// Browser voice client for the TeamSpeak dashboard.
// Talks to the Node gateway over /ws/voice (see gateway/src/voice-session.js
// for the wire protocol). No WebRTC: mic PCM goes up, Opus frames come down.
//
// UI layout:
// - Top bar: shows current identity on the left and a [ browser connect ] button
//   on the right that opens a modal for [ nickname ] and [ server password ]
//   (both saved in localStorage).
// - Each channel card has a [ join ] button; while connected, non-self users
//   show a per-user volume slider and a [ msg ] button for direct messages,
//   and the joined channel expands an inline chat box (with tabs for #channel
//   and @user direct messages) directly underneath its user list.
// - Fixed bottom bar: mute / deafen / settings / leave controls.
(() => {
  "use strict";

  const cfgEl = document.getElementById("voice-config");
  const topbar = document.getElementById("voice-topbar");
  const dialog = document.getElementById("voice-dialog");
  if (!cfgEl || !topbar || !dialog) return;
  const cfg = JSON.parse(cfgEl.textContent || "{}");
  if (!cfg.enabled) return;

  const $ = (id) => document.getElementById(id);
  const ui = {
    topbar,
    topbarIdentity: $("voice-topbar-identity"),
    loginBtn: $("voice-login-btn"),
    dialog,
    dialogTarget: $("voice-dialog-target"),
    dialogMessage: $("voice-dialog-message"),
    form: $("voice-join-form"),
    nickname: $("voice-nickname"),
    password: $("voice-password"),
    submit: $("voice-submit"),
    cancel: $("voice-cancel"),
    message: $("voice-message"),
    notice: $("voice-notice"),
    bar: $("voice-bar"),
    barMessage: $("voice-bar-message"),
    channel: $("voice-channel"),
    self: $("voice-self"),
    meter: $("voice-meter"),
    threshold: $("voice-threshold"),
    mute: $("voice-mute"),
    deafen: $("voice-deafen"),
    settingsToggle: $("voice-settings-toggle"),
    settings: $("voice-settings"),
    mode: $("voice-mode"),
    ptt: $("voice-ptt"),
    leave: $("voice-leave"),
    sensitivity: $("voice-sensitivity"),
    volume: $("voice-volume"),
    container: $("ajax-container"),
  };

  const STORE = {
    nickname: "ts6voice.nickname",
    password: "ts6voice.password",
    identity: "ts6voice.identity",
    sensitivity: "ts6voice.sensitivity",
    volume: "ts6voice.volume",
    mode: "ts6voice.mode",
    userVolumes: "ts6voice.userVolumes",
  };
  const store = {
    get: (k) => { try { return localStorage.getItem(k); } catch { return null; } },
    set: (k, v) => { try { localStorage.setItem(k, v); } catch { /* private mode */ } },
  };

  const KIND_PCM = 0xf0;
  const PTT_KEY = "KeyV";
  const VAD_HANG_MS = 350;
  const TALK_TIMEOUT_MS = 300;
  const START_LATENCY_S = 0.06;
  const MAX_AHEAD_S = 0.25;
  const MAX_SEND_BUFFER = 16 * 1024;
  const MAX_CHAT_HISTORY = 100;

  let session = null;     // active session, see startJoin()
  let pendingJoin = null; // undefined = save only; null = join default channel; {cid,name} = join specific channel

  // ---- per-user volume storage -----------------------------------------------

  let savedUserVolumes = {};
  try {
    const raw = store.get(STORE.userVolumes);
    if (raw) {
      const parsed = JSON.parse(raw);
      if (parsed && typeof parsed === "object") savedUserVolumes = parsed;
    }
  } catch {
    savedUserVolumes = {};
  }

  function clampUserVolume(val) {
    const num = Number(val);
    if (!Number.isFinite(num)) return 100;
    return Math.max(0, Math.min(200, Math.round(num)));
  }

  function getUserVolumePercent(clientId, nickname) {
    if (session && session.userVolumes.has(clientId)) {
      return session.userVolumes.get(clientId);
    }
    if (nickname && Object.prototype.hasOwnProperty.call(savedUserVolumes, nickname)) {
      return clampUserVolume(savedUserVolumes[nickname]);
    }
    return 100;
  }

  function setUserVolumePercent(clientId, nickname, percent) {
    const clamped = clampUserVolume(percent);
    if (session) {
      session.userVolumes.set(clientId, clamped);
      if (session.playback) session.playback.setUserVolume(clientId, clamped / 100);
    }
    if (nickname) {
      savedUserVolumes[nickname] = clamped;
      store.set(STORE.userVolumes, JSON.stringify(savedUserVolumes));
    }
    return clamped;
  }

  // ---- messages & topbar summary ---------------------------------------------

  function setText(node, text, kind = "info") {
    if (!node) return;
    node.textContent = text || "";
    node.dataset.kind = kind;
    node.hidden = !text;
  }

  /** Route a message to wherever the user is looking right now. */
  function say(text, kind = "info") {
    if (session && session.ready) setText(ui.barMessage, text, kind);
    else if (ui.dialog.open) setText(ui.dialogMessage, text, kind);
    else setText(ui.message, text, kind);
  }

  function updateTopbarSummary() {
    const name = (ui.nickname.value || "").trim();
    const pass = ui.password.value || "";
    if (session && session.ready) {
      ui.topbarIdentity.textContent = `[ ${session.nickname} // connected ]`;
      ui.topbarIdentity.dataset.ready = "1";
    } else if (name.length >= 3 && pass) {
      ui.topbarIdentity.textContent = `[ ${name} // password saved ]`;
      ui.topbarIdentity.dataset.ready = "1";
    } else if (name.length >= 3) {
      ui.topbarIdentity.textContent = `[ ${name} // no password ]`;
      ui.topbarIdentity.dataset.ready = "";
    } else {
      ui.topbarIdentity.textContent = "[ not logged in ]";
      ui.topbarIdentity.dataset.ready = "";
    }
  }

