function getDateTimeStringWithLeadingZeros(pDate) {
    var dateStr = getDateStringWithLeadingZeros(pDate);

    var hh = (pDate.getHours() < 10 ? "0" : "") + pDate.getHours();
    var m = (pDate.getMinutes() < 10 ? "0" : "") + pDate.getMinutes();
    var ss = (pDate.getSeconds() < 10 ? "0" : "") + pDate.getSeconds();

    return dateStr + " " + hh + ":" + m + ":" + ss;
}

function getDateStringWithLeadingZeros(pDate) {
    var dd = (pDate.getDate() < 10 ? "0" : "") + pDate.getDate().toString();
    var mm = ((pDate.getMonth() + 1) < 10 ? "0" : "") + (pDate.getMonth() + 1);
    var yyyy = pDate.getFullYear();

    return dd + "." + mm + "." + yyyy;
}

function subtractDates(date1, date2) {
    var t1 = date1.getTime();
    var t2 = date2.getTime();
    var diff = (t2 - t1) / 60000;

    return Math.abs(diff);
}

function addMinutes(date, minutes) {
    return new Date(date.getTime() + minutes * 60000);
}

function stringToTime(str) {
    var defaultResult = [-1, -1];

    str = str.replace(":", "");
    str = str.replace(".", "");
    str = str.replace(" ", "");

    if(str.length < 3) {
        if(str.length < 2) {
            //str = `0${str}`;
            str = '0' + str;
        }
        while(str.length < 4) {
            str = str + "0";
        }
    } else {
        while(str.length < 4) {
            //str = `0${str}`;
            str = '0' + str;
        }
    }

    var minutes = str.slice(2, 4);
    var hours = str.slice(0, 2);

    defaultResult[0] = parseInt(hours);
    defaultResult[1] = parseInt(minutes);

    return defaultResult;
}

function actualDurationWithEndDate() {
    if($("#enddatum_textbox").val() !== "") {
        if($("#enddatum_textbox").val() !== $("#datum_textbox").val()) {
            var endDateObj = getEndDateObj();
            var startDateObj = getDateObj(true);

            if(endDateObj < startDateObj) {
                endDateObj = setHoursAndMinutes(new Date(startDateObj.getTime()), $("#ende_textbox").val());

                //console.log(`start date: ${startDateObj}`);
                //console.log(`end date:   ${endDateObj}`);

                console.log('start date: ' + startDateObj);
                console.log('end date: ' + endDateObj);
            }

            var endDate = endDateObj.getDate();
            var startDate = startDateObj.getDate();

            var diffInMs = endDateObj - startDateObj;
            var diffInS = diffInMs / 1000;
            var diffInMins = diffInS / 60;

            //console.log(`end date:              ${endDate}`);
            //console.log(`difference in minutes: ${diffInMins}`);

            console.log('end date: ' + endDate);
            console.log('difference in minutes: ' + diffInMins);

            var dateDifference = endDate - startDate;

            var endDateString = $("#ende_textbox").val();

            var startDateString = $("#start_textbox").val();

            var duration = diffInMins;// - startDateString;
            //console.log(`dateDifference: ${dateDifference}`);
            console.log('dateDifference: ' + dateDifference);

            var rest = duration % 100;

            duration = duration - rest;

            duration = duration / 100 * 60;

            duration = dateDifference * 24 * 60 + duration + rest;

            $("#duration_textbox").val(duration).trigger("change");
        }
    }
}

function getEndDateObj() {
    var rawEnddate = $("#enddatum_textbox").val();
    var day = parseInt(rawEnddate.slice(0, 2));
    var month = parseInt(rawEnddate.slice(3, 5));
    var year = parseInt(rawEnddate.slice(6, 10));
    var hoursAndMinutes = [0, 0];

    var date = new Date();
    if(!isNaN(day) && !isNaN(month) && !isNaN(year)) {
        date = new Date(year, month - 1, day);
    }

    var endDateString = $("#ende_textbox").val();

    if(endDateString !== "") {
        hoursAndMinutes = stringToTime(endDateString);
    }

    date.setHours(hoursAndMinutes[0]);
    date.setMinutes(hoursAndMinutes[1]);

    return date;
}

function setHoursAndMinutes(date, timeString) {
    var hoursAndMinutes = [0, 0];

    if(timeString !== "") {
        hoursAndMinutes = stringToTime(timeString);
    }

    date.setHours(hoursAndMinutes[0]);
    date.setMinutes(hoursAndMinutes[1]);

    return date;
}

function getHoursAndMinutesWithLeadingZeros(pDate) {
    var hours = pDate.getHours();
    var minutes = pDate.getMinutes();

