//autoSuggest gathers suggestions to provide the user in type ahead and dropdown suggestion boxes using suggestions from the suggestion objects

function AutoSuggestControl(oTextbox,oProvider)
{
    this.cur = -1;
    this.layer = null;
    this.provider = oProvider;
    this.textbox = oTextbox;
    this.init();
}

AutoSuggestControl.prototype.init = function()
{
    var oThis = this;
    
    this.textbox.onkeyup = function(oEvent)
    {
        if(!oEvent)
        {
            oEvent = window.event;
        }
        oThis.handleKeyUp(oEvent);
    }
    
    this.textbox.onkeydown = function(oEvent)
    {
        if(!oEvent)
        {
            oEvent = window.event;
        }
        
        oThis.handleKeyDown(oEvent);
    }
    
    this.textbox.onblur = function()
    {
        oThis.hideSuggestions();
    }
    
    this.createDropDown();
}

AutoSuggestControl.prototype.selectRange = function(iStart, iLength)
{
    if (this.textbox.createTextRange) 
    {
        var oRange = this.textbox.createTextRange(); 
        oRange.moveStart("character", iStart); 
        oRange.moveEnd("character", iLength - this.textbox.value.length); 
        oRange.select();
    } 
    else if (this.textbox.setSelectionRange) 
    {
        this.textbox.setSelectionRange(iStart, iLength);
    }

    this.textbox.focus(); 
}

AutoSuggestControl.prototype.typeAhead = function(sSuggestion)
{
    if(this.textbox.createTextRange||this.textbox.setSelectionRange)
    {
        var iLen = this.textbox.value.length;
        this.textbox.value = sSuggestion;
        this.selectRange(iLen, sSuggestion.length);
    }
}

AutoSuggestControl.prototype.autosuggest = function(aSuggestions, bTypeAhead)
{
    if(aSuggestions.length > 0)
    {
        if(bTypeAhead)
        {
            this.typeAhead(aSuggestions[0]);
        }
        this.showSuggestions(aSuggestions);
    }
    else
    {
        this.hideSuggestions();
    }
}

AutoSuggestControl.prototype.handleKeyDown = function (oEvent)
{
    switch(oEvent.keyCode)
    {
        case 38: //up arrow
            this.previousSuggestion();
            break;
        case 40: //down arrow 
            this.nextSuggestion();
            break;
        case 13: //enter
            this.hideSuggestions();
            break;
    }
}


AutoSuggestControl.prototype.handleKeyUp = function(oEvent) 
{
    var iKeyCode = oEvent.keyCode;

    if(iKeyCode == 8||iKeyCode == 46)
    {
        this.provider.requestSuggestions(this,true);
    }
    else if (iKeyCode < 32 || (iKeyCode >= 33 && iKeyCode <= 46) || (iKeyCode >= 112 && iKeyCode <= 123)) 
    {
       //ignore
    } 
    else 
    {
        this.provider.requestSuggestions(this, true);
    }
}

AutoSuggestControl.prototype.highlightSuggestion = function(oSuggestionNode)
{
    for(var i=0; i < this.layer.childNodes.length; i++)
    {
        var oNode = this.layer.childNodes[i];
        if(oNode == oSuggestionNode)
        {
            oNode.className = "current";
        }
        else if(oNode.className == "current")
        {
            oNode.className="";
        }
    }
}

AutoSuggestControl.prototype.createDropDown = function()
{
    this.layer = document.createElement("div");
    this.layer.className = "suggestions";
    this.layer.style.visibility = "hidden";
    this.layer.style.width = this.textbox.offsetWidth;
    document.body.appendChild(this.layer);
    
    var oThis = this;
    
    this.layer.onmousedown = this.layer.onmouseup = this.layer.onmouseover = function(oEvent)
    {
        oEvent = oEvent||window.event;
        oTarget = oEvent.target||oEvent.srcElement;
        
        if(oEvent.type == "mousedown")
        {
            oThis.textbox.value = oTarget.firstChild.nodeValue;
            oThis.hideSuggestions();
        }
        else if(oEvent.type == "mouseover")
        {
            oThis.highlightSuggestion(oTarget);
        }
        else
        {
            oThis.textbox.focus();
        }
    }
}

AutoSuggestControl.prototype.getLeft = function ()
{
    var oNode = this.textbox;
    var iLeft = 0;

    while(oNode.tagName != "BODY")
    {
        iLeft += oNode.offsetLeft;
        oNode = oNode.offsetParent; 
    }

    return iLeft;
}

AutoSuggestControl.prototype.getTop = function ()
{
    var oNode = this.textbox;
    var iTop = 0;

    while(oNode.tagName != "BODY")
    {
        iTop += oNode.offsetTop;
        oNode = oNode.offsetParent; 
    }

    return iTop;
}

AutoSuggestControl.prototype.showSuggestions = function (aSuggestions)
{
    var oDiv = null;
    this.layer.innerHTML = "";

    for (var i=0; i < aSuggestions.length; i++)
    {
        oDiv = document.createElement("div");
        oDiv.appendChild(document.createTextNode(aSuggestions[i]));
        this.layer.appendChild(oDiv);
    }

    this.layer.style.left = this.getLeft() + "px";
    this.layer.style.top = (this.getTop()+this.textbox.offsetHeight) + "px";
    this.layer.style.visibility = "visible";
}

AutoSuggestControl.prototype.hideSuggestions = function ()
{
    this.layer.style.visibility = "hidden";
}

AutoSuggestControl.prototype.nextSuggestion = function ()
{
    var cSuggestionNodes = this.layer.childNodes;

    if (cSuggestionNodes.length > 0 && this.cur < cSuggestionNodes.length-1)
    {
        var oNode = cSuggestionNodes[++this.cur];
        this.highlightSuggestion(oNode);
        this.textbox.value = oNode.firstChild.nodeValue; 
    }
}

AutoSuggestControl.prototype.previousSuggestion = function ()
{
    var cSuggestionNodes = this.layer.childNodes;

    if (cSuggestionNodes.length > 0 && this.cur > 0)
    {
        var oNode = cSuggestionNodes[--this.cur];
        this.highlightSuggestion(oNode);
        this.textbox.value = oNode.firstChild.nodeValue; 
    }
}