  // ---- browser connect modal --------------------------------------------------

  function openLoginModal(joinIntent = null, errorMsg = "") {
    pendingJoin = joinIntent;
    if (joinIntent === undefined) {
      ui.dialogTarget.textContent = "credentials";
      ui.submit.textContent = "save";
    } else if (joinIntent && joinIntent.name) {
      ui.dialogTarget.textContent = joinIntent.name;
      ui.submit.textContent = "connect";
    } else {
      ui.dialogTarget.textContent = "default channel";
      ui.submit.textContent = "connect";
    }
    setText(ui.dialogMessage, errorMsg, errorMsg ? "error" : "info");
    if (!ui.dialog.open) ui.dialog.showModal();
    (ui.nickname.value.trim().length >= 3 ? ui.password : ui.nickname).focus();
  }

  function closeLoginModal() {
    pendingJoin = null;
    if (ui.dialog.open) ui.dialog.close();
  }

  ui.loginBtn.addEventListener("click", () => {
    if (session && session.ready) openLoginModal(undefined);
    else openLoginModal(null);
  });
  ui.cancel.addEventListener("click", () => {
    if (session && !session.ready) teardown("", "info");
    closeLoginModal();
  });
  ui.dialog.addEventListener("cancel", (e) => {
    if (session && !session.ready) {
      e.preventDefault();
      teardown("", "info");
      closeLoginModal();
    }
  });
  ui.dialog.addEventListener("click", (e) => {
    if (e.target === ui.dialog && (!session || session.ready)) closeLoginModal();
  });

  // ---- preferences --------------------------------------------------------------

  ui.nickname.value = store.get(STORE.nickname) || "";
  ui.password.value = store.get(STORE.password) || "";
  if (store.get(STORE.sensitivity) !== null) ui.sensitivity.value = store.get(STORE.sensitivity);
  if (store.get(STORE.volume) !== null) ui.volume.value = store.get(STORE.volume);
  let mode = store.get(STORE.mode) === "ptt" ? "ptt" : "vad";
  updateTopbarSummary();

  ui.nickname.addEventListener("input", () => {
    store.set(STORE.nickname, ui.nickname.value.trim());
    updateTopbarSummary();
    setText(ui.dialogMessage, "");
  });
  ui.password.addEventListener("input", () => {
    store.set(STORE.password, ui.password.value);
    updateTopbarSummary();
    setText(ui.dialogMessage, "");
  });

  function levelFromRms(rms) {
    const db = 20 * Math.log10(Math.max(rms, 1e-6));
    return Math.min(1, Math.max(0, (db + 60) / 60));
  }
  const threshold = () => 1 - Number(ui.sensitivity.value) / 100;
  function updateThresholdMark() { ui.threshold.style.left = `${threshold() * 100}%`; }
  function applyModeUi() {
    ui.mode.textContent = mode === "ptt" ? "push to talk" : "voice activity";
    ui.ptt.hidden = mode !== "ptt";
    ui.threshold.hidden = mode === "ptt";
  }
  updateThresholdMark();
  applyModeUi();

  // ---- live channel list & chat (channel + individual DMs) --------------------

  function sortChannels(channels, pid = "0", depth = 0) {
    const byOrder = new Map();
    for (const c of channels) if (c.parentId === pid) byOrder.set(c.order, c);
    const ordered = [];
    let current = "0";
    let guard = 0;
    while (byOrder.has(current) && guard++ <= channels.length && depth < 32) {
      const channel = byOrder.get(current);
      ordered.push(channel);
      ordered.push(...sortChannels(channels, channel.id, depth + 1));
      current = channel.id;
    }
    return ordered;
  }

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

  function safeUrl(path) {
    return encodeURI(String(path || "")).replace(/["'()\\]/g, (c) => "%" + c.charCodeAt(0).toString(16));
  }

  function statItem(label, value) {
    const item = el("div", "stat-item");
    item.append(el("span", "stat-label", label), el("span", "stat-value", String(value)));
    return item;
  }

  const displayName = (name) => name.replace("[Cspacer]", "");

  function formatTime(ts) {
    try {
      const d = new Date(ts || Date.now());
      return `${String(d.getHours()).padStart(2, "0")}:${String(d.getMinutes()).padStart(2, "0")}`;
    } catch {
      return "";
    }
  }

  function findClientName(clientId, fallback = "") {
    if (session && session.snapshot) {
      const found = session.snapshot.clients.find((c) => c.id === clientId);
      if (found && found.nickname) return found.nickname;
    }
    const existing = session && session.dmByUser.get(clientId);
    if (existing && existing.peerName) return existing.peerName;
    return fallback || `user #${clientId}`;
  }

  function ensureDmEntry(peerId, peerName) {
    let dm = session.dmByUser.get(peerId);
    const resolvedName = findClientName(peerId, peerName);
    if (!dm) {
      dm = { peerId, peerName: resolvedName, messages: [], unread: 0 };
      session.dmByUser.set(peerId, dm);
    } else if (resolvedName && dm.peerName !== resolvedName) {
      dm.peerName = resolvedName;
    }
    return dm;
  }

