/**
* o------------------------------------------------------------------------------o
* | This package is licensed under the Phpguru license. A quick summary is       |
* | that for commercial use, there is a small one-time licensing fee to pay. For |
* | registered charities and educational institutes there is a reduced license   |
* | fee available. You can read more  at:                                        |
* |                                                                              |
* |                  http://www.phpguru.org/static/license.html                  |
* o------------------------------------------------------------------------------o
*
* © Copyright 2008,2009 Richard Heyes
*/

/**
* Global vars
*/
__AutoComplete = new Array();

// Basic UA detection
isIE = document.all ? true : false;
isGecko = navigator.userAgent.toLowerCase().indexOf('gecko') != -1;
isOpera = navigator.userAgent.toLowerCase().indexOf('opera') != -1;


/**
* Attachs the autocomplete object to a form element. Sets
* onkeypress event on the form element.
* 
* @param string formElement Name of form element to attach to
* @param array  data        Array of strings of which to use as the autocomplete data
*/
function AutoComplete_Create (id, data, idId, minimum)
{
    __AutoComplete[id] = {'data':data.sort(),
                          'isVisible':false,
                          'element':document.getElementById(id),
                          'elementId':document.getElementById(idId),
                          'minimum':minimum,
                          'dropdown':null,
                          'highlighted':null};

    __AutoComplete[id]['element'].setAttribute('autocomplete', 'off');
    __AutoComplete[id]['element'].onkeydown  = function(e) {return AutoComplete_KeyDown(this.getAttribute('id'), e);}
    __AutoComplete[id]['element'].onkeyup    = function(e) {return AutoComplete_KeyUp(this.getAttribute('id'), e);}
    __AutoComplete[id]['element'].onkeypress = function(e) {if (!e) e = window.event; if (e.keyCode == 13 || isOpera) return false;}
    __AutoComplete[id]['element'].ondblclick = function() {AutoComplete_ShowDropdown(this.getAttribute('id'));}
    __AutoComplete[id]['element'].onclick    = function(e) {if (!e) e = window.event; e.cancelBubble = true; e.returnValue = false;}

    // Hides the dropdowns when document clicked
    var docClick = function()
    {
       for (id in __AutoComplete) {
           AutoComplete_HideDropdown(id);
       }
    }

    if (document.addEventListener) {
        document.addEventListener('click', docClick, false);
    } else if (document.attachEvent) {
        document.attachEvent('onclick', docClick, false);
    }


    // Max number of items shown at once
    if (arguments[2] != null) {
        __AutoComplete[id]['maxitems'] = arguments[2];
        __AutoComplete[id]['firstItemShowing'] = 0;
        __AutoComplete[id]['lastItemShowing']  = arguments[2] - 1;
    }

    AutoComplete_CreateDropdown(id);

    // Prevent select dropdowns showing thru
    if (isIE) {
        __AutoComplete[id]['iframe'] = document.createElement('iframe');
        __AutoComplete[id]['iframe'].id = id +'_iframe';
        __AutoComplete[id]['iframe'].style.position = 'absolute';
        __AutoComplete[id]['iframe'].style.top = '0';
        __AutoComplete[id]['iframe'].style.left = '0';
        __AutoComplete[id]['iframe'].style.width = '0px';
        __AutoComplete[id]['iframe'].style.height = '0px';
        __AutoComplete[id]['iframe'].style.zIndex = '98';
        __AutoComplete[id]['iframe'].style.visibility = 'hidden';

        __AutoComplete[id]['element'].parentNode.insertBefore(__AutoComplete[id]['iframe'], __AutoComplete[id]['element']);
    }
}


/**
* Creates the dropdown layer
* 
* @param string id The form elements id. Used to identify the correct dropdown.
*/
function AutoComplete_CreateDropdown(id)
{
    var left  = AutoComplete_GetLeft(__AutoComplete[id]['element']);
    var top   = AutoComplete_GetTop(__AutoComplete[id]['element']) + __AutoComplete[id]['element'].offsetHeight;
    var width = __AutoComplete[id]['element'].offsetWidth;

    __AutoComplete[id]['dropdown'] = document.createElement('div');
    __AutoComplete[id]['dropdown'].className = 'autocomplete'; // Don't use setAttribute()

