/** 
 * Functions providing overlay functionality for map server maps
 */
var minMapLat = -90;
var maxMapLat = 90;
var minMapLong = -180;
var maxMapLong = 180;
var boxWidth = 40;
var boxHeight = 20;
var boxWidthInDegrees=20;
var boxHeightInDegrees=10;
var snapHalf=true;        
var capture=false;
var minX;
var minY;
var nudge=5;
var zoom=1;
var isIE = false;

var northCoordinate=0;
var westCoordinate=0;
var southCoordinate=0;
var eastCoordinate=0;

var overviewMapName="overviewMap";
var mapSelectorName="mapSelector";


function mouseMove(ev){
	if (capture) {
		ev = ev || window.event;
		var mousePos = mouseCoords(ev);
		var selector = document.getElementById(mapSelectorName);
		moveSelector(selector, mousePos.x, mousePos.y);			
		setCoordinates(overviewMapName);
	}
}


/**
 * Supports 5 zooming levels.
 * 
 * level 1 - global (180x360)
 * level 2- quadrant (90x180)
 * level 3 -  is an area of 40x80
 * level 4 -  is an area of 20x40
 * level 5 -  is an area of 10x20
 * 
 * levels 1-4 when selected all zoom into a level 5 view, ie. 10x20
 */
function selectBox() {
	
	//alert('minX:'+minX+', minY:'+minY);
	//map size is 360px by 720px
	
	// zoom of 1 is the global view - 180x360
	if (zoom==1) {
		// 2 pixels represents 1 degree		
		var lon = - 180 + Math.floor(minX/2) ;
		var lat = 90  - Math.floor(minY/2) - 10;
		zoom2level5(lon, lat);
	}

	// zoom of 2 is a quadrant of the global view - 90x180
	if (zoom==2) {
		// 4 pixels represents 1 degree
		var lon = minMapLong + Math.floor(minX/4);
		var lat = maxMapLat - Math.floor(minY/4) - 10;
		zoom2level5(lon, lat);
	}
	
	// zoom of 3 is an area of 40x80
	if (zoom==3) {
		// 9 pixels represents 1 degree
		var lon = minMapLong + Math.floor(minX/9);
		var lat = maxMapLat - Math.floor(minY/9) - 10;
		zoom2level5(lon, lat);
	}	
	
	// zoom of 4 is an area of  20x40
	if (zoom==4) {
		// 18 pixels represents 1 degree
		var lon = minMapLong + Math.floor(minX/18);
		var lat = maxMapLat - Math.floor(minY/18) - 10;
		zoom2level5(lon, lat);
	}	

	// zoom of 5 is an area of 10x20
	if (zoom==5) {
		// 36 pixels represents 1 degree
		var lat = maxMapLat - (minY/36) - 1;
		var lon = minMapLong + (minX/36);
		refocus(zoom+1, lon, lat, lon+2, lat+1);
	}
}

/**
 * Zoom in to level 5 - 10x20 using the specified min lat/long
 */
function zoom2level5(minLongitude, minLatitude){
	refocus(5, minLongitude, minLatitude, minLongitude+20, minLatitude+10);
}

/**
 * Redirects to the specified zoom level.
 */
function refocus(zoom, minLongitude, minLatitude,  maxLongitude, maxLatitude){
//		alert("refocus: "+zoom+', '+minLongitude+', '+minLatitude+', '+maxLongitude+', '+maxLatitude);
		// %2B is a plus (+)
		var extent = minLongitude + "%2B" + minLatitude + "%2B" + maxLongitude + "%2B" +maxLatitude;
		document.location=document.location.pathname 
			+ "?extent=" + extent 
			+ "&zoom=" + zoom			
			+ "&minMapLong=" + minLongitude			
			+ "&minMapLat=" + minLatitude
			+ "&maxMapLong=" + maxLongitude
			+ "&maxMapLat=" + maxLatitude
			+ "&"+extraParams;	
}

/**
 * Redirects to occurrence search.
 */
function occurrenceSearch() {
	// 36 pixels represents 0.1 degrees
	var latMin = maxMapLat - (minY/360) - 0.1;
	latMin = (Math.round(latMin*10) )/10;	
	var latMax = latMin + 0.1;
	latMax = (Math.round(latMax*10) )/10;	
	var longMax = minMapLong + (minX/360) + 0.1;
	longMax = (Math.round(longMax*10) )/10;
	var longMin = longMax - 0.1;
	longMin = (Math.round(longMin*10) )/10;
	//alert("Searching for:\n 1) Name = " + name + "\n 2) " + latMin + " <= Latitude <= " + latMax + "\n 3) " + longMin + " <= Longitude <= " + longMax);
	redirectToCell(longMin, latMin, longMax, latMax);
}