  function openDmConversation(peerId, peerName) {
    if (!session || !session.ready || !peerId || peerId === session.selfId) return;
    const dm = ensureDmEntry(peerId, peerName);
    dm.unread = 0;
    session.activeChatTab = { type: "dm", peerId, peerName: dm.peerName };
    render();
    const input = ui.container.querySelector(".channel-chat-input");
    if (input) {
      input.focus();
      input.scrollIntoView({ behavior: "smooth", block: "nearest" });
    }
  }

  function buildChatMsgRow(m, selfId) {
    const isSelf = m.invokerId === selfId;
    const row = el(
      "div",
      "channel-chat-msg"
        + (isSelf ? " is-self" : "")
        + (m.scope === "private" ? " is-private" : m.scope === "server" ? " is-server" : "")
    );
    row.append(el("span", "channel-chat-time", formatTime(m.timestamp)));
    const authorLabel = m.scope === "server" ? `[server] ${m.invokerName}` : m.invokerName;
    row.append(el("span", "channel-chat-author", `${authorLabel}:`));
    row.append(el("span", "channel-chat-text", m.message));
    return row;
  }

  function buildChannelChat(channelId, channelTitle) {
    const wrap = el("section", "channel-chat");
    wrap.dataset.chatCid = channelId;

    const activeTab = session ? session.activeChatTab : { type: "channel" };
    const isDmTab = activeTab && activeTab.type === "dm";
    const activeDm = isDmTab && session ? session.dmByUser.get(activeTab.peerId) : null;
    if (isDmTab && !activeDm && session) {
      session.activeChatTab = { type: "channel" };
    }
    const showingDm = Boolean(isDmTab && activeDm);

    const head = el("header", "channel-chat-header");
    const tabs = el("div", "channel-chat-tabs");

    const chTab = el(
      "button",
      "channel-chat-tab" + (!showingDm ? " is-active" : ""),
      `# ${channelTitle}`
    );
    chTab.type = "button";
    chTab.dataset.chatTab = "channel";
    tabs.append(chTab);

    if (session) {
      for (const dm of session.dmByUser.values()) {
        const isCurrentDm = showingDm && activeDm.peerId === dm.peerId;
        const dmBtn = el(
          "button",
          "channel-chat-tab is-dm" + (isCurrentDm ? " is-active" : "") + (dm.unread > 0 ? " has-unread" : ""),
          dm.unread > 0 ? `@ ${dm.peerName} (${dm.unread})` : `@ ${dm.peerName}`
        );
        dmBtn.type = "button";
        dmBtn.dataset.chatTab = "dm";
        dmBtn.dataset.dmPeer = String(dm.peerId);
        tabs.append(dmBtn);
      }
    }
    head.append(tabs);

    const log = el("div", "channel-chat-messages");
    log.id = "voice-chat-log";
    if (showingDm) {
      const msgs = activeDm.messages;
      if (msgs.length === 0) {
        log.append(el("div", "channel-chat-empty", `No private messages with ${activeDm.peerName} yet.`));
      } else {
        for (const m of msgs) log.append(buildChatMsgRow(m, session.selfId));
      }
    } else {
      const msgs = (session && session.chatByChannel.get(channelId)) || [];
      if (msgs.length === 0) {
        log.append(el("div", "channel-chat-empty", "No messages in this channel yet."));
      } else {
        for (const m of msgs) log.append(buildChatMsgRow(m, session.selfId));
      }
    }

    const draftKey = showingDm ? `dm:${activeDm.peerId}` : `channel:${channelId}`;
    const form = el("form", "channel-chat-form");
    form.dataset.chatScope = showingDm ? "private" : "channel";
    form.dataset.chatCid = channelId;
    if (showingDm) form.dataset.chatTargetId = String(activeDm.peerId);

    const input = el("input", "channel-chat-input");
    input.type = "text";
    input.name = "message";
    input.maxLength = 1024;
    input.autocomplete = "off";
    input.placeholder = showingDm ? `message @${activeDm.peerName}...` : `message #${channelTitle}...`;
    input.value = (session && session.chatDrafts.get(draftKey)) || "";
    input.addEventListener("input", () => {
      if (session) session.chatDrafts.set(draftKey, input.value);
    });
    const sendBtn = el("button", "channel-chat-send", "send");
    sendBtn.type = "submit";
    form.append(input, sendBtn);

    wrap.append(head, log, form);
    queueMicrotask(() => { log.scrollTop = log.scrollHeight; });
    return wrap;
  }

  function appendChatMessage(msg) {
    if (!session || !session.snapshot) return;

    if (msg.scope === "private") {
      const isFromSelf = msg.invokerId === session.selfId;
      const peerId = isFromSelf ? Number(msg.targetId) : Number(msg.invokerId);
      if (!peerId) return;
      const peerName = isFromSelf ? findClientName(peerId) : (msg.invokerName || findClientName(peerId));
      const dm = ensureDmEntry(peerId, peerName);
      dm.messages.push(msg);
      if (dm.messages.length > MAX_CHAT_HISTORY) dm.messages.shift();

      const viewingThisDm = session.activeChatTab
        && session.activeChatTab.type === "dm"
        && session.activeChatTab.peerId === peerId;

      if (viewingThisDm) {
        dm.unread = 0;
        const log = document.getElementById("voice-chat-log");
        if (log) {
          const empty = log.querySelector(".channel-chat-empty");
          if (empty) empty.remove();
          log.append(buildChatMsgRow(msg, session.selfId));
          log.scrollTop = log.scrollHeight;
          return;
        }
      } else if (!isFromSelf) {
        dm.unread += 1;
      }
      render();
      return;
    }