    __AutoComplete[id]['element'].parentNode.insertBefore(__AutoComplete[id]['dropdown'], __AutoComplete[id]['element']);

    // Position it
    __AutoComplete[id]['dropdown'].style.left       = left + 'px';
    __AutoComplete[id]['dropdown'].style.top        = top + 'px';
    __AutoComplete[id]['dropdown'].style.width      = width + 'px';
    __AutoComplete[id]['dropdown'].style.zIndex     = '99';
    __AutoComplete[id]['dropdown'].style.visibility = 'hidden';
}


/**
* Gets left coord of given element
* 
* @param object element The element to get the left coord for
*/
function AutoComplete_GetLeft(element)
{
    var curNode = element;
    var left    = 0;

    do {
        left += curNode.offsetLeft;
        curNode = curNode.offsetParent;

    } while(curNode.tagName.toLowerCase() != 'body');

    return left;
}


/**
* Gets top coord of given element
* 
* @param object element The element to get the top coord for
*/
function AutoComplete_GetTop(element)
{
    var curNode = element;
    var top    = 0;

    do {
        top += curNode.offsetTop;
        curNode = curNode.offsetParent;

    } while(curNode.tagName.toLowerCase() != 'body');

    return top;
}


/**
* Shows the dropdown layer
* 
* @param string id The form elements id. Used to identify the correct dropdown.
*/
function AutoComplete_ShowDropdown(id)
{
    AutoComplete_HideAll();

    var value = __AutoComplete[id]['element'].value;
    var toDisplay = new Array();
    var newDiv    = null;
    var text      = null;
    var numItems  = __AutoComplete[id]['dropdown'].childNodes.length;

    // Remove all child nodes from dropdown
    while (__AutoComplete[id]['dropdown'].childNodes.length > 0) {
        __AutoComplete[id]['dropdown'].removeChild(__AutoComplete[id]['dropdown'].childNodes[0]);
    }

    // Go thru data searching for matches
    for (i=0; i<__AutoComplete[id]['data'].length; ++i) {
        if (__AutoComplete[id]['data'][i].toLowerCase().indexOf(value.toLowerCase()) != -1) {
          if(__AutoComplete[id]['data'][i].indexOf('###') > -1) {
            toDisplay[toDisplay.length] = __AutoComplete[id]['data'][i].substring(0, __AutoComplete[id]['data'][i].indexOf('###'));
          } else {
            toDisplay[toDisplay.length] = __AutoComplete[id]['data'][i];
          }
        }
    }

    // No matches?
    if (toDisplay.length == 0) {
        AutoComplete_HideDropdown(id);
        return;
    }



    // Add data to the dropdown layer
    for (i=0; i<toDisplay.length; ++i) {
        newDiv = document.createElement('div');
        newDiv.className = 'autocomplete_item'; // Don't use setAttribute()
        newDiv.setAttribute('id', 'autocomplete_item_' + i);
        newDiv.setAttribute('index', i);
        newDiv.style.zIndex = '99';

         // Scrollbars are on display ?
        if (toDisplay.length > __AutoComplete[id]['maxitems'] && navigator.userAgent.indexOf('MSIE') == -1) {
            newDiv.style.width = __AutoComplete[id]['element'].offsetWidth - 22 + 'px';
        }

        newDiv.onmouseover = function() {AutoComplete_HighlightItem(__AutoComplete[id]['element'].getAttribute('id'), this.getAttribute('index'));};
        newDiv.onclick     = function() {AutoComplete_SetValue(__AutoComplete[id]['element'].getAttribute('id')); AutoComplete_HideDropdown(__AutoComplete[id]['element'].getAttribute('id'));}

        text   = document.createTextNode(toDisplay[i]);
        newDiv.appendChild(text);

        __AutoComplete[id]['dropdown'].appendChild(newDiv);
    }


    // Too many items?
    if (toDisplay.length > __AutoComplete[id]['maxitems']) {
        __AutoComplete[id]['dropdown'].style.height = (__AutoComplete[id]['maxitems'] * 15) + 2 + 'px';

    } else {
        __AutoComplete[id]['dropdown'].style.height = '';
    }


    /**
    * Set left/top in case of document movement/scroll/window resize etc
    */
    __AutoComplete[id]['dropdown'].style.left = AutoComplete_GetLeft(__AutoComplete[id]['element']);
    __AutoComplete[id]['dropdown'].style.top  = AutoComplete_GetTop(__AutoComplete[id]['element']) + __AutoComplete[id]['element'].offsetHeight;


