/* functions for displaying event icons on a map
 * Just include this js file in your html code and add an "event_map" div:
 *	<script type="text/javascript" src="event_map.js"></script>
 *	<div id="event_map"></div>
 *
 * Additionally you may want to override some variables, eg:
 *	<script type="text/javascript">
 *		var event_map_center_longitude = <?php echo $_GET['longitude'] + 0 ?>;
 *		var event_map_center_latitude = <?php echo $_GET['latitude'] + 0 ?>;
 *		var event_map_zoom = <?php echo $_GET['zoom'] + 0 ?>;
 *	</script>
 * BEWARE: above overrides MUST be placed before including the "event_map.js" file.
 *
 * Copyright:	2010 by Lars Kruse <devel@sumpfralle.de>
 * License:	GNU GPL v3 or higher (http://www.gnu.org/licenses/gpl-3.0.txt)
 */


var event_map_zoom_default_for_events = 13;
var event_map_zoom_default_for_marker = 15;
var event_map_zoom_default_for_edit = 12;

// names of fields to be manipulated in "edit" mode
var event_map_fieldname_lat = "edit-field-lat-0-value";
var event_map_fieldname_lon = "edit-field-long-0-value";

// some default startup definitions (can be overwritten in the html file)
// define the base url of local resources - the trailing slash is required!
if (typeof(event_map_base_url) == 'undefined') {
	var event_map_base_url = '/event_map/';
}
// location of our css file - relative to the URL of the main html file
if (typeof(event_map_css_file) == 'undefined') {
	var event_map_css_file = event_map_base_url + 'html/event_map.css';
}
// location of the GML file to be loaded - relative to the URL of the main html file
if (typeof(event_map_gml_file) == 'undefined') {
	var event_map_gml_file = event_map_base_url + 'html/events.gml';
}
// display types: "events" (default), "marker" or "edit"
if (typeof(event_map_display_type) == 'undefined') {
	var event_map_display_type = 'events';
}
// set display_type to default, if the value is unknown
// also set default zoom level for that mode
var event_map_default_zoom;
if (event_map_display_type == 'events') {
	event_map_default_zoom = event_map_zoom_default_for_events;
} else if (event_map_display_type == 'marker') {
	event_map_default_zoom = event_map_zoom_default_for_marker;
} else if (event_map_display_type == 'edit') {
	event_map_default_zoom = event_map_zoom_default_for_edit;
} else {
	// unknown display_type
	event_map_display_type = 'events';
	event_map_default_zoom = event_map_zoom_default_for_events;
}
// latitude and longitude of the center of the map - set to zero if undefined
// the real default value will be set a little bit later
// note: zero is the magic value for "undefined"
if (typeof(event_map_center_latitude) == 'undefined') {
	var event_map_center_latitude = 0;
}
if (typeof(event_map_center_longitude) == 'undefined') {
	var event_map_center_longitude = 0;
}
// remember, if the coordinates were not initialized
var event_map_coordinates_unset = false;
// event mode: set default latitude or longitude, if necessary (center of Rostock)
if (event_map_center_latitude == 0) {
	event_map_coordinates_unset = true;
	event_map_center_latitude = 54.082004;
}
if (event_map_center_longitude == 0) {
	event_map_coordinates_unset = true;
	event_map_center_longitude = 12.128275;
}
// initial zoom level of the map
if (typeof(event_map_zoom) == 'undefined') {
	var event_map_zoom = 0;
}
// this must be done separately from the previous "undefined" check to avoid re-initialization via "var"
if (event_map_zoom == 0) {
	event_map_zoom = event_map_default_zoom;
}
// url of the marker icon
if (typeof(event_map_marker_icon) == 'undefined') {
	var event_map_marker_icon = event_map_base_url + 'icons/marker.png';
}


// global variables
var event_map;
var event_map_selectControl;
var event_map_marker_layer;
var event_map_marker;