    const cid = msg.scope === "channel" && msg.targetId
      ? String(msg.targetId)
      : String(session.snapshot.self.channelId);
    let list = session.chatByChannel.get(cid);
    if (!list) {
      list = [];
      session.chatByChannel.set(cid, list);
    }
    list.push(msg);
    if (list.length > MAX_CHAT_HISTORY) list.shift();

    const viewingChannel = !session.activeChatTab || session.activeChatTab.type === "channel";
    if (cid !== String(session.snapshot.self.channelId) || !viewingChannel) return;
    const log = document.getElementById("voice-chat-log");
    if (!log) return;
    const empty = log.querySelector(".channel-chat-empty");
    if (empty) empty.remove();
    log.append(buildChatMsgRow(msg, session.selfId));
    log.scrollTop = log.scrollHeight;
  }

  function render() {
    if (!session || !session.snapshot) return;
    const activeEl = document.activeElement;
    const restoreChatFocus = Boolean(activeEl && activeEl.classList && activeEl.classList.contains("channel-chat-input"));
    const selectionStart = restoreChatFocus ? activeEl.selectionStart : null;
    const selectionEnd = restoreChatFocus ? activeEl.selectionEnd : null;
    const activeVolClid = activeEl && activeEl.classList && activeEl.classList.contains("client-volume-slider")
      ? activeEl.dataset.volClid
      : null;

    const snap = session.snapshot;
    const channels = sortChannels(snap.channels);
    const realClients = snap.clients.filter((c) => c.type !== 1);
    const byChannel = new Map();
    for (const c of realClients) {
      if (!byChannel.has(c.channelId)) byChannel.set(c.channelId, []);
      byChannel.get(c.channelId).push(c);
      if (c.id !== snap.self.id && !session.userVolumes.has(c.id)) {
        const vol = getUserVolumePercent(c.id, c.nickname);
        session.userVolumes.set(c.id, vol);
        if (session.playback) session.playback.setUserVolume(c.id, vol / 100);
      }
      if (session.dmByUser.has(c.id)) {
        session.dmByUser.get(c.id).peerName = c.nickname;
      }
    }

    // Stats mirror build_context() in app.py.
    let afk = 0;
    let afkChannel = null;
    for (const ch of snap.channels) if (ch.name.includes("AFK")) afkChannel = ch;
    if (afkChannel) afk = Math.max(0, snap.clients.filter((c) => c.channelId === afkChannel.id).length - 1);
    afk += realClients.filter((c) => c.away).length;

    const stats = el("div", "server-stats");
    stats.append(statItem("Users Connected", realClients.length), statItem("AFK Users", afk));

    const list = el("div", "channel-list");
    for (const ch of channels) {
      if (ch.name.includes("[Cspacer]") && !ch.name.includes("AFK")) continue; // spacer
      const name = displayName(ch.name);
      const members = byChannel.get(ch.id) || [];
      const isCurrent = ch.id === snap.self.channelId;

      const article = el("article", "channel" + (isCurrent ? " is-current" : ""));
      article.dataset.cid = ch.id;

      const header = el("header", "channel-header");
      const bg = (cfg.channelBanners || {})[name] || (cfg.genericImages || {}).background || "";
      if (bg) {
        header.style.backgroundImage =
          `linear-gradient(90deg, rgba(9, 18, 32, 0.96) 0%, rgba(9, 18, 32, 0.78) 45%, rgba(9, 18, 32, 0.94) 100%), url("${safeUrl(bg)}")`;
      }
      const title = el("div", "channel-title-group");
      const icon = (cfg.channelIcons || {})[name] || (cfg.genericImages || {}).icon || "";
      if (icon) {
        const img = el("img", "channel-icon");
        img.src = safeUrl(icon);
        img.alt = "";
        img.setAttribute("aria-hidden", "true");
        title.append(img);
      }
      title.append(el("h2", null, name));
      if (ch.hasPassword) title.append(el("span", "channel-lock", "pw"));

      const actions = el("div", "channel-actions");
      actions.append(el("span", "channel-meta", String(members.length)));
      if (isCurrent) {
        actions.append(el("span", "channel-here", "joined"));
      } else {
        const joinBtn = el("button", "channel-join", "join");
        joinBtn.type = "button";
        joinBtn.dataset.cid = ch.id;
        joinBtn.dataset.name = name;
        joinBtn.dataset.locked = ch.hasPassword ? "1" : "";
        joinBtn.setAttribute("aria-label", `Move to ${name}`);
        actions.append(joinBtn);
      }
      header.append(title, actions);

      const ul = el("ul", "client-list");
      for (const c of members) {
        const li = el("li", "client");
        li.dataset.clid = String(c.id);
        const isSelf = c.id === snap.self.id;
        if (isSelf) li.classList.add("is-self");
        if (session.talking.has(c.id)) li.classList.add("is-talking");

        let roleIcon = "";
        for (const g of c.serverGroups) if (!roleIcon && cfg.roleIcons && cfg.roleIcons[g]) roleIcon = cfg.roleIcons[g];
        if (roleIcon) {
          const img = el("img", "role-icon");
          img.src = safeUrl(roleIcon);
          img.alt = "Role";
          li.append(img);
        } else {
          li.append(el("span", "client-no-role-icon"));
        }
        li.append(el("span", "client-name", c.nickname));
        if (isSelf) li.append(el("span", "client-you", "(you)"));
        if (c.away) li.append(el("span", "client-afk", c.awayMessage ? `(AFK: ${c.awayMessage})` : "(AFK)"));
        if (c.outputMuted) li.append(el("span", "client-muted", "(deafened)"));
        else if (c.inputMuted) li.append(el("span", "client-muted", "(muted)"));