    // Show the iframe for IE
    if (isIE) {
        __AutoComplete[id]['iframe'].style.top    = __AutoComplete[id]['dropdown'].style.top;
        __AutoComplete[id]['iframe'].style.left   = __AutoComplete[id]['dropdown'].style.left;
        __AutoComplete[id]['iframe'].style.width  = __AutoComplete[id]['dropdown'].offsetWidth;
        __AutoComplete[id]['iframe'].style.height = __AutoComplete[id]['dropdown'].offsetHeight;

        __AutoComplete[id]['iframe'].style.visibility = 'visible';
    }


    // Show dropdown
    if (!__AutoComplete[id]['isVisible']) {
        __AutoComplete[id]['dropdown'].style.visibility = 'visible';
        __AutoComplete[id]['isVisible'] = true;
    }


    // If now showing less items than before, reset the highlighted value
    if (__AutoComplete[id]['dropdown'].childNodes.length != numItems) {
        __AutoComplete[id]['highlighted'] = null;
    }
}


/**
* Hides the dropdown layer
* 
* @param string id The form elements id. Used to identify the correct dropdown.
*/
function AutoComplete_HideDropdown(id)
{
    if (__AutoComplete[id]['iframe']) {
        __AutoComplete[id]['iframe'].style.visibility = 'hidden';
    }


    __AutoComplete[id]['dropdown'].style.visibility = 'hidden';
    __AutoComplete[id]['highlighted'] = null;
    __AutoComplete[id]['isVisible']   = false;
}


/**
* Hides all dropdowns
*/
function AutoComplete_HideAll()
{
    for (id in __AutoComplete) {
        AutoComplete_HideDropdown(id);
    }
}


/**
* Highlights a specific item
* 
* @param string id    The form elements id. Used to identify the correct dropdown.
* @param int    index The index of the element in the dropdown to highlight
*/
function AutoComplete_HighlightItem(id, index)
{
    if (__AutoComplete[id]['dropdown'].childNodes[index]) {
        for (var i=0; i<__AutoComplete[id]['dropdown'].childNodes.length; ++i) {
            if (__AutoComplete[id]['dropdown'].childNodes[i].className == 'autocomplete_item_highlighted') {
                __AutoComplete[id]['dropdown'].childNodes[i].className = 'autocomplete_item';
            }
        }

        __AutoComplete[id]['dropdown'].childNodes[index].className = 'autocomplete_item_highlighted';
        __AutoComplete[id]['highlighted'] = index;
    }
}


/**
* Highlights the menu item with the given index
* 
* @param string id    The form elements id. Used to identify the correct dropdown.
* @param int    index The index of the element in the dropdown to highlight
*/
function AutoComplete_Highlight(id, index)
{
    // Out of bounds checking
    if (index == 1 && __AutoComplete[id]['highlighted'] == __AutoComplete[id]['dropdown'].childNodes.length - 1) {
        __AutoComplete[id]['dropdown'].childNodes[__AutoComplete[id]['highlighted']].className = 'autocomplete_item';
        __AutoComplete[id]['highlighted'] = null;

    } else if (index == -1 && __AutoComplete[id]['highlighted'] == 0) {
        __AutoComplete[id]['dropdown'].childNodes[0].className = 'autocomplete_item';
        __AutoComplete[id]['highlighted'] = __AutoComplete[id]['dropdown'].childNodes.length;
    }

    // Nothing highlighted at the moment
    if (__AutoComplete[id]['highlighted'] == null) {
        __AutoComplete[id]['dropdown'].childNodes[0].className = 'autocomplete_item_highlighted';
        __AutoComplete[id]['highlighted'] = 0;

    } else {
        if (__AutoComplete[id]['dropdown'].childNodes[__AutoComplete[id]['highlighted']]) {
            __AutoComplete[id]['dropdown'].childNodes[__AutoComplete[id]['highlighted']].className = 'autocomplete_item';
        }

        var newIndex = __AutoComplete[id]['highlighted'] + index;

        if (__AutoComplete[id]['dropdown'].childNodes[newIndex]) {
            __AutoComplete[id]['dropdown'].childNodes[newIndex].className = 'autocomplete_item_highlighted';

            __AutoComplete[id]['highlighted'] = newIndex;
        }
    }
}


/**
* Sets the input to a given value
* 
* @param string id    The form elements id. Used to identify the correct dropdown.
*/
function AutoComplete_SetValue(id)
{
    __AutoComplete[id]['element'].value = __AutoComplete[id]['dropdown'].childNodes[__AutoComplete[id]['highlighted']].innerHTML;
    
    if(__AutoComplete[id]['elementId']) {
      for (i=0; i<__AutoComplete[id]['data'].length; ++i) {
        if (__AutoComplete[id]['data'][i].indexOf('###') > -1 &&
            __AutoComplete[id]['data'][i].substring(0, __AutoComplete[id]['data'][i].indexOf('###')) == __AutoComplete[id]['element'].value) {
          __AutoComplete[id]['elementId'].value = __AutoComplete[id]['data'][i].substring(__AutoComplete[id]['data'][i].indexOf('###')+3);
        }
      }
    }
}


