// Inserts shortcut buttons after all of the following:
//     <input type="text" class="vDateField">
//     <input type="text" class="vTimeField">

var DateTimeShortcuts = {
    calendars: [],
    calendarInputs: [],
    clockInputs: [],
    dismissClockFunc: [],
    dismissCalendarFunc: [],
    calendarDivName1: 'calendarbox', // name of calendar <div> that gets toggled
    calendarDivName2: 'calendarin',  // name of <div> that contains calendar
    calendarLinkName: 'calendarlink',// name of the link that is used to toggle
    clockDivName: 'clockbox',        // name of clock <div> that gets toggled
    clockLinkName: 'clocklink',      // name of the link that is used to toggle
    shortCutsClass: 'datetimeshortcuts', // class of the clock and cal shortcuts
    timezoneWarningClass: 'timezonewarning', // class of the warning for timezone mismatch
    timezoneOffset: 0,
    admin_media_prefix: '',
    init: function() {
        // Get admin_media_prefix by grabbing it off the window object. It's
        // set in the admin/base.html template, so if it's not there, someone's
        // overridden the template. In that case, we'll set a clearly-invalid
        // value in the hopes that someone will examine HTTP requests and see it.
        if (window.__admin_media_prefix__ != undefined) {
            DateTimeShortcuts.admin_media_prefix = window.__admin_media_prefix__;
        } else {
            DateTimeShortcuts.admin_media_prefix = '/missing-admin-media-prefix/';
        }

        if (window.__admin_utc_offset__ != undefined) {
            var serverOffset = window.__admin_utc_offset__;
            var localOffset = new Date().getTimezoneOffset() * -60;
            DateTimeShortcuts.timezoneOffset = localOffset - serverOffset;
        }

        var inputs = document.getElementsByTagName('input');
        for (i=0; i<inputs.length; i++) {
            var inp = inputs[i];
            if (inp.getAttribute('type') == 'text' && inp.className.match(/vTimeField/)) {
                DateTimeShortcuts.addClock(inp);
                DateTimeShortcuts.addTimezoneWarning(inp);
            }
            else if (inp.getAttribute('type') == 'text' && inp.className.match(/vDateField/)) {
                DateTimeShortcuts.addCalendar(inp);
                DateTimeShortcuts.addTimezoneWarning(inp);
            }
        }
    },
    // Return the current time while accounting for the server timezone.
    now: function() {
        if (window.__admin_utc_offset__ != undefined) {
            var serverOffset = window.__admin_utc_offset__;
            var localNow = new Date();
            var localOffset = localNow.getTimezoneOffset() * -60;
            localNow.setTime(localNow.getTime() + 1000 * (serverOffset - localOffset));
            return localNow;
        } else {
            return new Date();
        }
    },
    // Add a warning when the time zone in the browser and backend do not match.
    addTimezoneWarning: function(inp) {
        var $ = django.jQuery;
        var warningClass = DateTimeShortcuts.timezoneWarningClass;
        var timezoneOffset = DateTimeShortcuts.timezoneOffset / 3600;

        // Only warn if there is a time zone mismatch.
        if (!timezoneOffset)
            return;

        // Check if warning is already there.
        if ($(inp).siblings('.' + warningClass).length)
            return;

        var message;
        if (timezoneOffset > 0) {
            message = ngettext(
                'Note: You are %s hour ahead of server time.',
                'Note: You are %s hours ahead of server time.',
                timezoneOffset
            );
        }
        else {
            timezoneOffset *= -1
            message = ngettext(
                'Note: You are %s hour behind server time.',
                'Note: You are %s hours behind server time.',
                timezoneOffset
            );
        }
        message = interpolate(message, [timezoneOffset]);

        var $warning = $('<span>');
        $warning.attr('class', warningClass);
        $warning.text(message);

        $(inp).parent()
            .append($('<br>'))
            .append($warning)
    },
    // Add clock widget to a given field
    addClock: function(inp) {
        var num = DateTimeShortcuts.clockInputs.length;
        DateTimeShortcuts.clockInputs[num] = inp;
        DateTimeShortcuts.dismissClockFunc[num] = function() { DateTimeShortcuts.dismissClock(num); return true; };

