"use strict";

const $ = (sel) => document.querySelector(sel);

const messagesEl = $("#messages");
const statusEl = $("#status");
const promptEl = $("#prompt");
const formEl = $("#prompt-form");
const micBtn = $("#mic");
const ttsSel = $("#tts");

// Gewählter TTS-Provider (leer = Default/piper) als Request-Override.
function overrides() {
  const t = ttsSel && ttsSel.value;
  return t ? { tts_provider: t } : {};
}

let busy = false;
let activeWs = null;     // aktive WS-Verbindung (fuer Barge-in von aussen erreichbar)
let activeSources = [];  // laufende AudioBufferSourceNodes (stoppbar per Barge-in)

// Session-ID pro Nutzer (sonst "gehoert einem anderen Nutzer"-Konflikt). Wird aus
// /api/me abgeleitet; bis dahin null -> ensureSession() wartet auf loadMe().
let sessionId = null;
let mePromise = null;

// ---------- Identitaet / Menue ----------
function loadMe() {
  mePromise = (async () => {
    try {
      const res = await fetch("/api/me", { headers: { Accept: "application/json" } });
      if (!res.ok) {
        $("#identity").textContent = "Nicht angemeldet";
        return null;
      }
      const me = await res.json();
      sessionId = "web-" + me.user_id;
      $("#identity").textContent = "Angemeldet als " + (me.display_name || me.external_id || "Gast");
      if (me.sso_logout_url) {
        const logout = $("#logout");
        logout.href = me.sso_logout_url;
        logout.classList.remove("hidden");
      }
      if (me.is_admin) {
        $("#admin-toggle").classList.remove("hidden");
      }
      return me;
    } catch (e) {
      $("#identity").textContent = "Verbindung fehlgeschlagen";
      return null;
    }
  })();
  return mePromise;
}

// Stellt sicher, dass eine nutzerspezifische Session-ID feststeht, bevor ein Turn startet.
async function ensureSession() {
  if (!sessionId && mePromise) {
    try { await mePromise; } catch (e) { /* ignore */ }
  }
  if (!sessionId) sessionId = "web-anon";
}

async function loadUsers() {
  const ul = $("#user-list");
  ul.innerHTML = "<li class='muted'>lade …</li>";
  try {
    const res = await fetch("/api/admin/users");
    if (!res.ok) { ul.innerHTML = "<li class='muted'>kein Zugriff</li>"; return; }
    const users = await res.json();
    ul.innerHTML = "";
    for (const u of users) {
      const li = document.createElement("li");
      li.textContent = (u.external_id || u.display_name) + " (" + u.user_id.slice(0, 8) + ")";
      ul.appendChild(li);
    }
    if (!users.length) ul.innerHTML = "<li class='muted'>keine Nutzer</li>";
  } catch (e) {
    ul.innerHTML = "<li class='muted'>Fehler</li>";
  }
}

// ---------- Nachrichten-UI ----------
// Nach dem naechsten Layout ans Ende scrollen -> die neueste Antwort ist sichtbar.
function scrollToBottom() {
  requestAnimationFrame(() => { messagesEl.scrollTop = messagesEl.scrollHeight; });
}

const BUBBLE = {
  user: "ml-auto max-w-[80%] rounded-2xl rounded-br-sm bg-blue-600 px-4 py-2 text-white whitespace-pre-wrap",
  assistant: "mr-auto max-w-[80%] rounded-2xl rounded-bl-sm border border-slate-200 bg-white px-4 py-2 whitespace-pre-wrap dark:border-slate-700 dark:bg-slate-800",
  system: "mx-auto max-w-[90%] rounded-lg bg-amber-100 px-3 py-1.5 text-xs text-amber-800 dark:bg-amber-900/40 dark:text-amber-200",
  emergency: "mx-auto max-w-[90%] rounded-lg bg-red-100 px-3 py-1.5 text-sm font-semibold text-red-800 dark:bg-red-900/40 dark:text-red-200",
};

function addMessage(role, text) {
  const div = document.createElement("div");
  div.className = BUBBLE[role] || BUBBLE.assistant;
  div.textContent = text;
  messagesEl.appendChild(div);
  scrollToBottom();
  return div;
}