/**
* Checks if the dropdown needs scrolling
* 
* @param string id    The form elements id. Used to identify the correct dropdown.
*/
function AutoComplete_ScrollCheck(id)
{
    // Scroll down, or wrapping around from scroll up
    if (__AutoComplete[id]['highlighted'] > __AutoComplete[id]['lastItemShowing']) {
        __AutoComplete[id]['firstItemShowing'] = __AutoComplete[id]['highlighted'] - (__AutoComplete[id]['maxitems'] - 1);
        __AutoComplete[id]['lastItemShowing']  = __AutoComplete[id]['highlighted'];
    }

    // Scroll up, or wrapping around from scroll down
    if (__AutoComplete[id]['highlighted'] < __AutoComplete[id]['firstItemShowing']) {
        __AutoComplete[id]['firstItemShowing'] = __AutoComplete[id]['highlighted'];
        __AutoComplete[id]['lastItemShowing']  = __AutoComplete[id]['highlighted'] + (__AutoComplete[id]['maxitems'] - 1);
    }

    __AutoComplete[id]['dropdown'].scrollTop = __AutoComplete[id]['firstItemShowing'] * 15;
}


/**
* Function which handles the keypress event
* 
* @param string id    The form elements id. Used to identify the correct dropdown.
*/
function AutoComplete_KeyDown(id)
{
    // Mozilla
    if (arguments[1] != null) {
        event = arguments[1];
    }

    var keyCode = event.keyCode;

    switch (keyCode) {

        // Return/Enter
        case 13:
            if (__AutoComplete[id]['highlighted'] != null) {
                AutoComplete_SetValue(id);
                AutoComplete_HideDropdown(id);
            }

            event.returnValue = false;
            event.cancelBubble = true;
            break;

        // Escape
        case 27:
            AutoComplete_HideDropdown(id);
            event.returnValue = false;
            event.cancelBubble = true;
            break;

        // Up arrow
        case 38:
            if (!__AutoComplete[id]['isVisible']) {
                AutoComplete_ShowDropdown(id);
            }

            AutoComplete_Highlight(id, -1);
            AutoComplete_ScrollCheck(id, -1);
            return false;
            break;

        // Tab
        case 9:
            if (__AutoComplete[id]['isVisible']) {
                AutoComplete_HideDropdown(id);
            }
            return;

        // Down arrow
        case 40:
            if (!__AutoComplete[id]['isVisible']) {
                AutoComplete_ShowDropdown(id);
            }

            AutoComplete_Highlight(id, 1);
            AutoComplete_ScrollCheck(id, 1);
            return false;
            break;
    }
}


/**
* Function which handles the keyup event
* 
* @param string id    The form elements id. Used to identify the correct dropdown.
*/
function AutoComplete_KeyUp(id)
{
    // Mozilla
    if (arguments[1] != null) {
        event = arguments[1];
    }

    var keyCode = event.keyCode;

    switch (keyCode) {
        case 13:
            event.returnValue = false;
            event.cancelBubble = true;
            break;

        case 27:
            AutoComplete_HideDropdown(id);
            event.returnValue = false;
            event.cancelBubble = true;
            break;

        case 38:
        case 40:
            return false;
            break;

        default:
            if(window.getData) {
              if(__AutoComplete[id].data.length == 0 && document.getElementById(id).value.length == 1) {
                __AutoComplete[id].data = getData(document.getElementById(id).value).sort();
              } else if(__AutoComplete[id].data.length != 0 && document.getElementById(id).value.length == 0) {
                __AutoComplete[id].data = new Array();
              }
            }
            if(!__AutoComplete[id].minimum || document.getElementById(id).value.length >= __AutoComplete[id].minimum) {
              AutoComplete_ShowDropdown(id); 
            } else {
              AutoComplete_HideDropdown(id);
            }
            break;

    }
}

/**
* Returns whether the dropdown is visible
* 
* @param string id    The form elements id. Used to identify the correct dropdown.
*/
function AutoComplete_isVisible(id)
{
    return __AutoComplete[id]['dropdown'].style.visibility == 'visible';
}