/**
 * Sibilla — Frontend search interface
 * Mobile-friendly, smooth UX
 */

document.addEventListener('DOMContentLoaded', () => {
    const form = document.getElementById('search-form');
    const queryInput = document.getElementById('query');
    const submitBtn = document.getElementById('submit-btn');
    const responseArea = document.getElementById('response-area');
    const loading = document.getElementById('loading');
    const answerDiv = document.getElementById('answer');
    const sourcesDiv = document.getElementById('sources');
    const metaBar = document.getElementById('meta-bar');
    const newSearchBtn = document.getElementById('new-search-btn');

    const btnText = submitBtn.querySelector('span').textContent;
    let isSearching = false;

    form.addEventListener('submit', async (e) => {
        e.preventDefault();

        if (isSearching) return;

        const query = queryInput.value.trim();
        if (!query) return;

        // Reset and show UI
        isSearching = true;
        responseArea.style.display = 'block';
        loading.style.display = 'flex';
        answerDiv.innerHTML = '';
        sourcesDiv.innerHTML = '';
        metaBar.innerHTML = '';
        metaBar.style.display = 'none';
        newSearchBtn.classList.remove('visible');
        submitBtn.disabled = true;
        submitBtn.querySelector('span').textContent = 'Consultando...';

        // Scroll to loading indicator on mobile
        loading.scrollIntoView({ behavior: 'smooth', block: 'start' });

        try {
            const res = await fetch('/api/ask', {
                method: 'POST',
                headers: { 'Content-Type': 'application/json' },
                body: JSON.stringify({ query }),
            });

            if (!res.ok) {
                const err = await res.json();
                throw new Error(err.error || 'Errore sconosciuto');
            }

            const data = await res.json();

            // Render answer — prefer server-rendered HTML, fall back to client-side markdown
            if (data.html_answer) {
                answerDiv.innerHTML = data.html_answer;
            } else {
                answerDiv.innerHTML = renderMarkdown(data.answer);
            }

            // Render metadata bar
            if (data.search_engine || data.tokens_used) {
                let metaHtml = '';
                if (data.search_engine && data.search_engine !== 'none') {
                    metaHtml += `<span class="meta-badge engine">🔍 ${data.search_engine}</span>`;
                }
                if (data.model) {
                    metaHtml += `<span class="meta-badge">🧠 ${data.model}</span>`;
                }
                if (data.tokens_used) {
                    metaHtml += `<span class="meta-badge">📊 ~${data.tokens_used} token</span>`;
                }
                metaBar.innerHTML = metaHtml;
                metaBar.style.display = 'flex';
            }

            // Render sources
            if (data.sources && data.sources.length > 0) {
                sourcesDiv.innerHTML = '<h3>📚 Fonti</h3>' +
                    data.sources.map(s =>
                        `<a href="${escapeHtml(s.url)}" target="_blank" rel="noopener" class="source-item">
                            <span class="source-index">${s.index}</span>
                            <span class="source-title">${escapeHtml(s.title)}</span>
                            <span class="source-url">${escapeHtml(s.url)}</span>
                        </a>`
                    ).join('');
            }

            // Show "new search" button and scroll to results
            newSearchBtn.classList.add('visible');
            answerDiv.scrollIntoView({ behavior: 'smooth', block: 'start' });

        } catch (err) {
            answerDiv.innerHTML = `<div class="error-box">⚠️ ${escapeHtml(err.message)}</div>`;
            answerDiv.scrollIntoView({ behavior: 'smooth', block: 'start' });
        } finally {
            loading.style.display = 'none';
            submitBtn.disabled = false;
            submitBtn.querySelector('span').textContent = btnText;
            isSearching = false;
        }
    });

    // "New search" button — scroll back to query input
    newSearchBtn.addEventListener('click', () => {
        queryInput.focus();
        queryInput.scrollIntoView({ behavior: 'smooth', block: 'center' });
    });

    // Allow Ctrl+Enter or Cmd+Enter to submit
    queryInput.addEventListener('keydown', (e) => {
        if (e.key === 'Enter' && (e.ctrlKey || e.metaKey)) {
            form.dispatchEvent(new Event('submit'));
        }
    });
});

// ── Tiny Markdown renderer ─────────────────────────────────────

function renderMarkdown(text) {
    if (!text) return '';

    let html = escapeHtml(text);

    // Headers
    html = html.replace(/^### (.+)$/gm, '<h3>$1</h3>');
    html = html.replace(/^## (.+)$/gm, '<h2>$1</h2>');
    html = html.replace(/^# (.+)$/gm, '<h1>$1</h1>');

    // Bold + italic
    html = html.replace(/\*\*\*(.+?)\*\*\*/g, '<strong><em>$1</em></strong>');
    html = html.replace(/\*\*(.+?)\*\*/g, '<strong>$1</strong>');
    html = html.replace(/\*(.+?)\*/g, '<em>$1</em>');

    // Inline code
    html = html.replace(/`(.+?)`/g, '<code>$1</code>');

    // Links
    html = html.replace(/\[(.+?)\]\((.+?)\)/g, '<a href="$2" target="_blank" rel="noopener">$1</a>');

    // Paragraphs (double newlines)
    html = html.replace(/\n\n/g, '</p><p>');
    html = '<p>' + html + '</p>';
    html = html.replace(/<p>\s*<\/p>/g, '');

    // Line breaks
    html = html.replace(/\n/g, '<br>');

    return html;
}

function escapeHtml(text) {
    const div = document.createElement('div');
    div.textContent = text;
    return div.innerHTML;
}