const conversation = document.querySelector("#conversation");
const statusDot = document.querySelector("#statusDot");
const statusText = document.querySelector("#statusText");
const textInput = document.querySelector("#textInput");
const sendButton = document.querySelector("#sendButton");
const voiceButton = document.querySelector("#voiceButton");
const voiceLabel = document.querySelector("#voiceLabel");
const resetButton = document.querySelector("#resetButton");
const audioToggle = document.querySelector("#audioToggle");

const SILENCE_DELAY_MS = 2000;
const MIN_VOICE_MS = 450;
const MAX_UTTERANCE_MS = 30000;
const VOICE_THRESHOLD = 0.025;

const sessionId = getSessionId();
let recorder = null;
let chunks = [];
let audioUnlocked = false;
let handsFreeMode = false;
let processingVoice = false;
let mediaStream = null;
let audioContext = null;
let analyser = null;
let analyserData = null;
let monitorFrame = null;
let speechDetected = false;
let speechStartedAt = 0;
let silenceStartedAt = null;
let utteranceStartedAt = 0;

if ("serviceWorker" in navigator) {
  navigator.serviceWorker.register("/sw.js").catch(() => {});
}

sendButton.addEventListener("click", sendText);
voiceButton.addEventListener("click", toggleVoice);
resetButton.addEventListener("click", resetConversation);
textInput.addEventListener("keydown", (event) => {
  if (event.key === "Enter" && !event.shiftKey) {
    event.preventDefault();
    sendText();
  }
});

function getSessionId() {
  const key = "opensquared_assistant_session";
  let value = localStorage.getItem(key);
  if (!value) {
    if (window.crypto && typeof window.crypto.randomUUID === "function") {
      value = window.crypto.randomUUID();
    } else {
      value = `session-${Date.now()}-${Math.random().toString(16).slice(2)}`;
    }
    localStorage.setItem(key, value);
  }
  return value;
}

function setStatus(text, mode = "idle") {
  statusText.textContent = text;
  statusDot.classList.toggle("live", mode === "live");
  statusDot.classList.toggle("error", mode === "error");
}

function addBubble(text, role = "assistant") {
  const bubble = document.createElement("article");
  bubble.className = `bubble ${role}`;
  bubble.textContent = text;
  conversation.appendChild(bubble);
  conversation.scrollTop = conversation.scrollHeight;
  return bubble;
}

async function unlockAudio() {
  if (audioUnlocked) return;
  try {
    const AudioContext = window.AudioContext || window.webkitAudioContext;
    if (AudioContext) {
      const context = new AudioContext();
      if (context.state === "suspended") {
        await context.resume();
      }
      await context.close();
    }
  } catch {
    // The click itself is enough to authorize later playback in most browsers.
  }
  audioUnlocked = true;
}

async function sendText() {
  const text = textInput.value.trim();
  if (!text) return;

  textInput.value = "";
  addBubble(text, "user");
  setStatus("Analyse en cours", "live");

  try {
    const response = await fetch("/api/chat", {
      method: "POST",
      headers: {"Content-Type": "application/json"},
      body: JSON.stringify({
        sessionId,
        text,
        withAudio: false,
      }),
    });
    const data = await response.json();
    if (!response.ok) throw new Error(data.error || "Erreur serveur");
    await handleAssistantResponse(data);
  } catch (error) {
    addBubble(error.message, "error");
    setStatus("Erreur", "error");
  }
}

async function toggleVoice() {
  if (handsFreeMode) {
    stopHandsFree("Arrete");
    return;
  }
  await startHandsFree();
}

async function startHandsFree() {
  setStatus("Activation du micro", "live");
  await unlockAudio();

  if (!navigator.mediaDevices || !navigator.mediaDevices.getUserMedia) {
    addBubble("Le micro n'est pas disponible dans ce navigateur. Ouvre l'app en HTTPS avec Chrome.", "error");
    setStatus("Micro indisponible", "error");
    return;
  }

