////////////////////////////////////////////////////////////////////////////////////
//GET IMPORTANT VARS
////////////////////////////////////////////////////////////////////////////////////

var addon_CDdrilldown_base = 'http://www.propshopspain.com/property';

////////////////////////////////////////////////////////////////////////////////////
//THOUSAND SEPARATION
//	Function to separate thousands
////////////////////////////////////////////////////////////////////////////////////

function addon_CDdrilldown_thousands( val, separator)
{
	var regExpRule = new RegExp('(-?[0-9]+)([0-9]{3})');
	sVal = val + '';
	
	if(separator === undefined)
	{
		separator = ",";
	}
	while(regExpRule.test(sVal))
	{
		sVal = sVal.replace(regExpRule, '$1'+separator+'$2');
	}
	return sVal;
}

////////////////////////////////////////////////////////////////////////////////////
//AJAX CODE, LOAD XMLHTTPREQUEST
//	Should work for various browsers
////////////////////////////////////////////////////////////////////////////////////

function addon_CDdrilldown_getHTTPObject() {
    if (typeof XMLHttpRequest != 'undefined') {
        return new XMLHttpRequest();
    }
    try {
        return new ActiveXObject("Msxml2.XMLHTTP");
    } catch (e) {
        try {
            return new ActiveXObject("Microsoft.XMLHTTP");
        } catch (e) {}
    }
    return false;
}


////////////////////////////////////////////////////////////////////////////////////
//VARIABLES
////////////////////////////////////////////////////////////////////////////////////
var http = addon_CDdrilldown_getHTTPObject();
var elementList = new Array();
var selectList = new Array();
var container;
var addon_CDdrilldown_errors = '';

////////////////////////////////////////////////////////////////////////////////////
//INITIALISE
//	Get a list of all elements
//	Format them
////////////////////////////////////////////////////////////////////////////////////

function addon_CDdrilldown_init()
{
	/** CREATE AN INDEX OF SELECT OBJECTS **/
	container = document.getElementById('addon_CDdrilldown');
	selectList = container.getElementsByTagName('select');
	nSelects = selectList.length;
	for( x in selectList )
	{
		if(typeof(selectList[x])!== 'object' ){continue;}	// Don't parse any non-objects;

		if(selectList[x].id == '')
		{
			selectList[x].id = selectList[x].name;
		} else {
			selectList[x].name = selectList[x].id;
		}

		selectList[x].id = selectList[x].name;

		elementList.push(selectList[x].id);
		selectList[x].onchange = addon_CDdrilldown_lock;
		
		/** CREATE A SPAN TO REPLACE SELECTS WHEN LOCKED **/
		var newSpan = document.createElement('span');
		newSpan.id = selectList[x].id + "-change";
		newSpan.onclick = addon_CDdrilldown_unlock;
		newSpan.className = 'addon_CDdrilldown_changeSpan';
		newSpan.style.display = 'none';
		
		selectList[x].parentNode.insertBefore(newSpan, selectList[x]);
		
		/** MAKE A LOADING IMAGE TOO **/
		newImage = new Image();
		newImage.src = addon_CDdrilldown_base+"/addons/CDdrilldown/images/load.gif";
		newImage.id = selectList[x].id + "-loading";
		newImage.className = 'addon_CDdrilldown_loadImg';
		newImage.style.visibility = 'hidden';
		selectList[x].parentNode.insertBefore(newImage, selectList[x].nextSibling);
	}
	
	/** FORMAT THE SELECT OBJECTS **/
	/** Probably best to do this in the loop above, so we're adding
	  * to the list and also updating the selects as we go.
	  **/
	
	/** LOAD THE FIRST UPDATE **/
	addon_CDdrilldown_update();
}


////////////////////////////////////////////////////////////////////////////////////
//REQUEST AN UPDATE
//	Perform the update request and update the fields
//	This is done by parsing the index and finding which
//	 elements are invisible (sending) and which are visible
//	 (used).
//	The sending ones have their values added to the
//	 'arguments' string.
//	The result is a GET transaction to query.php which
//	 is registered against a response handler function.
////////////////////////////////////////////////////////////////////////////////////

function addon_CDdrilldown_update()
{
	var send = new Array();
	var used = new Array();
	var arguments = '';

	
	/** DISABLE WHILE LOADING **/
	for(x in selectList)
	{
		if(typeof(selectList[x]) !== 'object'){ continue; }
		selectList[x].disabled = 'disabled';
	}
	
