/*

 * Copyright (C) 2004 Baron Schwartz <baron at sequent dot org>

 *

 * This program is free software; you can redistribute it and/or modify it

 * under the terms of the GNU Lesser General Public License as published by the

 * Free Software Foundation, version 2.1.

 *

 * This program is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS

 * FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more

 * details.

 *

 * $Revision: 1.1 $

 */

// Shows or hides the date chooser on the page

function showChooser(obj, inputId, divId, start, end, format, isTimeChooser) {

    if (document.getElementById) {

        var input = document.getElementById(inputId);

        var div = document.getElementById(divId);

        if (input !== undefined && div !== undefined) {

            if (input.DateChooser === undefined) {

                input.DateChooser = new DateChooser(input, div, start, end, format, isTimeChooser);

            }

            input.DateChooser.setDate(Date.parseDate(input.value, format));

            if (input.DateChooser.isVisible()) {

                input.DateChooser.hide();

            }

            else {

                input.DateChooser.show();

            }

        }

    }

}

// Sets a date on the object attached to 'inputId'

function dateChooserSetDate(inputId, value) {

    var input = document.getElementById(inputId);

    if (input !== undefined && input.DateChooser !== undefined) {

        input.DateChooser.setDate(Date.parseDate(value, input.DateChooser._format));

        if (input.DateChooser.isTimeChooser()) {

            var theForm = input.form;

            var prefix = input.DateChooser._prefix;

            input.DateChooser.setTime(

                parseInt(theForm.elements[prefix + 'hour'].options[

                    theForm.elements[prefix + 'hour'].selectedIndex].value)

                    + parseInt(theForm.elements[prefix + 'ampm'].options[

                    theForm.elements[prefix + 'ampm'].selectedIndex].value),

                parseInt(theForm.elements[prefix + 'min'].options[

                    theForm.elements[prefix + 'min'].selectedIndex].value));

        }

        input.value = input.DateChooser.getValue();

        input.DateChooser.hide();

    }

}

// The callback function for when someone changes the pulldown menus on the date

// chooser

function dateChooserDateChange(theForm, prefix) {

    var input = document.getElementById(

        theForm.elements[prefix + 'inputId'].value);

    var newDate = new Date(

        theForm.elements[prefix + 'year'].options[

            theForm.elements[prefix + 'year'].selectedIndex].value,

        theForm.elements[prefix + 'month'].options[

            theForm.elements[prefix + 'month'].selectedIndex].value,

        1);

    // Try to preserve the day of month (watch out for months with 31 days)

    newDate.setDate(Math.max(1, Math.min(newDate.getDaysInMonth(),

                    input.DateChooser._date.getDate())));

    input.DateChooser.setDate(newDate);

    if (input.DateChooser.isTimeChooser()) {

        input.DateChooser.setTime(

            parseInt(theForm.elements[prefix + 'hour'].options[

                theForm.elements[prefix + 'hour'].selectedIndex].value)

                + parseInt(theForm.elements[prefix + 'ampm'].options[

                theForm.elements[prefix + 'ampm'].selectedIndex].value),

            parseInt(theForm.elements[prefix + 'min'].options[

                theForm.elements[prefix + 'min'].selectedIndex].value));

    }

    input.DateChooser.show();

}

// Gets the absolute position on the page of the element passed in

function getAbsolutePosition(obj) {

    var result = [0, 0];

    while (obj != null) {

        result[0] += obj.offsetTop;

        result[1] += obj.offsetLeft;

        obj = obj.offsetParent;

    }

    return result;

}

// DateChooser constructor

function DateChooser(input, div, start, end, format, isTimeChooser) {

    this._input = input;

    this._div = div;

    this._start = start;

    this._end = end;

    this._format = format;

    this._date = new Date();

    this._isTimeChooser = isTimeChooser;

    // Choose a random prefix for all pulldown menus

    this._prefix = "";

    var letters = ["a", "b", "c", "d", "e", "f", "h", "i", "j", "k", "l",

        "m", "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z"];

    for (var i = 0; i < 10; ++i) {

        this._prefix += letters[Math.floor(Math.random() * letters.length)];

    }

}

// DateChooser prototype variables

DateChooser.prototype._isVisible = false;

// Returns true if the chooser is currently visible

DateChooser.prototype.isVisible = function() {

    return this._isVisible;

}

// Returns true if the chooser is to allow choosing the time as well as the date

DateChooser.prototype.isTimeChooser = function() {

    return this._isTimeChooser;

}

// Gets the value, as a formatted string, of the date attached to the chooser

DateChooser.prototype.getValue = function() {

    return this._date.dateFormat(this._format);

}

// Hides the chooser

DateChooser.prototype.hide = function() {

    this._div.style.visibility = "hidden";

    this._div.style.display = "none";

    this._div.innerHTML = "";

    this._isVisible = false;

}

// Shows the chooser on the page

DateChooser.prototype.show = function() {

    // calculate the position before making it visible

    var inputPos = getAbsolutePosition(this._input);

    this._div.style.top = (inputPos[0] + this._input.offsetHeight) + "px";

    this._div.style.left = (inputPos[1] + this._input.offsetWidth) + "px";

    this._div.innerHTML = this.createChooserHtml();

    this._div.style.display = "block";

    this._div.style.visibility = "visible";

    this._div.style.position = "absolute";

    this._isVisible = true;

