//=========================//
//						   //
// Live Search Javascript  //
//						   //
//=========================//

//$Id:livesearch.js 711 2009-06-10 14:31:55Z jamescollier $

$(document).ready(function(){

	//Global variables.
	var link_number; //Hyperlink number that is appearing as being 'hovered' over.
	var arrows_active; //True if updown arrows have been used to navigate live search items, false if not.
	
	//Function: showLiveSearchResult()
	//Called 'onKeyUp' when an entry is made in the live search box.
	//Takes a variable and submits it to live_search_results.php as a get parameter.
	showLiveSearchResult = function(str,event)
	{
		//Variables
		var live_search_results_page_url="live_search_results.php"; //Url of results page.
		live_search_results_page_url=live_search_results_page_url+"?p_live_search_input="+str;	//Add string to be found; the user's entry.
		live_search_results_page_url=live_search_results_page_url+"&sid="+Math.random(); //Add random number to stop caching. Shouldn't be a problem for our update frequency, though.
	
		//Handle event variable, and place code of key struck into key_code.
		if (!event) event = window.event;
		var key_code=event.keyCode? event.keyCode : event.charCode
	
		if (key_code == 40 || key_code == 38 || key_code == 13){
		 	 processMenuNavigation(key_code) //If 40 (Down Arrow), 38 (Up Arrow) or 13 (Return Key) are struck pass to processMenuNavigation().
		 }else{
		 	//If any other key if struck, handle it.
	
			link_number = 0; //Set link number to 0, so that up/down arrows start from the top.
			arrows_active = false; //Set to false so that return key will submit the form, as no entries are highlightem.
	
			//If string is 2 characters or under ignore so as to return too many results.
			if (str.length<=2)
			{
				document.getElementById("liveSearchDiv").style.display="none";
			  	return;
			}
			
			//Load ajax URL
			doRequest(live_search_results_page_url);
		}
	}
	
	//Function: doRequest()
	//Called by showLiveSearchResult() to load request URL
	doRequest = function(url){
		
		//Do ajax request (use JQuery method, for cross browser platform)
		$.ajax({
		  url: url,
		  success: function(html){
		    loadResults(html);
		  }
		});
	}
	
	//Function: stateChanged()
	//Called by doRequest() when ready state changes, ie results page is returned.
	//The response text (the results) are placed into the live search div.
	//Returns html.
	loadResults = function(result_string)
	{
		var response = result_string.split('\n').join(''); //Remove newline.
		if(response !== "") //Check if there's been a response (Any results found).
		{
			document.getElementById("liveSearchDiv").innerHTML=result_string; //Insert response text.
			document.getElementById("liveSearchDiv").style.display="block"; //Make div viewable.
		}
	}
	
	//Function processMenuNavigation()
	//Called by showLiveSearchResult() when up, down or enter is struck.
	//Recieves a keycode (a code that represents a keyboard press) and uses it to navigate the live search results appropriately.
	processMenuNavigation = function(key_code)
	{
		switch(key_code)
		{
			case 38: //Arrow Up
			    
				link_number -= 1; //When down arrow is pressed select previous url.
	
			    //If we are are the first url...
			    if(link_number == 0)
			    {
				   	var link_number_previous = link_number + 1; //Set previous to be last in the list.
			      	document.getElementById("liveSearchTextField").value = "" ; //Empty the search text field.
			      	arrows_active = true; //Set to true to that search box cannot be submitted.
			 	}else{
			 		//Set to true to that search box cannot be submitted
					arrows_active = true;
					//Previous is higher url, further up the url list.
			 	  	var link_number_previous = link_number + 1;
		 			//Set search text field to contain highlighted value (like google suggest).
			 	  	document.getElementById("liveSearchTextField").value = document.getElementById("livesearch_hyperlink_id_"+link_number).innerHTML.replace("&nbsp;&nbsp;","").replace("&nbsp;&nbsp;","");
			 	 	//Set url to appear as though being hovered over.
			 	 	document.getElementById("livesearch_hyperlink_id_"+link_number).className="liveSearchLinkHover";
			 	 	document.getElementById("livesearch_hyperlink_id_"+link_number).style.color="#fff";
			 	}
	
				//Set url to appear as though not being hovered over.
			    document.getElementById("livesearch_hyperlink_id_"+link_number_previous).className="liveSearchLink";
			    document.getElementById("livesearch_hyperlink_id_"+link_number_previous).style.color='';
			    break;
	
		    case 40: //Arrow down
	
			    link_number ++; //When down arrow is pressed, increment url to be highlighted.
			    var link_number_previous = link_number - 1; //Url to be un-highlighted, previous highlighted url.
	
				//If there are no more urls in list, keep last url highlighted.
			    if(document.getElementById("livesearch_hyperlink_id_"+link_number) == null){
			      	link_number = link_number - 1;
			      	link_number_previous = link_number_previous + 1;
			    }
	
			    //Set arrows active to true, to precent return key submitting form.
				arrows_active = true;
			    //Set search text field to contain highlighted value (like google suggest).
			    document.getElementById("liveSearchTextField").value = document.getElementById("livesearch_hyperlink_id_"+link_number).innerHTML.replace("&nbsp;&nbsp;","").replace("&nbsp;&nbsp;","");
	
			    //Set next url to appear as if hovered.
			    document.getElementById("livesearch_hyperlink_id_"+link_number).className="liveSearchLinkHover";
			    document.getElementById("livesearch_hyperlink_id_"+link_number).style.color="#fff";
			    //Set previous url to appear as if not hovered.
			    document.getElementById("livesearch_hyperlink_id_"+link_number_previous).className="liveSearchLink";
				document.getElementById("livesearch_hyperlink_id_"+link_number_previous).style.color='';
				break;
	
		    case 13: //Return key
	
			    var url = document.getElementById("livesearch_hyperlink_id_"+link_number).href; //Get highlighted url.
			    window.location = url; //Redirect to highlighted url.
		    	break;
	
		   }
	}
	
	//Function checkLiveSearchSubmission()
	//Called to return true or false when 'find' (submit) is pressed on the live search form.
	//Checks if enter should submit the form, or should follow highlighted link.
	checkLiveSearchSubmission = function(){
	
		if(arrows_active == true){
			//If any items have been highlighted via arrow keys, form cannot be submitted via return key.
			return false;
	
		}else{
			//Else, no highlited and search box can be submitted like a normal form.
			return true;
		}
	
	}
	
	//Function: resetHighlightedLinks()
	//Called when a user hovers a live search link.
	//Resets live search dropdown box items highlighted by the use of the arrow keys.
	resetHighlightedLinks = function()
	{
	
		document.getElementById("livesearch_hyperlink_id_"+link_number).style.color='';
		link_number = 0; //Set global variable to '0', so that next time the user wants to use arrow keys it starts from the top.
		var reset_link_number = 1;
	
		//Cycles through links and set CSS class, untill 'null', meaning there are no more.
		while(document.getElementById("livesearch_hyperlink_id_"+reset_link_number) != null){
			document.getElementById("livesearch_hyperlink_id_"+reset_link_number).className="liveSearchLink";
			reset_link_number ++;
		}
	}
});