import { Popup } from "/vendor/maplibre-gl/maplibre-gl.mjs";
import { LIVETRACK_ICON } from "/js/icons.js";
import { notifySidePanelOpen, onlyOneSidePanelOpen } from "/js/panels.js";

const SESSIONS_URL = "/api/livetrack/sessions";
const TRACK_SOURCE = "livetrack-track";
const TRACK_COLOR = "#7209b7";
// Garmin devices post a new point roughly every 15s (postTrackPointFrequency
// in the session data) — polling twice that often would just re-fetch the
// same 400+KB page for nothing most of the time.
const REFRESH_INTERVAL_MS = 30000;

// A sidebar icon that opens a side panel listing Garmin LiveTrack sessions
// received via the webhook (see docs/deployment.adoc). Clicking one fetches
// and draws its track on the map (only one shown at a time — clicking the
// active one again hides it).
export class LiveTrackPanelControl {
  constructor(map) {
    this._map = map;
    this._activeSessionId = null;
    this._geojson = null;
    this._hoverPopup = null;
    this._pointInteractivityRegistered = false;
    this._refreshTimer = null;

    // setStyle() (switching the Online/Offline base map) tears down all
    // custom sources and layers — put the track back afterwards, same as
    // GpxPanelControl does for visible GPX files.
    map.on("style.load", () => {
      if (this._geojson) this._showTrack(this._geojson, { fit: false });
    });
  }

  mount(sidebar) {
    this._container = document.createElement("div");
    this._container.className = "sidebar-item";
    this._container.innerHTML = `<button type="button" class="sidebar-icon" title="LiveTrack" aria-label="LiveTrack">${LIVETRACK_ICON}</button>`;
    this._icon = this._container.querySelector(".sidebar-icon");
    this._icon.addEventListener("click", () => this._togglePanel());

    this._panel = document.getElementById("livetrack-panel");
    this._list = this._panel.querySelector(".livetrack-panel__list");
    this._panel
      .querySelector(".basemap-panel__close")
      .addEventListener("click", () => this._togglePanel(false));

    onlyOneSidePanelOpen(this._panel, () => this._icon.classList.remove("active"));

    sidebar.appendChild(this._container);
  }

  _togglePanel(force) {
    const open = force === undefined ? this._panel.hidden : force;
    this._panel.hidden = !open;
    this._icon.classList.toggle("active", open);
    if (open) {
      notifySidePanelOpen(this._panel);
      this._loadSessions();
    }
  }

  async _loadSessions() {
    const response = await fetch(SESSIONS_URL);
    const { sessions } = await response.json();
    this._renderSessions(sessions);
  }

  _renderSessions(sessions) {
    this._list.innerHTML = "";

    if (sessions.length === 0) {
      const li = document.createElement("li");
      li.className = "gpx-tree__empty";
      li.textContent = "No sessions yet";
      this._list.appendChild(li);
      return;
    }

    sessions.forEach(({ id, received_at, summary, map_available }) => {
      const li = document.createElement("li");
      li.className = "livetrack-panel__item";

      const unavailable = map_available === false;

      const button = document.createElement("button");
      button.type = "button";
      button.className = "livetrack-panel__row";
      button.classList.toggle("active", id === this._activeSessionId);
      button.disabled = unavailable;
      button.title = unavailable ? "Garmin no longer serves this session's map" : id;

      const labelSpan = document.createElement("span");
      labelSpan.className = "livetrack-panel__label";
      labelSpan.classList.toggle("livetrack-panel__label--id", !summary);
      labelSpan.textContent = summary ? summaryLabel(summary) : id;

      const timeSpan = document.createElement("span");
      timeSpan.className = "livetrack-panel__time";
      timeSpan.textContent = new Date(received_at).toLocaleString();

      if (summary) {
        button.append(statusBadge(summary.active), labelSpan, timeSpan);
      } else {
        button.append(labelSpan, timeSpan);
      }
      if (!unavailable) button.addEventListener("click", () => this._toggleTrack(id, button));
      li.appendChild(button);
      this._list.appendChild(li);
    });
  }