}

// Sets the date to what is in the input box

DateChooser.prototype.initializeDate = function() {

    if (this._input.value != null && this._input.value != "") {

        this._date = Date.parseDate(this._input.value, this._format);

    }

    else {

        this._date = new Date();

    }

}

// Sets the date attached to the chooser

DateChooser.prototype.setDate = function(date) {

    this._date = date ? date : new Date();

}

// Sets the time portion of the date attached to the chooser

DateChooser.prototype.setTime = function(hour, minute) {

    this._date.setHours(hour);

    this._date.setMinutes(minute);

}

// Creates the HTML for the whole chooser

DateChooser.prototype.createChooserHtml = function() {

    var formHtml = "<input type=\"hidden\" name=\""

        + this._prefix + "inputId\" value=\""

        + this._input.getAttribute('id') + "\">"

        + "\r\n  <select name=\"" + this._prefix 

        + "month\" onChange=\"dateChooserDateChange(this.form, '"

        + this._prefix + "');\">";

    for (var monIndex = 0; monIndex <= 11; monIndex++) {

        formHtml += "\r\n    <option value=\"" + monIndex + "\""

            + (monIndex == this._date.getMonth() ? " selected=\"1\"" : "")

            + ">" + Date.monthNames[monIndex] + "</option>";

    }

    formHtml += "\r\n  </select>\r\n  <select name=\""

        + this._prefix + "year\" onChange=\"dateChooserDateChange(this.form, '"

        + this._prefix + "');\">";

    for (var i = this._start; i <= this._end; ++i) {

        formHtml += "\r\n    <option value=\"" + i + "\""

            + (i == this._date.getFullYear() ? " selected=\"1\"" : "")

            + ">" + i + "</option>";

    }

    formHtml += "\r\n  </select>";

    formHtml += this.createCalendarHtml();

    if (this._isTimeChooser) {

        formHtml += this.createTimeChooserHtml();

    }

    return formHtml;

}

// Creates the extra HTML needed for choosing the time

DateChooser.prototype.createTimeChooserHtml = function() {

    // Add hours

    var result = "\r\n  <select name=\"" + this._prefix + "hour\">";

    for (var i = 0; i < 12; ++i) {

        result += "\r\n    <option value=\"" + i + "\""

            + (((this._date.getHours() % 12) == i) ? " selected=\"1\">" : ">")

            + i + "</option>";

    }

    // Add extra entry for 12:00

    result += "\r\n    <option value=\"0\">12</option>";

    result += "\r\n  </select>";

    // Add minutes

    result += "\r\n  <select name=\"" + this._prefix + "min\">";

    for (var i = 0; i < 60; i += 15) {

        result += "\r\n    <option value=\"" + i + "\""

            + ((this._date.getMinutes() == i) ? " selected=\"1\">" : ">")

            + String.leftPad(i, 2, '0') + "</option>";

    }

    result += "\r\n  </select>";

    // Add AM/PM

    result += "\r\n  <select name=\"" + this._prefix + "ampm\">";

    result += "\r\n    <option value=\"0\""

        + (this._date.getHours() < 12 ? " selected=\"1\">" : ">")

        + "AM</option>";

    result += "\r\n    <option value=\"12\""

        + (this._date.getHours() >= 12 ? " selected=\"1\">" : ">")

        + "PM</option>";

    result += "\r\n  </select>";

    return result;

}

// Creates the HTML for the actual calendar part of the chooser

DateChooser.prototype.createCalendarHtml = function() {

    var result = "\r\n<table cellspacing=\"0\" class=\"dateChooser\">"

        + "\r\n  <tr><th>S</th><th>M</th><th>T</th>"

        + "<th>W</th><th>T</th><th>F</th><th>S</th></tr>\r\n  <tr>";

    // Fill up the days of the week until we get to the first day of the month

    var firstDay = this._date.getFirstDayOfMonth();

    var lastDay = this._date.getLastDayOfMonth();

    if (firstDay != 0) {

        result += "<td colspan=\"" + firstDay + "\">&nbsp;</td>";

    }

    // Fill in the days of the month

    var i = 0;

    while (i < this._date.getDaysInMonth()) {

        if (((i++ + firstDay) % 7) == 0) {

            result += "</tr>\r\n  <tr>";

        }

        var thisDay = new Date(

            this._date.getFullYear(),

            this._date.getMonth(), i);

        var js = '"dateChooserSetDate(\''

            + this._input.getAttribute('id') + "', '"

            + thisDay.dateFormat(this._format) + '\');"'

        result += "\r\n    <td class=\"dateChooserActive"

            // If the date is the currently chosen date, highlight it

            + (i == this._date.getDate() ? " dateChooserActiveToday" : "")

            + "\" onClick=" + js + ">" + i + "</td>";

    }

    // Fill in any days after the end of the month

    if (lastDay != 6) {

        result += "<td colspan=\"" + (6 - lastDay) + "\">&nbsp;</td>";

    }

    return result + "\r\n  </tr>\r\n</table><!--[if lte IE 6.5]><iframe></iframe><![endif]-->";

}