        // Shortcut links (clock icon and "Now" link)
        var shortcuts_span = document.createElement('span');
        shortcuts_span.className = DateTimeShortcuts.shortCutsClass;
        inp.parentNode.insertBefore(shortcuts_span, inp.nextSibling);
        var now_link = document.createElement('a');
        now_link.setAttribute('href', "javascript:DateTimeShortcuts.handleClockQuicklink(" + num + ", -1);");
        now_link.appendChild(document.createTextNode(gettext('Now')));
        var clock_link = document.createElement('a');
        clock_link.setAttribute('href', 'javascript:DateTimeShortcuts.openClock(' + num + ');');
        clock_link.id = DateTimeShortcuts.clockLinkName + num;
        quickElement('img', clock_link, '', 'src', DateTimeShortcuts.admin_media_prefix + 'img/icon_clock.gif', 'alt', gettext('Clock'));
        shortcuts_span.appendChild(document.createTextNode('\240'));
        shortcuts_span.appendChild(now_link);
        shortcuts_span.appendChild(document.createTextNode('\240|\240'));
        shortcuts_span.appendChild(clock_link);

        // Create clock link div
        //
        // Markup looks like:
        // <div id="clockbox1" class="clockbox module">
        //     <h2>Choose a time</h2>
        //     <ul class="timelist">
        //         <li><a href="#">Now</a></li>
        //         <li><a href="#">Midnight</a></li>
        //         <li><a href="#">6 a.m.</a></li>
        //         <li><a href="#">Noon</a></li>
        //     </ul>
        //     <p class="calendar-cancel"><a href="#">Cancel</a></p>
        // </div>

        var clock_box = document.createElement('div');
        clock_box.style.display = 'none';
        clock_box.style.position = 'absolute';
        clock_box.className = 'clockbox module';
        clock_box.setAttribute('id', DateTimeShortcuts.clockDivName + num);
        document.body.appendChild(clock_box);
        addEvent(clock_box, 'click', cancelEventPropagation);

        quickElement('h2', clock_box, gettext('Choose a time'));
        var time_list = quickElement('ul', clock_box);
        time_list.className = 'timelist';
        quickElement("a", quickElement("li", time_list), gettext("Now"), "href", "javascript:DateTimeShortcuts.handleClockQuicklink(" + num + ", -1);");
        quickElement("a", quickElement("li", time_list), gettext("Midnight"), "href", "javascript:DateTimeShortcuts.handleClockQuicklink(" + num + ", 0);");
        quickElement("a", quickElement("li", time_list), gettext("6 a.m."), "href", "javascript:DateTimeShortcuts.handleClockQuicklink(" + num + ", 6);");
        quickElement("a", quickElement("li", time_list), gettext("Noon"), "href", "javascript:DateTimeShortcuts.handleClockQuicklink(" + num + ", 12);");

        var cancel_p = quickElement('p', clock_box);
        cancel_p.className = 'calendar-cancel';
        quickElement('a', cancel_p, gettext('Cancel'), 'href', 'javascript:DateTimeShortcuts.dismissClock(' + num + ');');
        django.jQuery(document).bind('keyup', function(event) {
            if (event.which == 27) {
                // ESC key closes popup
                DateTimeShortcuts.dismissClock(num);
                event.preventDefault();
            }
        });
    },
    openClock: function(num) {
        var clock_box = document.getElementById(DateTimeShortcuts.clockDivName+num)
        var clock_link = document.getElementById(DateTimeShortcuts.clockLinkName+num)

        // Recalculate the clockbox position
        // is it left-to-right or right-to-left layout ?
        if (getStyle(document.body,'direction')!='rtl') {
            clock_box.style.left = findPosX(clock_link) + 17 + 'px';
        }
        else {
            // since style's width is in em, it'd be tough to calculate
            // px value of it. let's use an estimated px for now
            // TODO: IE returns wrong value for findPosX when in rtl mode
            //       (it returns as it was left aligned), needs to be fixed.
            clock_box.style.left = findPosX(clock_link) - 110 + 'px';
        }
        clock_box.style.top = Math.max(0, findPosY(clock_link) - 30) + 'px';

