/**
 * Imagery Switcher: Verschiedene Satellitenbilder + historische Aufnahmen.
 * Unterstuetzt URL-Template (Esri, Sentinel, OSM) und WMTS (NASA GIBS).
 */
const ImagerySwitch = {
    _viewer: null,
    _currentLayer: null,
    _currentId: "default",

    _sources: {
        "default": { name: "Cesium Ion (Standard)", url: null },
        "esri": {
            name: "Esri World Imagery",
            url: "https://server.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer/tile/{z}/{y}/{x}",
        },
        "nasa-modis": {
            name: "NASA MODIS Terra (Heute)",
            wmts: {
                url: "https://gibs.earthdata.nasa.gov/wmts/epsg4326/best/wmts.cgi",
                layer: "MODIS_Terra_CorrectedReflectance_TrueColor",
                tileMatrixSetID: "250m",
                format: "image/jpeg",
                time: "today",
                maxLevel: 8,
            },
        },
        "nasa-viirs": {
            name: "NASA VIIRS SNPP (Heute)",
            wmts: {
                url: "https://gibs.earthdata.nasa.gov/wmts/epsg4326/best/wmts.cgi",
                layer: "VIIRS_SNPP_CorrectedReflectance_TrueColor",
                tileMatrixSetID: "250m",
                format: "image/jpeg",
                time: "today",
                maxLevel: 8,
            },
        },
        "nasa-goes-east": {
            name: "NASA GOES East (Live)",
            wmts: {
                url: "https://gibs.earthdata.nasa.gov/wmts/epsg4326/best/wmts.cgi",
                layer: "GOES-East_ABI_GeoColor",
                tileMatrixSetID: "2km",
                format: "image/jpeg",
                time: null,
                maxLevel: 5,
            },
        },
        "nasa-goes-west": {
            name: "NASA GOES West (Live)",
            wmts: {
                url: "https://gibs.earthdata.nasa.gov/wmts/epsg4326/best/wmts.cgi",
                layer: "GOES-West_ABI_GeoColor",
                tileMatrixSetID: "2km",
                format: "image/jpeg",
                time: null,
                maxLevel: 5,
            },
        },
        "s2-2024": {
            name: "Sentinel-2 (2024)",
            url: "https://tiles.maps.eox.at/wmts/1.0.0/s2cloudless-2024_3857/default/GoogleMapsCompatible/{z}/{x}/{y}.jpg",
        },
        "s2-2023": {
            name: "Sentinel-2 (2023)",
            url: "https://tiles.maps.eox.at/wmts/1.0.0/s2cloudless-2023_3857/default/GoogleMapsCompatible/{z}/{x}/{y}.jpg",
        },
        "s2-2022": {
            name: "Sentinel-2 (2022)",
            url: "https://tiles.maps.eox.at/wmts/1.0.0/s2cloudless-2022_3857/default/GoogleMapsCompatible/{z}/{x}/{y}.jpg",
        },
        "s2-2020": {
            name: "Sentinel-2 (2020)",
            url: "https://tiles.maps.eox.at/wmts/1.0.0/s2cloudless-2020_3857/default/GoogleMapsCompatible/{z}/{x}/{y}.jpg",
        },
        "s2-2018": {
            name: "Sentinel-2 (2018)",
            url: "https://tiles.maps.eox.at/wmts/1.0.0/s2cloudless-2018_3857/default/GoogleMapsCompatible/{z}/{x}/{y}.jpg",
        },
        "topo": {
            name: "OpenTopoMap",
            url: "https://tile.opentopomap.org/{z}/{x}/{y}.png",
        },
        "osm": {
            name: "OpenStreetMap",
            url: "https://a.tile.openstreetmap.org/{z}/{x}/{y}.png",
        },
    },

    init(viewer) {
        this._viewer = viewer;
    },

    _getGibsLabels(maxLevel) {
        var labels = [];
        for (var i = 0; i <= maxLevel; i++) labels.push(String(i));
        return labels;
    },

    switchTo(id) {
        if (!this._viewer || this._currentId === id) return;
        var src = this._sources[id];
        if (!src) return;

        // Alten Layer entfernen
        if (this._currentLayer) {
            this._viewer.imageryLayers.remove(this._currentLayer);
            this._currentLayer = null;
        }

        if (id === "default") {
            this._currentId = id;
        } else if (src.wmts) {
            // NASA GIBS WMTS Provider
            var w = src.wmts;
            var opts = {
                url: w.url,
                layer: w.layer,
                tileMatrixSetID: w.tileMatrixSetID,
                format: w.format,
                style: "default",
                tileWidth: 512,
                tileHeight: 512,
                tilingScheme: new Cesium.GeographicTilingScheme(),
                tileMatrixLabels: this._getGibsLabels(w.maxLevel),
                credit: "NASA GIBS",
            };
            if (w.time === "today") {
                opts.times = new Cesium.TimeIntervalCollection([
                    new Cesium.TimeInterval({
                        start: Cesium.JulianDate.fromIso8601(new Date().toISOString().slice(0, 10)),
                        stop: Cesium.JulianDate.fromIso8601("9999-12-31"),
                    }),
                ]);
                opts.clock = this._viewer.clock;
            } else if (w.time) {
                opts.times = new Cesium.TimeIntervalCollection([
                    new Cesium.TimeInterval({
                        start: Cesium.JulianDate.fromIso8601(w.time),
                        stop: Cesium.JulianDate.fromIso8601("9999-12-31"),
                    }),
                ]);
                opts.clock = this._viewer.clock;
            }
            this._currentLayer = this._viewer.imageryLayers.addImageryProvider(
                new Cesium.WebMapTileServiceImageryProvider(opts)
            );
            this._viewer.imageryLayers.lower(this._currentLayer);
            this._currentId = id;
        } else {
            // URL Template Provider (Esri, Sentinel, OSM)
            this._currentLayer = this._viewer.imageryLayers.addImageryProvider(
                new Cesium.UrlTemplateImageryProvider({
                    url: src.url,
                    maximumLevel: 18,
                    credit: src.name,
                })
            );
            this._viewer.imageryLayers.lower(this._currentLayer);
            this._currentId = id;
        }

        // Dropdown aktualisieren
        var sel = document.getElementById("imagery-select");
        if (sel) sel.value = id;
        var label = document.getElementById("imagery-label");
        if (label) label.textContent = src.name;
    },
};