const i18n = XProI18n.createI18n();
const t = i18n.t;

const DEFAULT_CENTER = [-8.65, 39.55];
const DEFAULT_ZOOM = 7;
const DEFAULT_ROTATION = 0;
const API_CAPABILITIES = "/api/capabilities";
const API_WMS = "/api/wms";
const PARCEL_LAYER_NAME = "xpro:parcelas";
const BUILDING_LAYER_NAME = "xpro:predios";
const DWELLING_PARCEL_LAYER_NAME = "xpro:parcelas_habitacao";
const FEATURE_INFO_LAYER_NAMES = new Set(["parcelas", "predios"]);
const DEVICE_ORIENTATION_EVENTS = ["deviceorientationabsolute", "deviceorientation"];
const COMPASS_HEADING_DEADBAND = 2;
const SMALL_SCREEN_MEDIA_QUERY = "(max-width: 920px)";
const MODAL_VIEWPORT_PADDING = 24;
const MESSAGE_DURATIONS = {
  info: 5000,
  warning: 6500,
  error: 9000,
};
const MAP_URL_PARAMS = {
  latitude: "map-lat",
  longitude: "map-lon",
  zoom: "map-zoom",
  rotation: "map-rotation",
  layers: "map-layers",
  background: "map-background",
  featureLayer: "map-feature-layer",
  featureId: "map-feature-id",
};
const BACKGROUND_VALUES = new Set(["soft", "openstreetmap", "satellite"]);

const els = {
  appShell: document.querySelector(".app-shell"),
  messageRegion: document.getElementById("message-region"),
  sidebar: document.getElementById("sidebar"),
  sidebarOpen: document.getElementById("sidebar-open"),
  sidebarClose: document.getElementById("sidebar-close"),
  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"),
  backgroundSelect: document.getElementById("background-select"),
  settingsOpen: document.getElementById("settings-open"),
  settingsModal: document.getElementById("settings-modal"),
  settingsModalClose: document.getElementById("settings-modal-close"),
  settingsForm: document.getElementById("settings-form"),
  languageSelect: document.getElementById("language-select"),
  featureModal: document.getElementById("feature-modal"),
  featureModalDialog: document.querySelector(".feature-modal-dialog"),
  featureModalClose: document.getElementById("feature-modal-close"),
  featureModalContent: document.getElementById("feature-modal-content"),
};

localizeDocument();
populateLanguageOptions();

// A view link must be complete before it is applied. This prevents a typo or
// a partially copied URL from leaving the map in an arbitrary half-restored
// state.
let sharedMapState = readSharedMapState();
let urlStateReady = false;
let applyingSharedMapState = false;

const softBasemapLayer = new ol.layer.Tile({
  source: new ol.source.XYZ({
    url: "https://{a-d}.basemaps.cartocdn.com/light_nolabels/{z}/{x}/{y}.png",
    attributions: t("softAttribution"),
  }),
});

const openStreetMapLayer = new ol.layer.Tile({
  visible: false,
  source: new ol.source.OSM(),
});

const satelliteLayer = new ol.layer.Tile({
  visible: false,
  source: new ol.source.XYZ({
    url: "https://server.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer/tile/{z}/{y}/{x}",
    attributions: t("satelliteAttribution"),
  }),
});

// 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: "",
    FORMAT: "image/png",
    TRANSPARENT: true,
  },
  // Keep a slightly oversized image while the compass rotates the view so a
  // small heading change does not require a new WMS image every time.
  ratio: 1.5,
  crossOrigin: "anonymous",
});

const wmsLayer = new ol.layer.Image({
  opacity: 0.8,
  visible: false,
  source: wmsSource,
});

const dwellingParcelSource = new ol.source.Vector();
const dwellingParcelLayer = new ol.layer.Vector({
  source: dwellingParcelSource,
  // The pale halo keeps the red dwelling boundary distinct over every
  // supported basemap and the existing parcel fills.
  style: [
    new ol.style.Style({
      stroke: new ol.style.Stroke({ color: "rgba(255, 255, 255, 0.9)", width: 6 }),
    }),
    new ol.style.Style({
      stroke: new ol.style.Stroke({ color: "#d71920", width: 3.5 }),
    }),
  ],
});

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 selectedFeatureSource = new ol.source.Vector();
const selectedFeatureLayer = new ol.layer.Vector({
  source: selectedFeatureSource,
  style: [
    new ol.style.Style({
      stroke: new ol.style.Stroke({ color: "rgba(255, 255, 255, 0.9)", width: 6 }),
    }),
    new ol.style.Style({
      stroke: new ol.style.Stroke({ color: "#1877d1", width: 3.5 }),
    }),
  ],
});

const areaZoomInteraction = new ol.interaction.DragBox({
  className: "ol-area-zoom-box",
  condition: ol.events.condition.primaryAction,
  minArea: 16,
});
areaZoomInteraction.setActive(false);
let areaZoomButton;
let deviceCompassButton;
let deviceCompassStatus;
let deviceCompassActive = false;
let deviceCompassSource;
let lastCompassHeading;
let pendingCompassHeading;
let compassAnimationFrame;
let deviceCompassFallbackTimer;
let modalDrag;
let featureHoverRequest;
let featureHoverRequestId = 0;
let featureHoverTimer;
let featureModalRequestId = 0;
let featureModalRestoreRequestId = 0;

const map = new ol.Map({
  target: "map",
  controls: ol.control
    .defaults.defaults({
      rotate: false,
      zoomOptions: {
        zoomInTipLabel: t("zoomIn"),
        zoomOutTipLabel: t("zoomOut"),
      },
      attributionOptions: {
        tipLabel: t("attribution"),
      },
    })
    .extend([
      createVisibleLayersExtentControl(),
      createAreaZoomControl(),
      ...(shouldShowDeviceCompassControl() ? [createDeviceCompassControl()] : []),
      createShareControl(),
      createNorthPointerControl(),
    ]),
  layers: [
    softBasemapLayer,
    openStreetMapLayer,
    satelliteLayer,
    wmsLayer,
    dwellingParcelLayer,
    parcelSearchLayer,
    selectedFeatureLayer,
  ],
  view: new ol.View({
    center: ol.proj.fromLonLat(sharedMapState.view?.center || DEFAULT_CENTER),
    zoom: sharedMapState.view?.zoom ?? DEFAULT_ZOOM,
    rotation: sharedMapState.view?.rotation ?? DEFAULT_ROTATION,
  }),
});
map.addInteraction(areaZoomInteraction);

let availableLayers = [];
let selectedLayers = [];

