/**
* An autosuggest textbox control.
* @class
* @scope public
*/
function AutoSuggestControl(oTextbox /*:HTMLInputElement*/,
                            oProvider /*:SuggestionProvider*/) {

    /**
    * The currently selected suggestions.
    * @scope private
    */
    this.cur /*:int*/ = -1;

    /**
    * The dropdown list view.
    * @scope private
    */
    this.layer = null;

    /**
    * The dropdown list layer.
    * @scope private
    */
    this.innerLayer = null;

    /**
    * Suggestion provider for the autosuggest feature.
    * @scope private.
    */
    this.provider /*:SuggestionProvider*/ = oProvider;

    /**
    * The textbox to capture.
    * @scope private
    */
    this.textbox /*:HTMLInputElement*/ = oTextbox;

    //initialize the control
    this.init();

}

/**
* Autosuggests one or more suggestions for what the user has typed.
* If no suggestions are passed in, then no autosuggest occurs.
* @scope private
* @param aSuggestions An array of suggestion strings.
* @param bTypeAhead If the control should provide a type ahead suggestion.
*/
AutoSuggestControl.prototype.autosuggest = function(aSuggestions /*:Array*/) {

    //make sure there's at least one suggestion
    if (aSuggestions.length > 0) {
        this.showSuggestions(aSuggestions);
    } else {
        this.hideSuggestions();
    }
};

/**
* Creates the dropdown layer to display multiple suggestions.
* @scope private
*/
AutoSuggestControl.prototype.createDropDown = function() {

    var oThis = this;
    //old makeup
    //create the layer and assign styles
    //    this.layer = document.createElement("div");
    //    this.layer.className = "suggestions";
    //    this.layer.style.visibility = "hidden";
    //    var img = document.createElement("img");
    //    img.src = "/img/townsT.gif";
    //    img.className = "imgBlock";
    //    this.layer.appendChild(img);
    //    var div1 = document.createElement("div");
    //    div1.className = "townsB";
    //    this.layer.appendChild(div1);
    //    this.innerLayer = document.createElement("div");
    //    this.innerLayer.className = "townsIn";
    //    div1.appendChild(this.innerLayer);
    //    img = document.createElement("img");
    //    img.src = "/img/townsB.gif";
    //    img.className = "imgBlock";
    //    this.layer.appendChild(img);


    this.layer = document.createElement("div");
    this.layer.className = "suggestions";
    this.layer.style.visibility = "hidden";
    var img = document.createElement("img");
    img.src = "/img/townsT.gif";
    img.className = "imgBlock";
    this.layer.appendChild(img);
    var div1 = document.createElement("div");
    div1.className = "townsB";
    this.layer.appendChild(div1);
    this.innerLayer = document.createElement("div");
    this.innerLayer.className = "townsIn";
    div1.appendChild(this.innerLayer);
    //"close window" elements
    var p = document.createElement("p");
    var a1 = document.createElement("a");
    a1.href = "#";
    a1.title = "закрыть";
    a1.innerHTML = "Закрыть!";

    var a2 = document.createElement("a");
    a2.href = "#";
    a2.title = "закрыть";
    a2.innerHTML = '<img width="24" height="24" border="0" align="absmiddle" alt="закрыть" src="/img/0705closecal.gif">';

    p.appendChild(a1);
    p.appendChild(a2);
    div1.appendChild(p);

    img = document.createElement("img");
    img.src = "/img/townsB.gif";
    img.className = "imgBlock";
    this.layer.appendChild(img);
    //when the user clicks on the a suggestion, get the text (innerHTML)
    //and place it into a textbox
    this.innerLayer.onmousedown =
    this.innerLayer.onmouseup =
    this.innerLayer.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();
        }
    };


    document.body.appendChild(this.layer);
};

/**
* Gets the left coordinate of the textbox.
* @scope private
* @return The left coordinate of the textbox in pixels.
*/
AutoSuggestControl.prototype.getLeft = function() /*:int*/{

    var oNode = this.textbox;
    var id = this.textbox.id;
    return $("#" + id).offset().left;
};

/**
* Gets the top coordinate of the textbox.
* @scope private
* @return The top coordinate of the textbox in pixels.
*/
AutoSuggestControl.prototype.getTop = function() /*:int*/{

    var oNode = this.textbox;
    var id = this.textbox.id;
    return $("#" + id).offset().top;
};

/**
* Handles three keydown events.
* @scope private
* @param oEvent The event object for the keydown event.
*/
AutoSuggestControl.prototype.handleKeyDown = function(oEvent /*:Event*/) {

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

};

/**
* Handles keyup events.
* @scope private
* @param oEvent The event object for the keyup event.
*/
AutoSuggestControl.prototype.handleKeyUp = function(oEvent /*:Event*/) {

    var iKeyCode = oEvent.keyCode;