        if (!isSelf) {
          const controls = el("div", "client-controls");

          const volPct = getUserVolumePercent(c.id, c.nickname);
          const volWrap = el("label", "client-volume");
          volWrap.title = `Volume for ${c.nickname}`;
          const slider = el("input", "client-volume-slider");
          slider.type = "range";
          slider.min = "0";
          slider.max = "200";
          slider.step = "5";
          slider.value = String(volPct);
          slider.dataset.volClid = String(c.id);
          slider.dataset.volName = c.nickname;
          slider.setAttribute("aria-label", `Volume for ${c.nickname}`);
          const volVal = el("span", "client-volume-value", `${volPct}%`);
          volWrap.append(slider, volVal);

          const dmEntry = session.dmByUser.get(c.id);
          const unread = dmEntry ? dmEntry.unread : 0;
          const isDmOpen = session.activeChatTab
            && session.activeChatTab.type === "dm"
            && session.activeChatTab.peerId === c.id;
          const msgBtn = el(
            "button",
            "client-msg-btn" + (isDmOpen ? " is-active" : "") + (unread > 0 ? " has-unread" : ""),
            unread > 0 ? `msg (${unread})` : "msg"
          );
          msgBtn.type = "button";
          msgBtn.dataset.msgClid = String(c.id);
          msgBtn.dataset.msgName = c.nickname;
          msgBtn.title = `Message ${c.nickname}`;

          controls.append(volWrap, msgBtn);
          li.append(controls);
        }
        ul.append(li);
      }
      article.append(header, ul);
      if (isCurrent) {
        article.append(buildChannelChat(ch.id, name));
      }
      list.append(article);
    }

    ui.container.replaceChildren(stats, list);

    if (restoreChatFocus) {
      const nextInput = ui.container.querySelector(".channel-chat-input");
      if (nextInput) {
        nextInput.focus();
        try {
          if (selectionStart !== null && selectionEnd !== null) nextInput.setSelectionRange(selectionStart, selectionEnd);
        } catch { /* ignore */ }
      }
    } else if (activeVolClid) {
      const nextSlider = ui.container.querySelector(`.client-volume-slider[data-vol-clid="${activeVolClid}"]`);
      if (nextSlider) nextSlider.focus();
    }

    const current = snap.channels.find((c) => c.id === snap.self.channelId);
    ui.channel.textContent = current ? displayName(current.name) : "-";
    const me = snap.clients.find((c) => c.id === snap.self.id);
    ui.self.textContent = me ? me.nickname : session.nickname;
    updateTopbarSummary();
  }

  // ---- talking indicators -------------------------------------------------------

  function setTalking(clientId, talking) {
    if (!session) return;
    const timers = session.talkTimers;
    clearTimeout(timers.get(clientId));
    if (talking) {
      timers.set(clientId, setTimeout(() => setTalking(clientId, false), TALK_TIMEOUT_MS));
      if (session.talking.has(clientId)) return;
      session.talking.add(clientId);
    } else {
      timers.delete(clientId);
      if (!session.talking.delete(clientId)) return;
    }
    for (const li of ui.container.querySelectorAll(`.client[data-clid="${clientId}"]`)) {
      li.classList.toggle("is-talking", talking);
    }
  }

  // ---- playback (with per-user GainNode) ----------------------------------------

  function createPlayback(ctx, output, getInitialGain) {
    const speakers = new Map();

    function stream(clientId) {
      let s = speakers.get(clientId);
      if (!s) {
        const gain = ctx.createGain();
        gain.gain.value = getInitialGain ? getInitialGain(clientId) : 1;
        gain.connect(output);
        s = { playTime: 0, timestamp: 0, decoder: null, gain };
        speakers.set(clientId, s);
      }
      return s;
    }

    function schedule(s, buffer) {
      const now = ctx.currentTime;
      if (s.playTime < now) s.playTime = now + START_LATENCY_S;
      if (s.playTime > now + MAX_AHEAD_S) return;
      const src = ctx.createBufferSource();
      src.buffer = buffer;
      src.connect(s.gain);
      src.onended = () => src.disconnect();
      src.start(s.playTime);
      s.playTime += buffer.duration;
    }

    function playPcm(clientId, bytes) {
      const samples = new Int16Array(bytes.buffer, bytes.byteOffset, bytes.byteLength >> 1);
      const buffer = ctx.createBuffer(1, samples.length, 48000);
      const data = buffer.getChannelData(0);
      for (let i = 0; i < samples.length; i++) data[i] = samples[i] / 32768;
      schedule(stream(clientId), buffer);
    }

    function playOpus(clientId, bytes) {
      const s = stream(clientId);
      if (!s.decoder || s.decoder.state === "closed") {
        s.decoder = new AudioDecoder({
          output: (audio) => {
            try {
              const n = audio.numberOfFrames;
              const buffer = ctx.createBuffer(1, n, audio.sampleRate);
              const tmp = new Float32Array(n);
              audio.copyTo(tmp, { planeIndex: 0, format: "f32-planar" });
              buffer.copyToChannel(tmp, 0);
              schedule(s, buffer);
            } catch { /* drop frame */ } finally {
              audio.close();
            }
          },
          error: () => { s.decoder = null; },
        });
        s.decoder.configure({ codec: "opus", sampleRate: 48000, numberOfChannels: 1 });
        s.timestamp = 0;
      }
      if (s.decoder.decodeQueueSize > 5) return;
      s.decoder.decode(new EncodedAudioChunk({ type: "key", timestamp: s.timestamp, duration: 20000, data: bytes }));
      s.timestamp += 20000;
    }

