(sy+'-'+((sm+1)<10?('0'+(sm+1)):(sm+1))+'-'+(sd<10?('0'+sd):sd)).getDay(),date:sy+'-'+((sm+1)<10?('0'+(sm+1)):(sm+1))+'-'+(sd<10?('0'+sd):sd)}
        }
        return montharea;
    },
    //获取周区间
    getWeekArea(yy=nowdate.getFullYear(),mm=nowdate.getMonth()+1,dd=nowdate.getDate(),xx=nowdate.getDay()){
		this.getRunnian(yy);
		
        if(xx==0){
            xx=7
        }
        var endday=dd+7-xx;
        for(var i=0; i<7;i++){
            var sy=yy,sm=mm,sd=endday-i;
            //上一个月
            if(sd<=0){
                sm--;
            }
            //下一个月
            else if(sd>monthday[mm-1]){
                sm++;
            }
            if(sm==0){
                sm=12;
                sy--;
            }
            if(sm>12){
                sm=1;
                sy++;
            }
            if(sd<=0){
               sd=monthday[sm-1]+sd;
            }
            else if(sd>monthday[mm-1]){
                sd=sd-monthday[mm-1];
            }
            weekarea[6-i]={yy:sy,mm:sm,dd:sd,date:sy+'-'+(sm<10?('0'+sm):sm)+'-'+(sd<10?('0'+sd):sd),xingqi:weekName[i]}
        }
        return weekarea;
    },
    //获取日期区间
    getDayArea(yy=nowdate.getFullYear(),mm=nowdate.getMonth()+1,dd=nowdate.getDate(),xx=nowdate.getDay()){
        return {yy,mm,dd,xx,date:yy+'-'+(mm<10?('0'+mm):mm)+'-'+(dd<10?('0'+dd):dd)};
    },
    //获取当前月份天数
    getMonthDayNum(yy=nowdate.getFullYear(),mm=nowdate.getMonth()+1){
      this.getRunnian(yy);
      return monthday[mm-1];
    },
    //上一周
    beforeWeek(data){
        let {yy,mm,dd}=this.before(data);
        var d=new Date(yy,mm-1,dd);
        return this.getWeekArea(yy,mm,dd,d.getDay());
    },
    //下一周
    afterWeek(data){
        let {yy,mm,dd}=this.after(data);
        var d=new Date(yy,mm-1,dd);
        return this.getWeekArea(yy,mm,dd,d.getDay());
    },
    //上一月
    beforeMouth(data){
        let {yy,mm,dd}=data;
        if(dd==1){
            mm--;
            if(mm==0){
                mm=12;
                yy--;
            }
        }
        var d=new Date(yy,mm-1,dd);
        return this.getMonthArea(yy,mm,dd);
    },
    //下一月
    afterMouth(data){
        let {yy,mm,dd}=data;
        this.getRunnian(yy);
        if(dd==monthday[mm-1]){
            dd=1;
            mm++;
            if(mm==13){
                mm=1;
                yy++;
            }
        }
        var d=new Date(yy,mm-1,dd);
        return this.getMonthArea(yy,mm,dd);
    },
    //前一天
    beforeDay(data){
        let {yy,mm,dd}=this.before(data);
        var d=new Date(yy,mm-1,dd);
        return this.getDayArea(yy,mm,dd,d.getDay());
    },
    //后一天
    afterDay(data){
        let {yy,mm,dd}=this.after(data);
        var d=new Date(yy,mm-1,dd);
        return this.getDayArea(yy,mm,dd,d.getDay());
    },
    //前
    before(data){
        let {yy,mm,dd}=data;
        dd--;
        if(dd==0){
            mm--;
            if(mm==0){
                mm=12;
                yy--;
            }
            this.getRunnian(yy);
            dd=monthday[mm-1];
        }
        return {yy,mm,dd};
    },
    //后
    after(data){
        let {yy,mm,dd}=data;
        dd++;
        if(dd>monthday[mm-1]){
            dd=1;
            mm++;
            if(mm==13){
                mm=1;
                yy++;
            }
        }
        return {yy,mm,dd};
    }
};
export default timeinterval;