// ---------- Barge-in-Hilfsfunktionen ----------
function stopAudio() {
  activeSources.forEach((s) => { try { s.stop(); } catch (e) {} });
  activeSources = [];
}

function setMicIdle() {
  micBtn.textContent = "🎤";
  micBtn.title = "Mikrofon";
  micBtn.classList.remove("bg-red-600", "animate-pulse", "bg-amber-500");
  micBtn.classList.add("bg-emerald-600");
}

function setMicRecording() {
  micBtn.classList.remove("bg-emerald-600", "bg-amber-500");
  micBtn.classList.add("bg-red-600", "animate-pulse");
  micBtn.title = "Aufnahme stoppen";
}

function setMicBusy() {
  micBtn.textContent = "⏹";
  micBtn.title = "KI unterbrechen (Barge-in)";
  micBtn.classList.remove("bg-emerald-600", "bg-red-600", "animate-pulse");
  micBtn.classList.add("bg-amber-500");
}

// ---------- Audio-Wiedergabe (PCM s16le) ----------
let audioCtx = null;
function playPcm(chunks, sampleRate) {
  if (!chunks.length) return;
  const total = chunks.reduce((n, c) => n + c.byteLength, 0);
  const merged = new Uint8Array(total);
  let off = 0;
  for (const c of chunks) { merged.set(new Uint8Array(c), off); off += c.byteLength; }
  const view = new DataView(merged.buffer);
  const n = Math.floor(merged.byteLength / 2);
  audioCtx = audioCtx || new (window.AudioContext || window.webkitAudioContext)();
  const buf = audioCtx.createBuffer(1, n, sampleRate || 24000);
  const ch = buf.getChannelData(0);
  for (let i = 0; i < n; i++) ch[i] = view.getInt16(i * 2, true) / 32768;
  const src = audioCtx.createBufferSource();
  src.buffer = buf;
  src.connect(audioCtx.destination);
  activeSources.push(src);
  src.onended = () => { activeSources = activeSources.filter((s) => s !== src); };
  src.start();
}

// ---------- WS-Turn (Text und Sprache teilen die Event-Logik) ----------
function wsUrl(path) {
  const proto = location.protocol === "https:" ? "wss" : "ws";
  return `${proto}://${location.host}${path}?session_id=${encodeURIComponent(sessionId)}`;
}

// onopen: (ws) => sendet die Eingabe. Liefert ein Promise, das beim done-Event endet.
function runTurn(path, onopen) {
  return new Promise((resolve) => {
    const ws = new WebSocket(wsUrl(path));
    activeWs = ws;
    ws.binaryType = "arraybuffer";
    const pcm = [];
    let answerEl = null;
    let sampleRate = 24000;

    ws.onopen = () => onopen(ws);
    ws.onerror = () => { statusEl.textContent = "Verbindungsfehler"; resolve(); };
    ws.onclose = () => { activeWs = null; resolve(); };

    ws.onmessage = (event) => {
      if (typeof event.data !== "string") { pcm.push(event.data); return; }
      let msg;
      try { msg = JSON.parse(event.data); } catch { return; }
      switch (msg.type) {
        case "transcript":
          if (msg.text) addMessage("user", msg.text);
          break;
        case "token":
          if (!answerEl) answerEl = addMessage("assistant", "");
          answerEl.textContent += msg.text || "";
          scrollToBottom();
          break;
        case "semantic":
          if (!answerEl) answerEl = addMessage("assistant", "");
          if (msg.text) answerEl.textContent = msg.text;
          scrollToBottom();
          break;
        case "emergency":
          addMessage("emergency", "⚠ Notfall erkannt (" + (msg.category || "?") + ")");
          break;
        case "done":
          sampleRate = msg.sample_rate || 24000;
          playPcm(pcm, sampleRate);
          statusEl.textContent = "";
          scrollToBottom();
          ws.close();
          break;
        case "error":
          addMessage("system", "Fehler: " + (msg.detail || msg.status || "unbekannt"));
          ws.close();
          break;
        case "interrupted":
          statusEl.textContent = "";
          ws.close();  // → ws.onclose → resolve() → busy=false → setMicIdle()
          break;
      }
    };
  });
}

// ---------- Text senden ----------
async function sendText(text) {
  if (busy || !text.trim()) return;
  busy = true;
  setMicBusy();
  await ensureSession();
  addMessage("user", text);
  statusEl.textContent = "denkt …";
  await runTurn("/ws/chat", (ws) => {
    ws.send(JSON.stringify({ text, stream: true, audio_stream: true, ...overrides() }));
  });
  busy = false;
  setMicIdle();
}

formEl.addEventListener("submit", (e) => {
  e.preventDefault();
  const text = promptEl.value;
  promptEl.value = "";
  sendText(text);
});

