// static/script.js
(function() {
    'use strict';

    // =============================================
    // State
    // =============================================
    const State = {
        token: localStorage.getItem('token'),
        user: null,
        ws: null,
        wsState: 'disconnected',
        messages: new Map(),
        messageOrder: [],
        cursor: null,
        hasMore: true,
        replyTo: null,
        pendingFile: null,
        typingUsers: new Map(),
        onlineUsers: new Map(),
        isAtBottom: true,
        theme: localStorage.getItem('theme') || 'light',
        customColors: {
            self: localStorage.getItem('custom-self') || '#2563EB',
            other: localStorage.getItem('custom-other') || '#F3F4F6',
            text: localStorage.getItem('custom-text') || '#111827'
        }
    };

    // =============================================
    // DOM Cache
    // =============================================
    const DOM = {
        // Screens
        authScreen: document.getElementById('auth-screen'),
        chatScreen: document.getElementById('chat-screen'),

        // Auth
        loginForm: document.getElementById('login-form'),
        signupForm: document.getElementById('signup-form'),
        authTabs: document.querySelectorAll('.auth-tab'),
        authError: document.getElementById('auth-error'),
        authErrorText: document.getElementById('auth-error-text'),
        authLoading: document.getElementById('auth-loading'),

        // Header
        headerDisplayName: document.getElementById('header-display-name'),
        headerAvatar: document.getElementById('header-avatar'),
        headerAvatarPlaceholder: document.getElementById('header-avatar-placeholder'),
        headerStatus: document.getElementById('header-status'),
        onlineBadge: document.getElementById('online-badge'),

        // Connection
        connectionStatus: document.getElementById('connection-status'),
        connectionText: document.getElementById('connection-text'),

        // Messages
        messagesList: document.getElementById('messages-list'),
        messagesScroll: document.getElementById('messages-scroll'),
        emptyState: document.getElementById('empty-state'),
        loadOlderBtn: document.getElementById('load-older-btn'),
        scrollBottomBtn: document.getElementById('scroll-bottom-btn'),

        // Typing
        typingIndicator: document.getElementById('typing-indicator'),
        typingText: document.getElementById('typing-text'),

        // Reply
        replyPreview: document.getElementById('reply-preview'),
        replyUser: document.getElementById('reply-user'),
        replyText: document.getElementById('reply-text'),

        // Compose
        composeForm: document.getElementById('compose-form'),
        messageInput: document.getElementById('message-input'),
        sendBtn: document.getElementById('send-btn'),
        attachBtn: document.getElementById('attach-btn'),
        emojiBtn: document.getElementById('emoji-btn'),
        fileInput: document.getElementById('file-input'),

        // Upload
        uploadPreview: document.getElementById('upload-preview'),
        uploadFilename: document.getElementById('upload-filename'),
        cancelUpload: document.getElementById('cancel-upload'),
        uploadProgress: document.getElementById('upload-progress'),
        progressFill: document.getElementById('progress-fill'),
        progressText: document.getElementById('progress-text'),

        // Modals
        settingsModal: document.getElementById('settings-modal'),
        onlineModal: document.getElementById('online-modal'),
        emojiPicker: document.getElementById('emoji-picker'),
        emojiGrid: document.getElementById('emoji-grid'),

        // Settings
        settingsDisplayName: document.getElementById('settings-display-name'),
        settingsUsername: document.getElementById('settings-username'),
        settingsAvatarPreview: document.getElementById('settings-avatar-preview'),
        settingsAvatarImg: document.getElementById('settings-avatar-img'),
        avatarInput: document.getElementById('avatar-input'),
        avatarUploadBtn: document.getElementById('avatar-upload-btn'),
        themeOptions: document.querySelectorAll('.theme-option'),
        customThemeSettings: document.getElementById('custom-theme-settings'),
        customSelfColor: document.getElementById('custom-self-color'),
        customOtherColor: document.getElementById('custom-other-color'),
        customTextColor: document.getElementById('custom-text-color'),
        selfColorHex: document.getElementById('self-color-hex'),
        otherColorHex: document.getElementById('other-color-hex'),
        textColorHex: document.getElementById('text-color-hex'),

        // Online users modal
        onlineBtn: document.getElementById('online-btn'),
        onlineUsersList: document.getElementById('online-users-list'),
        onlineTotal: document.getElementById('online-total'),

        // Toast
        toastContainer: document.getElementById('toast-container')
    };

    const API = window.location.origin;

    // =============================================
    // Theme
    // =============================================
    function applyTheme(theme) {
        document.documentElement.setAttribute('data-theme', theme);
        State.theme = theme;
        localStorage.setItem('theme', theme);
        if (theme === 'custom') {
            const selfColor = State.customColors.self;
            const otherColor = State.customColors.other;
            const textColor = State.customColors.text;
            document.documentElement.style.setProperty('--bubble-self', selfColor);
            document.documentElement.style.setProperty('--bubble-other', otherColor);
            document.documentElement.style.setProperty('--bubble-other-text', textColor);
            const isLight = (c) => {
                const r = parseInt(c.slice(1,3),16), g = parseInt(c.slice(3,5),16), b = parseInt(c.slice(5,7),16);
                return (0.299 * r + 0.587 * g + 0.114 * b) > 150;
            };
            document.documentElement.style.setProperty('--bubble-self-text', isLight(selfColor) ? '#111827' : '#FFFFFF');
        } else {
            // Remove inline custom properties to let CSS variables take over
            document.documentElement.style.removeProperty('--bubble-self');
            document.documentElement.style.removeProperty('--bubble-other');
            document.documentElement.style.removeProperty('--bubble-other-text');
            document.documentElement.style.removeProperty('--bubble-self-text');
        }
    }

    applyTheme(State.theme);

