feat: add parcel search to map visualizer

app.js

@@ -1,37 +1,52 @@
 const DEFAULT_CENTER = [-8.65, 39.55];
 const API_CAPABILITIES = "/api/capabilities";
 const API_WMS = "/api/wms";
+const PARCEL_LAYER_NAME = "xpro:parcelas";
 
 const els = {
   status: document.getElementById("status"),
   layerList: document.getElementById("layer-list"),
   layerCount: document.getElementById("layer-count"),
+  parcelSearchForm: document.getElementById("parcel-search-form"),
+  parcelSearchInput: document.getElementById("parcel-search-input"),
+  parcelSearchStatus: document.getElementById("parcel-search-status"),
 };
 
 const osmLayer = new ol.layer.Tile({
   source: new ol.source.OSM(),
 });
 
-const wmsSource = new ol.source.TileWMS({
+// Use one WMS image for the viewport so GeoServer can de-conflict parcel
+// labels across the whole map, rather than placing the same label per tile.
+const wmsSource = new ol.source.ImageWMS({
   url: API_WMS,
   params: {
     LAYERS: "",
-    TILED: true,
     FORMAT: "image/png",
     TRANSPARENT: true,
   },
+  ratio: 1,
   crossOrigin: "anonymous",
 });
 
-const wmsLayer = new ol.layer.Tile({
+const wmsLayer = new ol.layer.Image({
   opacity: 0.8,
   visible: false,
   source: wmsSource,
 });
 
+const parcelSearchSource = new ol.source.Vector();
+const parcelSearchLayer = new ol.layer.Vector({
+  source: parcelSearchSource,
+  style: new ol.style.Style({
+    stroke: new ol.style.Stroke({ color: "#d9582b", width: 3 }),
+    fill: new ol.style.Fill({ color: "rgba(255, 201, 82, 0.22)" }),
+  }),
+});
+
 const map = new ol.Map({
   target: "map",
-  layers: [osmLayer, wmsLayer],
+  layers: [osmLayer, wmsLayer, parcelSearchLayer],
   view: new ol.View({
     center: ol.proj.fromLonLat(DEFAULT_CENTER),
     zoom: 7,
@@ -41,8 +56,67 @@ const map = new ol.Map({
 let availableLayers = [];
 let selectedLayers = [];
 
+els.parcelSearchForm.addEventListener("submit", searchParcela);
+
 loadLayers();
 
+async function searchParcela(event) {
+  event.preventDefault();
+
+  const parcelNumber = els.parcelSearchInput.value.trim();
+  if (!parcelNumber) {
+    updateParcelSearchStatus("Enter a parcel number to search.", "error");
+    return;
+  }
+
+  updateParcelSearchStatus("Searching for parcel…");
+  parcelSearchSource.clear();
+
+  try {
+    const params = new URLSearchParams({
+      service: "WFS",
+      version: "2.0.0",
+      request: "GetFeature",
+      typeNames: PARCEL_LAYER_NAME,
+      outputFormat: "application/json",
+      srsName: "EPSG:3857",
+      CQL_FILTER: `cod_parcela = '${escapeCqlLiteral(parcelNumber)}'`,
+    });
+    const response = await fetch(`${API_WMS}?${params}`);
+
+    if (!response.ok) {
+      throw new Error(`Search failed with status ${response.status}.`);
+    }
+
+    const featureCollection = await response.json();
+    const features = new ol.format.GeoJSON().readFeatures(featureCollection, {
+      featureProjection: "EPSG:3857",
+    });
+
+    if (!features.length) {
+      updateParcelSearchStatus(`No parcel found with number “${parcelNumber}”.`, "error");
+      return;
+    }
+
+    parcelSearchSource.addFeatures(features);
+    map.getView().fit(parcelSearchSource.getExtent(), {
+      padding: [64, 64, 64, 64],
+      duration: 500,
+      maxZoom: features.length === 1 ? 19 : 16,
+    });
+
+    updateParcelSearchStatus(
+      features.length === 1
+        ? `Found parcel ${parcelNumber}.`
+        : `Found ${features.length} parcels numbered ${parcelNumber}.`,
+      "success",
+    );
+  } catch (error) {
+    console.error(error);
+    updateParcelSearchStatus(error.message || "Unable to search for that parcel.", "error");
+  }
+}
+
 async function loadLayers() {
   updateStatus("Loading WMS layers...");
 
@@ -198,3 +272,12 @@ function updateStatus(message, tone) {
   els.status.textContent = message;
   els.status.className = tone ? `status ${tone}` : "status";
 }
+
+function updateParcelSearchStatus(message, tone) {
+  els.parcelSearchStatus.textContent = message;
+  els.parcelSearchStatus.className = tone ? `status ${tone}` : "status";
+}
+
+function escapeCqlLiteral(value) {
+  return value.replaceAll("'", "''");
+}