    return {
      play(kind, clientId, bytes) {
        try {
          if (kind === KIND_PCM) playPcm(clientId, bytes);
          else playOpus(clientId, bytes);
        } catch { /* ignore broken frames */ }
      },
      setUserVolume(clientId, gainValue) {
        const s = speakers.get(clientId);
        if (s && s.gain) s.gain.gain.value = gainValue;
      },
      close() {
        for (const s of speakers.values()) {
          try { s.decoder && s.decoder.close(); } catch { /* closed */ }
          try { s.gain && s.gain.disconnect(); } catch { /* disconnected */ }
        }
        speakers.clear();
      },
    };
  }

  async function browserDecodesOpus() {
    if (typeof AudioDecoder === "undefined" || typeof EncodedAudioChunk === "undefined") return false;
    try {
      const res = await AudioDecoder.isConfigSupported({ codec: "opus", sampleRate: 48000, numberOfChannels: 1 });
      return Boolean(res.supported);
    } catch {
      return false;
    }
  }

  // ---- microphone ---------------------------------------------------------------

  function gateOpen(s, rms) {
    if (s.muted) return false;
    if (mode === "ptt") return s.pttDown;
    const now = performance.now();
    if (levelFromRms(rms) >= threshold()) s.vadUntil = now + VAD_HANG_MS;
    return now < s.vadUntil;
  }

  function onMicFrame(s, { samples, rms }) {
    if (session !== s) return;
    ui.meter.style.width = `${levelFromRms(rms) * 100}%`;
    const open = s.ready && gateOpen(s, rms);
    ui.meter.classList.toggle("is-open", open);
    if (!open) {
      if (s.wasTalking) { s.wasTalking = false; setTalking(s.selfId, false); }
      return;
    }
    if (s.ws.readyState !== WebSocket.OPEN || s.ws.bufferedAmount > MAX_SEND_BUFFER) return;
    const pcm = new Int16Array(samples.length);
    for (let i = 0; i < samples.length; i++) {
      const v = Math.max(-1, Math.min(1, samples[i]));
      pcm[i] = v < 0 ? v * 0x8000 : v * 0x7fff;
    }
    s.ws.send(pcm.buffer);
    s.wasTalking = true;
    setTalking(s.selfId, true);
  }

  // ---- session lifecycle --------------------------------------------------------

  function setPhase(phase) {
    document.body.classList.toggle("voice-connecting", phase === "connecting");
    document.body.classList.toggle("voice-live", phase === "live");
    ui.bar.hidden = phase !== "live";
    ui.submit.disabled = phase === "connecting";
  }

  async function startJoin(targetChannel = null) {
    if (session) return;
    const nickname = ui.nickname.value.trim();
    const password = ui.password.value;
    if (nickname.length < 3 || !password) {
      openLoginModal(targetChannel);
      return;
    }
    if (!window.isSecureContext || !navigator.mediaDevices || !navigator.mediaDevices.getUserMedia) {
      return say("Browser voice needs HTTPS (or localhost) for microphone access.", "error");
    }

    store.set(STORE.nickname, nickname);
    store.set(STORE.password, password);
    updateTopbarSummary();
    setText(ui.notice, "");

    const s = {
      nickname, target: targetChannel, ws: null, ctx: null, stream: null, worklet: null, playback: null, output: null,
      ready: false, muted: false, deafened: false, pttDown: false, vadUntil: 0, wasTalking: false,
      selfId: 0, snapshot: null, talking: new Set(), talkTimers: new Map(),
      userVolumes: new Map(),
      chatByChannel: new Map(), dmByUser: new Map(), activeChatTab: { type: "channel" }, chatDrafts: new Map(),
      closed: false,
    };
    session = s;
    setPhase("connecting");
    say(`Requesting microphone to join ${targetChannel && targetChannel.name ? targetChannel.name : "voice"}…`);

    try {
      // The AudioContext must be created inside the click handler's turn.
      s.ctx = new AudioContext({ latencyHint: "interactive" });
      const resume = s.ctx.resume();
      s.stream = await navigator.mediaDevices.getUserMedia({
        audio: { echoCancellation: true, noiseSuppression: true, autoGainControl: true, channelCount: 1 },
      });
      await resume;
      await s.ctx.audioWorklet.addModule("/static/mic-worklet.js");
      if (s.closed) return;

      const source = s.ctx.createMediaStreamSource(s.stream);
      s.worklet = new AudioWorkletNode(s.ctx, "ts6-mic-capture", { numberOfInputs: 1, numberOfOutputs: 1, outputChannelCount: [1] });
      const sink = s.ctx.createGain();
      sink.gain.value = 0;
      source.connect(s.worklet).connect(sink).connect(s.ctx.destination);
      s.worklet.port.onmessage = (e) => onMicFrame(s, e.data);

      s.output = s.ctx.createGain();
      s.output.gain.value = Number(ui.volume.value) / 100;
      s.output.connect(s.ctx.destination);
      s.playback = createPlayback(s.ctx, s.output, (clientId) => {
        const nick = findClientName(clientId, "");
        return getUserVolumePercent(clientId, nick) / 100;
      });
    } catch (error) {
      if (s.closed) return;
      const denied = error && (error.name === "NotAllowedError" || error.name === "SecurityError");
      teardown(denied ? "Microphone access was denied." : `Could not start audio: ${error && error.message ? error.message : error}`, "error");
      return;
    }

