const { once, listen } = window.__TAURI__.event;
const { invoke } = window.__TAURI__.core;

const connectScreen = document.querySelector("#connect");
const workoutScreen = document.querySelector("#workout");
const startBtn = document.querySelector("#start-btn");

const groups = {
  hr_sensors: { list: document.querySelector("#hr-list"), category: "hr" },
  cad_sensors: { list: document.querySelector("#cadence-list"), category: "cadence" },
  trainers: { list: document.querySelector("#trainer-list"), category: "trainer" },
};

const deviceCards = new Map(); // device_id -> li
const selected = {}; // category -> { btn, card } подключённого датчика
const pendingStatus = {}; // category -> status (пришёл до установки selected)

function el(tag, className, text) {
  const node = document.createElement(tag);
  if (className) node.className = className;
  if (text != null) node.textContent = text;
  return node;
}

// --- Батарея ---
function batteryIcon(percent) {
  const low = percent < 20;
  const wrap = el("span", "battery" + (low ? " battery--low" : ""));
  wrap.title = `${percent}%`;

  const ns = "http://www.w3.org/2000/svg";
  const svg = document.createElementNS(ns, "svg");
  svg.setAttribute("viewBox", "0 0 24 12");
  svg.classList.add("battery__icon");

  const rect = (x, y, w, h, cls) => {
    const r = document.createElementNS(ns, "rect");
    r.setAttribute("x", x);
    r.setAttribute("y", y);
    r.setAttribute("width", w);
    r.setAttribute("height", h);
    if (cls) r.classList.add(cls);
    return r;
  };

  svg.append(
    rect(0, 0, 20, 12, "battery__body"),
    rect(21, 3, 2, 6, "battery__terminal"),
    rect(1, 1, low ? 0 : (18 * percent) / 100, 10, "battery__fill"),
  );

  if (low) {
    const warn = document.createElementNS(ns, "text");
    warn.setAttribute("x", "10");
    warn.setAttribute("y", "10");
    warn.setAttribute("text-anchor", "middle");
    warn.classList.add("battery__warn");
    warn.textContent = "!";
    svg.append(warn);
  }

  wrap.append(svg);
  return wrap;
}

// --- Датчики ---
function renderDevice(device, category) {
  const li = el("li", "device");
  deviceCards.set(device.id, li);

  const head = el("div", "device__head");
  head.append(el("span", "device__name", device.display_name || "без имени"));
  head.append(el("span", "device__rssi", device.rssi != null ? `${device.rssi} dBm` : ""));

  const connectBtn = el("button", "device__connect", "подключить");
  connectBtn.addEventListener("click", () => connect(device.id, connectBtn, category, li));

  li.append(head, el("span", "device__meta", device.address), connectBtn);
  return li;
}

function renderGroup(group, devices) {
  group.list.replaceChildren();
  if (!devices.length) {
    group.list.appendChild(el("li", "device device--empty", "нет"));
    return;
  }
  for (const d of devices) group.list.appendChild(renderDevice(d, group.category));
}

// --- Подключение (режим радио-кнопки: один на категорию) ---
function resetSelected(category) {
  const prev = selected[category];
  if (!prev) return;
  prev.btn.textContent = "подключить";
  prev.btn.classList.remove("device__connect--done");
  prev.btn.disabled = false;
  const battery = prev.card.querySelector(".battery");
  if (battery) battery.remove();
  selected[category] = null;
}

async function connect(deviceId, btn, category, card) {
  btn.disabled = true;
  btn.textContent = "…";
  try {
    await invoke("connect", { deviceId, category });
    resetSelected(category);
    btn.textContent = "✓";
    btn.classList.add("device__connect--done");
    selected[category] = { btn, card };
    if (pendingStatus[category]) {
      applyStatus(selected[category], category, pendingStatus[category]);
      delete pendingStatus[category];
    }
    if (category === "trainer") startBtn.disabled = false;
  } catch (e) {
    console.error(e);
    btn.disabled = false;
    btn.textContent = "ошибка";
  }
}

// --- Переход на экран упражнения ---
startBtn.addEventListener("click", async () => {
  connectScreen.hidden = true;
  workoutScreen.hidden = false;
  sizeGraph();
  await loadWorkouts();
});

// --- Телеметрия ---
function setMetric(id, value) {
  document.querySelector(`#${id}`).textContent = value;
}

once("devices-loaded", (event) => {
  const repo = event.payload;
  renderGroup(groups.hr_sensors, repo.hr_sensors ?? []);
  renderGroup(groups.cad_sensors, repo.cad_sensors ?? []);
  renderGroup(groups.trainers, repo.trainers ?? []);
});

