const APP_VERSION = "3.0.0";

const wall = document.querySelector("#wall");
const canvas = document.querySelector("#motionCanvas");
const ctx = canvas.getContext("2d", { alpha: true });
const hud = document.querySelector("#hud");
const sceneTitle = document.querySelector("#sceneTitle");
const versionText = document.querySelector("#versionText");
const clockText = document.querySelector("#clockText");
const tileId = location.pathname.startsWith("/output/") ? location.pathname.split("/").pop() : "left";

const sceneTitles = {
  overview: "LED 大屏投放平台",
  energy: "能源驾驶舱",
  security: "安防态势",
};

let tile = null;
let state = null;
let ws = null;
let nodeId = sessionStorage.getItem("led-platform-node-id");
let serverOffsetFromPerfMs = Date.now() - performance.now();
let bestRttMs = Number.POSITIVE_INFINITY;
let clockSamples = [];
let scheduledJobs = new Map();
let frameCount = 0;
let fps = 0;
let frameTimeMs = 0;
let droppedFrames = 0;
let lastFrameAt = performance.now();
let lastFpsAt = performance.now();
let pageIndex = 0;
let paused = false;

if (!nodeId) {
  const randomId = crypto.randomUUID ? crypto.randomUUID() : Math.random().toString(16).slice(2);
  nodeId = `${tileId}-${randomId}`;
  sessionStorage.setItem("led-platform-node-id", nodeId);
}

function serverNowMs() {
  return performance.now() + serverOffsetFromPerfMs;
}

function clientNowMs() {
  return Date.now();
}

async function bootstrap() {
  const response = await fetch(`/api/bootstrap/${tileId}`);
  const data = await response.json();
  tile = data.tile;
  applyState(data.state);
  buildStaticContent();
  layout();
  connectWs();
  requestAnimationFrame(renderLoop);
}

function buildStaticContent() {
  document.querySelector("#overviewCards").innerHTML = [
    ["同步模式", "时间轴"],
    ["渲染节点", "双 GPU"],
    ["逻辑宽度", "14880"],
    ["逻辑高度", "3510"],
    ["半屏宽度", "7440"],
    ["目标帧率", "60"],
  ].map(([label, value]) => `<article class="metric-card"><span>${label}</span><strong>${value}</strong></article>`).join("");

  const bars = document.querySelector("#timelineBars");
  bars.innerHTML = "";
  for (let index = 0; index < 32; index += 1) {
    const bar = document.createElement("i");
    bar.style.height = `${180 + ((index * 137) % 760)}px`;
    bars.append(bar);
  }

  document.querySelector("#cameraGrid").innerHTML = Array.from({ length: 8 }, (_, index) => {
    const id = String(index + 1).padStart(2, "0");
    return `<article class="camera-card"><strong>CAM-${id}</strong><span>在线 | 1080P | 低延迟</span></article>`;
  }).join("");

  document.querySelector("#alertRail").innerHTML = [
    "北侧通道人员聚集",
    "机房门禁异常",
    "消防通道占用",
    "视频质量波动",
  ].map((text) => `<article class="alert-card">${text}</article>`).join("");
}

function layout() {
  if (!tile) return;
  const scale = Math.min(window.innerWidth / tile.width, window.innerHeight / tile.height);
  document.documentElement.style.setProperty("--wall-width", `${tile.wall_width}px`);
  document.documentElement.style.setProperty("--wall-height", `${tile.wall_height}px`);
  document.documentElement.style.setProperty("--scale", `${scale}`);
  document.documentElement.style.setProperty("--offset-x", `${-tile.x * scale}px`);
  document.documentElement.style.setProperty("--offset-y", `${-tile.y * scale}px`);
  canvas.width = tile.wall_width;
  canvas.height = tile.wall_height;
}

function applyState(nextState) {
  state = nextState;
  const view = state.active_view || "overview";
  document.querySelectorAll(".scene").forEach((scene) => {
    scene.classList.toggle("active", scene.dataset.view === view);
  });
  sceneTitle.textContent = sceneTitles[view] || sceneTitles.overview;
  versionText.textContent = `v${state.version || 0}`;
  pulse();
}