    // =============================================
    // Toast Notifications
    // =============================================
    function showToast(message, type = 'info') {
        const toast = document.createElement('div');
        toast.className = `toast toast-${type}`;
        let icon = 'info-circle';
        if (type === 'success') icon = 'check-circle';
        else if (type === 'error') icon = 'exclamation-circle';
        else if (type === 'warning') icon = 'exclamation-triangle';
        toast.innerHTML = `<i class="fas fa-${icon}"></i><span>${message}</span>`;
        DOM.toastContainer.appendChild(toast);
        setTimeout(() => toast.remove(), 4000);
    }

    // =============================================
    // Authentication
    // =============================================
    DOM.authTabs.forEach(tab => {
        tab.addEventListener('click', () => {
            const target = tab.dataset.tab;
            DOM.authTabs.forEach(t => t.classList.remove('active'));
            tab.classList.add('active');
            DOM.loginForm.classList.toggle('active', target === 'login');
            DOM.signupForm.classList.toggle('active', target === 'signup');
            DOM.authError.style.display = 'none';
        });
    });

    DOM.loginForm.addEventListener('submit', async (e) => {
        e.preventDefault();
        const username = document.getElementById('login-username').value.trim();
        const password = document.getElementById('login-password').value;
        await login(username, password);
    });

    DOM.signupForm.addEventListener('submit', async (e) => {
        e.preventDefault();
        const username = document.getElementById('signup-username').value.trim();
        const display = document.getElementById('signup-display').value.trim() || username;
        const password = document.getElementById('signup-password').value;
        await signup(username, password, display);
    });

    async function login(username, password) {
        DOM.authLoading.classList.remove('hidden');
        hideAuthError();
        try {
            const res = await fetch(`${API}/api/auth/login?username=${encodeURIComponent(username)}&password=${encodeURIComponent(password)}`, { method: 'POST' });
            const data = await res.json();
            if (!res.ok) throw new Error(data.detail || 'Login failed');
            handleAuthSuccess(data);
        } catch (err) {
            showAuthError(err.message);
        } finally {
            DOM.authLoading.classList.add('hidden');
        }
    }

    async function signup(username, password, display) {
        DOM.authLoading.classList.remove('hidden');
        hideAuthError();
        try {
            const res = await fetch(`${API}/api/auth/signup?username=${encodeURIComponent(username)}&password=${encodeURIComponent(password)}&display_name=${encodeURIComponent(display)}`, { method: 'POST' });
            const data = await res.json();
            if (!res.ok) throw new Error(data.detail || 'Signup failed');
            handleAuthSuccess(data);
        } catch (err) {
            showAuthError(err.message);
        } finally {
            DOM.authLoading.classList.add('hidden');
        }
    }

    function handleAuthSuccess(data) {
        State.token = data.token;
        State.user = data.user;
        localStorage.setItem('token', State.token);
        showChat();
        connectWebSocket();
    }

    function showAuthError(msg) {
        DOM.authErrorText.textContent = msg;
        DOM.authError.style.display = 'flex';
    }

    function hideAuthError() {
        DOM.authError.style.display = 'none';
    }

    // =============================================
    // WebSocket
    // =============================================
    function connectWebSocket() {
        if (!State.token) return;
        if (State.ws && State.ws.readyState === WebSocket.OPEN) return;

        State.wsState = 'connecting';
        updateConnectionUI();

        const proto = location.protocol === 'https:' ? 'wss:' : 'ws:';
        const url = `${proto}//${location.host}/ws?token=${encodeURIComponent(State.token)}`;
        State.ws = new WebSocket(url);

        State.ws.onopen = () => {
            State.wsState = 'connected';
            updateConnectionUI();
            loadMessages();
            requestOnlineUsers();
        };

        State.ws.onmessage = (event) => {
            try {
                const msg = JSON.parse(event.data);
                handleWSMessage(msg);
            } catch (e) {
                console.error('WS parse error', e);
            }
        };

        State.ws.onclose = () => {
            if (State.wsState === 'connected') {
                State.wsState = 'reconnecting';
                updateConnectionUI();
                setTimeout(connectWebSocket, 3000);
            } else {
                State.wsState = 'disconnected';
                updateConnectionUI();
            }
        };

        State.ws.onerror = () => {
            State.wsState = 'disconnected';
            updateConnectionUI();
        };
    }

    function updateConnectionUI() {
        const status = DOM.connectionStatus;
        status.className = 'connection-status';
        switch (State.wsState) {
            case 'connected':
                status.classList.add('connected');
                DOM.connectionText.textContent = 'Connected';
                break;
            case 'reconnecting':
                status.classList.add('reconnecting');
                DOM.connectionText.textContent = 'Reconnecting...';
                break;
            default:
                status.classList.add('disconnected');
                DOM.connectionText.textContent = 'Disconnected';
        }
    }

    function handleWSMessage(msg) {
        switch (msg.type) {
            case 'connection_established':
                State.user = {
                    id: msg.user_id,
                    username: msg.username,
                    display_name: msg.display_name,
                    avatar_path: msg.avatar_path
                };
                msg.online_users.forEach(u => State.onlineUsers.set(u.id, u));
                updateHeader();
                updateOnlineBadge();
                break;

