// bsearch-based array element check
function contains(array, elem) {
	let min = 0, max = array.length;

	while (min < max) {
		const i = min + Math.floor((max-min)/2);
		const cur = array[i];

		if (cur === elem)
			return true;
		else if (cur < elem)
			min = i + 1;
		else
			max = i;
	}

	return false;
}

const MinedMapLayer = L.TileLayer.extend({
	initialize: function (mipmaps, layer) {
		L.TileLayer.prototype.initialize.call(this, '', {
			detectRetina: true,
			tileSize: 512,
			zoomReverse: true,
			minZoom: -(mipmaps.length-1),
			maxZoom: 0,
			attribution: 'Generated by <a href="https://github.com/neocturne/MinedMap">MinedMap</a>',
		});

		this.options.maxNativeZoom = this.options.maxZoom;
		this.options.maxZoom = undefined;

		this.mipmaps = mipmaps;
		this.layer = layer;
	},

	createTile: function (coords, done) {
		const tile = L.TileLayer.prototype.createTile.call(this, coords, done);

		if (coords.z - this.options.zoomOffset >= 0)
			L.DomUtil.addClass(tile, 'overzoomed');

		return tile;
	},

	getTileUrl: function (coords) {
		let z = -coords.z + this.options.zoomOffset;
		if (z < 0)
			z = 0;

		const mipmap = this.mipmaps[z];

		if (coords.x < mipmap.bounds.minX || coords.x > mipmap.bounds.maxX ||
		    coords.y < mipmap.bounds.minZ || coords.y > mipmap.bounds.maxZ ||
		    !contains(mipmap.regions[coords.y] || [], coords.x))
			return L.Util.emptyImageUrl;


		return 'data/'+this.layer+'/'+z+'/r.'+coords.x+'.'+coords.y+'.png';
	},
});


const CoordControl = L.Control.extend({
	initialize: function () {
		this.options.position = 'bottomleft';
	},

	onAdd: function (map) {
		this._container = L.DomUtil.create('div', 'leaflet-control-attribution');

		return this._container;
	},

	update: function (x, z) {
		if (!this._map) { return; }

		this._container.innerHTML = 'X: ' + x + '&nbsp;&nbsp;&nbsp;Z: ' + z;
	}
});


const parseHash = function () {
	const args = {};

	if (window.location.hash) {
		const parts = window.location.hash.substring(1).split('&');

		for (const part of parts) {
			const key_value = part.split('=');
			const key = key_value[0], value = key_value.slice(1).join('=');

			args[key] = value;
		}
	}

	return args;
}


window.createMap = function () {
	const xhr = new XMLHttpRequest();
	xhr.onload = function () {
		const res = JSON.parse(this.responseText),
		    mipmaps = res.mipmaps,
		    spawn = res.spawn;

		let x, z, zoom, light;

		const updateParams = function () {
			const args = parseHash();

			zoom = parseInt(args['zoom']);
			x = parseFloat(args['x']);
			z = parseFloat(args['z']);
			light = parseInt(args['light']);

			if (isNaN(zoom))
				zoom = 0;
			if (isNaN(x))
				x = spawn.x;
			if (isNaN(z))
				z = spawn.z;
		};

		updateParams();

		const map = L.map('map', {
			center: [-z, x],
			zoom: zoom,
			minZoom: -(mipmaps.length-1),
			maxZoom: 3,
			crs: L.CRS.Simple,
			maxBounds: [
				[-512*(mipmaps[0].bounds.maxZ+1), 512*mipmaps[0].bounds.minX],
				[-512*mipmaps[0].bounds.minZ, 512*(mipmaps[0].bounds.maxX+1)],
			],
		});

		const mapLayer = new MinedMapLayer(mipmaps, 'map');
		const lightLayer = new MinedMapLayer(mipmaps, 'light');

		mapLayer.addTo(map);

		if (light)
			map.addLayer(lightLayer);

		const overlayMaps = {
			"Illumination": lightLayer,
		};

		L.control.layers({}, overlayMaps).addTo(map);

		const coordControl = new CoordControl();
		coordControl.addTo(map);

		map.on('mousemove', function(e) {
			coordControl.update(Math.round(e.latlng.lng), Math.round(-e.latlng.lat));
		});

		const makeHash = function () {
			let ret = '#x='+x+'&z='+z;

			if (zoom != 0)
				ret += '&zoom='+zoom;

			if (map.hasLayer(lightLayer))
				ret += '&light=1';

			return ret;
		};

		const updateHash = function () {
			window.location.hash = makeHash();
		};

		const refreshHash = function () {
			zoom = map.getZoom();
			center = map.getCenter();
			x = Math.round(center.lng);
			z = Math.round(-center.lat);

			updateHash();
		}

		updateHash();

		map.on('moveend', refreshHash);
		map.on('zoomend', refreshHash);
		map.on('layeradd', refreshHash);
		map.on('layerremove', refreshHash);

		window.onhashchange = function () {
			if (window.location.hash === makeHash())
				return;

			updateParams();

			map.setView([-z, x], zoom);

			if (light)
				map.addLayer(lightLayer);
			else
				map.removeLayer(lightLayer);

			updateHash();
		};

	};

	xhr.open('GET', 'data/info.json', true);
	xhr.send();
}