// ── Chat Plugin Frontend ──
//
// Footer button + bottom-right flyout. Polls /api/chat/poll on a loop
// (faster while open, slower while closed). Blinks the footer button
// when new incoming messages arrive while the flyout is closed.

const hyprcrd = window.hyprcrd;
if (!hyprcrd) throw new Error('[chat plugin] window.hyprcrd missing');

const $ = (id) => document.getElementById(id);

// ── State ─────────────────────────────────────────────────────────

let conversations = [];
let currentPeer = null;
let currentMessages = [];
let pollHandle = null;
let pollIntervalMs = 20000; // closed default
let recipientCache = null;  // { tenants: [...], self: '...' }
let initialPollDone = false;

// Chat polls aggressively because the endpoint is cheap (single indexed
// SELECT with LIMIT 500). Card sync stays on its own slower interval —
// CalDAV is the expensive one. Tab-hidden pauses the timer entirely.
const POLL_OPEN_MS = 8000;
const POLL_CLOSED_MS = 20000;

// ── Helpers ───────────────────────────────────────────────────────

function escapeHtml(str) {
    return String(str ?? '')
        .replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;')
        .replace(/"/g, '&quot;').replace(/'/g, '&#39;');
}

function formatChatTime(iso) {
    if (!iso) return '';
    const d = new Date(iso.includes('T') ? iso : iso.replace(' ', 'T') + 'Z');
    if (isNaN(d.getTime())) return '';
    const now = new Date();
    const sameDay = d.toDateString() === now.toDateString();
    if (sameDay) return d.toLocaleTimeString([], { hour: '2-digit', minute: '2-digit' });
    const diffDays = (now - d) / 86400000;
    if (diffDays < 7) return d.toLocaleDateString([], { weekday: 'short' });
    return d.toLocaleDateString([], { month: 'short', day: 'numeric' });
}

function isOpen() {
    return !$('chat-flyout')?.classList.contains('hidden');
}

// ── Footer button ─────────────────────────────────────────────────

function injectFooterButton() {
    const footer = document.querySelector('footer');
    if (!footer) return;
    if (document.getElementById('chat-footer-btn')) return;

    // Append next to the help button on the right side of the footer
    const rightGroup = footer.querySelector('.flex.items-center.gap-2:last-of-type');
    if (!rightGroup) return;

    const btn = document.createElement('button');
    btn.id = 'chat-footer-btn';
    btn.title = 'chat';
    btn.innerHTML = `
        <i class="ph ph-chats-circle text-sm"></i>
        <span class="chat-footer-label">chat</span>
        <span id="chat-unread-count" class="chat-unread-dot"></span>
    `;
    btn.addEventListener('click', toggleFlyout);
    rightGroup.appendChild(btn);
}

function setUnreadBadge(n) {
    const btn = $('chat-footer-btn');
    if (!btn) return;
    if (n > 0) {
        btn.classList.add('has-unread');
    } else {
        btn.classList.remove('has-unread');
        btn.classList.remove('blinking');
    }
}

function startBlink() {
    if (isOpen()) return;
    $('chat-footer-btn')?.classList.add('blinking');
}

function stopBlink() {
    $('chat-footer-btn')?.classList.remove('blinking');
}

// ── Flyout open / close ───────────────────────────────────────────

async function toggleFlyout() {
    if (isOpen()) closeFlyout();
    else await openFlyout();
}

async function openFlyout() {
    $('chat-flyout').classList.remove('hidden');
    // Capture blink state BEFORE we clear it — it tells us a peer wrote since last close
    const wasBlinking = $('chat-footer-btn')?.classList.contains('blinking');
    stopBlink();
    pollIntervalMs = POLL_OPEN_MS;
    restartPoll();
    await loadConversations();
    await pollOnce(); // immediate refresh on open
    await loadConversations();

    // Pick the right initial view:
    //  1. If blinking → newest peer with unread (= someone wrote to us)
    //  2. Else → last peer the user opened manually (persisted)
    //  3. Else → list view
    let target = null;
    if (wasBlinking) {
        const unread = conversations
            .filter(c => parseInt(c.unread) > 0)
            .sort((a, b) => String(b.last_at).localeCompare(String(a.last_at)));
        if (unread.length) target = unread[0].peer;
    }
    if (!target) {
        const lastPeer = localStorage.getItem('chat-last-peer');
        if (lastPeer && conversations.some(c => c.peer === lastPeer)) target = lastPeer;
    }
    if (target) await openConversation(target);
    else showListView();
}

function closeFlyout() {
    $('chat-flyout').classList.add('hidden');
    pollIntervalMs = POLL_CLOSED_MS;
    restartPoll();
}

