L.BRouter = L.Class.extend({
    statics: {
        // NOTE: the routing API used here is not public!
        // /brouter?lonlats=1.1,1.2|2.1,2.2|3.1,3.2|4.1,4.2&nogos=-1.1,-1.2,1|-2.1,-2.2,2&profile=shortest&alternativeidx=1&format=kml
        URL_TEMPLATE: '/brouter?lonlats={lonlats}&nogos={nogos}&polylines={polylines}&polygons={polygons}&profile={profile}&alternativeidx={alternativeidx}&format={format}',
        URL_PROFILE_UPLOAD: BR.conf.host + '/brouter/profile',
        PRECISION: 6,
        NUMBER_SEPARATOR: ',',
        GROUP_SEPARATOR: '|',
        ABORTED_ERROR: 'aborted'
    },

    options: {
    },

    initialize: function (options) {
        L.setOptions(this, options);

        this.queue = async.queue(L.bind(function (task, callback) {
            this.getRoute(task.segment, callback);
        }, this), 1);

        // patch to call callbacks on kill for cleanup (loadingTrailer)
        this.queue.kill = function () {
            var aborted = this.tasks;
            this.drain = null;
            this.tasks = [];
            aborted.forEach(function(task) {
                task.callback(L.BRouter.ABORTED_ERROR);
            });
        };
    },

    setOptions: function(options) {
        L.setOptions(this, options);
    },

    getUrlParams: function(latLngs, format) {
        params = {};

        if (this._getLonLatsString(latLngs) != null)
            params.lonlats = this._getLonLatsString(latLngs);

        if (this.options.nogos && this._getNogosString(this.options.nogos).length > 0)
            params.nogos = this._getNogosString(this.options.nogos);

        if (this.options.polylines && this._getNogosPolylinesString(this.options.polylines).length > 0)
            params.polylines = this._getNogosPolylinesString(this.options.polylines);

        if (this.options.polygons && this._getNogosPolygonsString(this.options.polygons).length > 0)
            params.polygons = this._getNogosPolygonsString(this.options.polygons);

        if (this.options.profile != null)
            params.profile = this.options.profile;

        params.alternativeidx = this.options.alternative;

        if (format != null) {
            params.format = format;
        } else {
            // do not put values in URL if this is the default value (format===null)
            if (params.profile === BR.conf.profiles[0])
                delete params.profile;
            if (params.alternativeidx == 0)
                delete params.alternativeidx;

            // don't add custom profile, as these are only stored temporarily
            if (params.profile && params.profile.substring(0, 7) === 'custom_') {
                delete params.profile;
            }
        }

        return params;
    },

    parseUrlParams: function(params) {
        var opts = {};
        if (params.lonlats) {
            opts.lonlats = this._parseLonLats(params.lonlats);
        }
        if (params.nogos) {
            opts.nogos = this._parseNogos(params.nogos);
        }
        if (params.polylines) {
            opts.polylines = this._parseNogosPolylines(params.polylines);
        }
        if (params.polygons) {
            opts.polygons = this._parseNogosPolygons(params.polygons);
        }
        if (params.alternativeidx) {
            opts.alternative = params.alternativeidx;
        }
        if (params.profile) {
            opts.profile = params.profile;
        }
        return opts;
    },

    getUrl: function(latLngs, format) {
        var urlParams = this.getUrlParams(latLngs, format);

        var args = []
        if (urlParams.lonlats != null && urlParams.lonlats.length > 0)
            args.push(L.Util.template('lonlats={lonlats}', urlParams));
        if (urlParams.nogos != null)
            args.push(L.Util.template('nogos={nogos}', urlParams));
        if (urlParams.polylines != null)
            args.push(L.Util.template('polylines={polylines}', urlParams));
        if (urlParams.polygons != null)
            args.push(L.Util.template('polygons={polygons}', urlParams));
        if (urlParams.profile != null)
            args.push(L.Util.template('profile={profile}', urlParams));
        if (urlParams.alternativeidx != null)
            args.push(L.Util.template('alternativeidx={alternativeidx}', urlParams));
        if (urlParams.format != null)
            args.push(L.Util.template('format={format}', urlParams));