            case 'new_message':
                if (State.messages.has(msg.message.id)) return;
                State.messages.set(msg.message.id, msg.message);
                State.messageOrder.push(msg.message.id);
                renderMessage(msg.message);
                if (State.isAtBottom) scrollToBottom();
                if (document.visibilityState === 'visible') sendMarkRead(msg.message.id);
                if (document.visibilityState !== 'visible' && Notification.permission === 'granted') {
                    new Notification(`${msg.message.sender_display_name}`, {
                        body: msg.message.content || 'Sent a file',
                        icon: '/static/icon.png'
                    });
                }
                break;

            case 'messages_loaded':
                msg.messages.forEach(m => {
                    if (!State.messages.has(m.id)) {
                        State.messages.set(m.id, m);
                        State.messageOrder.unshift(m.id);
                    }
                });
                State.hasMore = msg.has_more;
                if (msg.next_cursor) State.cursor = msg.next_cursor;
                renderAllMessages();
                DOM.loadOlderBtn.classList.toggle('hidden', !msg.has_more);
                break;

            case 'user_status':
                if (msg.status === 'online') {
                    State.onlineUsers.set(msg.user_id, {
                        id: msg.user_id,
                        username: msg.username,
                        display_name: msg.display_name,
                        avatar_path: msg.avatar_path
                    });
                } else {
                    State.onlineUsers.delete(msg.user_id);
                }
                updateOnlineBadge();
                break;

            case 'typing_indicator':
                if (msg.is_typing) {
                    State.typingUsers.set(msg.user_id, msg);
                } else {
                    State.typingUsers.delete(msg.user_id);
                }
                updateTypingIndicator();
                break;

            case 'message_edited':
                if (State.messages.has(msg.message_id)) {
                    const msgObj = State.messages.get(msg.message_id);
                    msgObj.content = msg.content;
                    msgObj.is_edited = true;
                    updateMessageBubble(msg.message_id);
                }
                break;

            case 'message_deleted':
                if (State.messages.has(msg.message_id)) {
                    const msgObj = State.messages.get(msg.message_id);
                    msgObj.is_deleted = true;
                    updateMessageBubble(msg.message_id);
                }
                break;

            case 'message_read':
                if (State.messages.has(msg.message_id) && State.messages.get(msg.message_id).sender_id === State.user.id) {
                    State.messages.get(msg.message_id).status = 'read';
                    updateMessageBubble(msg.message_id);
                }
                break;

            case 'online_users':
                State.onlineUsers.clear();
                msg.users.forEach(u => State.onlineUsers.set(u.id, u));
                updateOnlineBadge();
                if (!DOM.onlineModal.classList.contains('hidden')) renderOnlineUsers();
                break;

            case 'error':
                showToast(msg.message, 'error');
        }
    }

    // =============================================
    // Message Actions
    // =============================================
    function loadMessages() {
        if (State.ws?.readyState === WebSocket.OPEN) {
            State.ws.send(JSON.stringify({ type: 'load_messages', limit: 50 }));
        }
    }

    function sendMarkRead(messageId) {
        if (State.ws?.readyState === WebSocket.OPEN) {
            State.ws.send(JSON.stringify({ type: 'mark_read', up_to_message_id: messageId }));
        }
    }

    // =============================================
    // Rendering
    // =============================================
    function renderMessage(msg) {
        if (DOM.messagesList.querySelector(`[data-id="${msg.id}"]`)) return;
        const wrapper = document.createElement('div');
        wrapper.className = `message-wrapper ${msg.sender_id === State.user.id ? 'self' : 'other'}`;
        wrapper.dataset.id = msg.id;
        wrapper.innerHTML = buildMessageHTML(msg);
        DOM.messagesList.appendChild(wrapper);
    }

    function buildMessageHTML(msg) {
        if (msg.is_deleted) return '<div class="message-bubble deleted">This message was deleted</div>';
        const isSelf = msg.sender_id === State.user?.id;
        let html = '';
        // reply indicator
        if (msg.reply_to_id && State.messages.has(msg.reply_to_id)) {
            const reply = State.messages.get(msg.reply_to_id);
            html += `<div class="reply-indicator"><i class="fas fa-reply"></i><span>${reply.sender_username}: ${truncate(reply.content, 50)}</span></div>`;
        }
        html += `<div class="message-bubble">`;
        html += `<div class="message-text">${escapeHtml(msg.content)}</div>`;
        if (msg.file_path) html += buildAttachmentHTML(msg);
        html += `<div class="message-meta">`;
        html += `<span class="message-time">${formatTime(msg.timestamp_ms)}</span>`;
        if (msg.is_edited) html += ' <span class="edited-label">edited</span>';
        if (isSelf) {
            const icon = msg.status === 'read' ? '<i class="fas fa-check-double"></i>' : '<i class="fas fa-check"></i>';
            html += `<span class="message-status ${msg.status==='read'?'read':''}">${icon}</span>`;
        }
        html += `</div><div class="message-actions">`;
        html += `<button onclick="InfinityChat.replyTo(${msg.id})"><i class="fas fa-reply"></i></button>`;
        if (isSelf) {
            html += `<button onclick="InfinityChat.editMessage(${msg.id})"><i class="fas fa-pen"></i></button>`;
            html += `<button onclick="InfinityChat.deleteMessage(${msg.id})"><i class="fas fa-trash"></i></button>`;
        }
        html += `</div></div>`;
        return html;
    }