// Непрерывный скан: новые датчики добавляются в список по мере появления.
listen("device-found", (event) => {
  const { device, categories } = event.payload;
  for (const cat of categories) {
    const group = Object.values(groups).find((g) => g.category === cat);
    if (!group) continue;
    const empty = group.list.querySelector(".device--empty");
    if (empty) empty.remove();
    group.list.appendChild(renderDevice(device, cat));
  }
});

listen("battery", (event) => {
  const { device_id, percent } = event.payload;
  const card = deviceCards.get(device_id);
  if (!card) return;
  const head = card.querySelector(".device__head");
  head.querySelector(".battery")?.remove();
  head.append(batteryIcon(percent));
});

listen("telemetry", (event) => {
  const t = event.payload.telemetry;
  if (t.Power) {
    actualWatts = t.Power.watts;
    setMetric("power-value", `${actualWatts} W`);
    updatePowerDeviation();
    samplePower(actualWatts);
    scheduleDraw();
  } else if (t.Cadence) {
    actualCadence = Math.round(t.Cadence.rpm);
    setMetric("cadence-value", `${actualCadence} rpm`);
    updateCadenceDeviation();
  } else if (t.HeartRate) {
    actualHr = t.HeartRate.bpm;
    setMetric("hr-value", t.HeartRate.bpm);
    sampleHr(t.HeartRate.bpm);
    scheduleDraw();
  }
});

function applyStatus(sel, category, status) {
  const { btn } = sel;
  if (status === "reconnecting") {
    btn.textContent = "переподключение…";
    btn.disabled = true;
  } else if (status === "reconnected") {
    btn.textContent = "✓";
    btn.classList.add("device__connect--done");
    btn.disabled = true;
  } else if (status === "gave_up") {
    btn.textContent = "подключить";
    btn.classList.remove("device__connect--done");
    btn.disabled = false;
    selected[category] = null;
  }
}

listen("connection", (event) => {
  const { category, status } = event.payload;
  const sel = selected[category];
  if (!sel) {
    pendingStatus[category] = status;
    return;
  }
  applyStatus(sel, category, status);
});

// --- Воркаут ---
const timerEl = document.querySelector("#timer");
const workoutSelect = document.querySelector("#workout-select");
const ftpInput = document.querySelector("#ftp-input");
const workoutMeta = document.querySelector("#workout-meta");
const workoutName = document.querySelector("#workout-name");
const workoutStep = document.querySelector("#workout-step");
const workoutBar = document.querySelector("#workout-bar");
const workoutStartBtn = document.querySelector("#workout-start");
const workoutPauseBtn = document.querySelector("#workout-pause");
const workoutStopBtn = document.querySelector("#workout-stop");

// --- Отклонение от цели ---
const powerMetric = document.querySelector("#power-metric");
const powerTarget = document.querySelector("#power-target");
const cadenceMetric = document.querySelector("#cadence-metric");
const cadenceTarget = document.querySelector("#cadence-target");

const POWER_TOL_PCT = 0.1;
const POWER_TOL_ABS = 15; // Вт
const CADENCE_TOL_ABS = 5; // rpm

let targetWatts = null;
let targetCadence = null;
let actualWatts = null;
let actualCadence = null;
let actualHr = null;

function powerTolerance(target) {
  return Math.max(POWER_TOL_ABS, Math.round(target * POWER_TOL_PCT));
}

function updateDeviation(metricEl, targetEl, actual, target, tolerance, unit) {
  targetEl.textContent = target != null ? `${target} ${unit}` : "—";
  if (actual == null || target == null) {
    metricEl.classList.remove("metric--off");
    return;
  }
  const diff = actual - target;
  if (Math.abs(diff) > tolerance) {
    metricEl.classList.add("metric--off");
  } else {
    metricEl.classList.remove("metric--off");
  }
}

function updatePowerDeviation() {
  updateDeviation(powerMetric, powerTarget, actualWatts, targetWatts, powerTolerance(targetWatts ?? 0), "W");
}

function updateCadenceDeviation() {
  updateDeviation(cadenceMetric, cadenceTarget, actualCadence, targetCadence, CADENCE_TOL_ABS, "rpm");
}

function clearTargets() {
  targetWatts = null;
  targetCadence = null;
  updatePowerDeviation();
  updateCadenceDeviation();
}