        // Show the clock box
        clock_box.style.display = 'block';
        addEvent(document, 'click', DateTimeShortcuts.dismissClockFunc[num]);
    },
    dismissClock: function(num) {
       document.getElementById(DateTimeShortcuts.clockDivName + num).style.display = 'none';
       removeEvent(document, 'click', DateTimeShortcuts.dismissClockFunc[num]);
    },
    handleClockQuicklink: function(num, val) {
       var d;
       if (val == -1) {
           d = DateTimeShortcuts.now();
       }
       else {
           d = new Date(1970, 1, 1, val, 0, 0, 0)
       }
       DateTimeShortcuts.clockInputs[num].value = d.strftime(get_format('TIME_INPUT_FORMATS')[0]);
       DateTimeShortcuts.clockInputs[num].focus();
       DateTimeShortcuts.dismissClock(num);
    },
    // Add calendar widget to a given field.
    addCalendar: function(inp) {
        var num = DateTimeShortcuts.calendars.length;

        DateTimeShortcuts.calendarInputs[num] = inp;
        DateTimeShortcuts.dismissCalendarFunc[num] = function() { DateTimeShortcuts.dismissCalendar(num); return true; };

        // Shortcut links (calendar icon and "Today" link)
        var shortcuts_span = document.createElement('span');
        shortcuts_span.className = DateTimeShortcuts.shortCutsClass;
        inp.parentNode.insertBefore(shortcuts_span, inp.nextSibling);
        var today_link = document.createElement('a');
        today_link.setAttribute('href', 'javascript:DateTimeShortcuts.handleCalendarQuickLink(' + num + ', 0);');
        today_link.appendChild(document.createTextNode(gettext('Today')));
        var cal_link = document.createElement('a');
        cal_link.setAttribute('href', 'javascript:DateTimeShortcuts.openCalendar(' + num + ');');
        cal_link.id = DateTimeShortcuts.calendarLinkName + num;
        quickElement('img', cal_link, '', 'src', DateTimeShortcuts.admin_media_prefix + 'img/icon_calendar.gif', 'alt', gettext('Calendar'));
        shortcuts_span.appendChild(document.createTextNode('\240'));
        shortcuts_span.appendChild(today_link);
        shortcuts_span.appendChild(document.createTextNode('\240|\240'));
        shortcuts_span.appendChild(cal_link);

        // Create calendarbox div.
        //
        // Markup looks like:
        //
        // <div id="calendarbox3" class="calendarbox module">
        //     <h2>
        //           <a href="#" class="link-previous">&lsaquo;</a>
        //           <a href="#" class="link-next">&rsaquo;</a> February 2003
        //     </h2>
        //     <div class="calendar" id="calendarin3">
        //         <!-- (cal) -->
        //     </div>
        //     <div class="calendar-shortcuts">
        //          <a href="#">Yesterday</a> | <a href="#">Today</a> | <a href="#">Tomorrow</a>
        //     </div>
        //     <p class="calendar-cancel"><a href="#">Cancel</a></p>
        // </div>
        var cal_box = document.createElement('div');
        cal_box.style.display = 'none';
        cal_box.style.position = 'absolute';
        cal_box.className = 'calendarbox module';
        cal_box.setAttribute('id', DateTimeShortcuts.calendarDivName1 + num);
        document.body.appendChild(cal_box);
        addEvent(cal_box, 'click', cancelEventPropagation);

        // next-prev links
        var cal_nav = quickElement('div', cal_box);
        var cal_nav_prev = quickElement('a', cal_nav, '<', 'href', 'javascript:DateTimeShortcuts.drawPrev('+num+');');
        cal_nav_prev.className = 'calendarnav-previous';
        var cal_nav_next = quickElement('a', cal_nav, '>', 'href', 'javascript:DateTimeShortcuts.drawNext('+num+');');
        cal_nav_next.className = 'calendarnav-next';

        // main box
        var cal_main = quickElement('div', cal_box, '', 'id', DateTimeShortcuts.calendarDivName2 + num);
        cal_main.className = 'calendar';
        DateTimeShortcuts.calendars[num] = new Calendar(DateTimeShortcuts.calendarDivName2 + num, DateTimeShortcuts.handleCalendarCallback(num));
        DateTimeShortcuts.calendars[num].drawCurrent();