// ---------- Mikrofon (Push-to-Talk) ----------
let mediaRecorder = null;
let recChunks = [];

async function startRecording() {
  if (busy) return;
  const md = navigator.mediaDevices;
  if (!md || !md.getUserMedia) {
    addMessage("system", "Mikrofon nicht freigegeben: Bitte die Seite direkt in Safari öffnen (nicht im In-App-Browser) und keinen Privat-Modus verwenden.");
    return;
  }
  if (typeof MediaRecorder === "undefined") {
    addMessage("system", "Aufnahme nicht unterstützt (iOS < 14.3?). Bitte iOS aktualisieren.");
    return;
  }
  let stream;
  try {
    stream = await md.getUserMedia({ audio: true });
  } catch (e) {
    addMessage("system", "Mikrofon-Zugriff fehlgeschlagen: " + (e.name || "") +
      ". Tipp: iPhone → Einstellungen → Safari → Mikrofon = Erlauben/Fragen.");
    return;
  }
  recChunks = [];
  try {
    mediaRecorder = new MediaRecorder(stream);
  } catch (e) {
    stream.getTracks().forEach((t) => t.stop());
    addMessage("system", "Aufnahme nicht möglich: " + (e.name || e.message));
    return;
  }
  mediaRecorder.ondataavailable = (e) => { if (e.data.size) recChunks.push(e.data); };
  mediaRecorder.onstop = async () => {
    stream.getTracks().forEach((t) => t.stop());
    const mime = mediaRecorder.mimeType || "audio/mp4";
    const blob = new Blob(recChunks, { type: mime });
    const bytes = await blob.arrayBuffer();
    // Safari -> audio/mp4, andere -> webm; der Server erkennt das Format am Inhalt.
    sendVoice(bytes, mime.includes("mp4") || mime.includes("mpeg") ? "mp4" : "webm");
  };
  mediaRecorder.start();
  setMicRecording();
  statusEl.textContent = "Aufnahme … (zum Stoppen erneut tippen)";
}

function stopRecording() {
  if (mediaRecorder && mediaRecorder.state !== "inactive") mediaRecorder.stop();
  setMicIdle();
}

async function sendVoice(bytes, fmt = "webm") {
  if (busy) return;
  busy = true;
  setMicBusy();
  await ensureSession();
  statusEl.textContent = "verarbeite Sprache …";
  await runTurn("/ws/voice", (ws) => {
    ws.send(JSON.stringify({ type: "start", format: fmt, stream: true, audio_stream: true, ...overrides() }));
    ws.send(bytes);
    ws.send(JSON.stringify({ type: "end" }));
  });
  busy = false;
  setMicIdle();
}

micBtn.addEventListener("click", () => {
  if (busy) {
    // Barge-in: laufende KI-Antwort sofort unterbrechen
    if (activeWs) activeWs.send(JSON.stringify({ type: "interrupt" }));
    stopAudio();
    statusEl.textContent = "Unterbrochen";
    // busy + Button-Reset erfolgen sobald die WS schliesst (-> runTurn resolve -> sendVoice/sendText)
  } else if (mediaRecorder && mediaRecorder.state === "recording") {
    stopRecording();
  } else {
    startRecording();
  }
});

$("#reload-users").addEventListener("click", loadUsers);
$("#admin-toggle").addEventListener("click", () => $("#admin").classList.toggle("hidden"));

// Tag/Nacht: Umschalter (manuell) + automatisch dem System folgen, solange nichts gewählt.
const themeBtn = $("#theme-toggle");
const setThemeIcon = () =>
  (themeBtn.textContent = document.documentElement.classList.contains("dark") ? "☀️" : "🌙");
themeBtn.addEventListener("click", () => {
  const dark = document.documentElement.classList.toggle("dark");
  localStorage.setItem("theme", dark ? "dark" : "light");
  setThemeIcon();
});
matchMedia("(prefers-color-scheme: dark)").addEventListener("change", (e) => {
  if (!localStorage.getItem("theme")) {
    document.documentElement.classList.toggle("dark", e.matches);
    setThemeIcon();
  }
});
setThemeIcon();

// Wenn die Bildschirmtastatur die sichtbare Hoehe aendert (iOS), unten bleiben.
if (window.visualViewport) {
  window.visualViewport.addEventListener("resize", scrollToBottom);
}
window.addEventListener("resize", scrollToBottom);
promptEl.addEventListener("focus", () => setTimeout(scrollToBottom, 300));

loadMe();