const form = document.getElementById('chat-form');
const input = document.getElementById('user-input');
const sendBtn = document.getElementById('send-btn');
const chatHistory = document.getElementById('chat-history');
const apiKeyInput = document.getElementById('api-key');
const dot = document.getElementById('connection-dot');
const statusText = document.getElementById('connection-text');

let conversation = [];

// Auto-adjust textarea height
input.addEventListener('input', function () {
    this.style.height = 'auto';
    this.style.height = (this.scrollHeight) + 'px';
    if (this.value.trim() !== '' && apiKeyInput.value.trim() !== '') {
        sendBtn.disabled = false;
    } else {
        sendBtn.disabled = true;
    }
});

input.addEventListener('keydown', function (e) {
    if (e.key === 'Enter' && !e.shiftKey) {
        e.preventDefault();
        if (!sendBtn.disabled) form.dispatchEvent(new Event('submit'));
    }
});

apiKeyInput.addEventListener('input', () => {
    if (apiKeyInput.value.trim().length > 10) {
        dot.className = 'dot online';
        statusText.textContent = 'API Key Ready';
        if (input.value.trim() !== '') sendBtn.disabled = false;
    } else {
        dot.className = 'dot offline';
        statusText.textContent = 'Waiting for key...';
        sendBtn.disabled = true;
    }
});

function appendBubble(role, htmlContent) {
    const bubble = document.createElement('div');
    bubble.className = `bubble ${role}`;

    const avatar = document.createElement('div');
    avatar.className = 'avatar';
    avatar.innerHTML = role === 'assistant' ? '<i class="fa-solid fa-robot"></i>' : '<i class="fa-solid fa-user"></i>';

    const msg = document.createElement('div');
    msg.className = 'message';
    msg.innerHTML = htmlContent;

    bubble.appendChild(avatar);
    bubble.appendChild(msg);
    chatHistory.appendChild(bubble);
    chatHistory.scrollTop = chatHistory.scrollHeight;

    return msg;
}

form.addEventListener('submit', async (e) => {
    e.preventDefault();
    const userText = input.value.trim();
    if (!userText) return;

    const apiKey = apiKeyInput.value.trim();
    const llmModel = document.getElementById('llm-model').value.trim();
    const embedModel = document.getElementById('embed-model').value.trim();
    const endpoint = "https://prod-infinit-memory-production.up.railway.app/v1/chat/completions";
    const username = document.getElementById('username').value.trim() || 'demo_user';

    if (!apiKey) {
        alert("Please enter your OpenRouter API Key.");
        return;
    }

    // UI Update
    input.value = '';
    input.style.height = 'auto';
    sendBtn.disabled = true;
    appendBubble('user', `<p>${userText}</p>`);

    conversation.push({ role: "user", content: userText });

    // Show typing
    const typingMsg = appendBubble('assistant', '<div class="typing-indicator">Connecting to Backend...<br><small><i>Injecting context and pinging OpenRouter</i></small></div>');

    try {
        const payload = {
            model: llmModel,
            embed_model: embedModel,
            user: username,
            messages: conversation
        };

        const response = await fetch(endpoint, {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json',
                'Authorization': `Bearer ${apiKey}`
            },
            body: JSON.stringify(payload)
        });

        if (!response.ok) {
            let errText = await response.text();
            throw new Error(`Server Error (${response.status}): ${errText}`);
        }

        const data = await response.json();
        const aiAnswer = data.choices[0].message.content;

        // Update conversation history
        conversation.push({ role: "assistant", content: aiAnswer });

        // Parse markdown and show
        typingMsg.innerHTML = marked.parse(aiAnswer);

    } catch (err) {
        console.error(err);
        typingMsg.innerHTML = `<span style="color: #ef4444;">Connection failed: ${err.message}</span>`;
        // Remove the failed user message from internal state
        conversation.pop();
    }

    if (input.value.trim() !== '') sendBtn.disabled = false;
});