        // calendar shortcuts
        var shortcuts = quickElement('div', cal_box);
        shortcuts.className = 'calendar-shortcuts';
        quickElement('a', shortcuts, gettext('Yesterday'), 'href', 'javascript:DateTimeShortcuts.handleCalendarQuickLink(' + num + ', -1);');
        shortcuts.appendChild(document.createTextNode('\240|\240'));
        quickElement('a', shortcuts, gettext('Today'), 'href', 'javascript:DateTimeShortcuts.handleCalendarQuickLink(' + num + ', 0);');
        shortcuts.appendChild(document.createTextNode('\240|\240'));
        quickElement('a', shortcuts, gettext('Tomorrow'), 'href', 'javascript:DateTimeShortcuts.handleCalendarQuickLink(' + num + ', +1);');

        // cancel bar
        var cancel_p = quickElement('p', cal_box);
        cancel_p.className = 'calendar-cancel';
        quickElement('a', cancel_p, gettext('Cancel'), 'href', 'javascript:DateTimeShortcuts.dismissCalendar(' + num + ');');
        django.jQuery(document).bind('keyup', function(event) {
            if (event.which == 27) {
                // ESC key closes popup
                DateTimeShortcuts.dismissCalendar(num);
                event.preventDefault();
            }
        });
    },
    openCalendar: function(num) {
        var cal_box = document.getElementById(DateTimeShortcuts.calendarDivName1+num)
        var cal_link = document.getElementById(DateTimeShortcuts.calendarLinkName+num)
        var inp = DateTimeShortcuts.calendarInputs[num];

        // Determine if the current value in the input has a valid date.
        // If so, draw the calendar with that date's year and month.
        if (inp.value) {
            var format = get_format('DATE_INPUT_FORMATS')[0];
            var selected = inp.value.strptime(format);
            var year = selected.getUTCFullYear();
            var month = selected.getUTCMonth() + 1;
            var re = /\d{4}/
            if (re.test(year.toString()) && month >= 1 && month <= 12) {
                DateTimeShortcuts.calendars[num].drawDate(month, year, selected);
            }
        }

        // Recalculate the clockbox position
        // is it left-to-right or right-to-left layout ?
        if (getStyle(document.body,'direction')!='rtl') {
            cal_box.style.left = findPosX(cal_link) + 17 + 'px';
        }
        else {
            // since style's width is in em, it'd be tough to calculate
            // px value of it. let's use an estimated px for now
            // TODO: IE returns wrong value for findPosX when in rtl mode
            //       (it returns as it was left aligned), needs to be fixed.
            cal_box.style.left = findPosX(cal_link) - 180 + 'px';
        }
        cal_box.style.top = Math.max(0, findPosY(cal_link) - 75) + 'px';

        cal_box.style.display = 'block';
        addEvent(document, 'click', DateTimeShortcuts.dismissCalendarFunc[num]);
    },
    dismissCalendar: function(num) {
        document.getElementById(DateTimeShortcuts.calendarDivName1+num).style.display = 'none';
        removeEvent(document, 'click', DateTimeShortcuts.dismissCalendarFunc[num]);
    },
    drawPrev: function(num) {
        DateTimeShortcuts.calendars[num].drawPreviousMonth();
    },
    drawNext: function(num) {
        DateTimeShortcuts.calendars[num].drawNextMonth();
    },
    handleCalendarCallback: function(num) {
        var format = get_format('DATE_INPUT_FORMATS')[0];
        // the format needs to be escaped a little
        format = format.replace('\\', '\\\\');
        format = format.replace('\r', '\\r');
        format = format.replace('\n', '\\n');
        format = format.replace('\t', '\\t');
        format = format.replace("'", "\\'");
        return ["function(y, m, d) { DateTimeShortcuts.calendarInputs[",
               num,
               "].value = new Date(y, m-1, d).strftime('",
               format,
               "');DateTimeShortcuts.calendarInputs[",
               num,
               "].focus();document.getElementById(DateTimeShortcuts.calendarDivName1+",
               num,
               ").style.display='none';}"].join('');
    },
    handleCalendarQuickLink: function(num, offset) {
       var d = DateTimeShortcuts.now();
       d.setDate(d.getDate() + offset)
       DateTimeShortcuts.calendarInputs[num].value = d.strftime(get_format('DATE_INPUT_FORMATS')[0]);
       DateTimeShortcuts.calendarInputs[num].focus();
       DateTimeShortcuts.dismissCalendar(num);
    }
}

addEvent(window, 'load', DateTimeShortcuts.init);
