var map = null; //global map object

// base config
var attribOSM = '&copy; <a href="//openstreetmap.org">OpenStreetMap</a>-bidragydere, <a href="//creativecommons.org/licenses/by-sa/2.0/">CC-BY-SA</a>';
var OSMLayer = L.tileLayer('//{s}.tile.openstreetmap.org/{z}/{x}/{y}.png', { attribution: attribOSM } );
var Box = L.latLngBounds( [[54.5, 8.0],[57.8, 15.3]] );

// GeoJSON feature styling and grouping
function typecolor(type) {
	if (type == "center") { return ('darkgreen'); }
	else if (type == 'center-begin') { return ('green'); }
	else if (type == 'member') { return ('orange'); }
	else if (type == 'diploma') { return ('red'); }
	else if (type == 'diploma-aspiring') { return ('blue'); }
	else { return ('black'); };
};
function returnFeatureMarker(feature, latlng) {
	var hasPopup = (feature.properties.location && feature.properties.title);
	return L.circleMarker(latlng, {
		title: feature.properties.title,
		zIndexOffset: 1000*feature.properties.priority || 0,
		clickable: hasPopup,
		keyboard: hasPopup,
		color: typecolor(feature.properties.type)
	});
};
function addFeaturePopup(feature, layer) {
	if (feature.properties.location && feature.properties.title) {
		layer.bindPopup('<strong>'+feature.properties.title+'</strong><br>'+feature.properties.location);
	}
};
var center = L.geoJson([],{
	pointToLayer: returnFeatureMarker,
	onEachFeature: addFeaturePopup,
	filter: function(feature, layer) {
		return (feature.properties.type == "center");
	}
});
var center_begin = L.geoJson([],{
	pointToLayer: returnFeatureMarker,
	onEachFeature: addFeaturePopup,
	filter: function(feature, layer) {
		return (feature.properties.type == "center-begin");
	}
});
var member = L.geoJson([],{
	pointToLayer: returnFeatureMarker,
	onEachFeature: addFeaturePopup,
	filter: function(feature, layer) {
		return (feature.properties.type == "member");
	}
});
var diploma = L.geoJson([],{
	pointToLayer: returnFeatureMarker,
	onEachFeature: addFeaturePopup,
	filter: function(feature, layer) {
		return (feature.properties.type == "diploma");
	}
});
var diploma_aspiring = L.geoJson([],{
	pointToLayer: returnFeatureMarker,
	onEachFeature: addFeaturePopup,
	filter: function(feature, layer) {
		return (feature.properties.type == "diploma-aspiring");
	}
});
var unknown = L.geoJson([],{
	pointToLayer: returnFeatureMarker,
	onEachFeature: addFeaturePopup,
	filter: function(feature, layer) {
		return (feature.properties.type == null);
	}
});
var overlayMaps = {
	"LAND Centre": center,
	"LAND startere": center_begin,
	"Medlemmer": member,
	"Diplomholdere": diploma,
	"Diplomaspiranter": diploma_aspiring,
	"Øvrige": unknown
};
function overlayCallback(data) {
	center.addData(data).addTo(map);
	center_begin.addData(data).addTo(map);
	member.addData(data).addTo(map);
	diploma.addData(data).addTo(map);
	diploma_aspiring.addData(data).addTo(map);
	unknown.addData(data);
};

// position popup
function round(n,d) {
	return Math.round(Math.pow(10,d)*n)/Math.pow(10,d)
};
function lngLatString(latLng) {
	return round(latLng.lng,5) + ", " + round(latLng.lat,5)
};
var popup = L.popup();
function positionPopup(e) {
	popup
		.setLatLng(e.latlng)
		.setContent("Position (long, lat):<br>" + lngLatString(e.latlng))
		.openOn(map);
}

// http://mathiasbynens.be/notes/xhr-responsetype-json
var getJSON = function(url, successHandler, errorHandler) {
	var xhr = typeof XMLHttpRequest != 'undefined'
		? new XMLHttpRequest()
		: new ActiveXObject('Microsoft.XMLHTTP');
	var supportsJSON = (function() {
		if (typeof XMLHttpRequest == 'undefined') {
			return false;
		}
		xhr.open('get', '/', true);
		try {
			// some browsers throw when setting `responseType` to an unsupported value
			xhr.responseType = 'json';
		} catch(error) {
			return false;
		}
		return 'response' in xhr && xhr.responseType == 'json';
	}());
	xhr.open('get', url, true);
	if (supportsJSON) {
		xhr.responseType = 'json';
	}
	xhr.onreadystatechange = function() {
		var status;
		var data;
		// http://xhr.spec.whatwg.org/#dom-xmlhttprequest-readystate
		if (xhr.readyState == 4) { // `DONE`
			status = xhr.status;
			if (status == 200) {
				successHandler && successHandler(
					supportsJSON
						? xhr.response
						: JSON.parse(xhr.responseText)
				);
			} else {
				errorHandler && errorHandler(status);
			}
		}
	};
	xhr.send();
};

// create base map when DOM is ready, and then add features and controls
function initMap() {
	map = L.map('content', { layers: [OSMLayer] });
	map.attributionControl.setPrefix(false);
	map.fitBounds(Box);

	// micro-polyfill - http://mathiasbynens.be/notes/document-head
	var head = document.head || document.getElementsByTagName('head')[0];

	// load all rel=points links in html header as GeoJSON
	var links = head.getElementsByTagName("link")
	for (i=0;i< links.length;i++) {
		if (links[i].rel == "points") {
			getJSON(links[i].href, function (data) {
				overlayCallback(data);
			});
		}
	};

	L.control.layers([],overlayMaps).addTo(map);
	L.control.scale({ imperial: false }).addTo(map);

	map.on('contextmenu', positionPopup);
};
yepnope([
	{
		test : window.JSON,
//		https://code.google.com/p/json-sans-eval/
//		(json2: less secure; json3: larger - unneeded features)
		nope : 'json-minified.js',
	}, {
		test: document.addEventListener,
		nope: 'EventListener.js',
		complete: function() {
			document.addEventListener("DOMContentLoaded", initMap, false)
		}
	}
]);