// Keep the existing responsive breakpoint as the source of truth for the
// initial panel state. The menu remains available through the open control.
if (window.matchMedia(SMALL_SCREEN_MEDIA_QUERY).matches) {
  setSidebarCollapsed(true, { focus: false });
}

els.parcelSearchForm.addEventListener("submit", searchParcela);
els.backgroundSelect.addEventListener("change", syncBackground);
els.settingsOpen.addEventListener("click", openSettingsModal);
els.settingsModalClose.addEventListener("click", closeSettingsModal);
els.settingsForm.addEventListener("submit", applySettings);
els.settingsModal.addEventListener("click", (event) => {
  if (event.target.matches("[data-settings-modal-close]")) {
    closeSettingsModal();
  }
});
els.sidebarOpen.addEventListener("click", () => setSidebarCollapsed(false));
els.sidebarClose.addEventListener("click", () => setSidebarCollapsed(true));
els.featureModalClose.addEventListener("click", closeFeatureModal);
els.featureModalContent.addEventListener("click", handleFeatureModalNavigation);
els.featureModalDialog.addEventListener("pointerdown", startFeatureModalDrag);
els.featureModalDialog.addEventListener("pointermove", dragFeatureModal);
els.featureModalDialog.addEventListener("pointerup", stopFeatureModalDrag);
els.featureModalDialog.addEventListener("pointercancel", stopFeatureModalDrag);
els.featureModal.addEventListener("click", (event) => {
  if (event.target.matches("[data-feature-modal-close]")) {
    closeFeatureModal();
  }
});
document.addEventListener("keydown", (event) => {
  if (event.key === "Escape") {
    if (!els.settingsModal.hidden) {
      closeSettingsModal();
    } else if (!els.featureModal.hidden) {
      closeFeatureModal();
    } else if (areaZoomInteraction.getActive()) {
      setAreaZoomMode(false);
    } else if (!els.appShell.classList.contains("sidebar-is-collapsed")) {
      setSidebarCollapsed(true);
    }
  }
});
window.addEventListener("resize", keepFeatureModalInViewport);
window.addEventListener("popstate", restoreSharedMapState);
map.on("singleclick", showFeatureInformation);
map.on("pointermove", updateFeatureCursor);
map.on("moveend", syncSharedMapStateToUrl);
map.getView().on("change:rotation", syncSharedMapStateToUrl);
map.getViewport().addEventListener("pointerleave", clearFeatureCursor);
areaZoomInteraction.on("boxend", zoomToSelectedArea);
areaZoomInteraction.on("boxcancel", () => {
  // A click or a very short drag is not a selection. Exit on the next frame so
  // cancelling a drag while disabling the interaction cannot recursively
  // trigger another cancellation.
  requestAnimationFrame(() => {
    if (areaZoomInteraction.getActive()) {
      setAreaZoomMode(false);
    }
  });
});

if (sharedMapState.background) {
  els.backgroundSelect.value = sharedMapState.background;
  syncBackground();
}

loadLayers();

function setSidebarCollapsed(collapsed, { focus = true } = {}) {
  els.appShell.classList.toggle("sidebar-is-collapsed", collapsed);
  els.sidebar.inert = collapsed;
  els.sidebarOpen.setAttribute("aria-expanded", String(!collapsed));

  if (collapsed && focus) {
    els.sidebarOpen.focus();
  }
}

function localizeDocument() {
  document.documentElement.lang = i18n.language;
  document.querySelectorAll("[data-i18n]").forEach((element) => {
    element.textContent = t(element.dataset.i18n);
  });
  document.querySelectorAll("[data-i18n-aria-label]").forEach((element) => {
    element.setAttribute("aria-label", t(element.dataset.i18nAriaLabel));
  });
  document.querySelectorAll("[data-i18n-placeholder]").forEach((element) => {
    element.setAttribute("placeholder", t(element.dataset.i18nPlaceholder));
  });
}

function populateLanguageOptions() {
  const browserOption = document.createElement("option");
  browserOption.value = "browser";
  browserOption.textContent = t("useBrowserDefault");
  const languageOptions = i18n.supportedLanguages.map((language) => {
    const option = document.createElement("option");
    option.value = language;
    option.lang = language;
    option.textContent = XProI18n.TRANSLATIONS[language].languageName;
    return option;
  });
  els.languageSelect.replaceChildren(browserOption, ...languageOptions);
  els.languageSelect.value = i18n.preference || "browser";
}

function openSettingsModal() {
  els.languageSelect.value = i18n.preference || "browser";
  els.settingsModal.hidden = false;
  els.languageSelect.focus();
}

function closeSettingsModal() {
  els.settingsModal.hidden = true;
  els.settingsOpen.focus();
}

function applySettings(event) {
  event.preventDefault();
  i18n.setLanguage(els.languageSelect.value === "browser" ? null : els.languageSelect.value);
  // Reload so all transient statuses, map controls, and any open feature
  // dialog are recreated consistently in the newly selected language. The
  // current map view is already represented in the URL and is preserved.
  window.location.reload();
}

function createNorthPointerIcon() {
  const icon = document.createElement("img");
  icon.className = "north-pointer-icon";
  icon.src = "./assets/icons/north-pointer.svg";
  icon.alt = "";
  return icon;
}

function createNorthPointerControl() {
  const control = new ol.control.Rotate({
    autoHide: true,
    label: createNorthPointerIcon(),
    tipLabel: t("resetNorth"),
  });

  // Resetting the view while compass orientation remains subscribed lets the
  // next device event rotate it again. Stop the subscription when the north
  // pointer is used so its reset remains in effect.
  control.element.querySelector("button").addEventListener("click", () => {
    if (deviceCompassActive) {
      stopDeviceCompass();
    }
  });

  return control;
}

function createVisibleLayersExtentControl() {
  const element = document.createElement("div");
  element.className = "ol-visible-layers-extent ol-unselectable ol-control";

  const button = document.createElement("button");
  button.type = "button";
  button.title = t("zoomVisibleLayers");
  button.setAttribute("aria-label", t("zoomVisibleLayers"));
  button.textContent = "⤢";
  button.addEventListener("click", () => fitToVisibleLayers());

  element.append(button);
  return new ol.control.Control({ element });
}

function createShareControl() {
  const element = document.createElement("div");
  element.className = "ol-share ol-unselectable ol-control";

  const button = document.createElement("button");
  button.type = "button";
  button.title = t("copyMapLink");
  button.setAttribute("aria-label", t("copyMapLink"));
  const icon = document.createElement("span");
  icon.className = "material-symbols-outlined";
  icon.setAttribute("aria-hidden", "true");
  icon.textContent = "share";
  button.append(icon);
  button.addEventListener("click", copyCurrentViewUrl);

  element.append(button);
  return new ol.control.Control({ element });
}

async function copyCurrentViewUrl() {
  // Ensure the copied address reflects state changes that may not yet have
  // reached the next map movement event.
  syncSharedMapStateToUrl();