	/** PREPARE URL **/
	for (i=0; i < selectList.length; i++)
	{
		switch(selectList[i].style.display)
		{
		case 'none':
			if(selectList[i].name.indexOf('[]') > -1)				// Bug fix
			{									// ~~~~~~~
				var parsed_ptr  = selectList[i].name.indexOf('[]');		// This resolves an issue with
				var parsed_name = selectList[i].name.substr(0, parsed_ptr);	// PHP not reading url vars that
			} else {								// contain [] in their names, such
				var parsed_name = selectList[i].name;				// as 'pclass[]'.
			}									///////////////////////
			send.push(parsed_name);
			arguments += '&' + parsed_name + '=' + encodeURI(selectList[i].value);
			break;
		default:
			used.push(selectList[i].name);
			
			/** Also set its loading image to visible **/
			var loadImg = document.getElementById(selectList[i].name + '-loading');
			loadImg.style.visibility = 'visible';
		}
	}
	
	random    = new Date().getTime();
	arguments = '?used=' + used.join(',') + '&send=' + send.join(',') + arguments + '&rand=' + random;

	
	/** SEND REQUEST **/ // First using PHP address, then if failed use JS address
	try
	{
		http.open("GET", addon_CDdrilldown_base + "/addons/CDdrilldown/query.php" + arguments, true);
		http.onreadystatechange = addon_CDdrilldown_dataloader;
		http.send(null);
	} catch ( e ) {
		http.open("GET", window.location.href + "/addons/CDdrilldown/query.php" + arguments, true);
		http.onreadystatechange = addon_CDdrilldown_dataloader;
		http.send(null);
	}
}

////////////////////////////////////////////////////////////////////////////////////
//HANDLE RESPONSE
//	Summary: Process the response and load it into the relevant fields.
//	Read each line one by one.
//	Where 'FIELD' is in the first few characters, select that field name.
//	Subsequently enter the following data lines as options
////////////////////////////////////////////////////////////////////////////////////

function addon_CDdrilldown_dataloader()
{
	if( http.readyState < 4 )
	{
		/** SHOW 'LOADING' SEQUENCE **/
	}
	if( http.readyState == 4 )
	{
		/** READ THE DATA **/
		var fieldName;				// The current field name
		var fieldData;				// The field's data
		var response = http.responseText;
		var lines = new Array();
		lines = response.split('<br />');
		
		for(i=0; i < lines.length; i++)
		{
			/** READ EACH LINE **/
			
			/** END IT, FOR WEB HOSTS WHO APPEND THINGS TO PAGE OUTPUT **/
			if(lines[i] == "~QUERYEND~")
			{
				break;
			}
			
			if(lines[i].substr(0,7) == '~FIELD:')
			{
				/** IS A NEW FIELD **/
				fieldName = lines[i].substr(8, lines[i].length-8);
				
				/** ( has to do some tomfoolery to get the current select object ) **/
				var thisSelect;
				for(x in selectList)
				{
					selectList[x].name == fieldName	?	thisSelect = selectList[x] : false ;
				}
				
				/** Empty it **/
				while( thisSelect.hasChildNodes() )
				{
					thisSelect.removeChild( thisSelect.childNodes[0] );
				}
				
				var objOption = new Option('All', '');
				thisSelect.options[0] = objOption;
				thisSelect.disabled = '';
				//thisSelect.backgroundImage = '';
			}
			else if(lines[i].substr(0,7) == '~ERROR~')
			{
				/** IS AN ERROR **/
				addon_CDdrilldown_errors += "\n" + lines[i].substr(8,lines[i].length);
				/** should display error in a box if possible **/
				alert("Addon CD Drilldown Error:\n"+addon_CDdrilldown_errors);
				return 'error';
			}
			else if(lines[i] !== '')
			{
				/** IS DATA **/
				var thisSelect;
				for(x in selectList)
				{
					selectList[x].name == fieldName	?	thisSelect = selectList[x] : false ;
				}
				optionText  = lines[i];						// Option text, e.g. 'Detatched (5)'
				optionValue = lines[i].substr(0, lines[i].lastIndexOf(' '));	//  Above, less '_(5)';
				
				/** EXCEPTIONS FOR MIN/MAX **/
				switch( fieldName.substr(fieldName.length-4, fieldName.length) )
				{
					case '-max':
						optionText  = 'To ' + addon_CDdrilldown_thousands(lines[i]);
						optionValue = lines[i];
						break;
					case '-min':
						optionText  = 'From ' + addon_CDdrilldown_thousands(lines[i]);
						optionValue = lines[i];
						break;
				}
				