/**
 * Zooms out to the level above.
 */
function zoomOut() {
	
	if(zoom ==2){
		adjustViewArea(1, -180, -90, 360, 180);
	}
	if(zoom==3){
		//go to zoom 2
		adjustViewArea(2, -50, -25, 180, 90);
	}
	if(zoom==4){
		//go to zoom 3
		adjustViewArea(3, -20, -10, 80, 40);
	}
	if(zoom==5){
		//go to zoom 4
		adjustViewArea(4, -10, -5, 40, 20);
	}
	if(zoom==6){
		//go to zoom 5
		adjustViewArea(5, -9, -4, 20, 10);
	}
}

/**
 * Adjusts the view area by the specified amounts.
 */
function adjustViewArea(zoomLevel, longAdjustment, latAdjustment, longRange, latRange){
	var minLongitude = minMapLong +	longAdjustment;
	var minLatitude = minMapLat +latAdjustment;
	//sanity checks
	if(minLongitude<-180)
		minLongitude=-180
	if(minLatitude<-90)
		minLatitude=-90;	
		
	if(minLongitude+longRange>180){
		minLongitude=180-longRange;
	}	
	if(minLatitude+latRange>90){
		minLatitude=90-latRange;
	}
	refocus(zoomLevel, minLongitude, minLatitude, minLongitude+longRange, minLatitude+latRange);
}

function nudgeUp() {
	if (maxMapLat<90) {
		minMapLat = minMapLat+nudge;
		maxMapLat = maxMapLat+nudge;
		reload();
	}
}

function nudgeDown() {
	if (minMapLat>-90) {
		minMapLat = minMapLat-nudge;
		maxMapLat = maxMapLat-nudge;
		reload();
	}
}

function nudgeLeft() {
	if (minMapLong>-180) {
		minMapLong = minMapLong-nudge;
		maxMapLong = maxMapLong-nudge;
		reload();
	}
}

function nudgeRight() {
	if (maxMapLong<180) {
		minMapLong = minMapLong+nudge;
		maxMapLong = maxMapLong+nudge;
		reload();
	}
}

function reload() {
	document.location=document.location.pathname + "?extent=" + buildExtent() 
		+ "&minMapLat=" + minMapLat
		+ "&maxMapLat=" + maxMapLat
		+ "&minMapLong=" + minMapLong
		+ "&maxMapLong=" + maxMapLong
		+ "&zoom=" + zoom
		+ "&"+extraParams;
}

function buildExtent() {
	return minMapLong + "%2B" + minMapLat + "%2B" + maxMapLong + "%2B" + maxMapLat;
}

function moveSelector(selector, x, y) {
	
	var mapImg = document.getElementById(overviewMapName);
	var mapPos = findPos(mapImg);
	var mapLeft = mapPos.x;
	var mapTop = mapPos.y;
	if(isIE)
		y = y + document.documentElement.scrollTop;
	if (snapHalf) {
		x=Math.floor(x);
		y=Math.floor(y);		
	} else {
		x=((boxHeight)*Math.floor((x-mapLeft)/(boxHeight))) + mapLeft;
		y=((boxHeight)*Math.floor((y-mapTop)/(boxHeight))) + mapTop;
	}
	
	// make sure it is within limits
	if (x>(mapLeft+(mapImg.offsetWidth - boxWidth))) {
		x=(mapLeft+(mapImg.offsetWidth-boxWidth))
	} else if (x<(mapLeft)) {
		x=mapLeft;
	}
	
	if (y>(mapTop+(mapImg.offsetHeight-boxHeight))) {
		y=(mapTop+(mapImg.offsetHeight-boxHeight));
	} else if (y<mapTop) {
		y=(mapTop);
	} 
	selector.style.left = x+"px";
	selector.style.top = y+"px";
	minX = x-mapLeft;
	minY = y-mapTop;
	//alert("moved " + document.getElementById("mapSelector") + " to " + x + ":" + y + " \nset minX: " + minX + ", minY: " + minY);
}

/**
 * Sets coordinate values in the UI for positioning.
 */
function setCoordinates(mapImgName){
	var latRange = maxMapLat - minMapLat;
	var longRange = maxMapLong - minMapLong; 
	var mapHeight = document.getElementById(mapImgName).height;
	var mapWidth= document.getElementById(mapImgName).width;
		
	if(zoom==6){
		northCoordinate = maxMapLat - Math.round (( (minY *10)  /  (mapHeight/latRange) )) / 10;
		westCoordinate   = minMapLong + Math.round (( (minX*10)  /  (mapWidth/longRange) )) / 10;
		//round these values
		northCoordinate = (Math.round(northCoordinate*10))/10;
		westCoordinate = (Math.round(westCoordinate*10))/10;
		southCoordinate = (Math.round((northCoordinate-boxHeightInDegrees)*10))/10; 
		eastCoordinate = (Math.round((westCoordinate+boxWidthInDegrees)*10))/10;
	} else {
		northCoordinate = Math.floor(maxMapLat-(minY/(mapHeight/latRange)));
		westCoordinate = Math.floor(minMapLong+(minX/(mapWidth/longRange)));
		southCoordinate = northCoordinate-boxHeightInDegrees;
		eastCoordinate = westCoordinate+boxWidthInDegrees;		
	}
	