  try {
    if (!navigator.clipboard?.writeText) {
      throw new Error(t("clipboardUnavailable"));
    }

    await navigator.clipboard.writeText(window.location.href);
    showMessage(t("mapLinkCopied"));
  } catch (error) {
    console.error(error);
    showMessage(t("mapLinkCopyFailed"), {
      type: "error",
    });
  }
}

function createAreaZoomControl() {
  const element = document.createElement("div");
  element.className = "ol-area-zoom ol-unselectable ol-control";

  const button = document.createElement("button");
  button.type = "button";
  button.title = t("zoomArea");
  button.setAttribute("aria-label", t("zoomArea"));
  button.setAttribute("aria-pressed", "false");

  const icon = document.createElement("img");
  icon.className = "area-zoom-icon";
  icon.src = "./assets/icons/area-zoom.svg";
  icon.alt = "";
  button.append(icon);

  button.addEventListener("click", () => setAreaZoomMode(!areaZoomInteraction.getActive()));
  element.append(button);
  areaZoomButton = button;

  return new ol.control.Control({ element });
}

function createDeviceCompassControl() {
  const element = document.createElement("div");
  element.className = "ol-device-compass ol-unselectable ol-control";

  const button = document.createElement("button");
  button.type = "button";
  button.setAttribute("aria-pressed", "false");

  const status = document.createElement("span");
  status.id = "device-compass-status";
  status.className = "visually-hidden";
  status.setAttribute("role", "status");
  button.setAttribute("aria-describedby", status.id);

  const icon = createNorthPointerIcon();
  icon.classList.add("device-compass-icon");
  button.append(icon);
  button.addEventListener("click", toggleDeviceCompass);

  element.append(button, status);
  deviceCompassButton = button;
  deviceCompassStatus = status;
  updateDeviceCompassButton();

  return new ol.control.Control({ element });
}

function shouldShowDeviceCompassControl() {
  return window.matchMedia?.("(any-pointer: coarse)").matches || navigator.maxTouchPoints > 0;
}

async function toggleDeviceCompass() {
  if (deviceCompassActive) {
    stopDeviceCompass();
    return;
  }

  if (!window.isSecureContext) {
    updateDeviceCompassButton(t("compassRequiresHttps"));
    return;
  }

  if (!("DeviceOrientationEvent" in window)) {
    updateDeviceCompassButton(t("compassUnavailable"));
    return;
  }

  try {
    const permission = await requestDeviceOrientationPermission();
    if (permission !== "granted") {
      updateDeviceCompassButton(t("compassPermissionDenied"));
      return;
    }

    deviceCompassSource = null;
    lastCompassHeading = null;
    deviceCompassActive = true;
    window.addEventListener(DEVICE_ORIENTATION_EVENTS[0], syncMapToDeviceCompass);
    // Prefer an absolute event, but retain support for browsers (notably iOS)
    // that expose only the standard orientation event.
    deviceCompassFallbackTimer = window.setTimeout(() => {
      if (!deviceCompassSource && deviceCompassActive) {
        window.addEventListener(DEVICE_ORIENTATION_EVENTS[1], syncMapToDeviceCompass);
      }
    }, 300);
    updateDeviceCompassButton(t("compassOn"));
  } catch (error) {
    console.error(error);
    updateDeviceCompassButton(t("compassStartFailed"));
  }
}

function requestDeviceOrientationPermission() {
  if (typeof DeviceOrientationEvent.requestPermission !== "function") {
    return Promise.resolve("granted");
  }

  // iOS requires this call to be made directly from the button interaction.
  return DeviceOrientationEvent.requestPermission();
}

function stopDeviceCompass() {
  DEVICE_ORIENTATION_EVENTS.forEach((eventName) => {
    window.removeEventListener(eventName, syncMapToDeviceCompass);
  });
  clearTimeout(deviceCompassFallbackTimer);
  deviceCompassFallbackTimer = null;
  if (compassAnimationFrame) {
    cancelAnimationFrame(compassAnimationFrame);
  }
  compassAnimationFrame = null;
  pendingCompassHeading = null;
  deviceCompassSource = null;
  lastCompassHeading = null;
  deviceCompassActive = false;
  updateDeviceCompassButton(t("compassOff"));
}

function syncMapToDeviceCompass(event) {
  // Firefox and some Android browsers dispatch both streams. Once the
  // absolute stream arrives, never let a relative update overwrite it.
  if (event.type === "deviceorientationabsolute") {
    deviceCompassSource = "absolute";
    clearTimeout(deviceCompassFallbackTimer);
    window.removeEventListener(DEVICE_ORIENTATION_EVENTS[1], syncMapToDeviceCompass);
  } else if (deviceCompassSource === "absolute") {
    return;
  } else {
    deviceCompassSource = "standard";
  }

  const heading = getCompassHeading(event);

  if (heading == null || headingDifference(heading, lastCompassHeading) < COMPASS_HEADING_DEADBAND) {
    return;
  }

  pendingCompassHeading = heading;
  if (compassAnimationFrame) {
    return;
  }

  compassAnimationFrame = requestAnimationFrame(() => {
    compassAnimationFrame = null;
    lastCompassHeading = pendingCompassHeading;
    // OpenLayers applies a view rotation in the inverse direction of the map
    // image. Match the device heading by rotating the view the other way.
    map.getView().setRotation((-pendingCompassHeading * Math.PI) / 180);
  });
}

function getCompassHeading(event) {
  if (typeof event.webkitCompassHeading === "number" && Number.isFinite(event.webkitCompassHeading)) {
    return normalizeDegrees(event.webkitCompassHeading);
  }

  if (typeof event.alpha !== "number" || !Number.isFinite(event.alpha)) {
    return null;
  }

  // Standard orientation events report a counter-clockwise alpha angle. Add
  // the current screen angle so the heading remains correct in landscape.
  return normalizeDegrees(360 - event.alpha + getScreenOrientationAngle());
}

function getScreenOrientationAngle() {
  const angle = window.screen?.orientation?.angle ?? window.orientation ?? 0;
  return Number.isFinite(Number(angle)) ? Number(angle) : 0;
}

function normalizeDegrees(degrees) {
  return ((degrees % 360) + 360) % 360;
}

function headingDifference(first, second) {
  if (second == null) {
    return Infinity;
  }

  return Math.abs(normalizeDegrees(first - second + 180) - 180);
}

function updateDeviceCompassButton(message) {
  if (!deviceCompassButton) {
    return;
  }

  const label = deviceCompassActive
    ? t("compassTurnOff")
    : t("compassAlign");
  deviceCompassButton.setAttribute("aria-pressed", String(deviceCompassActive));
  deviceCompassButton.setAttribute("aria-label", label);
  deviceCompassButton.title = message || label;
  if (message && deviceCompassStatus) {
    deviceCompassStatus.textContent = message;
  }
}