  if (typeof MediaRecorder === "undefined") {
    addBubble("L'enregistrement audio n'est pas supporte par ce navigateur.", "error");
    setStatus("Enregistrement indisponible", "error");
    return;
  }

  try {
    mediaStream = await navigator.mediaDevices.getUserMedia({
      audio: {
        echoCancellation: true,
        noiseSuppression: true,
        autoGainControl: true,
      },
    });
    handsFreeMode = true;
    voiceButton.classList.add("recording");
    voiceLabel.textContent = "Arreter";
    await startListeningTurn();
  } catch (error) {
    addBubble("Micro indisponible : " + error.message, "error");
    setStatus("Micro indisponible", "error");
  }
}

async function startListeningTurn() {
  if (!handsFreeMode || processingVoice) return;

  cleanupRecorder();
  chunks = [];
  speechDetected = false;
  speechStartedAt = 0;
  silenceStartedAt = null;
  utteranceStartedAt = Date.now();

  const mimeType = pickMimeType();
  recorder = new MediaRecorder(mediaStream, mimeType ? {mimeType} : undefined);

  recorder.ondataavailable = (event) => {
    if (event.data.size) chunks.push(event.data);
  };

  recorder.onstop = async () => {
    stopVolumeMonitor();
    if (!handsFreeMode) return;

    const spokenLongEnough = speechDetected && Date.now() - speechStartedAt >= MIN_VOICE_MS;
    if (!spokenLongEnough) {
      window.setTimeout(startListeningTurn, 120);
      return;
    }

    const blob = new Blob(chunks, {type: recorder.mimeType || "audio/webm"});
    await sendVoiceBlob(blob);
  };

  recorder.start(250);
  startVolumeMonitor();
  setStatus("Je t'ecoute", "live");
}

function pickMimeType() {
  const types = ["audio/webm;codecs=opus", "audio/webm", "audio/ogg;codecs=opus"];
  return types.find((type) => MediaRecorder.isTypeSupported(type)) || "";
}

function startVolumeMonitor() {
  stopVolumeMonitor();

  const AudioContext = window.AudioContext || window.webkitAudioContext;
  audioContext = new AudioContext();
  const source = audioContext.createMediaStreamSource(mediaStream);
  analyser = audioContext.createAnalyser();
  analyser.fftSize = 2048;
  analyserData = new Uint8Array(analyser.fftSize);
  source.connect(analyser);

  const tick = () => {
    if (!recorder || recorder.state !== "recording") return;

    const now = Date.now();
    const volume = getCurrentVolume();
    if (volume > VOICE_THRESHOLD) {
      if (!speechDetected) {
        speechStartedAt = now;
        setStatus("Je t'entends", "live");
      }
      speechDetected = true;
      silenceStartedAt = null;
    } else if (speechDetected) {
      silenceStartedAt = silenceStartedAt || now;
      if (now - silenceStartedAt >= SILENCE_DELAY_MS) {
        setStatus("Message recu", "live");
        recorder.stop();
        return;
      }
    }

    if (now - utteranceStartedAt >= MAX_UTTERANCE_MS) {
      setStatus("Message recu", "live");
      recorder.stop();
      return;
    }

    monitorFrame = window.requestAnimationFrame(tick);
  };

  monitorFrame = window.requestAnimationFrame(tick);
}

function getCurrentVolume() {
  analyser.getByteTimeDomainData(analyserData);
  let sum = 0;
  for (const value of analyserData) {
    const centered = (value - 128) / 128;
    sum += centered * centered;
  }
  return Math.sqrt(sum / analyserData.length);
}

function stopVolumeMonitor() {
  if (monitorFrame) {
    window.cancelAnimationFrame(monitorFrame);
    monitorFrame = null;
  }
  if (audioContext) {
    audioContext.close().catch(() => {});
    audioContext = null;
  }
  analyser = null;
  analyserData = null;
}

function cleanupRecorder() {
  stopVolumeMonitor();
  recorder = null;
  chunks = [];
}

function stopHandsFree(label = "Pret") {
  handsFreeMode = false;
  processingVoice = false;

