GraphHopperEngine = function(vehicleName, vehicleParam, locale) {
    this.vehicleName = vehicleName;
    this.vehicleParam = vehicleParam;
    //At this point the local system isn't correctly initialised yet, so we don't have accurate information about current locale
    this.locale = locale;
    if (!locale)
        this.locale = "en";
};

GraphHopperEngine.prototype.createConfig = function() {
    var that = this;
    return {
        name: "javascripts.directions.engines.graphhopper_"+this.vehicleName.toLowerCase(),
            creditline: '<a href="http://graphhopper.com/" target="_blank">Graphhopper</a>',
        draggable: false,
        _hints: {},
        getRoute: function(isFinal, points) {
            var url = "http://graphhopper.com/routing/api/route?" 
                    + that.vehicleParam 
                    + "&locale=" + I18n.currentLocale();
            for (var i = 0; i < points.length; i++) {
                var pair = points[i].join(',');
                url += "&point=" + pair;
            }            
            if (isFinal)
                url += "&instructions=true";
            // GraphHopper supports json too
            this.requestJSONP(url + "&type=jsonp&callback=");
        },
        gotRoute: function(router, data) {
            if (!data.info.routeFound) {
                return false;
            }
            // Draw polyline
            var line = L.PolylineUtil.decode(data.route.coordinates);
            router.setPolyline(line);
            // Assemble instructions
            var steps = [];
            var instr = data.route.instructions;
            for (i = 0; i < instr.descriptions.length; i++) {
                var indi = instr.indications[i];
                var instrCode = (i == instr.descriptions.length - 1) ? 15 : this.GH_INSTR_MAP[indi];
                var instrText = "<b>" + (i + 1) + ".</b> ";
                instrText += instr.descriptions[i];
                var latlng = instr.latLngs[i];
                var distInMeter = instr.distances[i];
                steps.push([{lat: latlng[0], lng: latlng[1]}, instrCode, instrText, distInMeter, []]); // TODO does graphhopper map instructions onto line indices?
            }
            router.setItinerary({ steps: steps, distance: data.route.distance, time: data.route['time']/1000 });
            return true;
        },
        GH_INSTR_MAP: {
            "-3": 6, // sharp left
            "-2": 7, // left	
            "-1": 8, // slight left                
            0: 0, // straight
            1: 1, // slight right
            2: 2, // right
            3: 3 // sharp right		
        }
    };
};

OSM.RoutingEngines.add(false, new GraphHopperEngine("Bicycle", "vehicle=bike").createConfig());
OSM.RoutingEngines.add(false, new GraphHopperEngine("Foot", "vehicle=foot").createConfig());