	//sanity checks
	northCoordinate = northCoordinate>90 ? 90 :northCoordinate;
	southCoordinate = southCoordinate<-90 ? -90 :southCoordinate;
	westCoordinate = westCoordinate<-180 ? -180 :westCoordinate;
	eastCoordinate = eastCoordinate>180 ? 180 :eastCoordinate;
	
	document.getElementById("northCoordinate").innerHTML=northCoordinate	
	document.getElementById("southCoordinate").innerHTML=southCoordinate;
	document.getElementById("westCoordinate").innerHTML=westCoordinate;
	document.getElementById("eastCoordinate").innerHTML=eastCoordinate;		
}

function setBoundingBoxMarkerOnMap(mapImgName, imgContainerDiv, bbMarkerName, minLong, minLat, maxLong, maxLat){
	var bbMarker = document.getElementById(bbMarkerName);
	var mapImg = document.getElementById(mapImgName);

//	alert(mapImg.offsetWidth+":"+mapImg.offsetHeight);

	var bbMarkerWidth = Math.round((maxLong - minLong)*(mapImg.offsetWidth / 360));
	var bbMarkerHeight = Math.round((maxLat - minLat)*(mapImg.offsetHeight / 180));
	

	//set div dimensions

	var smallMapLeft = findPos(mapImg).x;
	var smallMapTop = findPos(mapImg).y;
	
	var posLeft = smallMapLeft + Math.round((minLong + 180)*(mapImg.offsetWidth / 360));
	var posTop = smallMapTop+Math.round((90 - maxLat)*(mapImg.offsetHeight / 180));
	var posRight = posLeft+bbMarkerWidth;
	var posBottom = posTop+bbMarkerHeight;
	
	var smallMapRight = smallMapLeft + mapImg.offsetWidth;	
	var smallMapBottom = smallMapTop + mapImg.offsetHeight;	
	
	var bbMarkerLeft = 0;
	var bbMarkerTop = 0;
		
	if(posRight > smallMapRight){
		bbMarkerLeft = smallMapRight - bbMarkerWidth;
	} else {
		bbMarkerLeft = posLeft;
	}	
	//sanity check
	if(posLeft < smallMapLeft){
		bbMarkerLeft = smallMapLeft;
	}	
	
	if(posBottom > smallMapBottom){
		bbMarkerTop = smallMapBottom - bbMarkerHeight;		
	} else {
		bbMarkerTop = posTop;
	}	
	//sanity check
	if(posTop < smallMapTop){
		bbMarkerTop = smallMapTop;
	}
	
	//set the position relative to the container div
	var containerDiv = document.getElementById(imgContainerDiv);

	//alert(containerDiv.id);

	//alert(bbMarkerWidth+":"+bbMarkerHeight);
		bbMarker.style.display = "block";	
		bbMarker.style.position = "relative";
//		bbMarker.style.width = "800px";
//	bbMarker.style.height = "200px";
	
		
	bbMarker.style.width = bbMarkerWidth +"px";
	bbMarker.style.height = bbMarkerHeight +"px";
	
	//alert(containerDiv.offsetLeft+":"+containerDiv.offsetTop);
	//alert(bbMarkerLeft+":"+bbMarkerTop);
//	bbMarker.style.position = "relative";
	bbMarker.style.left = (bbMarkerLeft - containerDiv.offsetLeft)+"px";
	bbMarker.style.top = (bbMarkerTop - containerDiv.offsetTop - mapImg.offsetHeight)+"px";
	bbMarker.style.visibility = "visible";

}

function mouseCoords(ev){
	if(ev.pageX || ev.pageY){
		return {x:ev.pageX, y:ev.pageY};
	}
	return {
		x:ev.clientX + document.body.scrollLeft - document.body.clientLeft,
		y:ev.clientY + document.body.scrollTop  - document.body.clientTop
	};
}

function findPos(obj) {
	var curleft = curtop = 0;
	if (obj.offsetParent) {
		curleft = obj.offsetLeft
		curtop = obj.offsetTop
		while (obj = obj.offsetParent) {
			curleft += obj.offsetLeft
			curtop += obj.offsetTop
		}
	}
	return {
		x:curleft,
		y:curtop
	};
}