// ── Views ─────────────────────────────────────────────────────────

function showListView() {
    $('chat-list-view').classList.remove('hidden');
    $('chat-thread-view').classList.add('hidden');
    $('chat-pick-view').classList.add('hidden');
    $('chat-flyout-title').textContent = 'chat';
    currentPeer = null;
}

function showThreadView(peer) {
    $('chat-list-view').classList.add('hidden');
    $('chat-thread-view').classList.remove('hidden');
    $('chat-pick-view').classList.add('hidden');
    $('chat-flyout-title').textContent = 'chat';
    $('chat-thread-peer').textContent = peer;
    currentPeer = peer;
}

function showPickView() {
    $('chat-list-view').classList.add('hidden');
    $('chat-thread-view').classList.add('hidden');
    $('chat-pick-view').classList.remove('hidden');
}

// ── Conversation list ─────────────────────────────────────────────

async function loadConversations() {
    const res = await fetch('api/chat/conversations').then(r => r.json()).catch(() => null);
    if (!res) return;
    conversations = res.conversations || [];
    setUnreadBadge(res.total_unread || 0);
    renderConversations();
}

function renderConversations() {
    const list = $('chat-list');
    const empty = $('chat-empty');
    if (!list || !empty) return;
    if (!conversations.length) {
        list.innerHTML = '';
        empty.classList.remove('hidden');
        return;
    }
    empty.classList.add('hidden');
    list.innerHTML = conversations.map(c => {
        const initial = (c.peer || '?').charAt(0).toUpperCase();
        const unreadBadge = parseInt(c.unread) > 0
            ? `<span class="chat-unread-badge">${c.unread}</span>` : '';
        const previewClass = c.last_direction === 'out' ? 'chat-list-preview outgoing' : 'chat-list-preview';
        return `
            <div class="chat-list-row" data-peer="${escapeHtml(c.peer)}">
                <div class="chat-list-avatar">${escapeHtml(initial)}</div>
                <div class="chat-list-info">
                    <div class="chat-list-peer">
                        <span>${escapeHtml(c.peer)}</span>
                        <span class="chat-list-time">${escapeHtml(formatChatTime(c.last_at))}</span>
                    </div>
                    <div class="${previewClass}">${escapeHtml((c.last_body || '').slice(0, 80))}</div>
                </div>
                ${unreadBadge}
            </div>
        `;
    }).join('');

    list.querySelectorAll('.chat-list-row').forEach(row => {
        row.addEventListener('click', () => openConversation(row.dataset.peer));
    });
}

// ── Thread ────────────────────────────────────────────────────────

async function openConversation(peer) {
    showThreadView(peer);
    localStorage.setItem('chat-last-peer', peer);
    await loadThread(peer);
    // Mark all incoming as read
    await hyprcrd.api('api/chat/read', { method: 'POST', body: { peer } }).catch(() => {});
    // Refresh badges in the background
    loadConversations();
    setTimeout(() => $('chat-thread-input')?.focus(), 50);
}

async function loadThread(peer) {
    const res = await fetch('api/chat/messages?peer=' + encodeURIComponent(peer))
        .then(r => r.json()).catch(() => null);
    if (!res) return;
    currentMessages = res.messages || [];
    renderThread();
}

function renderThread() {
    const wrap = $('chat-thread-messages');
    if (!wrap) return;
    wrap.innerHTML = currentMessages.map(m => {
        const cls = m.direction === 'out' ? 'out' : 'in';
        // Read receipts for outgoing messages: single check = recipient
        // polled (delivered), double check = recipient opened the thread
        // (seen). Incoming messages get no icon.
        let receipt = '';
        if (m.direction === 'out') {
            if (Number(m.seen)) receipt = '<i class="ph ph-checks chat-receipt seen"></i>';
            else if (Number(m.delivered)) receipt = '<i class="ph ph-check chat-receipt delivered"></i>';
            else receipt = '<i class="ph ph-clock chat-receipt pending"></i>';
        }
        return `
            <div class="chat-bubble ${cls}">${escapeHtml(m.body)}</div>
            <div class="chat-bubble-time">${escapeHtml(formatChatTime(m.sent_at))}${receipt}</div>
        `;
    }).join('');
    // Scroll to bottom
    wrap.scrollTop = wrap.scrollHeight;
}

async function sendMessage(e) {
    e?.preventDefault();
    const input = $('chat-thread-input');
    const body = input.value.trim();
    if (!body || !currentPeer) return;
    const sendBtn = $('chat-thread-send');
    sendBtn.disabled = true;
    input.disabled = true;

    try {
        const res = await hyprcrd.api('api/chat/send', {
            method: 'POST',
            body: { peer: currentPeer, body },
        });
        if (!res.ok) {
            const detail = [
                res.error || 'unknown',
                res.url ? `URL: ${res.url}` : null,
                res.response_body ? `Body: ${res.response_body}` : null,
            ].filter(Boolean).join('\n');
            await hyprcrd.dialog.show({
                title: 'send failed',
                message: detail,
                danger: true,
                okLabel: 'Ok',
                cancelLabel: '',
            });
            return;
        }
        input.value = '';
        await loadThread(currentPeer);
        await loadConversations();
    } catch (err) {
        await hyprcrd.dialog.show({
            title: 'send error',
            message: String(err?.message || err),
            danger: true,
            okLabel: 'Ok',
            cancelLabel: '',
        });
    } finally {
        sendBtn.disabled = false;
        input.disabled = false;
        input.focus();
    }
}

