window.onload = function() {
	if (navigator.geolocation) {
		navigator.geolocation.getCurrentPosition(fetchTown);
	}
}

function fetchTown(g) {

	var xhr = new XMLHttpRequest();
	xhr.open('GET', 'js/orter.txt', false);
	xhr.send(null);
	var contents = xhr.responseText.split("\n");
	var closest = {
		'name':'',
		'hypo':100,
		'srclat':g.coords.latitude,
		'srclong':g.coords.longitude,
	};
	
	for (var i = 0; i < contents.length; i++) {

		contents[i]	= contents[i].split(",");
		var name	= contents[i][0];
		var latitude	= parseFloat(contents[i][1]);
		var longitude	= parseFloat(contents[i][2]);

		var lati	= (latitude <= closest.srclat) ? closest.srclat - latitude : latitude - closest.srclat;
		var longi	= (longitude <= closest.srclong) ? closest.srclong - longitude : longitude - closest.srclong;
		var hypo	= Math.sqrt(Math.pow(lati, 2) + Math.pow(longi, 2));
		
		if (hypo < closest.hypo) {
			closest.name = name;
			closest.hypo = hypo;
		}
		
		contents[i][3] = hypo;

	}

	var location = document.getElementById('location');
	location.innerHTML = closest.name;
	
	contents.sort(function(a, b) { return a[3] - b[3] });
	
	location.innerHTML += '<p>N&auml;rliggande orter:</p><p>';
	for (var i = 1; i < 10; i++) {
		location.innerHTML += contents[i][0] + '<br>';
	}
	location.innerHTML += '</p>';
	
	return true;
	
}