// public/js/map/activities/activityClusters.js
// ===================================
// MAPBOX ACTIVITY CLUSTERS
// ===================================

(() => {
  "use strict";

  let mapboxMap = null;

  const clusterMarkers = new Map();

  let renderToken = 0;

  const SOURCE_ID = "activities";
  const CLUSTER_LAYER_ID = "activities-clusters";
  const COUNT_LAYER_ID = "activities-cluster-count";

  // ===================================
  // SET MAP
  // ===================================

  function setMap(map) {
    mapboxMap = map;

    console.log("[ActivityClusters] setMap");
  }

  // ===================================
  // CREA LAYER CLUSTER
  // ===================================

  function createLayer() {
    if (!mapboxMap) {
      return;
    }

    if (!mapboxMap.isStyleLoaded()) {
      return;
    }

    if (!mapboxMap.getSource(SOURCE_ID)) {
      console.warn(
        "[ActivityClusters] source activities non presente",
      );

      return;
    }

    // ---------------------------------
    // CLUSTER LAYER
    // ---------------------------------

    if (!mapboxMap.getLayer(CLUSTER_LAYER_ID)) {
      console.log(
        "[ActivityClusters] creo layer cluster",
      );

      mapboxMap.addLayer({
        id: CLUSTER_LAYER_ID,

        type: "circle",

        source: SOURCE_ID,

        filter: ["has", "point_count"],

        paint: {
          "circle-color": "#ff3333",

          "circle-radius": [
            "step",
            ["get", "point_count"],
            22,
            10,
            28,
            50,
            38,
          ],

          "circle-stroke-color": "#ffffff",

          "circle-stroke-width": 3,

          // --------------------------------
          // NASCONDI PALLINO MAPBOX
          // --------------------------------
          //
          // Il layer rimane presente per
          // queryRenderedFeatures().
          //

          "circle-opacity": 0,

          "circle-stroke-opacity": 0,
        },
      });
    }

    // ---------------------------------
    // COUNT LAYER
    // ---------------------------------

    if (!mapboxMap.getLayer(COUNT_LAYER_ID)) {
      mapboxMap.addLayer({
        id: COUNT_LAYER_ID,

        type: "symbol",

        source: SOURCE_ID,

        filter: ["has", "point_count"],

        layout: {
          "text-field": "{point_count_abbreviated}",

          "text-size": 14,
        },

        paint: {
          // Anche il numero Mapbox viene
          // sostituito dal marker HTML.

          "text-color": "#ffffff",

          "text-opacity": 0,
        },
      });
    }

    console.log(
      "[ActivityClusters] layer creati",
    );
  }

  // ===================================
  // CLUSTER VISIBILI
  // ===================================

  function getRenderedClusters() {
    if (!mapboxMap) {
      return [];
    }

    if (!mapboxMap.getLayer(CLUSTER_LAYER_ID)) {
      return [];
    }

    const rendered =
      mapboxMap.queryRenderedFeatures({
        layers: [CLUSTER_LAYER_ID],
      });

    const clusters = [];

    const seen = new Set();

    for (const feature of rendered) {
      const clusterId =
        feature.properties?.cluster_id;

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

      const id = String(clusterId);

      if (seen.has(id)) {
        continue;
      }

      seen.add(id);

      clusters.push(feature);
    }

    return clusters;
  }

  // ===================================
  // CREA ELEMENTO HTML
  // ===================================

  function createClusterElement(cluster) {
    const count =
      Number(cluster.properties?.point_count) || 0;

    const size = Math.min(
      72,
      Math.round(30 + Math.sqrt(count) * 5),
    );

    const cls =
      count > 200
        ? "cluster-xl"
        : count > 50
          ? "cluster-lg"
          : count > 10
            ? "cluster-md"
            : "cluster-sm";

    const el =
      document.createElement("div");

    el.className =
      "activity-cluster-wrapper";

    el.style.width = `${size}px`;
    el.style.height = `${size}px`;

    el.innerHTML = `
      <div
        class="gp-cluster activity-cluster ${cls}"
        style="
          width:${size}px;
          height:${size}px;
        "
      >
        <div class="gp-count">
          <span>${count}</span>
        </div>
      </div>
    `;

    return el;
  }

  // ===================================
  // CLICK CLUSTER
  // ===================================

  function handleClusterClick(
    clusterId,
    coordinates,
  ) {
    if (!mapboxMap) {
      return;
    }

    const source =
      mapboxMap.getSource(SOURCE_ID);

    if (!source) {
      return;
    }

    console.log(
      "[ActivityClusters] click cluster",
      {
        clusterId,
        coordinates,
      },
    );