// --- График мощности и пульса ---
const graph = document.querySelector("#graph");

const ZONE_COLORS = [
  "#b0bec5", // Z1 — восстановление
  "#42a5f5", // Z2 — выносливость
  "#66bb6a", // Z3 — темп
  "#ffca28", // Z4 — порог
  "#ff9800", // Z5 — VO2max
  "#ef5350", // Z6 — анаэробная
  "#ab47bc", // Z7 — нейромышечная
];

const GRAPH_WINDOW_MS = 30 * 1000;
const powerHistory = [];
const hrHistory = [];
let graphDirty = false;

function powerZone(watts, ftp) {
  const pct = (watts / ftp) * 100;
  if (pct < 55) return 0;
  if (pct < 76) return 1;
  if (pct < 91) return 2;
  if (pct < 106) return 3;
  if (pct < 121) return 4;
  if (pct < 151) return 5;
  return 6;
}

function currentFtp() {
  const v = Number(ftpInput.value);
  return Number.isFinite(v) && v > 0 ? v : 250;
}

function sizeGraph() {
  const dpr = window.devicePixelRatio || 1;
  const w = graph.clientWidth;
  const h = graph.clientHeight;
  if (w === 0 || h === 0) return;
  graph.width = Math.round(w * dpr);
  graph.height = Math.round(h * dpr);
}

function samplePower(watts) {
  const now = performance.now();
  powerHistory.push({ t: now, watts });
  while (powerHistory.length && powerHistory[0].t < now - GRAPH_WINDOW_MS) powerHistory.shift();
}

function sampleHr(bpm) {
  const now = performance.now();
  hrHistory.push({ t: now, bpm });
  while (hrHistory.length && hrHistory[0].t < now - GRAPH_WINDOW_MS) hrHistory.shift();
}

function scheduleDraw() {
  if (graphDirty) return;
  graphDirty = true;
  requestAnimationFrame(() => {
    graphDirty = false;
    drawGraph();
  });
}

function drawGraph() {
  const ctx = graph.getContext("2d");
  const dpr = window.devicePixelRatio || 1;
  const w = graph.clientWidth;
  const h = graph.clientHeight;
  if (w === 0 || h === 0) return;
  ctx.setTransform(dpr, 0, 0, dpr, 0, 0);
  ctx.clearRect(0, 0, w, h);

  const now = performance.now();
  const cutoff = now - GRAPH_WINDOW_MS;
  const power = powerHistory.filter((s) => s.t >= cutoff);
  const hr = hrHistory.filter((s) => s.t >= cutoff);

  const maxPower = Math.max(300, Math.ceil(Math.max(...power.map((s) => s.watts), 0) / 50) * 50);
  const maxHr = Math.max(160, Math.ceil(Math.max(...hr.map((s) => s.bpm), 0) / 10) * 10);

  const xFor = (t) => w - ((now - t) / GRAPH_WINDOW_MS) * w;
  const yPower = (v) => h - (v / maxPower) * h;
  const yHr = (v) => h - (v / maxHr) * h;

  // сетка мощности
  ctx.strokeStyle = "rgba(255,255,255,0.08)";
  ctx.fillStyle = "rgba(255,255,255,0.35)";
  ctx.font = "10px Inter, system-ui, sans-serif";
  ctx.lineWidth = 1;
  for (let g = 0; g <= maxPower; g += 50) {
    const y = yPower(g);
    ctx.beginPath();
    ctx.moveTo(0, y);
    ctx.lineTo(w, y);
    ctx.stroke();
    ctx.fillText(String(g), 4, y - 2);
  }

  // пульс — пунктирная линия
  if (hr.length >= 2) {
    ctx.strokeStyle = "#ef5350";
    ctx.lineWidth = 1.5;
    ctx.setLineDash([4, 3]);
    ctx.beginPath();
    hr.forEach((s, i) => {
      const x = xFor(s.t);
      const y = yHr(s.bpm);
      i === 0 ? ctx.moveTo(x, y) : ctx.lineTo(x, y);
    });
    ctx.stroke();
    ctx.setLineDash([]);
  }

  // мощность — заливка по зонам
  if (power.length >= 2) {
    const ftp = currentFtp();
    for (let i = 0; i < power.length - 1; i++) {
      const a = power[i];
      const b = power[i + 1];
      const color = ZONE_COLORS[powerZone(a.watts, ftp)];
      const xa = xFor(a.t);
      const ya = yPower(a.watts);
      const xb = xFor(b.t);
      const yb = yPower(b.watts);

      ctx.fillStyle = color;
      ctx.globalAlpha = 0.3;
      ctx.beginPath();
      ctx.moveTo(xa, h);
      ctx.lineTo(xa, ya);
      ctx.lineTo(xb, yb);
      ctx.lineTo(xb, h);
      ctx.closePath();
      ctx.fill();
      ctx.globalAlpha = 1;