/**
 * Display a short, non-blocking application message. Callers can override
 * `duration` in milliseconds; errors have the longest default reading time.
 */
function showMessage(message, { type = "info", duration = MESSAGE_DURATIONS[type] } = {}) {
  if (!els.messageRegion || !message) {
    return;
  }

  const supportedTypes = new Set(Object.keys(MESSAGE_DURATIONS));
  const messageType = supportedTypes.has(type) ? type : "info";
  const displayDuration = Number.isFinite(duration) && duration > 0
    ? duration
    : MESSAGE_DURATIONS[messageType];
  const toast = document.createElement("div");
  toast.className = `message message--${messageType}`;
  toast.setAttribute("role", messageType === "error" ? "alert" : "status");
  toast.style.setProperty("--message-duration", `${displayDuration}ms`);

  const text = document.createElement("p");
  text.className = "message-text";
  text.textContent = message;

  const dismiss = document.createElement("button");
  dismiss.className = "message-dismiss";
  dismiss.type = "button";
  dismiss.setAttribute("aria-label", t("dismissMessage"));
  dismiss.textContent = "×";

  const progress = document.createElement("span");
  progress.className = "message-progress";
  progress.setAttribute("aria-hidden", "true");

  let timer = window.setTimeout(removeMessage, displayDuration);
  function removeMessage() {
    if (timer === undefined) {
      return;
    }

    window.clearTimeout(timer);
    timer = undefined;
    toast.classList.add("is-leaving");
    window.setTimeout(() => toast.remove(), 180);
  }

  dismiss.addEventListener("click", removeMessage, { once: true });
  toast.append(text, dismiss, progress);
  els.messageRegion.append(toast);
}

function setAreaZoomMode(active) {
  areaZoomInteraction.setActive(active);
  map.getViewport().classList.toggle("area-zoom-is-active", active);
  areaZoomButton?.setAttribute("aria-pressed", String(active));
  areaZoomButton?.setAttribute(
    "title",
    active ? t("exitAreaZoom") : t("zoomArea"),
  );

  if (active) {
    clearFeatureCursor();
    closeFeatureModal();
  }
}

function zoomToSelectedArea() {
  const extent = areaZoomInteraction.getGeometry()?.getExtent();

  if (extent && extent.every(Number.isFinite)) {
    map.getView().fit(extent, {
      padding: [64, 64, 64, 64],
      duration: 500,
      maxZoom: 19,
    });
  }

  setAreaZoomMode(false);
}

async function searchParcela(event) {
  event.preventDefault();

  const parcelNumber = els.parcelSearchInput.value.trim();
  if (!parcelNumber) {
    updateParcelSearchStatus(t("enterParcel"), "error");
    showMessage(t("enterParcel"), { type: "warning" });
    return;
  }

  updateParcelSearchStatus(t("searchingParcel"));
  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: buildParcelSearchFilter(parcelNumber),
    });
    const response = await fetch(`${API_WMS}?${params}`);

    if (!response.ok) {
      throw new Error(t("searchFailedStatus", { status: response.status }));
    }

    const featureCollection = await response.json();
    const features = new ol.format.GeoJSON().readFeatures(featureCollection, {
      featureProjection: "EPSG:3857",
    });

    if (!features.length) {
      const notFoundMessage = t("noParcelFound", { parcelNumber });
      updateParcelSearchStatus(notFoundMessage, "error");
      showMessage(notFoundMessage, { type: "warning" });
      return;
    }

    parcelSearchSource.addFeatures(features);
    map.getView().fit(parcelSearchSource.getExtent(), {
      padding: [64, 64, 64, 64],
      duration: 500,
      maxZoom: features.length === 1 ? 19 : 16,
    });

    const searchMessage = features.length === 1
      ? t("foundParcel", { parcelNumber })
      : t("foundParcels", { count: features.length, parcelNumber });
    updateParcelSearchStatus(searchMessage, "success");
    showMessage(searchMessage);
  } catch (error) {
    console.error(error);
    const searchMessage = error.message || t("parcelSearchFailed");
    updateParcelSearchStatus(searchMessage, "error");
    showMessage(searchMessage, { type: "error" });
  }
}

function buildParcelSearchFilter(parcelNumber) {
  const escapedParcelNumber = escapeCqlLiteral(parcelNumber);

  // Whole parcel numbers identify a group: 278 includes sub-parcels such as
  // 278.1 and 278.2. A supplied sub-parcel number remains an exact lookup.
  if (/^\d+$/.test(parcelNumber)) {
    return `(cod_parcela = '${escapedParcelNumber}' OR cod_parcela LIKE '${escapedParcelNumber}.%')`;
  }

  return `cod_parcela = '${escapedParcelNumber}'`;
}

async function loadLayers() {
  updateStatus(t("loadingWmsLayers"));

  try {
    const capabilities = await loadCapabilities();
    availableLayers = extractLayers(capabilities);
    selectedLayers = selectedLayersFromSharedMapState(sharedMapState);

    renderLayerList();
    syncSelectedLayers();
    await loadDwellingParcels();
    // The normal first-load fit remains the fallback, but must not overwrite
    // the exact location represented by a shared view link.
    if (!sharedMapState.view) {
      fitToLayerExtent(availableLayers[0]);
    }
    restoreSharedFeatureModal();

    updateStatus("");
  } catch (error) {
    console.error(error);
    const loadMessage = error.message || t("wmsLoadFailed");
    updateStatus(loadMessage, "error");
    showMessage(loadMessage, { type: "error" });
    availableLayers = [];
    selectedLayers = [];
    dwellingParcelSource.clear();
    dwellingParcelLayer.setVisible(false);
    renderLayerList();
    syncSelectedLayers();
  } finally {
    // Do not replace a shared URL while layer discovery is still deciding
    // which layers it represents. Once ready, keep a canonical, copyable URL
    // for the current map state even if GeoServer was unavailable.
    urlStateReady = true;
    syncSharedMapStateToUrl();
  }
}

async function loadCapabilities() {
  const url = new URL(API_CAPABILITIES, window.location.origin);

  const response = await fetch(url);

  if (!response.ok) {
    throw new Error(t("geoserverConnectionFailed", { status: response.status }));
  }

  return response.text();
}

function extractLayers(xmlText) {
  const parser = new DOMParser();
  const xml = parser.parseFromString(xmlText, "text/xml");
  const capabilityNode = firstChildByName(xml.documentElement, "Capability");
  const rootLayerNode = firstChildByName(capabilityNode, "Layer");
  const nodes = collectNamedLayers(rootLayerNode);