    /*
     * Prima proviamo ad espandere
     * il cluster con lo zoom Mapbox.
     */

    source.getClusterExpansionZoom(
      Number(clusterId),
      (err, expansionZoom) => {
        if (err) {
          console.error(
            "[ActivityClusters] expansion zoom error",
            err,
          );

          return;
        }

        const currentZoom =
          mapboxMap.getZoom();

        const targetZoom = Math.max(
          expansionZoom,
          currentZoom + 1,
        );

        mapboxMap.easeTo({
          center: coordinates,

          zoom: targetZoom,

          duration: 600,
        });
      },
    );
  }

  // ===================================
  // CREA MARKER
  // ===================================

  function createClusterMarker(cluster) {
    if (!mapboxMap) {
      return null;
    }

    const coordinates =
      cluster.geometry?.coordinates;

    if (
      !coordinates ||
      coordinates.length < 2
    ) {
      return null;
    }

    const clusterId =
      String(
        cluster.properties?.cluster_id,
      );

    const el =
      createClusterElement(cluster);

    // ---------------------------------
    // CLICK
    // ---------------------------------

    el.addEventListener(
      "click",
      (event) => {
        event.stopPropagation();

        handleClusterClick(
          Number(clusterId),
          coordinates,
        );
      },
    );

    // ---------------------------------
    // MARKER
    // ---------------------------------

    const marker =
      new mapboxgl.Marker({
        element: el,

        anchor: "center",
      })
        .setLngLat(coordinates)
        .addTo(mapboxMap);

    marker.__clusterId = clusterId;

    return marker;
  }

  // ===================================
  // UPDATE
  // ===================================

  function update() {
    if (!mapboxMap) {
      return;
    }

    if (!mapboxMap.isStyleLoaded()) {
      return;
    }

    if (!mapboxMap.getSource(SOURCE_ID)) {
      return;
    }

    if (!mapboxMap.getLayer(CLUSTER_LAYER_ID)) {
      createLayer();
    }

    const token = ++renderToken;

    const clusters =
      getRenderedClusters();

    const currentIds =
      new Set(
        clusters.map((cluster) =>
          String(
            cluster.properties?.cluster_id,
          ),
        ),
      );

    console.log(
      "[ActivityClusters] rendered:",
      clusters.length,
    );

    // ===================================
    // CREA / AGGIORNA
    // ===================================

    for (const cluster of clusters) {
      const clusterId =
        String(
          cluster.properties?.cluster_id,
        );

      const coordinates =
        cluster.geometry?.coordinates;

      if (
        !coordinates ||
        coordinates.length < 2
      ) {
        continue;
      }

      // ---------------------------------
      // MARKER ESISTENTE
      // ---------------------------------

      if (
        clusterMarkers.has(clusterId)
      ) {
        const marker =
          clusterMarkers.get(
            clusterId,
          );

        marker.setLngLat(
          coordinates,
        );

        marker
          .getElement()
          .style.display = "";

        continue;
      }

      // ---------------------------------
      // TOKEN
      // ---------------------------------

      if (token !== renderToken) {
        continue;
      }

      // ---------------------------------
      // CREA MARKER
      // ---------------------------------

      const marker =
        createClusterMarker(cluster);

      if (!marker) {
        continue;
      }

      clusterMarkers.set(
        clusterId,
        marker,
      );
    }

    // ===================================
    // RIMUOVI NON VISIBILI
    // ===================================

    for (
      const [
        clusterId,
        marker,
      ] of clusterMarkers
    ) {
      if (
        !currentIds.has(
          String(clusterId),
        )
      ) {
        marker.remove();

        clusterMarkers.delete(
          clusterId,
        );
      }
    }
  }

  // ===================================
  // HIDE
  // ===================================

  function hide() {
    for (
      const marker of
        clusterMarkers.values()
    ) {
      marker
        .getElement()
        .style.display = "none";
    }
  }

  // ===================================
  // SHOW
  // ===================================

  function show() {
    for (
      const marker of
        clusterMarkers.values()
    ) {
      marker
        .getElement()
        .style.display = "";
    }
  }

  // ===================================
  // CLEAR
  // ===================================

  function clear() {
    renderToken++;

    for (
      const marker of
        clusterMarkers.values()
    ) {
      marker.remove();
    }

    clusterMarkers.clear();
  }

  // ===================================
  // SIZE
  // ===================================

  function size() {
    return clusterMarkers.size;
  }

  // ===================================
  // DEBUG
  // ===================================

  function debug() {
    console.log(
      "[ActivityClusters] debug",
      {
        markers:
          clusterMarkers.size,

        rendered:
          getRenderedClusters().length,

        layer:
          !!mapboxMap?.getLayer(
            CLUSTER_LAYER_ID,
          ),

        source:
          !!mapboxMap?.getSource(
            SOURCE_ID,
          ),
      },
    );
  }

  // ===================================
  // API PUBBLICA
  // ===================================

  window.MapboxActivityClusters = {
    setMap,

    createLayer,

    update,

    hide,

    show,

    clear,

    size,

    debug,

    getRenderedClusters,
  };
})();