        var prepend_host = (format != null);

        return (prepend_host ? BR.conf.host : '') + '/brouter?' + args.join('&');
    },

    getRoute: function(latLngs, cb) {
        var url = this.getUrl(latLngs, 'geojson'),
            xhr = new XMLHttpRequest();

        if (!url) {
            return cb(new Error(i18next.t('warning.cannot-get-route')));
        }

        xhr.open('GET', url, true);
        xhr.onload = L.bind(this._handleRouteResponse, this, xhr, cb);
        xhr.onerror = L.bind(function(xhr, cb) {
            cb(BR.Util.getError(xhr));
        }, this, xhr, cb);
        xhr.send();
    },

    _handleRouteResponse: function(xhr, cb) {
        var layer,
            geojson;

        if (xhr.status === 200
                && xhr.responseText
                // application error when not GeoJSON format (text/plain for errors)
                && xhr.getResponseHeader('Content-Type').split(';')[0] === 'application/vnd.geo+json') {

            // leaflet.spin
            //gpxLayer.fire('data:loaded');

            try {
                geojson = JSON.parse(xhr.responseText);
                layer = L.geoJSON(geojson).getLayers()[0];

                return cb(null, layer);
            } catch(e) {
                console.error(e, xhr.responseText);
                return cb(e);
            }
        } else {
            cb(BR.Util.getError(xhr));
        }
    },

    getRouteSegment: function(l1, l2, cb) {
        this.queue.push({ segment: [l1, l2] }, cb);
    },

    uploadProfile: function(profileId, profileText, cb) {
        var url = L.BRouter.URL_PROFILE_UPLOAD;
            xhr = new XMLHttpRequest();

        // reuse existing profile file
        if (profileId) {
            url += '/' + profileId;
        }

        xhr.open('POST', url, true);
        xhr.onload = L.bind(this._handleProfileResponse, this, xhr, cb);
        xhr.onerror = function(evt) {
            var xhr = this;
            cb(i18next.t('warning.upload-error', {error: xhr.statusText}));
        };

        // send profile text only, as text/plain;charset=UTF-8
        xhr.send(profileText);
    },

    _handleProfileResponse: function(xhr, cb) {
        var response;

        if (xhr.status === 200 && xhr.responseText && xhr.responseText.length > 0) {
            response = JSON.parse(xhr.responseText);
            cb(response.error, response.profileid);
        } else {
            cb(i18next.t('warning.profile-error'));
        }
    },

    _getLonLatsString: function(latLngs) {
        var s = '';
        for (var i = 0; i < latLngs.length; i++) {
            s += this._formatLatLng(latLngs[i]);
            if (i < (latLngs.length - 1)) {
                s += L.BRouter.GROUP_SEPARATOR;
            }
        }
        return s;
    },

    _parseLonLats: function(s) {
        var groups,
            numbers,
            lonlats = [];

        if (!s) {
            return lonlats;
        }

        groups = s.split(L.BRouter.GROUP_SEPARATOR);
        for (var i = 0; i < groups.length; i++) {
            // lng,lat
            numbers = groups[i].split(L.BRouter.NUMBER_SEPARATOR);
            lonlats.push(L.latLng(numbers[1], numbers[0]));
        }

        return lonlats;
    },

    _getNogosString: function(nogos) {
        var s = '';
        for (var i = 0, circle; i < nogos.length; i++) {
            circle = nogos[i];
            s += this._formatLatLng(circle.getLatLng());
            s += L.BRouter.NUMBER_SEPARATOR;
            s += Math.round(circle.getRadius());
            if (circle.options.nogoWeight) {
                s += L.BRouter.NUMBER_SEPARATOR;
                s += circle.options.nogoWeight;
            }
            if (i < (nogos.length - 1)) {
                s += L.BRouter.GROUP_SEPARATOR;
            }
        }
        return s;
    },