  if (recorder && recorder.state !== "inactive") {
    recorder.onstop = null;
    recorder.stop();
  }
  cleanupRecorder();

  if (mediaStream) {
    mediaStream.getTracks().forEach((track) => track.stop());
    mediaStream = null;
  }

  window.speechSynthesis?.cancel();
  voiceButton.classList.remove("recording");
  voiceLabel.textContent = "Demarrer";
  setStatus(label, "idle");
}

async function sendVoiceBlob(blob) {
  processingVoice = true;
  setStatus("Transcription", "live");

  const form = new FormData();
  const extension = blob.type.includes("ogg") ? "ogg" : "webm";
  form.append("sessionId", sessionId);
  form.append("withAudio", "false");
  form.append("audio", blob, `voice.${extension}`);

  try {
    const response = await fetch("/api/voice", {method: "POST", body: form});
    const data = await response.json();
    if (!response.ok) throw new Error(data.error || "Erreur serveur");
    if (data.transcript) addBubble(data.transcript, "user");
    await handleAssistantResponse(data);
  } catch (error) {
    addBubble(error.message, "error");
    setStatus("Erreur", "error");
  } finally {
    processingVoice = false;
    if (handsFreeMode) {
      window.setTimeout(startListeningTurn, 250);
    }
  }
}

async function handleAssistantResponse(data) {
  const reply = data.reply || "";
  addBubble(reply, "assistant");
  const status = data.emailSent
    ? "Email envoye"
    : data.contactSaved
      ? "Contact ajoute"
      : data.memorySaved
        ? "Memoire mise a jour"
        : "Pret";
  setStatus(status, data.emailSent || data.contactSaved || data.memorySaved ? "live" : "idle");

  if (!audioToggle.checked || !reply) return;

  if (data.audioUrl) {
    try {
      const audio = new Audio(data.audioUrl);
      await audio.play();
      return;
    } catch {
      // Fall through to the local French browser voice.
    }
  }

  await speakInFrench(reply);
}

function speakInFrench(text) {
  return new Promise((resolve) => {
    if (!("speechSynthesis" in window) || !("SpeechSynthesisUtterance" in window)) {
      resolve();
      return;
    }

    window.speechSynthesis.cancel();
    const utterance = new SpeechSynthesisUtterance(text);
    utterance.lang = "fr-FR";
    utterance.rate = 0.9;
    utterance.pitch = 1.08;
    utterance.volume = 0.92;
    utterance.voice = pickSoftFrenchVoice();
    utterance.onend = resolve;
    utterance.onerror = resolve;
    window.speechSynthesis.speak(utterance);
  });
}

function pickSoftFrenchVoice() {
  const voices = window.speechSynthesis.getVoices();
  const frenchVoices = voices.filter((voice) => voice.lang && voice.lang.toLowerCase().startsWith("fr"));
  const preferredNames = [
    "audrey",
    "aurelie",
    "aurélie",
    "marie",
    "julie",
    "celine",
    "céline",
    "lea",
    "léa",
    "amelie",
    "amélie",
    "sylvie",
    "hortense"
  ];

  return (
    frenchVoices.find((voice) => preferredNames.some((name) => voice.name.toLowerCase().includes(name))) ||
    frenchVoices.find((voice) => voice.lang === "fr-FR" && /female|femme|google|microsoft/i.test(voice.name)) ||
    frenchVoices.find((voice) => voice.lang === "fr-FR") ||
    frenchVoices[0] ||
    null
  );
}

window.speechSynthesis?.addEventListener?.("voiceschanged", pickSoftFrenchVoice);

async function resetConversation() {
  await fetch("/api/reset", {
    method: "POST",
    headers: {"Content-Type": "application/json"},
    body: JSON.stringify({sessionId}),
  }).catch(() => {});
  conversation.innerHTML = "";
  addBubble("Nouvelle conversation. Je t'ecoute.", "assistant");
  setStatus("Conversation reinitialisee", "live");
}