  async _toggleTrack(id, button) {
    const wasActive = id === this._activeSessionId;
    this._removeTrack();
    this._list.querySelectorAll(".livetrack-panel__row.active").forEach((el) => el.classList.remove("active"));
    if (wasActive) return;

    button.classList.add("loading");
    try {
      this._geojson = await this._fetchTrack(id);
      this._showTrack(this._geojson);
      this._activeSessionId = id;
      button.classList.add("active");
      // The fetch above also computed and stored a summary server-side
      // (see LiveTrackClient.summarize) — reload so this row picks it up
      // instead of showing the raw id from here on.
      this._loadSessions();
      this._scheduleRefresh(id);
    } catch (err) {
      window.alert(err.message);
    } finally {
      button.classList.remove("loading");
    }
  }

  async _fetchTrack(id) {
    const response = await fetch(`/api/livetrack/sessions/${encodeURIComponent(id)}/track`);
    if (!response.ok) {
      const { error } = await response.json().catch(() => ({}));
      throw new Error(error || "Could not load track.");
    }
    return response.json();
  }

  // Re-fetches on a timer for as long as the session is still recording
  // (properties.active on the Point feature — see LiveTrackClient), so an
  // in-progress activity's line keeps growing instead of staying frozen at
  // whatever it looked like when first opened. Stops on its own once the
  // session ends, or immediately if the session is switched away from or
  // toggled off in the meantime.
  _scheduleRefresh(id) {
    if (!this._geojson.features[1].properties.active) return;

    this._refreshTimer = setTimeout(async () => {
      if (this._activeSessionId !== id) return;
      try {
        const geojson = await this._fetchTrack(id);
        if (this._activeSessionId !== id) return;
        this._geojson = geojson;
        this._map.getSource(TRACK_SOURCE)?.setData(geojson);
        this._loadSessions();
      } catch {
        // Transient fetch failure — leave the track as-is and try again
        // next tick rather than interrupting with an alert.
      }
      this._scheduleRefresh(id);
    }, REFRESH_INTERVAL_MS);
  }

  _showTrack(geojson, { fit = true } = {}) {
    if (this._map.getSource(TRACK_SOURCE)) return;

    this._map.addSource(TRACK_SOURCE, { type: "geojson", data: geojson });
    this._map.addLayer({
      id: `${TRACK_SOURCE}-line`,
      type: "line",
      source: TRACK_SOURCE,
      filter: ["==", ["geometry-type"], "LineString"],
      layout: { "line-cap": "round", "line-join": "round" },
      paint: { "line-color": TRACK_COLOR, "line-width": 3 },
    });
    this._map.addLayer({
      id: `${TRACK_SOURCE}-point`,
      type: "circle",
      source: TRACK_SOURCE,
      filter: ["==", ["geometry-type"], "Point"],
      paint: {
        "circle-radius": 6,
        "circle-color": TRACK_COLOR,
        "circle-stroke-color": "#fff",
        "circle-stroke-width": 1.5,
      },
    });
    this._registerPointInteractivity();

    if (!fit) return;

    const coordinates = geojson.features[0].geometry.coordinates;
    const bounds = coordinates.reduce(
      ([minLon, minLat, maxLon, maxLat], [lon, lat]) => [
        Math.min(minLon, lon),
        Math.min(minLat, lat),
        Math.max(maxLon, lon),
        Math.max(maxLat, lat),
      ],
      [Infinity, Infinity, -Infinity, -Infinity],
    );
    this._map.fitBounds(
      [
        [bounds[0], bounds[1]],
        [bounds[2], bounds[3]],
      ],
      { padding: 40 },
    );
  }