    function buildAttachmentHTML(msg) {
        const url = `${API}/api/download/${encodeURIComponent(msg.file_path)}?token=${encodeURIComponent(State.token)}`;
        if (msg.file_type && msg.file_type.startsWith('image/')) {
            return `<div class="attachment"><img src="${url}" alt="${msg.file_name}" loading="lazy" onclick="window.open(this.src)"></div>`;
        } else if (msg.file_type && msg.file_type.startsWith('video/')) {
            return `<div class="attachment"><video controls preload="metadata"><source src="${url}" type="${msg.file_type}"></video></div>`;
        } else if (msg.file_type && msg.file_type.startsWith('audio/')) {
            return `<div class="attachment"><audio controls src="${url}"></audio></div>`;
        } else {
            return `<div class="attachment-file" onclick="window.open('${url}')">
                        <i class="fas fa-file"></i>
                        <div class="file-info">
                            <div class="file-name">${msg.file_name || 'File'}</div>
                            <div class="file-size">${formatFileSize(msg.file_size)}</div>
                        </div>
                    </div>`;
        }
    }

    function updateMessageBubble(id) {
        const el = DOM.messagesList.querySelector(`[data-id="${id}"]`);
        if (!el) return;
        const msg = State.messages.get(id);
        if (msg) el.innerHTML = buildMessageHTML(msg);
    }

    function renderAllMessages() {
        DOM.messagesList.innerHTML = '';
        if (State.messageOrder.length === 0) {
            DOM.emptyState.style.display = 'flex';
        } else {
            DOM.emptyState.style.display = 'none';
            State.messageOrder.forEach(id => {
                const msg = State.messages.get(id);
                if (msg) renderMessage(msg);
            });
        }
        if (State.isAtBottom) scrollToBottom();
    }

    function scrollToBottom() {
        DOM.messagesScroll.scrollTop = DOM.messagesScroll.scrollHeight;
    }

    // =============================================
    // Scroll detection
    // =============================================
    DOM.messagesScroll.addEventListener('scroll', () => {
        const { scrollTop, scrollHeight, clientHeight } = DOM.messagesScroll;
        State.isAtBottom = (scrollHeight - scrollTop - clientHeight) < 60;
        DOM.scrollBottomBtn.classList.toggle('hidden', State.isAtBottom);
    });
    DOM.scrollBottomBtn.addEventListener('click', scrollToBottom);

    // =============================================
    // Compose
    // =============================================
    DOM.composeForm.addEventListener('submit', (e) => {
        e.preventDefault();
        sendMessage();
    });

    DOM.messageInput.addEventListener('input', () => {
        const hasContent = DOM.messageInput.value.trim().length > 0 || !!State.pendingFile;
        DOM.sendBtn.disabled = !hasContent;
        if (hasContent) sendTyping(true);
        autoResize();
    });

    function sendMessage() {
        const content = DOM.messageInput.value.trim();
        if (!content && !State.pendingFile) return;
        if (!State.ws || State.ws.readyState !== WebSocket.OPEN) {
            showToast('Not connected', 'warning');
            return;
        }

        const payload = {
            type: 'send_message',
            content: content,
            reply_to_id: State.replyTo ? State.replyTo.id : null,
            client_id: generateId()
        };

        if (State.pendingFile) {
            payload.file_path = State.pendingFile.file_path;
            payload.file_type = State.pendingFile.file_type;
            payload.file_name = State.pendingFile.file_name;
            payload.file_size = State.pendingFile.file_size;
        }

        State.ws.send(JSON.stringify(payload));
        DOM.messageInput.value = '';
        clearReply();
        clearPendingFile();
        autoResize();
        sendTyping(false);
    }

    function sendTyping(isTyping) {
        if (!State.ws || State.ws.readyState !== WebSocket.OPEN) return;
        clearTimeout(window.__typingTimer);
        if (isTyping) {
            State.ws.send(JSON.stringify({ type: 'typing', is_typing: true }));
            window.__typingTimer = setTimeout(() => sendTyping(false), 2000);
        } else {
            State.ws.send(JSON.stringify({ type: 'typing', is_typing: false }));
        }
    }

    function updateTypingIndicator() {
        const users = Array.from(State.typingUsers.values()).filter(u => u.user_id !== State.user.id);
        DOM.typingIndicator.classList.toggle('hidden', users.length === 0);
        if (users.length > 0) {
            DOM.typingText.textContent = users.map(u => u.display_name).join(', ') + ' typing...';
        }
    }

    // =============================================
    // Reply
    // =============================================
    function replyTo(messageId) {
        const msg = State.messages.get(messageId);
        if (!msg) return;
        State.replyTo = msg;
        DOM.replyUser.textContent = msg.sender_username;
        DOM.replyText.textContent = truncate(msg.content, 50);
        DOM.replyPreview.classList.remove('hidden');
        DOM.messageInput.focus();
    }

    function clearReply() {
        State.replyTo = null;
        DOM.replyPreview.classList.add('hidden');
    }

    document.addEventListener('click', (e) => {
        if (e.target.id === 'cancel-reply' || e.target.closest('#cancel-reply')) {
            clearReply();
        }
    });

    // =============================================
    // Edit / Delete
    // =============================================
    function editMessage(messageId) {
        const msg = State.messages.get(messageId);
        if (!msg) return;
        const newContent = prompt('Edit message:', msg.content);
        if (newContent !== null && newContent.trim() !== '') {
            if (State.ws?.readyState === WebSocket.OPEN) {
                State.ws.send(JSON.stringify({ type: 'edit_message', message_id: messageId, content: newContent.trim() }));
            }
        }
    }

    function deleteMessage(messageId) {
        if (confirm('Permanently delete this message?')) {
            if (State.ws?.readyState === WebSocket.OPEN) {
                State.ws.send(JSON.stringify({ type: 'delete_message', message_id: messageId }));
            }
        }
    }

