{% extends "base.html" %}
{% block title %}AI Coach{% endblock %}
{% set hide_sidebar = True %}
{% block content %}
<h1>AI Coach</h1>

<div class="chat-messages" id="chat-messages">
    {% for m in messages %}
    <div class="chat-message {{ m.role }}">
        <small>{{ m.role }} · {{ m.created_at[:10] if m.created_at else '' }}</small>
        <p>{{ m.content }}</p>
    </div>
    {% endfor %}
</div>

<form class="chat-input" id="chat-form" onsubmit="sendMessage(event)"
      data-first="{{ first }}" data-onboarding="{{ onboarding_prompt|e }}">
    <textarea id="chat-input" placeholder="Ask your coach..." rows="3" required autocomplete="off"></textarea>
    <button type="submit" id="chat-send-btn">Send</button>
</form>
<p id="chat-status" class="chat-status"></p>

<script>
const chatMessages = document.getElementById('chat-messages');
const chatInput = document.getElementById('chat-input');
const chatForm = document.getElementById('chat-form');
const chatSendBtn = document.getElementById('chat-send-btn');
const chatStatus = document.getElementById('chat-status');

const IS_FIRST = chatForm.dataset.first === '1';
const ONBOARDING_PROMPT = chatForm.dataset.onboarding;

chatInput.addEventListener('keydown', function(e) {
    if (e.key === 'Enter' && !e.shiftKey) {
        e.preventDefault();
        const event = new Event('submit', {cancelable: true});
        chatForm.dispatchEvent(event);
        if (!event.defaultPrevented) sendMessage(event);
    }
});

function appendMessage(role, content) {
    const div = document.createElement('div');
    div.className = 'chat-message ' + role;
    div.innerHTML = '<small>' + role + '</small><p>' + content + '</p>';
    chatMessages.appendChild(div);
    chatMessages.scrollTop = chatMessages.scrollHeight;
}

function setStatus(msg, isError) {
    chatStatus.textContent = msg;
    chatStatus.style.color = isError ? 'var(--del-color, #b33)' : 'var(--muted-color, #888)';
}

async function sendMessage(event) {
    event.preventDefault();
    const text = chatInput.value;
    if (!text.trim()) return;

    appendMessage('user', text);
    chatInput.value = '';
    chatInput.disabled = true;
    chatSendBtn.disabled = true;
    setStatus('Waiting for coach...');

    const assistantDiv = document.createElement('div');
    assistantDiv.className = 'chat-message assistant';
    assistantDiv.innerHTML = '<small>assistant</small><p><em>Thinking...</em></p>';
    chatMessages.appendChild(assistantDiv);
    chatMessages.scrollTop = chatMessages.scrollHeight;

    const formData = new FormData();
    formData.append('message', text);

    try {
        const response = await fetch('/chat', { method: 'POST', body: formData });
        if (!response.ok) {
            throw new Error('Server returned ' + response.status);
        }

        const reader = response.body.getReader();
        const decoder = new TextDecoder();
        const p = assistantDiv.querySelector('p');
        p.innerHTML = '';

        let buffer = '';
        while (true) {
            const { done, value } = await reader.read();
            if (done) break;
            buffer += decoder.decode(value, { stream: true });
            const lines = buffer.split('\n');
            buffer = lines.pop() || '';
            for (const line of lines) {
                if (line.startsWith('data: ')) {
                    const chunk = line.slice(6);
                    if (chunk.startsWith('[error] ')) {
                        p.innerHTML = '<strong style="color: var(--del-color, #b33)">' + chunk.slice(8) + '</strong>';
                        break;
                    }
                    p.innerHTML += chunk;
                }
            }
            chatMessages.scrollTop = chatMessages.scrollHeight;
        }

        if (!p.innerHTML.trim()) {
            p.innerHTML = '<em>No response received. Make sure the AI coach is running (<code>opencode serve</code>).</em>';
        }

        setStatus('');
        chatInput.disabled = false;
        chatSendBtn.disabled = false;
        chatInput.focus();
    } catch (err) {
        assistantDiv.querySelector('p').innerHTML = '<em>Error connecting to coach.</em>';
        setStatus('Could not reach the AI coach. Is <code>opencode serve</code> running?', true);
        chatInput.disabled = false;
        chatSendBtn.disabled = false;
    }
}

if (IS_FIRST && ONBOARDING_PROMPT) {
    chatInput.value = ONBOARDING_PROMPT;
    const event = new Event('submit', {cancelable: true});
    chatForm.dispatchEvent(event);
    if (!event.defaultPrevented) sendMessage(event);
}
</script>
{% endblock %}