  return nodes
    .map((layerNode) => {
      const name = textFromChild(layerNode, "Name");
      const title = textFromChild(layerNode, "Title") || name;
      const bbox = firstChildByName(layerNode, "EX_GeographicBoundingBox");
      const extent = bbox
        ? [
            Number(textFromChild(bbox, "westBoundLongitude")),
            Number(textFromChild(bbox, "southBoundLatitude")),
            Number(textFromChild(bbox, "eastBoundLongitude")),
            Number(textFromChild(bbox, "northBoundLatitude")),
          ]
        : null;

      return { name, title, extent };
    })
    .filter((layer) => layer.name);
}

function renderLayerList() {
  const userVisibleLayers = availableLayers.filter((layer) => !isInternalLayer(layer.name));
  els.layerCount.textContent = String(userVisibleLayers.length);

  if (!userVisibleLayers.length) {
    els.layerList.className = "layer-list empty";
    els.layerList.textContent = t("noPublishedLayers");
    return;
  }

  els.layerList.className = "layer-list";
  els.layerList.replaceChildren();

  userVisibleLayers.forEach((layer) => {
    const label = document.createElement("label");
    label.className = "layer-item";

    const checkbox = document.createElement("input");
    checkbox.type = "checkbox";
    checkbox.checked = selectedLayers.includes(layer.name);
    checkbox.addEventListener("change", () => {
      selectedLayers = checkbox.checked
        ? [...new Set([...selectedLayers, layer.name])]
        : selectedLayers.filter((name) => name !== layer.name);
      syncSelectedLayers();
    });

    const title = document.createElement("span");
    title.className = "layer-title";
    title.textContent = layer.title;

    label.append(checkbox, title);
    els.layerList.append(label);
  });
}

function syncSelectedLayers() {
  const orderedSelectedLayers = availableLayers
    .map((layer) => layer.name)
    .filter((name) => selectedLayers.includes(name));

  wmsLayer.setVisible(selectedLayers.length > 0);
  wmsSource.updateParams({
    LAYERS: [...orderedSelectedLayers].reverse().join(","),
    _: Date.now(),
  });
  dwellingParcelLayer.setVisible(
    selectedLayers.some((name) => {
      const layerName = unqualifiedLayerName(name);
      return layerName === "parcelas" || layerName === unqualifiedLayerName(DWELLING_PARCEL_LAYER_NAME);
    }),
  );
  clearFeatureCursor();
  syncSharedMapStateToUrl();
}

function isInternalLayer(name) {
  return unqualifiedLayerName(name) === unqualifiedLayerName(DWELLING_PARCEL_LAYER_NAME);
}

async function loadDwellingParcels() {
  const publishedDwellingLayer = availableLayers.find(
    (layer) => unqualifiedLayerName(layer.name) === unqualifiedLayerName(DWELLING_PARCEL_LAYER_NAME),
  );

  dwellingParcelSource.clear();
  if (!publishedDwellingLayer) {
    console.warn("The dwelling parcel layer is not published by GeoServer.");
    return;
  }

  try {
    const params = new URLSearchParams({
      service: "WFS",
      version: "2.0.0",
      request: "GetFeature",
      typeNames: publishedDwellingLayer.name,
      outputFormat: "application/json",
      srsName: "EPSG:3857",
    });
    const response = await fetch(`${API_WMS}?${params}`);

    if (!response.ok) {
      throw new Error(`Dwelling parcel request failed with status ${response.status}.`);
    }

    const featureCollection = await response.json();
    const features = new ol.format.GeoJSON().readFeatures(featureCollection, {
      featureProjection: "EPSG:3857",
    });
    dwellingParcelSource.addFeatures(features);
  } catch (error) {
    // Keep the normal map usable when a deployment has not yet published the
    // optional layer; the error remains available for operational diagnosis.
    console.error(error);
  }
}

async function showFeatureInformation(event) {
  if (areaZoomInteraction.getActive()) {
    return;
  }

  try {
    const feature = await getFeatureAtCoordinate(event.coordinate);
    if (feature) {
      openFeatureModal(feature);
    }
  } catch (error) {
    console.error(error);
  }
}

function updateFeatureCursor(event) {
  if (event.dragging || areaZoomInteraction.getActive()) {
    clearFeatureCursor();
    return;
  }

  window.clearTimeout(featureHoverTimer);
  const requestId = ++featureHoverRequestId;
  const coordinate = [...event.coordinate];
  featureHoverTimer = window.setTimeout(async () => {
    featureHoverRequest?.abort();
    featureHoverRequest = new AbortController();

    try {
      const feature = await getFeatureAtCoordinate(coordinate, featureHoverRequest.signal);
      if (requestId === featureHoverRequestId) {
        map.getViewport().style.cursor = feature ? "pointer" : "";
      }
    } catch (error) {
      if (error.name !== "AbortError" && requestId === featureHoverRequestId) {
        map.getViewport().style.cursor = "";
      }
    }
  }, 120);
}

function clearFeatureCursor() {
  window.clearTimeout(featureHoverTimer);
  featureHoverRequestId += 1;
  featureHoverRequest?.abort();
  featureHoverRequest = undefined;
  map.getViewport().style.cursor = "";
}

async function getFeatureAtCoordinate(coordinate, signal) {
  const queryLayers = availableLayers
    .map((layer) => layer.name)
    .filter(
      (name) => selectedLayers.includes(name) && FEATURE_INFO_LAYER_NAMES.has(unqualifiedLayerName(name)),
    );

  if (!queryLayers.length) {
    return null;
  }

  const url = wmsSource.getFeatureInfoUrl(coordinate, map.getView().getResolution(), "EPSG:3857", {
    INFO_FORMAT: "application/json",
    QUERY_LAYERS: queryLayers.join(","),
    FEATURE_COUNT: 1,
  });

  if (!url) {
    return null;
  }

  const response = await fetch(url, { signal });
  if (!response.ok) {
    throw new Error(`Feature information failed with status ${response.status}.`);
  }

  return (await response.json()).features?.[0] || null;
}

function openFeatureModal(feature) {
  const layerName = unqualifiedLayerName(feature.id?.split(".")[0] || "");
  const isParcel = layerName === "parcelas" || feature.properties?.cod_parcela != null;
  featureModalRestoreRequestId += 1;
  sharedMapState.feature = featureReference(feature, isParcel);
  const requestId = ++featureModalRequestId;
  highlightFeature(feature);
  els.featureModal.hidden = false;
  renderFeatureModal(feature, isParcel, requestId);
  els.featureModalClose.focus();
  syncSharedMapStateToUrl();
}

