// chat.js — Client Léa conversationnelle
// Logique minimaliste : pas de framework, fetch + polling.

const API_BASE = "/api/chat";  // Proxyfié par le dashboard Flask vers :5005

let sessionId = null;
let pollTimer = null;
let lastMessageCount = 0;
let currentState = "idle";

const STATE_LABELS = {
    idle: "En attente",
    planning: "Léa réfléchit…",
    awaiting_confirmation: "En attente de confirmation",
    executing: "Léa exécute le workflow…",
    done: "Terminé",
    error: "Erreur",
};

// -----------------------------------------------------------------------------
// Initialisation
// -----------------------------------------------------------------------------

async function initChat() {
    try {
        const resp = await fetch(`${API_BASE}/session`, {
            method: "POST",
            headers: { "Content-Type": "application/json" },
            body: JSON.stringify({ machine_id: "default" }),
        });
        if (!resp.ok) throw new Error(`HTTP ${resp.status}`);
        const data = await resp.json();
        sessionId = data.session_id;
        currentState = data.state || "idle";
        updateStatus(currentState);
        renderMessages(data.history || []);
        document.getElementById("sessionInfo").textContent = `Session ${sessionId}`;
        startPolling();
    } catch (err) {
        console.error("Impossible de créer la session chat :", err);
        showSystemMessage(`Impossible de créer la session chat : ${err.message}. Vérifiez que le serveur streaming (5005) est démarré.`);
    }
}

// -----------------------------------------------------------------------------
// Envoi de messages
// -----------------------------------------------------------------------------

async function sendMessage() {
    const input = document.getElementById("composerInput");
    const text = (input.value || "").trim();
    if (!text || !sessionId) return;

    const sendBtn = document.getElementById("sendBtn");
    sendBtn.disabled = true;
    input.value = "";
    autosizeTextarea();

    // Affichage optimiste
    appendMessage({
        role: "user",
        content: text,
        timestamp: Date.now() / 1000,
    });

    try {
        updateStatus("planning");
        const resp = await fetch(`${API_BASE}/${sessionId}/message`, {
            method: "POST",
            headers: { "Content-Type": "application/json" },
            body: JSON.stringify({ message: text }),
        });
        if (!resp.ok) throw new Error(`HTTP ${resp.status}`);
        const data = await resp.json();
        currentState = data.state || "idle";
        updateStatus(currentState);
        renderMessages(data.history || []);
    } catch (err) {
        console.error("Erreur envoi message :", err);
        showSystemMessage(`Erreur : ${err.message}`);
        updateStatus("error");
    } finally {
        sendBtn.disabled = false;
        input.focus();
    }
}

async function confirmPlan(confirmed) {
    if (!sessionId) return;
    const confirmBar = document.getElementById("confirmBar");
    confirmBar.classList.remove("visible");

    try {
        const resp = await fetch(`${API_BASE}/${sessionId}/confirm`, {
            method: "POST",
            headers: { "Content-Type": "application/json" },
            body: JSON.stringify({ confirmed }),
        });
        if (!resp.ok) throw new Error(`HTTP ${resp.status}`);
        const data = await resp.json();
        currentState = data.state || "idle";
        updateStatus(currentState);
        renderMessages(data.history || []);
    } catch (err) {
        console.error("Erreur confirmation :", err);
        showSystemMessage(`Erreur confirmation : ${err.message}`);
    }
}

// -----------------------------------------------------------------------------
// Polling
// -----------------------------------------------------------------------------

function startPolling() {
    if (pollTimer) clearInterval(pollTimer);
    pollTimer = setInterval(pollHistory, 2000);
}

async function pollHistory() {
    if (!sessionId) return;
    try {
        const resp = await fetch(`${API_BASE}/${sessionId}/history`);
        if (!resp.ok) return;
        const data = await resp.json();
        const snap = data.snapshot || {};
        currentState = snap.state || "idle";
        updateStatus(currentState, snap.progress || {});
        const messages = snap.messages || [];
        if (messages.length !== lastMessageCount) {
            renderMessages(messages);
        }
    } catch (err) {
        // Silencieux — on réessayera au prochain tick
    }
}

// -----------------------------------------------------------------------------
// Rendu
// -----------------------------------------------------------------------------

function renderMessages(messages) {
    const container = document.getElementById("messages");
    container.innerHTML = "";
    messages.forEach(msg => appendMessage(msg, false));
    lastMessageCount = messages.length;
    container.scrollTop = container.scrollHeight;

    // Afficher/masquer la barre de confirmation
    const confirmBar = document.getElementById("confirmBar");
    if (currentState === "awaiting_confirmation") {
        confirmBar.classList.add("visible");
    } else {
        confirmBar.classList.remove("visible");
    }
}

function appendMessage(msg, autoscroll = true) {
    const container = document.getElementById("messages");
    const div = document.createElement("div");
    div.className = `message ${msg.role}`;

    const avatar = document.createElement("div");
    avatar.className = "avatar";
    if (msg.role === "user") avatar.textContent = "Vous";
    else if (msg.role === "lea") avatar.textContent = "L";
    else avatar.textContent = "i";

    const bubbleWrap = document.createElement("div");
    const bubble = document.createElement("div");
    bubble.className = "bubble";
    bubble.textContent = msg.content || "";
    bubbleWrap.appendChild(bubble);

    const ts = document.createElement("div");
    ts.className = "timestamp";
    try {
        const d = new Date((msg.timestamp || 0) * 1000);
        ts.textContent = d.toLocaleTimeString("fr-FR");
    } catch (e) { ts.textContent = ""; }
    bubbleWrap.appendChild(ts);

    div.appendChild(avatar);
    div.appendChild(bubbleWrap);
    container.appendChild(div);

    if (autoscroll) container.scrollTop = container.scrollHeight;
}

function showSystemMessage(text) {
    appendMessage({
        role: "system",
        content: text,
        timestamp: Date.now() / 1000,
    });
}

function updateStatus(state, progress = {}) {
    const dot = document.getElementById("statusDot");
    const txt = document.getElementById("statusText");
    dot.className = `status-dot ${state}`;
    let label = STATE_LABELS[state] || state;

    if (state === "executing" && progress && progress.total_actions) {
        const done = progress.completed_actions || 0;
        const total = progress.total_actions || 0;
        label = `Léa exécute… ${done}/${total}`;
    }

    txt.textContent = label;

    // Bloquer la saisie pendant planning/executing
    const input = document.getElementById("composerInput");
    const sendBtn = document.getElementById("sendBtn");
    const blocked = (state === "planning" || state === "executing");
    input.disabled = blocked;
    sendBtn.disabled = blocked;
}

// -----------------------------------------------------------------------------
// UX composer
// -----------------------------------------------------------------------------

function handleKeydown(event) {
    if (event.key === "Enter" && !event.shiftKey) {
        event.preventDefault();
        sendMessage();
    }
}

function autosizeTextarea() {
    const input = document.getElementById("composerInput");
    input.style.height = "auto";
    input.style.height = Math.min(input.scrollHeight, 120) + "px";
}

document.addEventListener("DOMContentLoaded", () => {
    const input = document.getElementById("composerInput");
    input.addEventListener("input", autosizeTextarea);
    initChat();
});