    _parseNogos: function(s) {
        var groups,
            numbers,
            nogos = [];

        if (!s) {
            return nogos;
        }

        groups = s.split(L.BRouter.GROUP_SEPARATOR);
        for (var i = 0; i < groups.length; i++) {
            // lng,lat,radius(,weight)
            numbers = groups[i].split(L.BRouter.NUMBER_SEPARATOR);
            // TODO refactor: pass simple obj, create circle in NogoAreas; use shapeOptions of instance
            // [lat,lng],radius
            // Parse as a nogo circle
            var nogoOptions = {radius: numbers[2]};
            if (numbers.length > 3) {
                nogoOptions.nogoWeight = numbers[3];
            }
            nogos.push(L.circle([numbers[1], numbers[0]], nogoOptions));
        }

        return nogos;
    },

    _getNogosPolylinesString: function(nogos) {
        var s = '';
        for (var i = 0, polyline, vertices; i < nogos.length; i++) {
            polyline = nogos[i];
            vertices = polyline.getLatLngs();
            for (var j = 0; j < vertices.length; j++) {
                if (j > 0) {
                    s += L.BRouter.NUMBER_SEPARATOR;
                }
                s += this._formatLatLng(vertices[j]);
            }
            if (polyline.options.nogoWeight) {
                s += L.BRouter.NUMBER_SEPARATOR;
                s += polyline.options.nogoWeight;
            }
            if (i < (nogos.length - 1)) {
                s += L.BRouter.GROUP_SEPARATOR;
            }
        }
        return s;
    },

    _parseNogosPolylines: function(s) {
        var groups,
            numbers,
            latlngs,
            nogos = [];

        groups = s.split(L.BRouter.GROUP_SEPARATOR);
        for (var i = 0; i < groups.length; i++)
        {
            numbers = groups[i].split(L.BRouter.NUMBER_SEPARATOR);
            if (numbers.length > 1)
            {
                latlngs = [];
                for (var j = 0; j < numbers.length - 1;)
                {
                    var lng = Number.parseFloat(numbers[j++]);
                    var lat = Number.parseFloat(numbers[j++]);
                    latlngs.push([lat, lng]);
                }
                var nogoWeight;
                if (j < numbers.length) {
                    nogoWeight = Number.parseFloat(numbers[j++]);
                }
                nogos.push(L.polyline(latlngs, { nogoWeight: nogoWeight }));
            }
        }
        return nogos;
    },

    _getNogosPolygonsString: function(nogos) {
        var s = '';
        for (var i = 0, polygon, vertices; i < nogos.length; i++) {
            polygon = nogos[i];
            vertices = polygon.getLatLngs()[0];
            for (var j = 0; j < vertices.length; j++) {
                if (j > 0) {
                    s += L.BRouter.NUMBER_SEPARATOR;
                }
                s += this._formatLatLng(vertices[j]);
            }
            if (polygon.options.nogoWeight) {
                s += L.BRouter.NUMBER_SEPARATOR;
                s += polygon.options.nogoWeight;
            }
            if (i < (nogos.length - 1)) {
                s += L.BRouter.GROUP_SEPARATOR;
            }
        }
        return s;
    },

    _parseNogosPolygons: function(s) {
        var groups,
            numbers,
            latlngs,
            nogos = [];

        groups = s.split(L.BRouter.GROUP_SEPARATOR);
        for (var i = 0; i < groups.length; i++)
        {
            numbers = groups[i].split(L.BRouter.NUMBER_SEPARATOR);
            if (numbers.length > 1)
            {
                latlngs = [];
                for (var j = 0; j < numbers.length - 1;)
                {
                    var lng = Number.parseFloat(numbers[j++]);
                    var lat = Number.parseFloat(numbers[j++]);
                    latlngs.push([lat, lng]);
                }
                var nogoWeight;
                if (j < numbers.length) {
                    nogoWeight = Number.parseFloat(numbers[j++]);
                }
                nogos.push(L.polygon(latlngs, { nogoWeight: nogoWeight }));
            }
        }
        return nogos;
    },

    // formats L.LatLng object as lng,lat string
    _formatLatLng: function(latLng) {
        var s = '';
        s += L.Util.formatNum(latLng.lng, L.BRouter.PRECISION);
        s += L.BRouter.NUMBER_SEPARATOR;
        s += L.Util.formatNum(latLng.lat, L.BRouter.PRECISION);
        return s;
    }
});

L.bRouter = function (options) {
    return new L.BRouter(options);
};