function highlightFeature(feature) {
  selectedFeatureSource.clear();
  const geometry = new ol.format.GeoJSON().readGeometry(feature.geometry, {
    featureProjection: "EPSG:3857",
  });

  if (geometry) {
    selectedFeatureSource.addFeature(new ol.Feature(geometry));
  }
}

async function renderFeatureModal(feature, isParcel, requestId) {
  const content = document.createDocumentFragment();
  const properties = feature.properties || {};
  const featureId = isParcel ? properties.cod_parcela : properties.cod_predio;

  content.append(createFeatureHeading(isParcel ? t("parcel") : t("building"), featureId));
  content.append(createFeatureDetails([[t("area"), formatFeatureArea(feature)]]));

  if (isParcel) {
    if (isDwellingParcel(feature)) {
      const inhabited = document.createElement("p");
      inhabited.className = "feature-inhabited";
      inhabited.textContent = t("inhabited");
      content.append(inhabited);
    }

    if (properties.predio_uuid) {
      content.append(createFeatureNavigation(
        t("viewCorrespondingBuilding"),
        BUILDING_LAYER_NAME,
        properties.predio_uuid,
      ));
    }
  } else {
    const parcels = await getFeaturesByProperty(PARCEL_LAYER_NAME, "predio_uuid", properties.predio_uuid);
    const section = document.createElement("section");
    section.className = "feature-associations";
    const heading = document.createElement("h3");
    heading.textContent = t("associatedParcels");
    section.append(heading);

    if (parcels.length) {
      const list = document.createElement("ul");
      parcels.forEach((parcel) => {
        const item = document.createElement("li");
        const link = createFeatureNavigation(
          "",
          PARCEL_LAYER_NAME,
          parcel.properties?.parcela_uuid,
        );
        link.className = "feature-association";
        const parcelNumber = parcel.properties?.cod_parcela || "";
        link.setAttribute("aria-label", t("viewParcel", { parcelNumber }).trim());
        const label = document.createElement("span");
        label.className = "feature-association-label";
        label.textContent = t("parcelWithNumber", {
          parcelNumber: parcelNumber || t("unavailable"),
        });
        const area = document.createElement("span");
        area.className = "feature-association-area";
        area.textContent = formatFeatureArea(parcel);
        link.append(label, area);
        if (isDwellingParcel(parcel)) {
          const inhabited = document.createElement("span");
          inhabited.className = "feature-association-inhabited";
          inhabited.textContent = t("inhabited");
          link.append(inhabited);
        }
        item.append(link);
        list.append(item);
      });
      section.append(list);
    } else {
      const empty = document.createElement("p");
      empty.textContent = t("noAssociatedParcels");
      section.append(empty);
    }

    content.append(section);
  }

  content.append(createFeatureModalShareButton());

  // A linked-feature request may finish after a newer selection was made.
  if (!els.featureModal.hidden && requestId === featureModalRequestId) {
    els.featureModalContent.replaceChildren(content);
  }
}

function createFeatureModalShareButton() {
  const actions = document.createElement("div");
  actions.className = "feature-modal-actions";

  const button = document.createElement("button");
  button.type = "button";
  button.className = "feature-modal-share";
  button.title = t("copyMapLink");
  button.setAttribute("aria-label", t("copyMapLink"));

  const icon = document.createElement("span");
  icon.className = "material-symbols-outlined";
  icon.setAttribute("aria-hidden", "true");
  icon.textContent = "share";
  button.append(icon);
  button.addEventListener("click", copyCurrentViewUrl);

  actions.append(button);
  return actions;
}

function createFeatureHeading(kind, id) {
  const heading = document.createElement("h2");
  heading.id = "feature-modal-title";
  heading.textContent = id ? `${kind} ${id}` : kind;
  return heading;
}

function createFeatureDetails(entries) {
  const details = document.createElement("dl");
  details.className = "feature-details";
  entries.forEach(([label, value]) => {
    const row = document.createElement("div");
    const term = document.createElement("dt");
    const description = document.createElement("dd");
    term.textContent = label;
    description.textContent = value;
    row.append(term, description);
    details.append(row);
  });
  return details;
}

function createFeatureNavigation(label, layerName, featureUuid) {
  const link = document.createElement("button");
  link.type = "button";
  link.className = "feature-navigation";
  link.textContent = label;
  link.dataset.featureLayer = layerName;
  link.dataset.featureUuid = featureUuid || "";
  return link;
}

async function handleFeatureModalNavigation(event) {
  const link = event.target.closest("[data-feature-layer][data-feature-uuid]");
  if (!link.dataset.featureUuid) {
    return;
  }

  link.disabled = true;
  try {
    const idProperty = unqualifiedLayerName(link.dataset.featureLayer) === "parcelas"
      ? "parcela_uuid"
      : "predio_uuid";
    const [feature] = await getFeaturesByProperty(link.dataset.featureLayer, idProperty, link.dataset.featureUuid);
    if (feature) {
      openFeatureModal(feature);
    }
  } catch (error) {
    console.error(error);
  } finally {
    link.disabled = false;
  }
}

async function getFeaturesByProperty(layerName, property, value) {
  if (!value) {
    return [];
  }

  const params = new URLSearchParams({
    service: "WFS",
    version: "2.0.0",
    request: "GetFeature",
    typeNames: layerName,
    outputFormat: "application/json",
    srsName: "EPSG:3857",
    CQL_FILTER: `${property} = '${escapeCqlLiteral(value)}'`,
  });
  const response = await fetch(`${API_WMS}?${params}`);
  if (!response.ok) {
    throw new Error(`Feature request failed with status ${response.status}.`);
  }

  return (await response.json()).features || [];
}

function isDwellingParcel(feature) {
  const parcelUuid = feature.properties?.parcela_uuid;
  return dwellingParcelSource.getFeatures().some(
    (dwellingParcel) => dwellingParcel.get("parcela_uuid") === parcelUuid,
  );
}

function unqualifiedLayerName(name) {
  return name.split(":").at(-1);
}

function closeFeatureModal() {
  featureModalRequestId += 1;
  featureModalRestoreRequestId += 1;
  sharedMapState.feature = null;
  resetFeatureModalPosition();
  els.featureModal.hidden = true;
  selectedFeatureSource.clear();
  syncSharedMapStateToUrl();
}

function startFeatureModalDrag(event) {
  if (event.button !== 0 || event.target.closest("button, a, input, select, textarea, label")) {
    return;
  }