// run the "event_map_init" function after loading the page
window.onload = event_map_init;


function event_map_addJavascript(jsname, pos) {
	var th = document.getElementsByTagName(pos)[0];
	var s = document.createElement('script');
	s.setAttribute('type', 'text/javascript');
	s.setAttribute('src', jsname);
	th.appendChild(s);
}


function event_map_addCSSfile(cssfile, pos) {
	var th = document.getElementsByTagName(pos)[0];
	var s = document.createElement('link');
	s.setAttribute('rel', 'stylesheet');
	s.setAttribute('href', cssfile);
	th.appendChild(s);
}


event_map_addJavascript('http://www.openlayers.org/api/OpenLayers.js', 'head');
event_map_addJavascript('http://www.openstreetmap.org/openlayers/OpenStreetMap.js', 'head');
// in case of problems of a browser with loading external ccs files, we could use the local copy
//event_map_addCSSfile(event_map_base_url + 'html/openlayers/style.css', 'head');
event_map_addCSSfile('http://openlayers.org/api/theme/default/style.css', 'head');
event_map_addCSSfile(event_map_css_file, 'head');


function event_map_init() {
	event_map = new OpenLayers.Map('event_map', {
		maxExtent: new OpenLayers.Bounds(-20037508.34, -20037508.34, 20037508.34, 20037508.34),
		numZoomLevels: 19,
		maxResolution: 156543.0399,
		units: 'm',
		projection: new OpenLayers.Projection("EPSG:900913"),
		displayProjection: new OpenLayers.Projection("EPSG:4326")
	});

	// define the public transport map (oepnvkarte.de)
	OpenLayers.Layer.OSM.OePNV = OpenLayers.Class(OpenLayers.Layer.OSM, {
		initialize: function(name, options) {
			var url = [
				"http://tile.xn--pnvkarte-m4a.de/tilegen/${z}/${x}/${y}.png"
			];
			options = OpenLayers.Util.extend({ numZoomLevels: 19 }, options);
			var newArguments = [name, url, options];
			OpenLayers.Layer.OSM.prototype.initialize.apply(this, newArguments);
		},
		CLASS_NAME: "OpenLayers.Layer.OSM.OePNV"
	});


	var layerOePNV = new OpenLayers.Layer.OSM.OePNV("&Ouml;PNV-Karte");
	var layerCycle = new OpenLayers.Layer.OSM.CycleMap("Radweg-Karte");
	var layerMapnik = new OpenLayers.Layer.OSM.Mapnik("Mapnik");
	var layerTah = new OpenLayers.Layer.OSM.Osmarender("Osmarender");

	event_map.addLayers([layerOePNV, layerCycle, layerMapnik, layerTah]);
	// choose default layer
	event_map.setBaseLayer(layerMapnik);

	event_map_marker_layer = new OpenLayers.Layer.Markers("Markierung");
	event_map.addLayer(event_map_marker_layer)

	// allow to change the current layer (mapnik/tah/oepnv/cycle)
	event_map.addControl(new OpenLayers.Control.LayerSwitcher());

	var lonLat = new OpenLayers.LonLat(event_map_center_longitude,
		event_map_center_latitude).transform(event_map.displayProjection, event_map.projection);
	event_map.setCenter(lonLat, event_map_zoom);

	if (event_map_display_type == 'marker') {
		event_map_show_marker(lonLat);
	} else if (event_map_display_type == 'edit') {
		event_map_edit_position(lonLat);
	} else {
		event_map_show_gml();
	}
}


function event_map_get_marker(lonLat) {
	var size = new OpenLayers.Size(21, 25);
	var offset = new OpenLayers.Pixel(-(size.w/2), -size.h);
	var icon = new OpenLayers.Icon(event_map_marker_icon, size, offset)
	return new OpenLayers.Marker(lonLat, icon);
}


// return false, if no valid coordinate values are found in the form fields
function event_map_get_form_coordinates() {
	var lon;
	var lat;
	var field_lat = document.getElementById(event_map_fieldname_lat);
	var field_lon = document.getElementById(event_map_fieldname_lon);
	if (field_lat) { lat = field_lat.value; }
	if (field_lon) { lon = field_lon.value; }
	if ((lat != "") && (lat != 0) && (lon != "") && (lon != 0)) {
		return new OpenLayers.LonLat(lon, lat).transform(
				event_map.displayProjection, event_map.projection);
	} else {
		return false;
	}
}


function event_map_update_edit_marker() {
	event_map_marker_layer.clearMarkers();
	var lonLat = event_map_get_form_coordinates();
	if (lonLat) {
		event_map_marker = event_map_get_marker(lonLat);
		event_map_marker_layer.addMarker(event_map_marker);
		// center the map on the item
		event_map.setCenter(lonLat, event_map.zoom);
	}
}


function event_map_edit_position(lonLat) {
	event_map_update_edit_marker();

