import Spiderfy from 'https://cdn.jsdelivr.net/npm/@nazka/map-gl-js-spiderfy@1.2.10/dist/index.modern.js';

const MAP_SELECTOR = '[data-eventmanager-map="1"]';

const escapeHtml = (value) => {
    const stringValue = String(value ?? '');

    return stringValue
        .replace(/&/g, '&')
        .replace(/</g, '&lt;')
        .replace(/>/g, '&gt;')
        .replace(/"/g, '&quot;')
        .replace(/'/g, '&#039;');
};

const parseItems = (container) => {
    const dataElementId = container.dataset.mapDataId || '';

    if (!dataElementId) {
        return [];
    }

    const payload = document.getElementById(dataElementId);

    if (!payload) {
        return [];
    }

    try {
        const parsed = JSON.parse(payload.textContent || '[]');

        if (!Array.isArray(parsed)) {
            return [];
        }

        const unique = new Map();

        parsed.forEach((item) => {
            if (!item || !['event', 'location', 'organisation'].includes(item.type)) {
                return;
            }

            const id = Number(item.id || 0);
            const latitude = Number(item.latitude);
            const longitude = Number(item.longitude);

            if (!Number.isFinite(id) || id <= 0 || !Number.isFinite(latitude) || !Number.isFinite(longitude)) {
                return;
            }

            unique.set(`${item.type}:${id}`, {
                type: item.type,
                id,
                title: String(item.title || ''),
                latitude,
                longitude,
                extra: item.extra && typeof item.extra === 'object' ? item.extra : {},
            });
        });

        return Array.from(unique.values());
    } catch (error) {
        return [];
    }
};

const popupHtmlFor = (item) => {
    if (item.type === 'event') {
        const locationTitle = escapeHtml(item.extra.locationTitle || '');
        const startDate = escapeHtml(item.extra.startDate || '');

        return [
            `<strong>${escapeHtml(item.title)}</strong>`,
            locationTitle ? `<div>${locationTitle}</div>` : '',
            startDate ? `<div>${startDate}</div>` : '',
        ].join('');
    }

    return `<strong>${escapeHtml(item.title)}</strong>`;
};

const toFeature = (item) => ({
    type: 'Feature',
    geometry: {
        type: 'Point',
        coordinates: [item.longitude, item.latitude],
    },
    properties: {
        id: item.id,
        type: item.type,
        title: item.title,
        popupHtml: popupHtmlFor(item),
    },
});

const addSimpleMarker = (map, item) => {
    const popup = new maplibregl.Popup({ offset: 20 }).setHTML(popupHtmlFor(item));

    new maplibregl.Marker()
        .setLngLat([item.longitude, item.latitude])
        .setPopup(popup)
        .addTo(map);
};

const initEventLayers = (map, eventItems) => {
    const sourceId = 'eventmanager-events-source';
    const clusterLayerId = 'eventmanager-events-clusters';
    const clusterCountLayerId = 'eventmanager-events-cluster-count';
    const unclusteredLayerId = 'eventmanager-events-unclustered';

    const features = eventItems.map(toFeature);

    map.addSource(sourceId, {
        type: 'geojson',
        data: {
            type: 'FeatureCollection',
            features,
        },
        cluster: true,
        clusterMaxZoom: 22,
        clusterRadius: 22,
    });

    map.addLayer({
        id: clusterLayerId,
        type: 'circle',
        source: sourceId,
        filter: ['has', 'point_count'],
        paint: {
            'circle-radius': 18,
            'circle-opacity': 0.8,
        },
    });

    map.addLayer({
        id: clusterCountLayerId,
        type: 'symbol',
        source: sourceId,
        filter: ['has', 'point_count'],
        layout: {
            'text-field': ['get', 'point_count'],
            'text-size': 12,
        },
    });

    map.addLayer({
        id: unclusteredLayerId,
        type: 'circle',
        source: sourceId,
        filter: ['!', ['has', 'point_count']],
        paint: {
            'circle-radius': 9,
            'circle-stroke-width': 2,
        },
    });

    const openEventPopup = (feature, coordinatesOverride = null) => {
        const popupHtml = feature?.properties?.popupHtml || '';
        const rawCoords = coordinatesOverride || feature?.geometry?.coordinates || null;

        if (!Array.isArray(rawCoords) || rawCoords.length !== 2) {
            return;
        }