    const serverDecode = !(await browserDecodesOpus());
    if (s.closed) return;
    say("Connecting to TeamSpeak…");

    const proto = location.protocol === "https:" ? "wss:" : "ws:";
    const ws = new WebSocket(`${proto}//${location.host}${cfg.wsPath || "/ws/voice"}`);
    ws.binaryType = "arraybuffer";
    s.ws = ws;
    let fatalMessage = "";
    let fatalCode = "";

    ws.onopen = () => {
      ws.send(JSON.stringify({
        type: "join",
        nickname,
        password,
        channelId: s.target && s.target.cid ? s.target.cid : undefined,
        identity: store.get(STORE.identity) || undefined,
        serverDecode,
      }));
    };

    ws.onmessage = (e) => {
      if (session !== s) return;
      if (typeof e.data !== "string") {
        const bytes = new Uint8Array(e.data);
        if (bytes.length < 3) return;
        const kind = bytes[0];
        const clientId = (bytes[1] << 8) | bytes[2];
        const payload = bytes.subarray(3);
        if (payload.length === 0) return setTalking(clientId, false);
        setTalking(clientId, true);
        s.playback.play(kind, clientId, payload);
        return;
      }
      let msg;
      try { msg = JSON.parse(e.data); } catch { return; }
      switch (msg.type) {
        case "joined":
          s.ready = true;
          s.selfId = msg.self.id;
          s.snapshot = msg;
          if (msg.identity) store.set(STORE.identity, msg.identity);
          store.set(STORE.nickname, nickname);
          store.set(STORE.password, password);
          updateTopbarSummary();
          closeLoginModal();
          setText(ui.message, "");
          setText(ui.dialogMessage, "");
          setPhase("live");
          setText(ui.barMessage, serverDecode ? "Compatibility audio mode (your browser lacks WebCodecs)." : "");
          render();
          break;
        case "state":
          s.snapshot = msg;
          s.selfId = msg.self.id;
          render();
          break;
        case "chatMessage":
          appendChatMessage(msg);
          break;
        case "error":
          if (msg.fatal) {
            fatalMessage = msg.message;
            fatalCode = msg.code || "";
            break;
          }
          if (msg.code === "CHANNEL_PASSWORD" && msg.channelId) {
            promptChannelPassword(msg.channelId);
            break;
          }
          say(msg.message, "error");
          break;
        case "disconnected":
          fatalMessage = msg.reason || "Disconnected.";
          break;
      }
    };

    ws.onclose = (e) => {
      if (session !== s) return;
      let reason = fatalMessage;
      if (!reason) {
        if (s.ready) reason = e.code === 1006 ? "Connection to the voice gateway was lost." : "Disconnected.";
        else reason = "Voice gateway unreachable, full, or this origin is not allowed.";
      }
      const targetBeforeClose = s.target;
      teardown(reason, s.ready && !fatalMessage ? "info" : "error");
      if (fatalCode === "BAD_PASSWORD" || fatalCode === "NICKNAME_INVALID" || fatalCode === "NICKNAME_IN_USE") {
        openLoginModal(targetBeforeClose, reason);
      }
    };
  }

  function teardown(message, kind = "info") {
    const s = session;
    if (!s) return;
    s.closed = true;
    const wasReady = s.ready;
    session = null;
    for (const t of s.talkTimers.values()) clearTimeout(t);
    if (s.ws) {
      s.ws.onclose = null;
      try {
        if (s.ws.readyState === WebSocket.OPEN) s.ws.send(JSON.stringify({ type: "leave" }));
        s.ws.close(1000);
      } catch { /* closed */ }
    }
    if (s.stream) for (const track of s.stream.getTracks()) track.stop();
    if (s.worklet) s.worklet.port.onmessage = null;
    if (s.playback) s.playback.close();
    if (s.ctx) s.ctx.close().catch(() => undefined);

    setPhase("idle");
    updateTopbarSummary();
    ui.meter.style.width = "0%";
    ui.settings.hidden = true;
    ui.settingsToggle.setAttribute("aria-expanded", "false");
    setMuteUi(false);
    setDeafenUi(false);
    setText(ui.barMessage, "");
    if (!wasReady && ui.dialog.open) setText(ui.dialogMessage, message, kind);
    else if (!wasReady) setText(ui.message, message, kind);
    else setText(ui.notice, message, kind);
    if (wasReady && typeof window.refreshDashboard === "function") window.refreshDashboard();
  }

  // ---- channel moves, per-user volume & chat ------------------------------------

  function sendJson(message) {
    if (session && session.ready && session.ws.readyState === WebSocket.OPEN) session.ws.send(JSON.stringify(message));
  }

  function channelName(cid) {
    const ch = session && session.snapshot && session.snapshot.channels.find((c) => c.id === cid);
    return ch ? displayName(ch.name) : "this channel";
  }

  function promptChannelPassword(cid) {
    const password = window.prompt(`Password for ${channelName(cid)}`);
    if (password === null) return;
    sendJson({ type: "move", channelId: cid, password });
  }

  ui.container.addEventListener("input", (e) => {
    const slider = e.target.closest(".client-volume-slider");
    if (!slider) return;
    const clid = Number(slider.dataset.volClid);
    const name = slider.dataset.volName || "";
    const pct = setUserVolumePercent(clid, name, slider.value);
    const label = slider.parentElement && slider.parentElement.querySelector(".client-volume-value");
    if (label) label.textContent = `${pct}%`;
  });