				/** EXCEPTIONS FOR PCLASS **/
				if( fieldName == 'pclass[]' )
				{
					divider_colon 	= lines[i].indexOf(':');
					strlength 	= lines[i].length;
					pclass_id 	= lines[i].substr(0, divider_colon);
					pclass_text	= lines[i].substr(divider_colon+1, strlength);
					
					optionText	= pclass_text;
					optionValue	= pclass_id;
				}
				
				/** EXCEPTIONS FOR BLANK FIELDS **/ // Eg: Where 'city' returns ' (4)' because 4 have a blank reference.
				if(lines[i].substr(0, lines[i].lastIndexOf(' ')) == ''
				   && lines[i].substr(lines[i].length-1, lines[i].length) == ')')	// This second line avoids conflicts with price lines.
				{
						continue;	// They won't be displayed at all.
				}
				
				
				var objOption = new Option(optionText, optionValue);
				var nOptions  = thisSelect.options.length;
				thisSelect.options[nOptions] = objOption;
			}
		}
		/** MAKE LOADING IMAGES DISAPPEAR **/
		var loadImgs = container.getElementsByTagName('img');
		for(x in loadImgs)
		{
			if(typeof(loadImgs[x]) !== 'object'){ continue; }
			var id = loadImgs[x].id;
			if( id.substr( id.length - 8, id.length) == '-loading' )
			{
				loadImgs[x].style.visibility = 'hidden';
			}
		}

		/** ENABLE ONCE LOADED **/
		for(x in selectList)
		{
			if(typeof(selectList[x]) !== 'object'){ continue; }
			selectList[x].disabled = '';
		}

	
	} // <-- End readstate==4 (received)
}

////////////////////////////////////////////////////////////////////////////////////
//LOCK THE FIELD
//	Summary: When changed, a field will be 'locked' from being edited again.
////////////////////////////////////////////////////////////////////////////////////

function addon_CDdrilldown_lock( evt )
{
	/** FIND THE SELECT THAT HAS CHANGED **/
	var thisSelect;
	if(window.event === undefined)
	{
		/** it's standards-compliant **/
		thisSelect = evt.target;
	} else {
		/** it's IE **/
		thisSelect = window.event.srcElement;
	}
	
	/** LOCK IT **/
	var fieldName  = thisSelect.name;
	var fieldValue = thisSelect.options[thisSelect.selectedIndex].text;
	var fieldSpan;
	var spans = container.getElementsByTagName('span');
	for ( x in spans )
	{
		if(typeof(spans[x]) !== 'object'){continue;}
		var spanName = spans[x].id;
		if(spanName.substr(spanName.length-7, spanName.length) == '-change'
		   && spanName.substr(0, spanName.length-7) == fieldName)
		{
			fieldSpan = spans[x];
			break;
		}
	}
	if(    fieldName.substr(fieldName.length-4, fieldName.length) !== '-max'
	    && fieldName.substr(fieldName.length-4, fieldName.length) !== '-min'
	    && fieldValue !== 'All' )
	{
		fieldValue = fieldValue.substr(0, fieldValue.lastIndexOf(' '));
	}
	
	thisSelect.style.display = 'none';
	fieldSpan.style.display  = 'inline-block';
	fieldSpan.innerHTML 	 = fieldValue;
	
	addon_CDdrilldown_update();
}

////////////////////////////////////////////////////////////////////////////////////
//UNLOCK THE FIELD
//	Summary: When clicked, the field will 'unlock' again.
////////////////////////////////////////////////////////////////////////////////////

function addon_CDdrilldown_unlock( evt )
{
	/** FIND THE SELECT TO UNLOCK **/
	var thisSpan;
	var thisSelect;
	if(window.event === undefined)
	{
		/** it's standards-compliant **/
		thisSpan = evt.target;
	} else {
		/** it's IE **/
		thisSpan = window.event.srcElement;
	}
	
	/** Should now loop through all selects and find the one that matches the span's id **/
	for (x in selectList)
	{
		if(typeof(selectList[x]) !== 'object') { continue; }
		
		var field = thisSpan.id.substr(0, thisSpan.id.length-7);
		if(selectList[x].name == field)
		{
			thisSelect = selectList[x];
			break;
		}
	}
	
	/** UNLOCK IT **/
	thisSpan.style.display = 'none';
	thisSelect.style.display = 'inline-block';
	
	addon_CDdrilldown_update();
}