    // =============================================
    // File Upload (Chunked)
    // =============================================
    DOM.attachBtn.addEventListener('click', () => DOM.fileInput.click());
    DOM.fileInput.addEventListener('change', async (e) => {
        const file = e.target.files[0];
        if (!file) return;
        await uploadChunked(file);
        e.target.value = '';
    });

    async function uploadChunked(file) {
        const CHUNK_SIZE = 5 * 1024 * 1024; // 5MB
        const totalChunks = Math.ceil(file.size / CHUNK_SIZE);
        const uploadId = generateId();

        DOM.uploadProgress.classList.remove('hidden');
        updateProgress(0, file.name);

        for (let i = 0; i < totalChunks; i++) {
            const start = i * CHUNK_SIZE;
            const end = Math.min(start + CHUNK_SIZE, file.size);
            const blob = file.slice(start, end);
            const formData = new FormData();
            formData.append('file', blob);

            const url = `${API}/api/upload/chunk?chunk_index=${i}&total_chunks=${totalChunks}&file_name=${encodeURIComponent(file.name)}&file_type=${encodeURIComponent(file.type || 'application/octet-stream')}&file_size=${file.size}&upload_id=${uploadId}`;

            try {
                const res = await fetch(url, {
                    method: 'POST',
                    body: formData,
                    headers: { 'X-Auth-Token': State.token }
                });
                if (!res.ok) throw new Error('Upload failed');
                const data = await res.json();
                updateProgress(((i + 1) / totalChunks) * 100, file.name);

                if (data.status === 'complete') {
                    State.pendingFile = {
                        file_path: data.file_path,
                        file_type: data.file_type,
                        file_name: data.file_name,
                        file_size: data.file_size
                    };
                    showUploadPreview(data.file_name);
                    DOM.uploadProgress.classList.add('hidden');
                    return;
                }
            } catch (err) {
                showToast('Upload failed', 'error');
                DOM.uploadProgress.classList.add('hidden');
                break;
            }
        }
        DOM.uploadProgress.classList.add('hidden');
    }

    function updateProgress(percent, filename) {
        DOM.progressFill.style.width = `${percent}%`;
        DOM.progressText.textContent = `${Math.round(percent)}%`;
        if (filename) DOM.uploadFilename.textContent = filename;
    }

    function showUploadPreview(filename) {
        DOM.uploadPreview.classList.remove('hidden');
        DOM.uploadFilename.textContent = filename;
        DOM.sendBtn.disabled = false;
    }

    function clearPendingFile() {
        State.pendingFile = null;
        DOM.uploadPreview.classList.add('hidden');
    }

    DOM.cancelUpload.addEventListener('click', clearPendingFile);

    // =============================================
    // Emoji Picker (basic)
    // =============================================
    DOM.emojiBtn.addEventListener('click', (e) => {
        e.stopPropagation();
        DOM.emojiPicker.classList.toggle('hidden');
        if (!DOM.emojiPicker.classList.contains('hidden')) {
            renderEmojis('smileys');
        }
    });

    document.addEventListener('click', (e) => {
        if (!DOM.emojiPicker.contains(e.target) && e.target !== DOM.emojiBtn) {
            DOM.emojiPicker.classList.add('hidden');
        }
    });