	// catch click events
	OpenLayers.Control.Click = OpenLayers.Class(OpenLayers.Control, {                
		defaultHandlerOptions: {
			'single': true,
			'double': false,
			'pixelTolerance': 0,
			'stopSingle': false,
			'stopDouble': false
		},
		initialize: function(options) {
			this.handlerOptions = OpenLayers.Util.extend({}, this.defaultHandlerOptions);
			OpenLayers.Control.prototype.initialize.apply(this, arguments); 
			this.handler = new OpenLayers.Handler.Click(this, { 'click': this.trigger }, this.handlerOptions);
		}
	});

	var click = new OpenLayers.Control.Click({ trigger: event_map_edit_clicked });
	event_map.addControl(click);
	click.activate();
}


function event_map_show_marker(lonLat) {
	if (event_map_coordinates_unset) {
		// hide the map
		document.getElementById('event_map').style.display = "none";
	} else {
		// configure and display the map
		event_map_marker = event_map_get_marker(lonLat);
		event_map_marker_layer.addMarker(event_map_marker);
	}
}


function event_map_show_gml() {
	OpenLayers.Feature.prototype.popupClass = OpenLayers.Popup.FramedCloud;

	var pois = new OpenLayers.Layer.GML("Veranstaltungen", event_map_gml_file, {
		format: OpenLayers.Format.Text,
		projection: new OpenLayers.Projection("EPSG:4326")
	});

	event_map.addLayer(pois);

	// add the popups
	event_map_selectControl = new OpenLayers.Control.SelectFeature(pois, {
		onSelect: event_map_onFeatureSelect,
		onUnselect: event_map_onFeatureUnselect,
		toggle: true
	});

	event_map.addControl(event_map_selectControl);
	event_map_selectControl.activate();   
}


function event_map_onPopupClose(evnt) {
	event_map_selectControl.unselect(selectedFeature);
}


function event_map_edit_clicked(evnt) {
	var lonLat = event_map.getLonLatFromViewPortPx(evnt.xy).transform(
			event_map.projection, event_map.displayProjection);
	var field_lat = document.getElementById(event_map_fieldname_lat);
	var field_lon = document.getElementById(event_map_fieldname_lon);
	// round the numbers to a few digits - otherwise drupal complains about max number of chars
	if (field_lat) { field_lat.value = Math.round(lonLat.lat * 10000000) / 10000000; }
	if (field_lon) { field_lon.value = Math.round(lonLat.lon * 10000000) / 10000000; }
	event_map_update_edit_marker();
}


function event_map_onFeatureSelect(feature) {
    selectedFeature = feature;
		var content = '<div class="event_map_info">';
		content += '<h1>' + feature.attributes.title + '</h1>';
		/* the description contains six attributes:
		 *  time/date
		 *  place
		 *  address
		 *  organisation
		 *  details
		 *  url
		 */
		/* we don't do this formatting here - but in the gml file generation script instead
		var items = feature.attributes.description.split('#', 6);
		content += '<ul>';
		content += '<li>Wann: ' + items[0] + '</li>';
		content += '<li>Ort: ' + items[1] + '</li>';
		content += '<li>Adresse: ' + items[2] + '</li>';
		content += '<li>Veranstalter: ' + items[3] + '</li>';
		content += '<li>Details: ' + items[4] + '</li>';
		content += '<li><a href="' + items[5] + '" title="mehr Informationen">mehr ...</a></li>';
		content += '</ul></div>';
		*/
		content += feature.attributes.description
		content += '</div>'
    // do naive protection against Javascript.
    if (content.search("<script") != -1) {
	content = "Content contained Javascript! Escaped content below.<br />" + content.replace(/</g, "&lt;");
    }
    popup = new OpenLayers.Popup.FramedCloud("event", 
			     feature.geometry.getBounds().getCenterLonLat(),
			     new OpenLayers.Size(300, 200),
			     content,
			     null, true, event_map_onPopupClose);
    popup.maxSize = new OpenLayers.Size(350, 300);
    feature.popup = popup;
    event_map.addPopup(popup);
}


function event_map_onFeatureUnselect(feature) {
    event_map.removePopup(feature.popup);
    feature.popup.destroy();
    feature.popup = null;
}