    //var hoursString = hours < 10 ? `0${hours.toString()}` : hours.toString();
    //var minutesString = minutes < 10 ? `0${minutes.toString()}` : minutes.toString();

    var hoursString = hours < 10 ? '0' + hours.toString() : hours.toString();
    var minutesString = minutes < 10 ? '0' + minutes.toString() : minutes.toString();

    return hoursString + ":" + minutesString;
}

function toShortDateString(dateString, trennzeichen) {
    var geteilt = dateString.split(trennzeichen);
    var yyyy = "";
    var mm = geteilt[1];
    var dd = geteilt[0];

    for(var i = 0; i < 4 - geteilt[2].split(" ")[0].length; i++) {
        yyyy += "0";
    }

    yyyy += geteilt[2].split(" ")[0];

    return (dd < 10 ? "0" : "") + dd + "." + (mm < 10 ? "0" : "") + mm + "." + yyyy;
}

function toDateStringYearMonthDay(pDate) {
    var dd2 = pDate.getDate();
    var mm2 = pDate.getMonth() + 1;
    var yyyy2 = pDate.getFullYear();

    var ddStr2 = dd2 < 10 ? "0" + dd2 : dd2;
    var mmStr2 = mm2 < 10 ? "0" + mm2 : mm2;

    return yyyy2 + "-" + mmStr2 + "-" + ddStr2;
}

function checkEndDate() {
    $.ajax({
        type: "GET",
        url: CheckEndDateUrl,
        success: function(json) {
            var endDateSettingsString = $.parseJSON(json);
            var endDateSetting = parseInt(endDateSettingsString);

            if(endDateSetting === 1) {
                $("#EndDate_div").css("display", "block");
                $("#enddatum_textbox").val($("#datum_textbox").val());
            }
            else {
                $("#EndDate_div").css("display", "none");
            }
        }
    });
}

function endDateVisibleEh() {
    return $("#EndDate_div").css("display") !== "none";
}

function calcDurationByStartEnd() {
    //console.log(`is end date visible: ${endDateVisibleEh()}`);
    console.log('is end date visible: ' + endDateVisibleEh());

    if($("#enddatum_textbox").val() === $("#datum_textbox").val() || $("#enddatum_textbox").val() === "") {
        var shm = getDateObj(true);
        var ehm = getDateObj(false);

        var dur = 0;

        if(shm.getTime() < ehm.getTime()) {
            dur = parseInt(subtractDates(ehm, shm));
        }

        $("#duration_textbox").val(dur).trigger("change");
    }
    else {
        actualDurationWithEndDate();
    }
}

function calcEndByStartDuration() {
    if($("#enddatum_textbox").val() === $("#datum_textbox").val() || $("#enddatum_textbox").val() === "") {
        var shm2 = getDateObj(true);
        var dauer = parseInt($("#duration_textbox").val());

        if(isNaN(dauer)) {
            return;
        }

        var neu = addMinutes(shm2, dauer);

        var ende = (neu.getHours() < 10 ? "0" : "") + neu.getHours() + ":" + (neu.getMinutes() < 10 ? "0" : "") + neu.getMinutes();

        $("#ende_textbox").val(ende).trigger("change");
    }
    else {
        actualDurationWithEndDate();
    }
}

function calcStartByEndDuration() {
    var ehm2 = getDateObj(false);
    var dauer2 = parseInt($("#duration_textbox").val());

    if(isNaN(dauer2)) {
        return;
    }

    var neu2 = addMinutes(ehm2, dauer2 * -1);
    $("#start_textbox").val((neu2.getHours() < 10 ? "0" : "") + neu2.getHours() + (neu2.getMinutes() < 10 ? "0" : "") + neu2.getMinutes()).trigger("change");
}

function getDateObj(isFromStart) {
    var roh = $("#datum_textbox").val();
    var dd = parseInt(roh.slice(0, 2));
    var mm = parseInt(roh.slice(3, 5));
    var yyyy = parseInt(roh.slice(6, 10));

    var date = new Date();
    if(!isNaN(dd) && !isNaN(mm) && !isNaN(yyyy)) {
        date = new Date(yyyy, mm - 1, dd);
    }

    var hm = [0, 0];
    var ds = $("#ende_textbox").val();

    if(isFromStart) {
        ds = $("#start_textbox").val();
    }

    if(ds !== "") {
        hm = stringToTime(ds);
    }

    date.setHours(hm[0]);
    date.setMinutes(hm[1]);

    return date;
}