const chatbox = document.getElementById('chatbox');
const messageInput = document.getElementById('message-input');
const sendButton = document.getElementById('send-button');

// --- addMessage function (inchangée) ---
function addMessage(role, text) {
    const messageDiv = document.createElement('div');
    messageDiv.classList.add('message', role === 'user' ? 'user-message' : 'assistant-message');
    messageDiv.innerHTML = text.replace(/\n/g, '<br>');
    chatbox.appendChild(messageDiv);
    chatbox.scrollTop = chatbox.scrollHeight;
}

// --- processSSEBuffer function (inchangée - version Méthode 1) ---
function processSSEBuffer(buffer, targetDiv, currentResponseAccumulated) {
    console.log("Processing buffer:", buffer); // LOG AJOUTÉ
    let messages = buffer.split('\n\n');
    let incomplete = buffer.endsWith('\n\n') ? '' : messages.pop();
    let newResponsePart = '';

    messages.forEach(message => {
        if (!message.trim()) return;
        let eventType = 'message';
        let dataLines = [];
        message.split('\n').forEach(line => {
            if (line.startsWith('event: ')) {
                eventType = line.substring(7).trim();
            } else if (line.startsWith('data: ')) {
                dataLines.push(line.substring(6));
            }
        });
        let data = dataLines.join('\n');
        console.log(`--> SSE Event Parsed: ${eventType}, Data: ${data.substring(0, 100)}...`); // LOG AJOUTÉ

        if (eventType === 'message') {
            if (targetDiv.querySelector('.thinking')) {
                console.log("Replacing 'thinking' indicator"); // LOG AJOUTÉ
                targetDiv.innerHTML = '';
            }
            newResponsePart += data;
        } else if (eventType === 'end') {
            console.log("Fin de stream détectée (event: end)"); // LOG AJOUTÉ
            sendButton.disabled = false;
        } else if (eventType === 'error') {
            console.error("Erreur SSE du serveur:", data); // LOG AJOUTÉ
             currentResponseAccumulated += `<br><strong style="color: #ffaaaa;">خطأ من الخادم: ${data}</strong>`;
            sendButton.disabled = false;
        }
    });

    const updatedResponse = currentResponseAccumulated + newResponsePart;
    // Limiter la fréquence de mise à jour de innerHTML si beaucoup de petits chunks
    targetDiv.innerHTML = updatedResponse.replace(/\n/g, '<br>');
    chatbox.scrollTop = chatbox.scrollHeight;
    // console.log("Updated Response:", updatedResponse.substring(0, 100) + "..."); // Optionnel: peut être très verbeux

    return { incomplete: incomplete, updatedResponse: updatedResponse };
}

// --- adjustTextareaHeight function (inchangée) ---
function adjustTextareaHeight() { /* ... */ }


// --- askQuestion function (avec plus de logs) ---
async function askQuestion() {
    console.log("askQuestion called"); // LOG AJOUTÉ
    const question = messageInput.value.trim();
    if (!question) {
        console.log("Question is empty, aborting."); // LOG AJOUTÉ
        return;
    }

    addMessage('user', question);
    messageInput.value = '';
    sendButton.disabled = true;
    adjustTextareaHeight(); // Réajuste après vidage
    console.log("User message added, button disabled."); // LOG AJOUTÉ

    // Crée un placeholder pour la réponse de l'assistant
    const assistantMessageDiv = document.createElement('div');
    assistantMessageDiv.classList.add('message', 'assistant-message');
    assistantMessageDiv.innerHTML = '<span class="thinking">...</span>'; // Indicateur visuel simple
    chatbox.appendChild(assistantMessageDiv);
    chatbox.scrollTop = chatbox.scrollHeight;
    console.log("Assistant placeholder added."); // LOG AJOUTÉ

    let currentResponse = ""; // Déclaration initiale
    let buffer = '';        // Initialisation buffer
    const decoder = new TextDecoder(); // Initialisation decoder

    try {
        console.log("Initiating fetch to /ask"); // LOG AJOUTÉ
        const response = await fetch('/ask', {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json',
                'Accept': 'text/event-stream'
            },
            body: JSON.stringify({ question: question })
        });

        console.log(`Fetch response received. Status: ${response.status}, OK: ${response.ok}`); // LOG AJOUTÉ

        if (!response.ok || !response.body) {
             // Essayer de lire le corps de l'erreur si possible
             let errorBody = "N/A";
             try {
                errorBody = await response.text();
             } catch (e) {}
            throw new Error(`Erreur serveur: ${response.status} ${response.statusText}. Body: ${errorBody}`);
        }

        const reader = response.body.getReader();
        console.log("ReadableStream reader obtained. Starting read loop."); // LOG AJOUTÉ

        while (true) {
            console.log("Calling reader.read()..."); // LOG AJOUTÉ
            const { done, value } = await reader.read();

            if (done) {
                console.log("Reader finished (done=true). Processing remaining buffer."); // LOG AJOUTÉ
                // Traiter le reste du buffer
                const result = processSSEBuffer(buffer, assistantMessageDiv, currentResponse);
                currentResponse = result.updatedResponse;
                console.log("Final response after stream ended:", currentResponse.substring(0,100)+"..."); // LOG AJOUTÉ
                break; // Sort de la boucle
            }

            // Decode et ajoute au buffer
            const chunk = decoder.decode(value, { stream: true });
            console.log("Received chunk:", chunk); // LOG AJOUTÉ (peut être volumineux)
            buffer += chunk;

            // Traite le buffer et met à jour currentResponse/buffer
            console.log("Processing buffer with new chunk..."); // LOG AJOUTÉ
            const result = processSSEBuffer(buffer, assistantMessageDiv, currentResponse);
            currentResponse = result.updatedResponse;
            buffer = result.incomplete;
            console.log("Buffer remaining:", buffer); // LOG AJOUTÉ

        }

    } catch (error) {
        console.error('Erreur dans askQuestion (fetch ou stream):', error); // LOG AJOUTÉ
        // Affiche l'erreur dans la bulle de l'assistant
         if (assistantMessageDiv) {
             // Append error to existing content if any, otherwise set it
             assistantMessageDiv.innerHTML += `<br><br><strong style="color: #ffaaaa;">حدث خطأ: ${error.message}</strong>`;
             chatbox.scrollTop = chatbox.scrollHeight; // Scroll pour voir l'erreur
         } else {
             // Fallback si assistantMessageDiv n'existe pas (ne devrait pas arriver ici)
             addMessage('assistant', `<strong style="color: #ffaaaa;">حدث خطأ: ${error.message}</strong>`);
         }
    } finally {
        console.log("Executing finally block: Enabling button."); // LOG AJOUTÉ
        sendButton.disabled = false;
    }
}


// --- Écouteurs d'événements (inchangés) ---
sendButton.addEventListener('click', askQuestion);
messageInput.addEventListener('keypress', function(e) {
    if (e.key === 'Enter' && !e.shiftKey) {
        e.preventDefault();
        askQuestion();
    }
});
messageInput.addEventListener('input', adjustTextareaHeight);
adjustTextareaHeight(); // Appel initial

console.log("Chat script loaded and listeners attached."); // LOG AJOUTÉ