    const emojiSets = {
        smileys: ['😀','😃','😄','😁','😅','😂','🤣','😊','😇','🙂','😉','😌','😍','🥰','😘','😗','😋','😛','😜','🤪','😝','🤑','🤗','🤭','🤫','🤔','🤐','🤨','😐','😑','😶','😏','😒','🙄','😬','😮','🤥','😌','😔','😪','🤤','😴','😷','🤒','🤕','🤢','🤮','🤧','😵','🤯','🥵','🥶','😎','🤓','🧐','😕','😟','🙁','😮','😯','😲','😳','🥺','😦','😧','😨','😰','😥','😢','😭','😱','😖','😣','😞','😓','😩','😫','🥱','😤','😡','😠','🤬','😈','👿','💀','☠️','💩','🤡','👹','👺','👻','👽','👾','🤖'],
        people: ['👶','🧒','👦','👧','🧑','👱','👨','🧔','👩','🧓','👴','👵','👲','👳','🧕','👮','👷','💂','🕵️','🧑‍⚕️','👨‍⚕️','👩‍⚕️','🧑‍🎓','👨‍🎓','👩‍🎓','🧑‍🏫','👨‍🏫','👩‍🏫','🧑‍⚖️','👨‍⚖️','👩‍⚖️','🧑‍🌾','👨‍🌾','👩‍🌾','🧑‍🍳','👨‍🍳','👩‍🍳','🧑‍🔧','👨‍🔧','👩‍🔧','🧑‍🏭','👨‍🏭','👩‍🏭','🧑‍💼','👨‍💼','👩‍💼','🧑‍🔬','👨‍🔬','👩‍🔬','🧑‍💻','👨‍💻','👩‍💻','🧑‍🎤','👨‍🎤','👩‍🎤','🧑‍🎨','👨‍🎨','👩‍🎨','🧑‍✈️','👨‍✈️','👩‍✈️','🧑‍🚀','👨‍🚀','👩‍🚀','🧑‍🚒','👨‍🚒','👩‍🚒','👮‍♀️','👮‍♂️','🕵️‍♀️','🕵️‍♂️','💂‍♀️','💂‍♂️','👷‍♀️','👷‍♂️'],
        animals: ['🐶','🐱','🐭','🐹','🐰','🦊','🐻','🐼','🐻‍❄️','🐨','🐯','🦁','🐮','🐷','🐸','🐵','🙈','🙉','🙊','🐒','🐔','🐧','🐦','🐤','🐣','🐥','🦆','🦅','🦉','🦇','🐺','🐗','🐴','🦄','🐝','🪱','🐛','🦋','🐌','🐞','🐜','🪰','🪲','🪳','🦟','🦗','🕷️','🦂','🐢','🐍','🦎','🦖','🦕','🐙','🦑','🦐','🦞','🦀','🐡','🐠','🐟','🐬','🐳','🐋','🦈','🐊','🐅','🐆','🦓','🦍','🦧','🐘','🦛','🦏','🐪','🐫','🦒','🦘','🐃','🐂','🐄','🐎','🐖','🐏','🐑','🦙','🐐','🦌','🐕','🐩','🦮','🐕‍🦺','🐈','🐈‍⬛','🐓','🦃','🦤','🦚','🦜','🦢','🦩','🕊️','🐇','🦝','🦨','🦡','🦦','🦥','🐁','🐀','🐿️','🦔','🐾','🐉','🐲'],
        food: ['🍏','🍎','🍐','🍊','🍋','🍌','🍉','🍇','🍓','🫐','🍈','🍒','🍑','🥭','🍍','🥥','🥝','🍅','🍆','🥑','🥦','🥬','🥒','🌶️','🌽','🥕','🫒','🧄','🧅','🥔','🍠','🥐','🍞','🥖','🥨','🧀','🥚','🍳','🧈','🥞','🧇','🥓','🥩','🍗','🍖','🦴','🌭','🍔','🍟','🍕','🫓','🥪','🥙','🧆','🌮','🌯','🫔','🥗','🥘','🫕','🥫','🍝','🍜','🍲','🍛','🍣','🍱','🥟','🦪','🍤','🍙','🍚','🍘','🍥','🥠','🥮','🍢','🍡','🍧','🍨','🍦','🥧','🧁','🍰','🎂','🍮','🍭','🍬','🍫','🍿','🍩','🍪','🌰','🥜','🍯','🥛','🍼','🫖','☕','🍵','🧃','🥤','🧋','🍶','🍺','🍻','🥂','🍷','🥃','🍸','🍹','🧉','🍾','🧊','🥄','🍴','🍽️','🥣','🥡','🥢','🧂'],
        activities: ['⚽','🏀','🏈','⚾','🥎','🎾','🏐','🏉','🥏','🎱','🪀','🏓','🏸','🏒','🏑','🥍','🏏','🪃','🥅','⛳','🪁','🏹','🎣','🤿','🥊','🥋','🎽','🛹','🛼','🛷','⛸️','🥌','🎿','⛷️','🏂','🪂','🏋️','🤼','🤸','🤺','⛹️','🤾','🏌️','🏇','🧘','🏄','🏊','🤽','🚣','🧗','🚵','🚴','🏆','🥇','🥈','🥉','🏅','🎖️','🏵️','🎗️','🎫','🎟️','🎪','🤹','🎭','🩰','🎨','🎬','🎤','🎧','🎼','🎹','🥁','🪘','🎷','🎺','🪗','🎸','🪕','🎻','🎲','♟️','🎯','🎳','🎮','🎰','🧩'],
        objects: ['⌚','📱','💻','⌨️','🖥️','🖨️','🖱️','🖲️','🕹️','🗜️','💽','💾','💿','📀','📼','📷','📸','📹','🎥','📽️','🎞️','📞','☎️','📟','📠','📺','📻','🎙️','🎚️','🎛️','🧭','⏱️','⏲️','⏰','🕰️','⌛','📡','🔋','🔌','💡','🔦','🕯️','🪔','🧯','🛢️','💸','💵','💴','💶','💷','🪙','💰','💳','💎','⚖️','🪜','🧰','🪛','🔧','🔨','⚒️','🛠️','⛏️','🪚','🔩','⚙️','🪤','🧱','⛓️','🧲','🔫','💣','🧨','🪓','🔪','🗡️','⚔️','🛡️','🚬','⚰️','🪦','⚱️','🏺','🔮','📿','🧿','💈','⚗️','🔭','🔬','🕳️','🩻','🩹','🩺','💊','💉','🩸','🧬','🦠','🧫','🧪','🌡️','🧹','🪠','🧺','🧻','🚽','🚰','🚿','🛁','🛀','🧼','🪥','🪒','🧽','🪣','🧴','🪢','🧷','🧹','🧺','🧻','🧼','🪥','🪒','🧽','🪣','🧴','🪢','🧷'],
        symbols: ['❤️','🧡','💛','💚','💙','💜','🖤','🤍','🤎','💔','❣️','💕','💞','💓','💗','💖','💘','💝','💟','☮️','✝️','☪️','🕉️','☸️','✡️','🔯','🕎','☯️','☦️','🛐','⛎','♈','♉','♊','♋','♌','♍','♎','♏','♐','♑','♒','♓','🆔','⚛️','🉑','☢️','☣️','📴','📳','🈶','🈚','🈸','🈺','🈷️','✴️','🆚','💮','🉐','㊙️','㊗️','🈴','🈵','🈹','🈲','🅰️','🅱️','🆎','🆑','🅾️','🆘','❌','⭕','🛑','⛔','📛','🚫','💯','💢','♨️','🚷','🚯','🚳','🚱','🔞','📵','🚭','❗','❕','❓','❔','‼️','⁉️','🔅','🔆','〽️','⚠️','🚸','🔱','⚜️','🔰','♻️','✅','🈯','💹','❇️','✳️','❎','🌐','💠','Ⓜ️','🌀','💤','🏧','🚾','♿','🅿️','🛗','🈳','🈂️','🛂','🛃','🛄','🛅','🚰','🚹','🚺','🚼','⚧','🚻','🚮','🎦','📶','🈁','🔣','ℹ️','🔤','🔡','🔠','🆖','🆗','🆙','🆒','🆕','🆓','0️⃣','1️⃣','2️⃣','3️⃣','4️⃣','5️⃣','6️⃣','7️⃣','8️⃣','9️⃣','🔟','🔢','#️⃣','*️⃣','⏏️','▶️','⏸️','⏯️','⏹️','⏺️','⏭️','⏮️','⏩','⏪','⏫','⏬','◀️','🔼','🔽','➡️','⬅️','⬆️','⬇️','↗️','↘️','↙️','↖️','↕️','↔️','↪️','↩️','⤴️','⤵️','🔀','🔁','🔂','🔄','🔃','🎵','🎶','➕','➖','➗','✖️','♾️','💲','💱','™️','©️','®️','〰️','➰','➿','🔚','🔙','🔛','🔝','🔜','✔️','☑️','🔘','🔴','🟠','🟡','🟢','🔵','🟣','⚫','⚪','🟤','🔺','🔻','🔸','🔹','🔶','🔷','🔳','🔲','▪️','▫️','◾','◽','◼️','◻️','🟥','🟧','🟨','🟩','🟦','🟪','⬛','⬜','🟫'],
        flags: ['🏁','🚩','🎌','🏴','🏳️','🏳️‍🌈','🏳️‍⚧️','🏴‍☠️','🇿🇦','🇸🇽','🇸🇰','🇸🇮','🇸🇬','🇸🇪','🇸🇩','🇸🇷','🇸🇸','🇸🇹','🇸🇻','🇸🇾','🇸🇿','🇹🇨','🇹🇩','🇹🇫','🇹🇬','🇹🇭','🇹🇯','🇹🇰','🇹🇱','🇹🇲','🇹🇳','🇹🇴','🇹🇷','🇹🇹','🇹🇻','🇹🇼','🇹🇿','🇺🇦','🇺🇬','🇺🇳','🇺🇸','🇺🇾','🇺🇿','🇻🇦','🇻🇨','🇻🇪','🇻🇬','🇻🇮','🇻🇳','🇻🇺','🇼🇫','🇼🇸','🇽🇰','🇾🇪','🇾🇹','🇿🇦','🇿🇲','🇿🇼']
    };

