export default class Util
{
    static WeekDays = [ 'Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat' ];
    static Months = [ 'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec' ];

    static formatBytes(s)
    {
        if (!s) return '';
        if (s < 1024) return s+' B';
        else if (s < 1024*1024) return (Math.round(s*10/1024)/10)+' KB';
        else if (s < 1024*1024*1024) return (Math.round(s*10/1024/1024)/10)+' MB';
        return (Math.round(s*10/1024/1024/1024)/10)+' GB';
    }

    static formatDate(dt)
    {
        if (!(dt instanceof Date))
            dt = new Date(dt.replace(' ', 'T'));
        let tod = new Date();
        tod.setHours(0);
        tod.setMinutes(0);
        tod.setSeconds(0);
        tod.setMilliseconds(0);
        let prevweek = tod;
        prevweek = prevweek.getTime() - (7 + (prevweek.getDay()+6)%7)*86400000;
        if (dt.getTime() < prevweek)
        {
            let d = dt.getDate();
            let m = dt.getMonth()+1;
            return (d < 10 ? '0' : '')+d+'.'+(m < 10 ? '0' : '')+m+'.'+dt.getFullYear();
        }
        else if (dt.getTime() < tod.getTime())
        {
            return Util.WeekDays[dt.getDay()]+' '+dt.getDate()+' '+Util.Months[dt.getMonth()];
        }
        let h = dt.getHours();
        let m = dt.getMinutes();
        return (h < 10 ? '0' : '')+h+':'+(m < 10 ? '0' : '')+m;
    }

    static getGroupName(k)
    {
        if (k == 't')
        {
            return 'Today';
        }
        else if (k[0] == 'd')
        {
            return Util.WeekDays[k.substr(1)%7];
        }
        else if (k == 'pw')
        {
            return 'Last Week';
        }
        else if (k[0] == 'm')
        {
            return Util.Months[k.substr(1)-1];
        }
        return k;
    }
}