/* layers */

var default_pointer = "../media/images/default-pointer.png";

var view_projection = 'EPSG:3857';

var source_osm = function(options){
    return new ol.layer.Tile({
        source: new ol.source.OSM()
    });
};


var map_layers = {
    'osm': source_osm
};

var get_layers = function(layers){
    if (!layers){
        layers = [{'type': 'osm', 'options': null}];
    }
    var ol_layers = [];
    for (idx in layers){
        var layer_attr = layers[idx];
        ol_layers.push(
            map_layers[layer_attr['type']](layer_attr['options'])
        );
    }
    return ol_layers;
};

/* get markers */

var get_markers = function(points){
};

/* styles */
var get_style = function(feature){
    /*
    properties = feature.getProperties();
    var size = [properties.icon_width, properties.icon_height];
    var anchor = [properties.icon_offset_x,
                  properties.icon_offset_y];

    return new ol.style.Style({
        image: new ol.style.Icon({
            anchor: [17, 50],
            anchorXUnits: 'pixels',
            anchorYUnits: 'pixels',
            src: default_pointer,
            size: [35, 50]
        })
    });
    */
    var image = new ol.style.Circle({
        radius: 5,
        fill: null,
        stroke: new ol.style.Stroke({color: 'red', width: 1})
    });

    return new ol.style.Style({
        image: image
    });
};


/* display map */
var vector_source;
var vector_layer;
var map_layers;
var map;
var geojson_format = new ol.format.GeoJSON(
    {dataProjection:'EPSG:4326', featureProjection: view_projection});


var display_map = function(map_id, points, layers){
    vector_source = new ol.source.Vector({
        features: geojson_format.readFeatures(points)
    });

    vector_layer = new ol.layer.Vector({
        source: vector_source,
        style: get_style
    });

    map_layers = get_layers(layers);
    map_layers.push(vector_layer);
    map = new ol.Map({
        target: map_id,
        layers: map_layers,
        view: new ol.View({
            projection: view_projection,
            center: ol.proj.fromLonLat([37.41, 8.82]),
            zoom: 4
        })
    });

}