    //for backspace (8) and delete (46), shows suggestions without typeahead
    if (iKeyCode == 8 || iKeyCode == 46) {
        this.provider.requestSuggestions(this);

        //make sure not to interfere with non-character keys
    } else if (iKeyCode < 32 || (iKeyCode >= 33 && iKeyCode < 46) || (iKeyCode >= 112 && iKeyCode <= 123)) {
        //ignore
    } else {
        //request suggestions from the suggestion provider with typeahead
        this.provider.requestSuggestions(this);
    }
};

/**
* Hides the suggestion dropdown.
* @scope private
*/
AutoSuggestControl.prototype.hideSuggestions = function() {
    this.layer.style.visibility = "hidden";
};

/**
* Highlights the given node in the suggestions dropdown.
* @scope private
* @param oSuggestionNode The node representing a suggestion in the dropdown.
*/
AutoSuggestControl.prototype.highlightSuggestion = function(oSuggestionNode) {

    for (var i = 0; i < this.innerLayer.childNodes.length; i++) {
        var oNode = this.innerLayer.childNodes[i];
        if (oNode == oSuggestionNode) {
            oNode.className = "current"
        } else if (oNode.className == "current") {
            if(i != this.innerLayer.childNodes.length - 1)
                oNode.className = "town";
            else
                oNode.className = "townLast";
        }
    }
};

/**
* Initializes the textbox with event handlers for
* auto suggest functionality.
* @scope private
*/
AutoSuggestControl.prototype.init = function() {

    //save a reference to this object
    var oThis = this;

    //assign the onkeyup event handler
    this.textbox.onkeyup = function(oEvent) {

        //check for the proper location of the event object
        if (!oEvent) {
            oEvent = window.event;
        }

        //call the handleKeyUp() method with the event object
        oThis.handleKeyUp(oEvent);
    };

    //assign onkeydown event handler
    this.textbox.onkeydown = function(oEvent) {

        //check for the proper location of the event object
        if (!oEvent) {
            oEvent = window.event;
        }

        //call the handleKeyDown() method with the event object
        oThis.handleKeyDown(oEvent);
    };

    //assign onblur event handler (hides suggestions)    
    this.textbox.onblur = function() {
        oThis.hideSuggestions();
    };

    //create the suggestions dropdown
    this.createDropDown();
};

/**
* Highlights the next suggestion in the dropdown and
* places the suggestion into the textbox.
* @scope private
*/
AutoSuggestControl.prototype.nextSuggestion = function() {
    var cSuggestionNodes = this.innerLayer.childNodes;
    if (this.cur >= cSuggestionNodes.length) this.cur = -1;
    if (cSuggestionNodes.length > 0 && this.cur < cSuggestionNodes.length - 1) {
        var oNode = cSuggestionNodes[++this.cur];
        this.highlightSuggestion(oNode);
        this.textbox.value = oNode.firstChild.nodeValue;
    }
};

/**
* Highlights the previous suggestion in the dropdown and
* places the suggestion into the textbox.
* @scope private
*/
AutoSuggestControl.prototype.previousSuggestion = function() {
    var cSuggestionNodes = this.innerLayer.childNodes;
    if (this.cur >= cSuggestionNodes.length) this.cur = -1;
    if (cSuggestionNodes.length > 0 && this.cur > 0) {
        var oNode = cSuggestionNodes[--this.cur];
        this.highlightSuggestion(oNode);
        this.textbox.value = oNode.firstChild.nodeValue;
    }
};

/**
* Selects a range of text in the textbox.
* @scope public
* @param iStart The start index (base 0) of the selection.
* @param iLength The number of characters to select.
*/
AutoSuggestControl.prototype.selectRange = function(iStart /*:int*/, iLength /*:int*/) {

    //use text ranges for Internet Explorer
    if (this.textbox.createTextRange) {
        var oRange = this.textbox.createTextRange();
        oRange.moveStart("character", iStart);
        oRange.moveEnd("character", iLength - this.textbox.value.length);
        oRange.select();

        //use setSelectionRange() for Mozilla
    } else if (this.textbox.setSelectionRange) {
        this.textbox.setSelectionRange(iStart, iLength);
    }

    //set focus back to the textbox
    this.textbox.focus();
};

/**
* Builds the suggestion layer contents, moves it into position,
* and displays the layer.
* @scope private
* @param aSuggestions An array of suggestions for the control.
*/
AutoSuggestControl.prototype.showSuggestions = function(aSuggestions /*:Array*/) {

    var oDiv = null;
    this.cur = -1;
    this.innerLayer.innerHTML = "";  //clear contents of the layer

    for (var i = 0; i < aSuggestions.length; i++) {
        oDiv = document.createElement("div");
        if (i != aSuggestions.length - 1)
            oDiv.className = "town";
        else
            oDiv.className = "townLast";
        oDiv.appendChild(document.createTextNode(aSuggestions[i]));
        this.innerLayer.appendChild(oDiv);
    }

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

};