    document.querySelectorAll('.emoji-cat').forEach(btn => {
        btn.addEventListener('click', (e) => {
            e.stopPropagation();
            document.querySelectorAll('.emoji-cat').forEach(b => b.classList.remove('active'));
            btn.classList.add('active');
            renderEmojis(btn.dataset.cat);
        });
    });

    function renderEmojis(category) {
        const emojis = emojiSets[category] || [];
        DOM.emojiGrid.innerHTML = emojis.map(e => `<button class="emoji-item">${e}</button>`).join('');
        DOM.emojiGrid.querySelectorAll('.emoji-item').forEach(btn => {
            btn.addEventListener('click', () => {
                DOM.messageInput.value += btn.textContent;
                DOM.messageInput.focus();
                DOM.messageInput.dispatchEvent(new Event('input'));
                DOM.emojiPicker.classList.add('hidden');
            });
        });
    }

    // =============================================
    // Load More Messages
    // =============================================
    DOM.loadOlderBtn.addEventListener('click', () => {
        if (State.ws?.readyState === WebSocket.OPEN && State.hasMore && State.cursor) {
            State.ws.send(JSON.stringify({ type: 'load_messages', cursor: State.cursor, limit: 50 }));
        }
    });

    // =============================================
    // Online Users Modal
    // =============================================
    DOM.onlineBtn.addEventListener('click', () => {
        renderOnlineUsers();
        DOM.onlineModal.classList.remove('hidden');
    });

    document.querySelectorAll('[data-close="online-modal"]').forEach(btn => {
        btn.addEventListener('click', () => DOM.onlineModal.classList.add('hidden'));
    });

    function updateOnlineBadge() {
        DOM.onlineBadge.textContent = State.onlineUsers.size;
    }

    function renderOnlineUsers() {
        DOM.onlineUsersList.innerHTML = '';
        if (State.onlineUsers.size === 0) {
            DOM.onlineUsersList.innerHTML = '<div class="loading-state"><span>No users online</span></div>';
            DOM.onlineTotal.textContent = '0 users online';
            return;
        }
        State.onlineUsers.forEach(u => {
            const div = document.createElement('div');
            div.className = 'user-item';
            div.innerHTML = `<div class="user-avatar"><i class="fas fa-user-circle"></i></div>
                             <div class="user-info">
                                 <div class="user-name">${u.display_name || u.username}</div>
                                 <div class="user-status-text">${u.status || 'online'}</div>
                             </div>`;
            DOM.onlineUsersList.appendChild(div);
        });
        DOM.onlineTotal.textContent = `${State.onlineUsers.size} users online`;
    }

