var day;
var month;
var year;
var hour;
var minute;
var second;
var clock_set = 0;

/**
 * Opens calendar window.
 *
 * @param   string      calendar.php parameters
 * @param   string      form name
 * @param   string      field name
 * @param   string      edit type - date/timestamp
 */
function openCalendar(params, form, field, type) {
    window.open("./adm_kalendar_cz.php?" + params, "calendar", "width=400,height=250,status=yes");
    dateField = eval("document." + form + "." + field);
    dateType = type;
}

function openCalendarById(params, id, type) {
    window.open("./adm_kalendar_cz.php?" + params, "calendar", "width=400,height=250,status=yes");
    dateField = eval("document.getElementById('" + id + "')");
    dateType = type;
}

/**
 * Formats number to two digits.
 *
 * @param   int number to format.
 */
function formatNum2(i, valtype) {
    f = (i < 10 ? '0' : '') + i;
    if (valtype && valtype != '') {
        switch(valtype) {
            case 'month':
                f = (f > 12 ? 12 : f);
                break;

            case 'day':
                f = (f > 31 ? 31 : f);
                break;

            case 'hour':
                f = (f > 24 ? 24 : f);
                break;

            default:
            case 'second':
            case 'minute':
                f = (f > 59 ? 59 : f);
                break;
        }
    }

    return f;
}

/**
 * Formats number to four digits.
 *
 * @param   int number to format.
 */
function formatNum4(i) {
    return (i < 1000 ? i < 100 ? i < 10 ? '000' : '00' : '0' : '') + i;
}

/**
 * Initializes calendar window.
 */
function initCalendar() {
    if (!year && !month && !day) {
        /* Called for first time */
        if (window.opener.dateField.value) {
            value = window.opener.dateField.value;
            if (window.opener.dateType == 'datetime' || window.opener.dateType == 'date') {
                if (window.opener.dateType == 'datetime') {
                    parts   = value.split(' ');
                    value   = parts[0];

                    if (parts[1]) {
                        time    = parts[1].split(':');
                        hour    = parseInt(time[0],10);
                        minute  = parseInt(time[1],10);
                        second  = parseInt(time[2],10);
                    }
                }
                date        = value.split("-");
                day         = parseInt(date[2],10);
                month       = parseInt(date[1],10) - 1;
                year        = parseInt(date[0],10);
            } else {
                year        = parseInt(value.substr(0,4),10);
                month       = parseInt(value.substr(4,2),10) - 1;
                day         = parseInt(value.substr(6,2),10);
                hour        = parseInt(value.substr(8,2),10);
                minute      = parseInt(value.substr(10,2),10);
                second      = parseInt(value.substr(12,2),10);
            }
        }
        if (isNaN(year) || isNaN(month) || isNaN(day) || day == 0) {
            dt      = new Date();
            year    = dt.getFullYear();
            month   = dt.getMonth();
            day     = dt.getDate();
        }
        if (isNaN(hour) || isNaN(minute) || isNaN(second)) {
            dt      = new Date();
            hour    = dt.getHours();
            minute  = dt.getMinutes();
            second  = dt.getSeconds();
        }
    } else {
        /* Moving in calendar */
        if (month > 11) {
            month = 0;
            year++;
        }
        if (month < 0) {
            month = 11;
            year--;
        }
    }

    if (document.getElementById) {
        cnt = document.getElementById("calendar_data");
    } else if (document.all) {
        cnt = document.all["calendar_data"];
    }

    cnt.innerHTML = "";

    str = ""

    //heading table
    str += '<table class="calendar"><tr><th width="50%">';
    str += '<a href="#" onclick="month--; initCalendar();">&laquo;</a> ';
    str += month_names[month];
    str += ' <a href="#" onclick="month++; initCalendar();">&raquo;</a>';
    str += '</th><th width="50%">';
    str += '<a href="#" onclick="year--; initCalendar();">&laquo;</a> ';
    str += year;
    str += ' <a href="#" onclick="year++; initCalendar();">&raquo;</a>';
    str += '</th></tr></table>';

    str += '<table class="calendar"><tr>';
    for (i = 0; i < 7; i++) {
        str += "<th width=\"14%\">" + day_names[i] + "</th>";
    }
    str += "</tr>";

    var firstDay = new Date(year, month, 1).getDay();
    var lastDay = new Date(year, month + 1, 0).getDate();

    str += "<tr>";

    dayInWeek = 0;
    if (firstDay == 0)
      firstDay = 7;
    for (i = 1; i < firstDay; i++) {
        str += "<td>&nbsp;</td>";
        dayInWeek++;
    }
    for (i = 1; i <= lastDay; i++) {
        if (dayInWeek == 7) {
            str += "</tr><tr>";
            dayInWeek = 0;
        }

        dispmonth = 1 + month;

        if (window.opener.dateType == 'datetime' || window.opener.dateType == 'date') {
            actVal =  i + "." + dispmonth + "." + formatNum4(year);
        } else {
            actVal = "" + formatNum4(year) + formatNum2(dispmonth, 'month') + formatNum2(i, 'day');
        }
        if (i == day) {
            style = ' class="selected"';
        } else {
            style = '';
        }
        str += "<td" + style + "><a href='#' onclick='returnDate(\"" + actVal + "\");'>" + i + "</a></td>"
        dayInWeek++;
    }
    for (i = dayInWeek; i < 7; i++) {
        str += "<td>&nbsp;</td>";
    }

    str += "</tr></table>";

    cnt.innerHTML = str;

    // Should we handle time also?
    if (window.opener.dateType != 'date' && !clock_set) {

        if (document.getElementById) {
            cnt = document.getElementById("clock_data");
        } else if (document.all) {
            cnt = document.all["clock_data"];
        }

        str = '';
        str += '<form class="clock">Čas&nbsp;';
        str += '<input id="hour"    type="text" size="2" maxlength="2" onblur="this.value=formatNum2(this.value, \'hour\')" value="' + formatNum2(hour, 'hour') + '" />:';
        str += '<input id="minute"  type="text" size="2" maxlength="2" onblur="this.value=formatNum2(this.value, \'minute\')" value="' + formatNum2(minute, 'minute') + '" />';
        str += '<input id="second"  type="hidden" value="00" />';
        str += '</form>';

        cnt.innerHTML = str;
        clock_set = 1;
    }

}

/**
 * Returns date from calendar.
 *
 * @param   string     date text
 */
function returnDate(d) {
    txt = d;
    if (window.opener.dateType != 'date') {
        // need to get time
        h = parseInt(document.getElementById('hour').value,10);
        m = parseInt(document.getElementById('minute').value,10);
        s = parseInt(document.getElementById('second').value,10);
        if (window.opener.dateType == 'datetime') {
            txt += ' ' + formatNum2(h, 'hour') + ':' + formatNum2(m, 'minute') + ':' + formatNum2(s, 'second');
        } else {
            // timestamp
            txt += formatNum2(h, 'hour') + formatNum2(m, 'minute') + formatNum2(s, 'second');
        }
    }

    window.opener.dateField.value = txt;
    if (window.opener.dateField.onchange)
      window.opener.dateField.onchange();
    window.close();
}