BR.LayersConfig = L.Class.extend({
    overpassFrontend: new OverpassFrontend(
        (BR.conf.overpassBaseUrl || '//overpass-api.de/api/interpreter').replace('?data=', '')
    ),
    defaultBaseLayers: BR.confLayers.defaultBaseLayers,
    defaultOverlays: BR.confLayers.defaultOverlays,
    legacyNameToIdMap: BR.confLayers.legacyNameToIdMap,
    // hardcoded, built-in layers with an id set (for URL hash)
    builtInLayers: ['route-quality'],

    initialize: function (map) {
        this._map = map;
        this._overpassLoadingIndicator = new BR.Message('overpass_loading_indicator', { alert: false });
        this._overpassActiveRequestCount = 0;

        this._addLeafletProvidersLayers();
        this._customizeLayers();
        this.loadDefaultLayers();
        this._addLanguageDefaultLayer();
    },

    loadDefaultLayers: function () {
        if (BR.Util.localStorageAvailable()) {
            var item = localStorage.getItem('map/defaultLayers');
            if (item) {
                var defaultLayers = JSON.parse(item);
                this.defaultBaseLayers = defaultLayers.baseLayers;
                this.defaultOverlays = defaultLayers.overlays;
            }
        }
    },

    storeDefaultLayers: function (baseLayers, overlays) {
        if (BR.Util.localStorageAvailable()) {
            var defaultLayers = {
                baseLayers: baseLayers,
                overlays: overlays,
            };
            localStorage.setItem('map/defaultLayers', JSON.stringify(defaultLayers));
        }
    },

    _addLeafletProvidersLayers: function () {
        var includeList = BR.confLayers.leafletProvidersIncludeList;

        for (var i = 0; i < includeList.length; i++) {
            var id = includeList[i];
            var obj = {
                geometry: null,
                properties: {
                    id: id,
                    name: id.replace('.', ' '),
                    dataSource: 'leaflet-providers',
                },
                type: 'Feature',
            };
            BR.layerIndex[id] = obj;
        }
    },

    _customizeLayers: function () {
        var propertyOverrides = BR.confLayers.getPropertyOverrides();

        for (id in propertyOverrides) {
            var layer = BR.layerIndex[id];

            if (layer) {
                var properties = propertyOverrides[id];

                for (key in properties) {
                    var value = properties[key];
                    layer.properties[key] = value;
                }
            } else {
                console.error('Layer not found: ' + id);
            }
        }

        BR.layerIndex['MtbMap'].geometry = BR.confLayers.europeGeofabrik;
        BR.layerIndex['1069'].geometry = BR.confLayers.europeGeofabrik;

        BR.layerIndex['OpenStreetMap.CH'].geometry = BR.confLayers.switzerlandPadded;

        BR.layerIndex['1017'].geometry = BR.confLayers.osmapaPl;
    },

    _addLanguageDefaultLayer: function () {
        // language code -> layer id
        var languageLayersMap = {};
        var i;

        for (i = 0; i < BR.confLayers.languageDefaultLayers.length; i++) {
            var id = BR.confLayers.languageDefaultLayers[i];
            var layer = BR.layerIndex[id];
            if (layer) {
                var layerLanguage = layer.properties['language_code'] || layer.properties['pseudo_language_code'];
                if (layerLanguage) {
                    languageLayersMap[layerLanguage] = id;
                }
            }
        }

        // iterate language code hierarchy, e.g ["de-DE", "de", "en"] (includes `i18next.options.fallbackLng`)
        for (i = 0; i < i18next.languages.length; i++) {
            var language = i18next.languages[i];
            var layerId = languageLayersMap[language];

            if (layerId) {
                this.defaultBaseLayers.unshift(layerId);
                break;
            }
        }
    },

    isDefaultLayer: function (id, overlay) {
        var result = false;
        if (overlay) {
            result = this.defaultOverlays.indexOf(id) > -1;
        } else {
            result = this.defaultBaseLayers.indexOf(id) > -1;
        }
        return result;
    },

    getBaseLayers: function () {
        return this._getLayers(this.defaultBaseLayers);
    },

    getOverlays: function () {
        return this._getLayers(this.defaultOverlays);
    },

    _getLayers: function (ids) {
        var layers = {};

        for (var i = 0; i < ids.length; i++) {
            var layerId = ids[i];
            var layerData = BR.layerIndex[layerId];

            if (layerData) {
                // when key required only add if configured
                var keyObj = this.getKeyName(layerData.properties.url);
                if (!keyObj || (keyObj && BR.keys[keyObj.name])) {
                    layers[layerData.properties.name] = this.createLayer(layerData);
                }
            } else {
                console.error('Layer not found: ' + layerId);
            }
        }

        return layers;
    },

    // own convention: key placeholder with prefix
    // e.g. ?api_key={keys_openrouteservice}
    getKeyName: function (url) {
        var result = null;
        // L.Util.template only matches [\w_-]
        var prefix = 'keys_';
        var regex = new RegExp('{' + prefix + '([^}]*)}');
        var found, name;

        if (!url) return result;

        found = url.match(regex);
        if (found) {
            name = found[1];
            result = {
                name: name,
                urlVar: prefix + name,
            };
        }

        return result;
    },

    _showOverpassLoadingIndicator: function () {
        this._overpassActiveRequestCount++;
        this._overpassLoadingIndicator.showInfo(i18next.t('layers.overpass-loading-indicator'));
    },