  const dialogRect = els.featureModalDialog.getBoundingClientRect();
  els.featureModalDialog.style.position = "fixed";
  els.featureModalDialog.style.left = `${dialogRect.left}px`;
  els.featureModalDialog.style.top = `${dialogRect.top}px`;
  els.featureModalDialog.style.margin = "0";
  els.featureModalDialog.classList.add("is-dragging");
  modalDrag = {
    pointerId: event.pointerId,
    offsetX: event.clientX - dialogRect.left,
    offsetY: event.clientY - dialogRect.top,
  };
  els.featureModalDialog.setPointerCapture(event.pointerId);
}

function dragFeatureModal(event) {
  if (!modalDrag || event.pointerId !== modalDrag.pointerId) {
    return;
  }

  const dialogRect = els.featureModalDialog.getBoundingClientRect();
  const maxLeft = Math.max(MODAL_VIEWPORT_PADDING, window.innerWidth - dialogRect.width - MODAL_VIEWPORT_PADDING);
  const maxTop = Math.max(MODAL_VIEWPORT_PADDING, window.innerHeight - dialogRect.height - MODAL_VIEWPORT_PADDING);
  const left = Math.min(maxLeft, Math.max(MODAL_VIEWPORT_PADDING, event.clientX - modalDrag.offsetX));
  const top = Math.min(maxTop, Math.max(MODAL_VIEWPORT_PADDING, event.clientY - modalDrag.offsetY));

  els.featureModalDialog.style.left = `${left}px`;
  els.featureModalDialog.style.top = `${top}px`;
}

function stopFeatureModalDrag(event) {
  if (!modalDrag || event.pointerId !== modalDrag.pointerId) {
    return;
  }

  els.featureModalDialog.releasePointerCapture(event.pointerId);
  els.featureModalDialog.classList.remove("is-dragging");
  modalDrag = undefined;
}

function keepFeatureModalInViewport() {
  if (els.featureModal.hidden || !els.featureModalDialog.style.left) {
    return;
  }

  const dialogRect = els.featureModalDialog.getBoundingClientRect();
  const maxLeft = Math.max(MODAL_VIEWPORT_PADDING, window.innerWidth - dialogRect.width - MODAL_VIEWPORT_PADDING);
  const maxTop = Math.max(MODAL_VIEWPORT_PADDING, window.innerHeight - dialogRect.height - MODAL_VIEWPORT_PADDING);
  els.featureModalDialog.style.left = `${Math.min(maxLeft, Math.max(MODAL_VIEWPORT_PADDING, dialogRect.left))}px`;
  els.featureModalDialog.style.top = `${Math.min(maxTop, Math.max(MODAL_VIEWPORT_PADDING, dialogRect.top))}px`;
}

function resetFeatureModalPosition() {
  modalDrag = undefined;
  els.featureModalDialog.classList.remove("is-dragging");
  els.featureModalDialog.style.removeProperty("position");
  els.featureModalDialog.style.removeProperty("left");
  els.featureModalDialog.style.removeProperty("top");
  els.featureModalDialog.style.removeProperty("margin");
}

function formatFeatureArea(feature) {
  const properties = feature.properties || {};
  const areaEntry = Object.entries(properties).find(([name, value]) =>
    value != null && /(^|[_\s])area([_\s]|$)|shape_area/i.test(name),
  );
  const area = Number(areaEntry?.[1]);

  if (Number.isFinite(area) && area >= 0) {
    return `${new Intl.NumberFormat(i18n.locale, { maximumFractionDigits: 2 }).format(area)} m²`;
  }

  const geometry = new ol.format.GeoJSON().readGeometry(feature.geometry, {
    featureProjection: "EPSG:3857",
  });
  const calculatedArea = geometry?.getArea?.();
  return Number.isFinite(calculatedArea)
    ? `${new Intl.NumberFormat(i18n.locale, { maximumFractionDigits: 2 }).format(calculatedArea)} m²`
    : t("areaUnavailable");
}

function fitToLayerExtent(layer) {
  if (!layer?.extent || layer.extent.some((value) => Number.isNaN(value))) {
    return;
  }

  const projectedExtent = ol.proj.transformExtent(layer.extent, "EPSG:4326", "EPSG:3857");
  map.getView().fit(projectedExtent, {
    padding: [40, 40, 40, 40],
    duration: 500,
    maxZoom: 18,
  });
}

function fitToVisibleLayers() {
  const visibleLayers = availableLayers.filter((layer) => selectedLayers.includes(layer.name));
  const projectedExtents = visibleLayers
    .filter((layer) => layer.extent && layer.extent.every(Number.isFinite))
    .map((layer) => ol.proj.transformExtent(layer.extent, "EPSG:4326", "EPSG:3857"));

  if (!projectedExtents.length) {
    updateStatus(t("selectLayerToZoom"), "error");
    showMessage(t("selectLayerToZoom"), { type: "warning" });
    return;
  }

  const combinedExtent = projectedExtents.reduce(
    (combined, extent) => [
      Math.min(combined[0], extent[0]),
      Math.min(combined[1], extent[1]),
      Math.max(combined[2], extent[2]),
      Math.max(combined[3], extent[3]),
    ],
    [Infinity, Infinity, -Infinity, -Infinity],
  );

  map.getView().fit(combinedExtent, {
    padding: [64, 64, 64, 64],
    duration: 500,
    maxZoom: 18,
  });
}

function childElementsByName(node, localName) {
  return [...(node?.children || [])].filter((child) => child.localName === localName);
}

function firstChildByName(node, localName) {
  return childElementsByName(node, localName)[0] || null;
}

function textFromChild(node, localName) {
  return firstChildByName(node, localName)?.textContent?.trim() || "";
}

function collectNamedLayers(node) {
  return childElementsByName(node, "Layer").flatMap((layerNode) => {
    const children = collectNamedLayers(layerNode);
    return textFromChild(layerNode, "Name") ? [layerNode, ...children] : children;
  });
}