// ── Pick recipient ────────────────────────────────────────────────

async function openPickView() {
    showPickView();
    const list = $('chat-pick-list');
    list.innerHTML = '<div class="px-3 py-3 text-[10px] text-t-dim font-pixel">loading...</div>';

    if (!recipientCache) {
        const res = await fetch('api/chat/recipients').then(r => r.json()).catch(() => null);
        if (!res?.ok) {
            list.innerHTML = `<div class="px-3 py-3 text-[10px] text-t-danger font-pixel">${escapeHtml(res?.error || 'failed to load recipients')}</div>`;
            return;
        }
        recipientCache = res;
    }

    const tenants = recipientCache.tenants || [];
    const self = recipientCache.self;
    const others = tenants.filter(t => t.username !== self);
    if (!others.length) {
        list.innerHTML = '<div class="px-3 py-3 text-[10px] text-t-dim font-pixel cursor-blink">no other users on the relay</div>';
        return;
    }
    list.innerHTML = others.map(t => `
        <div class="chat-pick-row" data-peer="${escapeHtml(t.username)}">
            <i class="ph ph-user-circle text-sm"></i>
            <span>${escapeHtml(t.username)}</span>
        </div>
    `).join('');
    list.querySelectorAll('.chat-pick-row').forEach(row => {
        row.addEventListener('click', () => openConversation(row.dataset.peer));
    });
}

// ── Polling ───────────────────────────────────────────────────────

async function pollOnce() {
    const icon = $('chat-refresh-icon');
    if (icon && isOpen()) icon.classList.add('card-spinner');
    try {
        const res = await hyprcrd.api('api/chat/poll', { method: 'POST' }).catch(() => null);
        if (!res?.ok) return;
        const newCount = res.new || 0;
        const receiptUpdates = res.receipts || 0;
        if (newCount > 0) {
            await loadConversations();
            // If we're inside a thread for any peer, refresh + auto-read it
            if (isOpen() && currentPeer) {
                await loadThread(currentPeer);
                hyprcrd.api('api/chat/read', { method: 'POST', body: { peer: currentPeer } })
                    .then(() => loadConversations()).catch(() => {});
            }
            // Blink if the flyout is closed
            if (!isOpen()) startBlink();
        } else if (receiptUpdates > 0 && isOpen() && currentPeer) {
            // No new incoming, but receipts (delivered/seen) changed for
            // our outgoing — refresh the thread so the check icons update.
            await loadThread(currentPeer);
        } else if (initialPollDone === false) {
            // First poll: refresh badges in case we have unread from a previous session
            await loadConversations();
        }
        initialPollDone = true;
    } finally {
        if (icon) icon.classList.remove('card-spinner');
    }
}

function restartPoll() {
    if (pollHandle) clearInterval(pollHandle);
    pollHandle = setInterval(pollOnce, pollIntervalMs);
}

// ── Init ──────────────────────────────────────────────────────────

function init() {
    if (!$('chat-flyout')) return;

    injectFooterButton();

    $('chat-close-btn').addEventListener('click', closeFlyout);
    $('chat-refresh-btn').addEventListener('click', () => pollOnce().then(loadConversations));
    $('chat-new-btn').addEventListener('click', openPickView);
    $('chat-empty-start')?.addEventListener('click', openPickView);
    $('chat-thread-back').addEventListener('click', () => { showListView(); loadConversations(); });
    $('chat-pick-back').addEventListener('click', showListView);
    $('chat-thread-form').addEventListener('submit', sendMessage);

    // Esc closes flyout when focus is inside it
    $('chat-flyout').addEventListener('keydown', e => {
        if (e.key === 'Escape') { e.stopPropagation(); closeFlyout(); }
    });

    // Defer the first POST (poll) until auth has set csrf. GETs are fine immediately.
    loadConversations().catch(() => {});
    const startPolling = () => {
        pollOnce().catch(() => {});
        restartPoll();
    };
    if (hyprcrd.util.csrf?.()) {
        startPolling();
    } else {
        hyprcrd.hooks.on('csrf.ready', startPolling);
    }

    // Pause polling when the page is hidden
    document.addEventListener('visibilitychange', () => {
        if (document.hidden) {
            if (pollHandle) { clearInterval(pollHandle); pollHandle = null; }
        } else {
            pollOnce().catch(() => {});
            restartPoll();
        }
    });

    // Also refresh on the global sync heartbeat. Our own timer keeps
    // the faster flyout-open cadence (UX-specific); tick guarantees
    // that the header Sync button refreshes chat too, even when the
    // flyout is closed and our own timer sits at 20s.
    hyprcrd.hooks?.on?.('sync.tick', () => { pollOnce().catch(() => {}); });
}

if (document.readyState === 'loading') {
    document.addEventListener('DOMContentLoaded', init);
} else {
    init();
}

hyprcrd.registerPlugin?.({
    name: 'chat',
    version: '1.0.0',
    description: 'Encrypted chat between relay tenants',
});