        const [lng, lat] = rawCoords.map((coord) => Number(coord));

        if (!Number.isFinite(lng) || !Number.isFinite(lat)) {
            return;
        }

        new maplibregl.Popup({ offset: 15 })
            .setLngLat([lng, lat])
            .setHTML(String(popupHtml))
            .addTo(map);
    };

    map.on('click', unclusteredLayerId, (event) => {
        const feature = event.features && event.features[0] ? event.features[0] : null;

        if (!feature) {
            return;
        }

        openEventPopup(feature, event.lngLat ? [event.lngLat.lng, event.lngLat.lat] : null);
    });

    map.on('mouseenter', unclusteredLayerId, () => {
        map.getCanvas().style.cursor = 'pointer';
    });

    map.on('mouseleave', unclusteredLayerId, () => {
        map.getCanvas().style.cursor = '';
    });

    if (typeof Spiderfy === 'function') {
        const spiderfy = new Spiderfy(map, {
            closeOnLeafClick: true,
            onLeafClick: (feature, spiderEvent) => {
                const clickCoordinates = spiderEvent?.lngLat
                    ? [spiderEvent.lngLat.lng, spiderEvent.lngLat.lat]
                    : null;

                openEventPopup(feature, clickCoordinates);
            },
        });

        spiderfy.applyTo(clusterLayerId);
    } else {
        map.on('click', clusterLayerId, (event) => {
            const feature = event.features && event.features[0] ? event.features[0] : null;

            if (!feature) {
                return;
            }

            const clusterId = feature.properties?.cluster_id;

            if (undefined === clusterId || null === clusterId) {
                return;
            }

            const source = map.getSource(sourceId);

            if (!source || typeof source.getClusterExpansionZoom !== 'function') {
                return;
            }

            source.getClusterExpansionZoom(clusterId, (error, zoom) => {
                if (error) {
                    return;
                }

                map.easeTo({
                    center: event.lngLat,
                    zoom,
                });
            });
        });
    }

    map.on('mouseenter', clusterLayerId, () => {
        map.getCanvas().style.cursor = 'pointer';
    });

    map.on('mouseleave', clusterLayerId, () => {
        map.getCanvas().style.cursor = '';
    });

};

const initSingleMap = (container) => {
    if (container.dataset.mapInitialized === '1') {
        return;
    }

    const items = parseItems(container);

    if (!items.length || typeof maplibregl === 'undefined') {
        return;
    }

    container.dataset.mapInitialized = '1';

    if (typeof pmtiles !== 'undefined' && !window.__eventmanagerPmtilesRegistered) {
        const protocol = new pmtiles.Protocol();
        maplibregl.addProtocol('pmtiles', protocol.tile);
        window.__eventmanagerPmtilesRegistered = true;
    }

    const style = container.dataset.mapStyle || 'https://maps.mummert.media/metadaten/world-light.json';
    const map = new maplibregl.Map({
        container,
        style,
        zoom: 12,
        pitch: 0,
        bearing: 0,
        center: [items[0].longitude, items[0].latitude],
    });

    map.addControl(new maplibregl.NavigationControl({ visualizePitch: true }));

    const fitBounds = (coordinates) => {
        const points = coordinates.filter((coord) => Array.isArray(coord) && coord.length === 2);

        if (!points.length) {
            return;
        }

        if (1 === points.length) {
            map.setCenter(points[0]);
            map.setZoom(14);

            return;
        }

        const bounds = new maplibregl.LngLatBounds();
        points.forEach((coord) => bounds.extend(coord));

        map.fitBounds(bounds, {
            padding: 60,
            maxZoom: 15,
        });
    };

    map.on('load', () => {
        const nonEventItems = items.filter((item) => item.type !== 'event');
        const eventItems = items.filter((item) => item.type === 'event');
        const allCoordinates = items.map((item) => [item.longitude, item.latitude]);

        nonEventItems.forEach((item) => {
            addSimpleMarker(map, item);
        });

        if (eventItems.length) {
            initEventLayers(map, eventItems);
        }

        fitBounds(allCoordinates);
    });
};

const bootstrapMapModules = () => {
    const modules = document.querySelectorAll(MAP_SELECTOR);
    modules.forEach((container) => initSingleMap(container));
};

if ('loading' === document.readyState) {
    document.addEventListener('DOMContentLoaded', bootstrapMapModules, { once: true });
} else {
    bootstrapMapModules();
}