      ctx.strokeStyle = color;
      ctx.lineWidth = 2;
      ctx.beginPath();
      ctx.moveTo(xa, ya);
      ctx.lineTo(xb, yb);
      ctx.stroke();
    }
  }
}

window.addEventListener("resize", () => {
  sizeGraph();
  scheduleDraw();
});

let workouts = [];
let workoutPaused = false;
let workoutSamples = [];
let workoutStartMs = 0;
let workoutSaveName = "workout";
let lastSampleSecs = -1;

function formatClock(sec) {
  const m = Math.floor(sec / 60);
  const s = Math.floor(sec % 60);
  return `${String(m).padStart(2, "0")}:${String(s).padStart(2, "0")}`;
}

async function loadWorkouts() {
  try {
    workouts = await invoke("list_workouts");
    workoutSelect.replaceChildren();
    const empty = el("option", null, "— выбери воркаут —");
    empty.value = "";
    workoutSelect.append(empty);
    for (const w of workouts) {
      const opt = el("option", null, `${w.date.slice(0, 10)} · ${w.name} · ${w.duration_min} мин`);
      opt.value = w.path;
      workoutSelect.append(opt);
    }
    ftpInput.value = await invoke("get_ftp");
  } catch (e) {
    console.error(e);
  }
}

function selectedWorkout() {
  return workouts.find((w) => w.path === workoutSelect.value);
}

workoutSelect.addEventListener("change", () => {
  const w = selectedWorkout();
  workoutName.textContent = w ? w.name : "—";
  workoutMeta.textContent = w ? `${w.duration_min} мин · load ${w.load ?? "—"}` : "";
});

async function setRunning(active) {
  workoutStartBtn.disabled = active;
  workoutPauseBtn.disabled = !active;
  workoutStopBtn.disabled = !active;
  workoutSelect.disabled = active;
  ftpInput.disabled = active;
  if (!active) {
    workoutPaused = false;
    workoutPauseBtn.textContent = "пауза";
    workoutStep.textContent = "—";
    workoutBar.style.width = "0%";
    timerEl.textContent = "00:00";
    clearTargets();
  }
}

workoutStartBtn.addEventListener("click", async () => {
  const w = selectedWorkout();
  const ftp = Number(ftpInput.value);
  if (!w || !Number.isFinite(ftp) || ftp <= 0) return;
  workoutSamples = [];
  workoutStartMs = Date.now();
  workoutSaveName = w.name;
  actualWatts = null;
  actualCadence = null;
  actualHr = null;
  lastSampleSecs = -1;
  try {
    await invoke("set_ftp", { ftp });
    await invoke("start_workout", { path: w.path });
    await setRunning(true);
  } catch (e) {
    console.error(e);
  }
});

workoutPauseBtn.addEventListener("click", async () => {
  workoutPaused = !workoutPaused;
  workoutPauseBtn.textContent = workoutPaused ? "продолжить" : "пауза";
  try {
    await invoke("pause_workout", { paused: workoutPaused });
  } catch (e) {
    console.error(e);
  }
});

workoutStopBtn.addEventListener("click", async () => {
  try {
    await invoke("stop_workout");
  } catch (e) {
    console.error(e);
  }
  await setRunning(false);
});

listen("workout-progress", (event) => {
  const p = event.payload;
  workoutStep.textContent = p.step_name || `шаг ${p.step_index + 1}`;
  targetWatts = p.target_watts;
  targetCadence = p.target_cadence;
  updatePowerDeviation();
  updateCadenceDeviation();
  timerEl.textContent = formatClock(p.elapsed_secs);
  const pct = p.total_secs > 0 ? (p.elapsed_secs / p.total_secs) * 100 : 0;
  workoutBar.style.width = `${Math.min(100, pct)}%`;
  if (p.elapsed_secs > lastSampleSecs) {
    lastSampleSecs = p.elapsed_secs;
    workoutSamples.push({
      time: new Date(workoutStartMs + p.elapsed_secs * 1000).toISOString(),
      watts: actualWatts,
      cadence: actualCadence,
      hr: actualHr,
    });
  }
});

listen("workout-finished", (event) => {
  setRunning(false);
  if (event.payload?.ok && workoutSamples.length) {
    saveWorkout();
  }
});

async function saveWorkout() {
  try {
    const path = await invoke("save_workout", {
      name: workoutSaveName,
      samples: workoutSamples,
    });
    console.log("saved workout:", path);
    workoutMeta.textContent = `сохранено: ${path}`;
  } catch (e) {
    console.error(e);
  }
}