  // Registered once, ever — map.on(type, layerId, fn) is a delegated
  // listener that lives on the map itself and keeps matching that layer id
  // after setStyle() removes and (via _showTrack) re-adds it, so
  // re-registering on every re-add would stack duplicate popups (same
  // reasoning as GpxPanelControl's own point interactivity).
  _registerPointInteractivity() {
    if (this._pointInteractivityRegistered) return;
    this._pointInteractivityRegistered = true;

    const layerId = `${TRACK_SOURCE}-point`;
    this._map.on("mouseenter", layerId, (event) => {
      this._map.getCanvas().style.cursor = "pointer";
      const feature = event.features[0];
      if (!feature) return;
      this._hoverPopup = new Popup({ closeButton: false, closeOnClick: false, offset: 10 })
        .setLngLat(event.lngLat)
        .setHTML(popupHtml(feature.properties))
        .addTo(this._map);
    });
    this._map.on("mouseleave", layerId, () => {
      this._map.getCanvas().style.cursor = "";
      this._hoverPopup?.remove();
      this._hoverPopup = null;
    });
  }

  _removeTrack() {
    clearTimeout(this._refreshTimer);
    this._refreshTimer = null;
    this._activeSessionId = null;
    this._geojson = null;
    this._hoverPopup?.remove();
    this._hoverPopup = null;
    [`${TRACK_SOURCE}-line`, `${TRACK_SOURCE}-point`].forEach((layerId) => {
      if (this._map.getLayer(layerId)) this._map.removeLayer(layerId);
    });
    if (this._map.getSource(TRACK_SOURCE)) this._map.removeSource(TRACK_SOURCE);
  }
}

// Properties come straight off the GeoJSON the server built from Garmin
// data — session_name in particular is user-supplied (whatever the LiveTrack
// session was named on the watch/app) — so escape before it lands in HTML,
// same as GpxPanelControl's popups do for GPX file contents.
function popupHtml({ session_name, activity_type, distance_meters, duration_secs, active, time, speed_meters_per_sec, heart_rate_beats_per_min }) {
  const status = active ? `<span class="livetrack-badge livetrack-badge--live">Live</span>` : `<span class="livetrack-badge">Ended</span>`;
  const parts = [`<strong>${escapeHtml(session_name || "LiveTrack session")}</strong> ${status}`];

  const stats = [];
  if (activity_type) stats.push(escapeHtml(titleCase(activity_type)));
  if (typeof distance_meters === "number") stats.push(`${(distance_meters / 1000).toFixed(1)} km`);
  if (typeof duration_secs === "number") stats.push(formatDuration(duration_secs));
  if (stats.length > 0) parts.push(`<p>${stats.join(" · ")}</p>`);

  const latest = [];
  if (typeof speed_meters_per_sec === "number") latest.push(`${(speed_meters_per_sec * 3.6).toFixed(1)} km/h`);
  if (typeof heart_rate_beats_per_min === "number") latest.push(`${heart_rate_beats_per_min} bpm`);
  if (latest.length > 0) parts.push(`<p>${latest.join(" · ")}</p>`);

  if (time) {
    const parsed = new Date(time);
    if (!Number.isNaN(parsed.getTime())) {
      parts.push(`<p class="gpx-popup__time">${escapeHtml(parsed.toLocaleString())}</p>`);
    }
  }

  return parts.join("");
}

function escapeHtml(text) {
  const div = document.createElement("div");
  div.textContent = text;
  return div.innerHTML;
}

function statusBadge(active) {
  const badge = document.createElement("span");
  badge.className = "livetrack-badge";
  badge.classList.toggle("livetrack-badge--live", !!active);
  badge.textContent = active ? "Live" : "Ended";
  return badge;
}

function summaryLabel({ session_name, activity_type, distance_meters, duration_secs }) {
  const parts = [];
  if (activity_type) parts.push(titleCase(activity_type));
  if (typeof distance_meters === "number") parts.push(`${(distance_meters / 1000).toFixed(1)} km`);
  if (typeof duration_secs === "number") parts.push(formatDuration(duration_secs));
  const stats = parts.join(" · ");
  if (session_name && stats) return `${session_name} — ${stats}`;
  return session_name || stats || "Untitled session";
}

function titleCase(text) {
  return text.charAt(0) + text.slice(1).toLowerCase();
}

function formatDuration(totalSeconds) {
  const hours = Math.floor(totalSeconds / 3600);
  const minutes = Math.floor((totalSeconds % 3600) / 60);
  return hours > 0 ? `${hours}h ${minutes}m` : `${minutes}m`;
}