function scheduleJob(message, kind, callback) {
  const applyAtMs = Number(message.payload.apply_at_ms);
  scheduledJobs.set(message.command_id, {
    id: message.command_id,
    kind,
    applyAtMs,
    message,
    callback,
    preparedAtMs: serverNowMs(),
  });
}

function drainScheduledJobs() {
  if (!scheduledJobs.size) return;
  const now = serverNowMs();
  const ready = Array.from(scheduledJobs.values())
    .filter((job) => now >= job.applyAtMs)
    .sort((a, b) => a.applyAtMs - b.applyAtMs);
  for (const job of ready) {
    scheduledJobs.delete(job.id);
    const late = now - job.applyAtMs > 50;
    job.callback(late);
  }
}

function prepareScene(message) {
  sendAck(message, "prepared");
}

function commitScene(message) {
  scheduleJob(message, "scene", (late) => {
    applyState(message.payload.state);
    sendAck(message, late ? "late" : "committed");
  });
}

function runComponentAction(message) {
  scheduleJob(message, "action", (late) => {
    applyAction(message.payload.action, message.payload.args || {});
    sendAck(message, late ? "late" : "action_committed");
  });
}

function applyAction(action, args) {
  if (action === "page.next") {
    pageIndex += 1;
    const views = ["overview", "energy", "security"];
    applyState({ ...state, active_view: views[pageIndex % views.length], version: (state?.version || 0) + 1 });
  } else if (action === "page.prev") {
    pageIndex = Math.max(0, pageIndex - 1);
    const views = ["overview", "energy", "security"];
    applyState({ ...state, active_view: views[pageIndex % views.length], version: (state?.version || 0) + 1 });
  } else if (action === "energy.mode") {
    document.querySelector("#modeValue").textContent = args.mode || "削峰";
  } else if (action === "security.alert") {
    const rail = document.querySelector("#alertRail");
    const alert = document.createElement("article");
    alert.className = "alert-card pulse";
    alert.textContent = args.text || "新增联动告警";
    rail.prepend(alert);
    while (rail.children.length > 5) rail.lastElementChild.remove();
  } else if (action === "timeline.pause") {
    paused = true;
  } else if (action === "timeline.resume") {
    paused = false;
  }
  pulse();
}

function timelineMs() {
  if (!state) return 0;
  return Math.max(0, serverNowMs() - state.scene_started_at_ms);
}

function renderLoop(now) {
  frameTimeMs = now - lastFrameAt;
  if (frameTimeMs > 40) droppedFrames += 1;
  frameCount += 1;
  if (now - lastFpsAt >= 1000) {
    fps = frameCount * 1000 / (now - lastFpsAt);
    frameCount = 0;
    lastFpsAt = now;
  }
  lastFrameAt = now;

  drainScheduledJobs();
  drawMotion(paused ? 0 : timelineMs());
  animateBars(paused ? 0 : timelineMs());
  updateHud();
  requestAnimationFrame(renderLoop);
}

function drawMotion(t) {
  ctx.clearRect(0, 0, canvas.width, canvas.height);
  ctx.globalAlpha = 0.75;
  for (let i = 0; i < 28; i += 1) {
    const phase = t / 1200 + i * 0.43;
    const x = (Math.sin(phase * 0.46) * 0.5 + 0.5) * canvas.width;
    const y = (Math.cos(phase * 0.37) * 0.5 + 0.5) * canvas.height;
    const radius = 260 + (i % 6) * 70;
    const gradient = ctx.createRadialGradient(x, y, 0, x, y, radius * 3.4);
    gradient.addColorStop(0, i % 2 ? "rgba(249,115,22,0.18)" : "rgba(20,184,166,0.22)");
    gradient.addColorStop(1, "rgba(0,0,0,0)");
    ctx.fillStyle = gradient;
    ctx.beginPath();
    ctx.arc(x, y, radius * 3.4, 0, Math.PI * 2);
    ctx.fill();
  }
  ctx.globalAlpha = 1;
}

function animateBars(t) {
  document.querySelectorAll("#timelineBars i").forEach((bar, index) => {
    const scale = 0.82 + (Math.sin(t / 720 + index * 0.38) + 1) * 0.16;
    bar.style.transform = `scaleY(${scale.toFixed(3)})`;
  });
}

function pulse() {
  wall.classList.remove("pulse");
  requestAnimationFrame(() => wall.classList.add("pulse"));
}

