/**
 * Funkmasten-Layer: Mobilfunkmasten aus OpenStreetMap via Overpass.
 */
const CelltowersLayer = {
    _viewer: null,
    _points: null,
    _labels: null,
    _count: 0,
    _interval: null,
    _lastBbox: null,

    start: function(viewer) {
        if (this._points) return;
        this._viewer = viewer;
        this._points = viewer.scene.primitives.add(new Cesium.PointPrimitiveCollection());
        this._labels = viewer.scene.primitives.add(new Cesium.LabelCollection());
        this._fetch();
        var self = this;
        this._interval = setInterval(function() { self._fetchIfMoved(); }, 8000);
    },

    stop: function() {
        if (this._interval) { clearInterval(this._interval); this._interval = null; }
        if (this._points && this._viewer) { this._viewer.scene.primitives.remove(this._points); this._points = null; }
        if (this._labels && this._viewer) { this._viewer.scene.primitives.remove(this._labels); this._labels = null; }
        this._count = 0;
        this._lastBbox = null;
        var c = document.getElementById('count-celltowers');
        if (c) c.textContent = '-';
    },

    _getBbox: function() {
        var rect = this._viewer.camera.computeViewRectangle();
        if (!rect) return null;
        return {
            south: Cesium.Math.toDegrees(rect.south),
            west: Cesium.Math.toDegrees(rect.west),
            north: Cesium.Math.toDegrees(rect.north),
            east: Cesium.Math.toDegrees(rect.east),
        };
    },

    _fetchIfMoved: function() {
        var bbox = this._getBbox();
        if (!bbox) return;
        // Nur bei deutlicher Bewegung neu laden
        if (this._lastBbox) {
            var dLat = Math.abs(bbox.south - this._lastBbox.south) + Math.abs(bbox.north - this._lastBbox.north);
            var dLon = Math.abs(bbox.west - this._lastBbox.west) + Math.abs(bbox.east - this._lastBbox.east);
            if (dLat + dLon < 0.5) return;
        }
        // Nur bei Zoom nah genug (< ~500 km Sichtfeld)
        var cam = this._viewer.camera.positionCartographic;
        if (cam && cam.height > 600000) return;
        this._fetch();
    },

    _fetch: function() {
        var bbox = this._getBbox();
        if (!bbox) return;
        // Viewport zu gross -> nicht laden
        if (Math.abs(bbox.north - bbox.south) > 5 || Math.abs(bbox.east - bbox.west) > 5) {
            var s = document.getElementById('status-celltowers');
            if (s) { s.textContent = 'Naeher heranzoomen'; s.classList.add('active'); }
            return;
        }
        this._lastBbox = bbox;
        var self = this;
        fetch('/api/geoint/celltowers', {
            method: 'POST',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify(bbox),
        })
        .then(function(r) { return r.json(); })
        .then(function(data) {
            self._render(data.towers || []);
        })
        .catch(function() {});
    },

    _render: function(towers) {
        if (!this._points) return;
        this._points.removeAll();
        this._labels.removeAll();

        var color = Cesium.Color.fromCssColorString('#e040fb');
        var colorDim = color.withAlpha(0.6);

        for (var i = 0; i < towers.length; i++) {
            var t = towers[i];
            this._points.add({
                position: Cesium.Cartesian3.fromDegrees(t.lon, t.lat, 0),
                pixelSize: 6,
                color: color,
                outlineColor: Cesium.Color.BLACK,
                outlineWidth: 1,
            });
            var label = t.operator || t.name || '';
            if (label && towers.length < 200) {
                this._labels.add({
                    position: Cesium.Cartesian3.fromDegrees(t.lon, t.lat, 0),
                    text: label,
                    font: '9px monospace',
                    fillColor: colorDim,
                    outlineColor: Cesium.Color.BLACK,
                    outlineWidth: 2,
                    style: Cesium.LabelStyle.FILL_AND_OUTLINE,
                    pixelOffset: new Cesium.Cartesian2(6, -4),
                    scale: 0.6,
                    distanceDisplayCondition: new Cesium.DistanceDisplayCondition(0, 100000),
                });
            }
        }
        this._count = towers.length;
        var c = document.getElementById('count-celltowers');
        if (c) c.textContent = this._count.toLocaleString('de-DE');
        var s = document.getElementById('status-celltowers');
        if (s) { s.textContent = ''; s.classList.remove('active'); }
    },
};