    _hideOverpassLoadingIndicator: function () {
        if (--this._overpassActiveRequestCount === 0) {
            this._overpassLoadingIndicator.hide();
        }
    },

    createOverpassLayer: function (query) {
        return Object.assign(
            new OverpassLayer({
                overpassFrontend: this.overpassFrontend,
                query: query,
                minZoom: 12,
                feature: {
                    title: '{{ tags.name }}',
                    body:
                        '<table class="overpass-tags">{% for k, v in tags %}{% if k[:5] != "addr:" %}<tr><th>{{ k }}</th><td>{% if k matches "/email/" %}<a href="mailto:{{ v }}">{{ v }}</a>{% elseif v matches "/^http/" %}<a href="{{ v }}">{{ v }}</a>{% elseif v matches "/^www/" %}<a href="http://{{ v }}">{{ v }}</a>{% else %}{{ v }}{% endif %}</td></tr>{% endif %}{% endfor %}</table>',
                    markerSymbol: null,
                },
            }),
            {
                onLoadStart: this._showOverpassLoadingIndicator.bind(this),
                onLoadEnd: this._hideOverpassLoadingIndicator.bind(this),
            }
        );
    },

    createLayer: function (layerData) {
        var props = layerData.properties;
        var url = props.url;
        var layer;

        // JOSM:    https://{switch:a,b,c}.tile.openstreetmap.org/{zoom}/{x}/{y}.png
        // Leaflet: https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png
        function convertUrlJosm(url) {
            var rxSwitch = /{switch:[^}]*}/;
            var rxZoom = /{zoom}/g;
            var result = url.replace(rxSwitch, '{s}');
            result = result.replace(rxZoom, '{z}');
            return result;
        }

        // JOSM:    https://{switch:a,b,c}.tile.openstreetmap.org/{zoom}/{x}/{y}.png
        // Leaflet: ['a','b','c']
        function getSubdomains(url) {
            var result = 'abc';
            var regex = /{switch:([^}]*)}/;
            var found = url.match(regex);
            if (found) {
                result = found[1].split(',');
            }
            return result;
        }

        function convertAttributionJosm(props) {
            var result = '';
            var attr = props.attribution;

            if (attr) {
                if (attr.html) {
                    result = attr.html;
                } else if (attr.url && attr.text) {
                    result = '<a href="' + attr.url + '" target="_blank" rel="noopener">' + attr.text + '</a>';
                } else if (attr.text) {
                    result = attr.text;
                }
            }
            if (!result) {
                console.warn('No attribution: ' + props.id);
            }

            return result;
        }

        var options = {
            maxZoom: this._map.getMaxZoom(),
            bounds: layerData.geometry && !props.worldTiles ? L.geoJson(layerData.geometry).getBounds() : null,
        };
        if (props.mapUrl) {
            options.mapLink =
                '<a target="_blank" href="' + props.mapUrl + '">' + (props.nameShort || props.name) + '</a>';
        }
        if (props.attribution) {
            options.attribution = props.attribution;
        }

        var keyObj = this.getKeyName(url);
        if (keyObj && BR.keys[keyObj.name]) {
            options[keyObj.urlVar] = BR.keys[keyObj.name];
        }

        if (props.dataSource === 'leaflet-providers') {
            layer = L.tileLayer.provider(props.id);

            var layerOptions = L.Util.extend(options, {
                maxNativeZoom: layer.options.maxZoom,
            });
            L.setOptions(layer, layerOptions);
        } else if (props.dataSource === 'LayersCollection') {
            layer = L.tileLayer(
                url,
                L.Util.extend(options, {
                    minZoom: props.minZoom || 0,
                    maxNativeZoom: props.maxZoom,
                })
            );
            if (props.subdomains) {
                layer.subdomains = props.subdomains;
            }
        } else if (props.dataSource === 'OverpassAPI') {
            layer = this.createOverpassLayer(props.query);
        } else {
            // JOSM
            var josmUrl = url;
            var url = convertUrlJosm(josmUrl);

            var josmOptions = L.Util.extend(options, {
                minZoom: props.min_zoom || 0,
                maxNativeZoom: props.max_zoom,
                subdomains: getSubdomains(josmUrl),
                attribution: convertAttributionJosm(props),
            });

            if (props.type && props.type === 'wms') {
                layer = L.tileLayer.wms(
                    url,
                    L.Util.extend(josmOptions, {
                        layers: props.layers,
                        format: props.format,
                    })
                );
            } else {
                layer = L.tileLayer(url, josmOptions);
            }
        }

        // Layer attribution here only as short link to original site,
        // to keep current position use placeholders: {zoom}/{lat}/{lon}
        // Copyright attribution in index.html #credits
        var getAttribution = function () {
            return this.options.mapLink;
        };
        layer.getAttribution = getAttribution;

        layer.id = props.id;

        return layer;
    },
});

BR.layersConfig = function (map) {
    return new BR.LayersConfig(map);
};