function syncClock() {
  if (!ws || ws.readyState !== WebSocket.OPEN) return;
  ws.send(JSON.stringify({
    type: "clock_ping",
    node_id: nodeId,
    client_send_ms: clientNowMs(),
    client_send_perf_ms: performance.now(),
  }));
}

function handleClockPong(payload) {
  const receivePerf = performance.now();
  const sendPerf = Number(payload.client_send_perf_ms ?? payload.client_send_ms);
  if (!Number.isFinite(sendPerf)) return;
  const rtt = receivePerf - sendPerf;
  const midpointPerf = sendPerf + rtt / 2;
  const offset = Number(payload.server_time_ms) - midpointPerf;
  clockSamples.push({ rtt, offset });
  clockSamples = clockSamples.sort((a, b) => a.rtt - b.rtt).slice(0, 8);
  bestRttMs = clockSamples[0].rtt;
  serverOffsetFromPerfMs = clockSamples.slice(0, 4).reduce((sum, item) => sum + item.offset, 0) / Math.min(4, clockSamples.length);
}

function sendAck(message, status) {
  if (!ws || ws.readyState !== WebSocket.OPEN || !tile) return;
  ws.send(JSON.stringify({
    type: "ack",
    command_id: message.command_id,
    node_id: nodeId,
    tile_id: tile.id,
    status,
    client_time_ms: clientNowMs(),
    server_estimated_ms: serverNowMs(),
    clock_offset_ms: serverOffsetFromPerfMs - (Date.now() - performance.now()),
    rtt_ms: Number.isFinite(bestRttMs) ? bestRttMs : null,
  }));
}

function sendTelemetry() {
  if (!ws || ws.readyState !== WebSocket.OPEN || !tile) return;
  ws.send(JSON.stringify({
    type: "telemetry",
    node_id: nodeId,
    tile_id: tile.id,
    fps,
    frame_time_ms: frameTimeMs,
    dropped_frames: droppedFrames,
  }));
}

function connectWs() {
  const protocol = location.protocol === "https:" ? "wss" : "ws";
  ws = new WebSocket(`${protocol}://${location.host}/ws/output/${tile.id}`);
  ws.addEventListener("open", () => {
    ws.send(JSON.stringify({
      type: "hello",
      node_id: nodeId,
      tile_id: tile.id,
      app_version: APP_VERSION,
      user_agent: navigator.userAgent,
    }));
    for (let i = 0; i < 5; i += 1) setTimeout(syncClock, i * 120);
  });
  ws.addEventListener("close", () => setTimeout(connectWs, 1200));
  ws.addEventListener("message", (event) => {
    const message = JSON.parse(event.data);
    if (message.type === "clock_pong") handleClockPong(message.payload);
    if (message.type === "state") scheduleJob({ command_id: message.command_id, payload: message.payload }, "state", () => applyState(message.payload.state || message.payload));
    if (message.type === "prepare_scene") prepareScene(message);
    if (message.type === "commit_scene") commitScene(message);
    if (message.type === "component_action") runComponentAction(message);
  });
}

function updateHud() {
  if (!tile) return;
  const rtt = Number.isFinite(bestRttMs) ? `${Math.round(bestRttMs)}ms` : "--";
  const scale = Number.parseFloat(getComputedStyle(document.documentElement).getPropertyValue("--scale"));
  const preview = scale < 0.75 ? " | 本地预览已缩小，生产 4K 拼接桌面会更清晰" : "";
  hud.innerHTML = `${tile.id} | ${nodeId.slice(0, 18)} | ${fps.toFixed(1)}fps | ${frameTimeMs.toFixed(1)}ms | rtt ${rtt} | jobs ${scheduledJobs.size}<span class="preview-note">${preview}</span>`;
}

function tickClock() {
  clockText.textContent = new Date().toLocaleTimeString("zh-CN", { hour12: false });
}

window.addEventListener("resize", layout);
window.addEventListener("keydown", (event) => {
  if (event.key.toLowerCase() === "h") hud.hidden = !hud.hidden;
});

bootstrap();
tickClock();
setInterval(tickClock, 1000);
setInterval(syncClock, 2000);
setInterval(sendTelemetry, 1000);