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("'", "''");
}

function syncBackground() {
  const background = els.backgroundSelect.value;
  softBasemapLayer.setVisible(background === "soft");
  openStreetMapLayer.setVisible(background === "openstreetmap");
  satelliteLayer.setVisible(background === "satellite");
  syncSharedMapStateToUrl();
}

function readSharedMapState(url = new URL(window.location.href)) {
  const params = url.searchParams;
  const viewParamNames = [
    MAP_URL_PARAMS.latitude,
    MAP_URL_PARAMS.longitude,
    MAP_URL_PARAMS.zoom,
    MAP_URL_PARAMS.rotation,
  ];
  const hasViewParams = viewParamNames.some((name) => params.has(name));
  const view = hasViewParams ? readSharedView(params) : null;
  const requestedBackground = params.get(MAP_URL_PARAMS.background);

  return {
    view,
    background: BACKGROUND_VALUES.has(requestedBackground) ? requestedBackground : null,
    // An empty value deliberately represents no visible published layers.
    layers: params.has(MAP_URL_PARAMS.layers)
      ? params
          .get(MAP_URL_PARAMS.layers)
          .split(",")
          .map((name) => name.trim())
          .filter(Boolean)
      : null,
    feature: readSharedFeature(params),
  };
}

function readSharedView(params) {
  const values = [
    params.get(MAP_URL_PARAMS.latitude),
    params.get(MAP_URL_PARAMS.longitude),
    params.get(MAP_URL_PARAMS.zoom),
    params.get(MAP_URL_PARAMS.rotation),
  ];
  if (values.some((value) => value === null || value.trim() === "")) {
    return null;
  }

  const [latitude, longitude, zoom, rotationDegrees] = values.map(Number);

  if (
    !Number.isFinite(latitude) ||
    !Number.isFinite(longitude) ||
    !Number.isFinite(zoom) ||
    !Number.isFinite(rotationDegrees) ||
    latitude < -90 ||
    latitude > 90 ||
    longitude < -180 ||
    longitude > 180 ||
    zoom < 0 ||
    zoom > 28 ||
    rotationDegrees < -360 ||
    rotationDegrees > 360
  ) {
    return null;
  }

  return {
    center: [longitude, latitude],
    zoom,
    rotation: (rotationDegrees * Math.PI) / 180,
  };
}

function selectedLayersFromSharedMapState(state) {
  const visibleLayers = availableLayers.filter((layer) => !isInternalLayer(layer.name));
  const defaultLayers = visibleLayers.map((layer) => layer.name);

  if (state.layers === null) {
    return defaultLayers;
  }

  const requestedLayers = new Set(state.layers);
  const matchedLayers = visibleLayers
    .map((layer) => layer.name)
    .filter((name) => requestedLayers.has(name));

  // An explicit empty list is valid. A non-empty list with no known layers is
  // malformed or from another deployment, so retain the useful default.
  return state.layers.length === 0 || matchedLayers.length ? matchedLayers : defaultLayers;
}

function readSharedFeature(params) {
  const layerName = params.get(MAP_URL_PARAMS.featureLayer);
  const featureId = params.get(MAP_URL_PARAMS.featureId);
  if (!layerName || !featureId) {
    return null;
  }

  if (![PARCEL_LAYER_NAME, BUILDING_LAYER_NAME].includes(layerName)) {
    return null;
  }

  return { layerName, featureId };
}

function featureReference(feature, isParcel) {
  const featureId = isParcel ? feature.properties?.parcela_uuid : feature.properties?.predio_uuid;
  if (typeof featureId !== "string" || !featureId.trim()) {
    return null;
  }

  return {
    layerName: isParcel ? PARCEL_LAYER_NAME : BUILDING_LAYER_NAME,
    featureId,
  };
}

async function restoreSharedFeatureModal() {
  const feature = sharedMapState.feature;
  const restoreRequestId = ++featureModalRestoreRequestId;

  if (!feature) {
    if (!els.featureModal.hidden) {
      closeFeatureModal();
    }
    return;
  }

  try {
    const idProperty = feature.layerName === PARCEL_LAYER_NAME ? "parcela_uuid" : "predio_uuid";
    const [restoredFeature] = await getFeaturesByProperty(feature.layerName, idProperty, feature.featureId);
    if (restoreRequestId === featureModalRestoreRequestId && restoredFeature) {
      openFeatureModal(restoredFeature);
    }
  } catch (error) {
    // Keep the map usable if a linked feature no longer exists or GeoServer is
    // temporarily unavailable; the map view itself still restores normally.
    console.error(error);
  }
}

function restoreSharedMapState() {
  sharedMapState = readSharedMapState();
  applyingSharedMapState = true;

  try {
    const viewState = sharedMapState.view;
    const view = map.getView();
    if (viewState) {
      view.setCenter(ol.proj.fromLonLat(viewState.center));
      view.setZoom(viewState.zoom);
      view.setRotation(viewState.rotation);
    } else {
      // A history entry without a valid map state behaves like a fresh visit.
      view.setCenter(ol.proj.fromLonLat(DEFAULT_CENTER));
      view.setZoom(DEFAULT_ZOOM);
      view.setRotation(DEFAULT_ROTATION);
    }

    els.backgroundSelect.value = sharedMapState.background || "soft";
    syncBackground();

    if (availableLayers.length) {
      selectedLayers = selectedLayersFromSharedMapState(sharedMapState);
      renderLayerList();
      syncSelectedLayers();
    }
    restoreSharedFeatureModal();
  } finally {
    applyingSharedMapState = false;
  }
}

function syncSharedMapStateToUrl() {
  if (!urlStateReady || applyingSharedMapState) {
    return;
  }

  const view = map.getView();
  const center = view.getCenter();
  const zoom = view.getZoom();
  const rotation = view.getRotation();
  if (!center || !Number.isFinite(zoom) || !Number.isFinite(rotation)) {
    return;
  }

  const [longitude, latitude] = ol.proj.toLonLat(center);
  if (!Number.isFinite(latitude) || !Number.isFinite(longitude)) {
    return;
  }

  const url = new URL(window.location.href);
  url.searchParams.set(MAP_URL_PARAMS.latitude, formatUrlNumber(latitude, 6));
  url.searchParams.set(MAP_URL_PARAMS.longitude, formatUrlNumber(longitude, 6));
  url.searchParams.set(MAP_URL_PARAMS.zoom, formatUrlNumber(zoom, 3));
  url.searchParams.set(
    MAP_URL_PARAMS.rotation,
    formatUrlNumber(normalizeRotationDegrees((rotation * 180) / Math.PI), 2),
  );
  url.searchParams.set(MAP_URL_PARAMS.background, els.backgroundSelect.value);
  url.searchParams.set(MAP_URL_PARAMS.layers, selectedLayers.join(","));
  if (sharedMapState.feature) {
    url.searchParams.set(MAP_URL_PARAMS.featureLayer, sharedMapState.feature.layerName);
    url.searchParams.set(MAP_URL_PARAMS.featureId, sharedMapState.feature.featureId);
  } else {
    url.searchParams.delete(MAP_URL_PARAMS.featureLayer);
    url.searchParams.delete(MAP_URL_PARAMS.featureId);
  }

  // Replacing, rather than pushing, avoids one browser-history entry for every
  // pan or zoom while still keeping normal back/forward navigation intact.
  window.history.replaceState(window.history.state, "", `${url.pathname}${url.search}${url.hash}`);
}

function normalizeRotationDegrees(rotation) {
  return ((rotation + 180) % 360 + 360) % 360 - 180;
}

function formatUrlNumber(value, fractionDigits) {
  return Number(value.toFixed(fractionDigits)).toString();
}