  ui.container.addEventListener("click", (e) => {
    const msgBtn = e.target.closest(".client-msg-btn");
    if (msgBtn) {
      const clid = Number(msgBtn.dataset.msgClid);
      const name = msgBtn.dataset.msgName || "";
      if (clid) openDmConversation(clid, name);
      return;
    }

    const tabBtn = e.target.closest(".channel-chat-tab");
    if (tabBtn && session && session.ready) {
      if (tabBtn.dataset.chatTab === "dm") {
        const peerId = Number(tabBtn.dataset.dmPeer);
        if (peerId) openDmConversation(peerId);
      } else {
        session.activeChatTab = { type: "channel" };
        render();
        const input = ui.container.querySelector(".channel-chat-input");
        if (input) input.focus();
      }
      return;
    }

    const button = e.target.closest(".channel-join");
    if (!button) return;
    const cid = button.dataset.cid;
    if (!session) return void startJoin({ cid, name: button.dataset.name || "" });
    if (!session.ready) return;
    setText(ui.barMessage, "");
    if (button.dataset.locked) return promptChannelPassword(cid);
    sendJson({ type: "move", channelId: cid });
  });

  ui.container.addEventListener("submit", (e) => {
    const form = e.target.closest(".channel-chat-form");
    if (!form || !session || !session.ready) return;
    e.preventDefault();
    const input = form.querySelector(".channel-chat-input");
    if (!input) return;
    const text = input.value.trim();
    if (!text) return;
    const scope = form.dataset.chatScope || "channel";
    if (scope === "private") {
      const targetId = Number(form.dataset.chatTargetId);
      if (!targetId) return;
      input.value = "";
      session.chatDrafts.set(`dm:${targetId}`, "");
      sendJson({ type: "chat", scope: "private", targetId, message: text });
    } else {
      const cid = form.dataset.chatCid;
      input.value = "";
      session.chatDrafts.set(`channel:${cid}`, "");
      sendJson({ type: "chat", scope: "channel", message: text });
    }
  });

  // ---- controls -----------------------------------------------------------------

  function setMuteUi(on) {
    ui.mute.setAttribute("aria-pressed", String(on));
    ui.mute.textContent = on ? "unmute" : "mute";
  }

  function setDeafenUi(on) {
    ui.deafen.setAttribute("aria-pressed", String(on));
    ui.deafen.textContent = on ? "undeafen" : "deafen";
  }

  ui.form.addEventListener("submit", (e) => {
    e.preventDefault();
    const nickname = ui.nickname.value.trim();
    const password = ui.password.value;
    if (nickname.length < 3) return setText(ui.dialogMessage, "Nickname must be 3-30 characters.", "error");
    if (!password) return setText(ui.dialogMessage, "The server password is required.", "error");
    store.set(STORE.nickname, nickname);
    store.set(STORE.password, password);
    updateTopbarSummary();
    const targetToJoin = pendingJoin;
    closeLoginModal();
    if (targetToJoin !== undefined && !session) {
      void startJoin(targetToJoin);
    }
  });

  ui.leave.addEventListener("click", () => teardown("You left voice."));

  ui.mute.addEventListener("click", () => {
    if (!session) return;
    session.muted = !session.muted;
    setMuteUi(session.muted);
    sendJson({ type: "mute", muted: session.muted });
  });

  ui.deafen.addEventListener("click", () => {
    if (!session) return;
    session.deafened = !session.deafened;
    setDeafenUi(session.deafened);
    if (session.output) session.output.gain.value = session.deafened ? 0 : Number(ui.volume.value) / 100;
    sendJson({ type: "deafen", deafened: session.deafened });
  });

  ui.settingsToggle.addEventListener("click", () => {
    const open = ui.settings.hidden;
    ui.settings.hidden = !open;
    ui.settingsToggle.setAttribute("aria-expanded", String(open));
  });

  ui.mode.addEventListener("click", () => {
    mode = mode === "ptt" ? "vad" : "ptt";
    store.set(STORE.mode, mode);
    applyModeUi();
  });

  ui.sensitivity.addEventListener("input", () => {
    store.set(STORE.sensitivity, ui.sensitivity.value);
    updateThresholdMark();
  });

  ui.volume.addEventListener("input", () => {
    store.set(STORE.volume, ui.volume.value);
    if (session && session.output && !session.deafened) session.output.gain.value = Number(ui.volume.value) / 100;
  });

  const setPtt = (down) => {
    if (!session) return;
    session.pttDown = down;
    ui.ptt.classList.toggle("is-active", down);
  };
  ui.ptt.addEventListener("pointerdown", (e) => { e.preventDefault(); setPtt(true); });
  for (const ev of ["pointerup", "pointerleave", "pointercancel"]) ui.ptt.addEventListener(ev, () => setPtt(false));

  const typingTarget = (t) => t && (t.isContentEditable || /^(INPUT|TEXTAREA|SELECT)$/.test(t.tagName));
  document.addEventListener("keydown", (e) => {
    if (e.code === PTT_KEY && mode === "ptt" && session && !e.repeat && !typingTarget(e.target)) setPtt(true);
  });
  document.addEventListener("keyup", (e) => { if (e.code === PTT_KEY) setPtt(false); });
  window.addEventListener("blur", () => setPtt(false));

  window.addEventListener("pagehide", () => { if (session) teardown(""); });
})();