    // =============================================
    // Settings Modal
    // =============================================
    document.getElementById('settings-btn').addEventListener('click', openSettings);
    document.querySelectorAll('[data-close="settings-modal"]').forEach(btn => {
        btn.addEventListener('click', () => DOM.settingsModal.classList.add('hidden'));
    });
    document.getElementById('save-settings').addEventListener('click', saveSettings);

    function openSettings() {
        DOM.settingsDisplayName.value = State.user?.display_name || '';
        DOM.settingsUsername.value = State.user?.username || '';
        if (State.user?.avatar_path) {
            DOM.settingsAvatarImg.src = `${API}/api/download/${encodeURIComponent(State.user.avatar_path)}?token=${encodeURIComponent(State.token)}`;
            DOM.settingsAvatarImg.classList.remove('hidden');
            DOM.settingsAvatarPreview.classList.add('hidden');
        } else {
            DOM.settingsAvatarImg.classList.add('hidden');
            DOM.settingsAvatarPreview.classList.remove('hidden');
        }

        // Theme selection
        DOM.themeOptions.forEach(opt => {
            opt.classList.toggle('active', opt.dataset.theme === State.theme);
        });
        DOM.customThemeSettings.classList.toggle('hidden', State.theme !== 'custom');
        if (State.theme === 'custom') {
            DOM.customSelfColor.value = State.customColors.self;
            DOM.customOtherColor.value = State.customColors.other;
            DOM.customTextColor.value = State.customColors.text;
            DOM.selfColorHex.textContent = State.customColors.self;
            DOM.otherColorHex.textContent = State.customColors.other;
            DOM.textColorHex.textContent = State.customColors.text;
        }

        DOM.settingsModal.classList.remove('hidden');
    }

    async function saveSettings() {
        const newName = DOM.settingsDisplayName.value.trim();
        if (newName && newName !== State.user?.display_name) {
            await fetch(`${API}/api/profile?display_name=${encodeURIComponent(newName)}`, {
                method: 'PATCH',
                headers: { 'X-Auth-Token': State.token }
            });
            State.user.display_name = newName;
            updateHeader();
            showToast('Profile updated', 'success');
        }

        // Avatar
        const avatarFile = DOM.avatarInput.files[0];
        if (avatarFile) {
            const formData = new FormData();
            formData.append('file', avatarFile);
            const res = await fetch(`${API}/api/profile/avatar`, {
                method: 'POST',
                body: formData,
                headers: { 'X-Auth-Token': State.token }
            });
            if (res.ok) {
                const data = await res.json();
                State.user.avatar_path = data.avatar_path;
                DOM.settingsAvatarImg.src = `${API}/api/download/${encodeURIComponent(data.avatar_path)}?token=${encodeURIComponent(State.token)}`;
                DOM.settingsAvatarImg.classList.remove('hidden');
                DOM.settingsAvatarPreview.classList.add('hidden');
                showToast('Avatar updated', 'success');
            }
        }

        // Theme
        const selectedTheme = document.querySelector('.theme-option.active')?.dataset.theme || 'light';
        if (selectedTheme !== State.theme || selectedTheme === 'custom') {
            if (selectedTheme === 'custom') {
                State.customColors.self = DOM.customSelfColor.value;
                State.customColors.other = DOM.customOtherColor.value;
                State.customColors.text = DOM.customTextColor.value;
                localStorage.setItem('custom-self', State.customColors.self);
                localStorage.setItem('custom-other', State.customColors.other);
                localStorage.setItem('custom-text', State.customColors.text);
            }
            applyTheme(selectedTheme);
        }

        DOM.settingsModal.classList.add('hidden');
    }

    // Custom color picker listeners
    DOM.customSelfColor.addEventListener('input', () => DOM.selfColorHex.textContent = DOM.customSelfColor.value);
    DOM.customOtherColor.addEventListener('input', () => DOM.otherColorHex.textContent = DOM.customOtherColor.value);
    DOM.customTextColor.addEventListener('input', () => DOM.textColorHex.textContent = DOM.customTextColor.value);

    // Theme selection clicks
    DOM.themeOptions.forEach(opt => {
        opt.addEventListener('click', () => {
            DOM.themeOptions.forEach(o => o.classList.remove('active'));
            opt.classList.add('active');
            DOM.customThemeSettings.classList.toggle('hidden', opt.dataset.theme !== 'custom');
            if (opt.dataset.theme === 'custom') {
                DOM.customSelfColor.value = State.customColors.self;
                DOM.customOtherColor.value = State.customColors.other;
                DOM.customTextColor.value = State.customColors.text;
                DOM.selfColorHex.textContent = State.customColors.self;
                DOM.otherColorHex.textContent = State.customColors.other;
                DOM.textColorHex.textContent = State.customColors.text;
            }
        });
    });

    // Avatar upload button
    DOM.avatarUploadBtn.addEventListener('click', () => DOM.avatarInput.click());
    DOM.avatarInput.addEventListener('change', () => {
        const file = DOM.avatarInput.files[0];
        if (file) {
            const reader = new FileReader();
            reader.onload = (e) => {
                DOM.settingsAvatarImg.src = e.target.result;
                DOM.settingsAvatarImg.classList.remove('hidden');
                DOM.settingsAvatarPreview.classList.add('hidden');
            };
            reader.readAsDataURL(file);
        }
    });

    // =============================================
    // Utility
    // =============================================
    function generateId() {
        return Date.now().toString(36) + Math.random().toString(36).substr(2, 9);
    }

    function truncate(str, n) {
        if (!str) return '';
        return str.length > n ? str.substr(0, n - 1) + '…' : str;
    }

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

    function formatTime(ms) {
        const date = new Date(ms);
        const now = new Date();
        const diff = now - date;
        if (diff < 60000) return 'now';
        if (date.toDateString() === now.toDateString()) {
            return date.toLocaleTimeString([], { hour: '2-digit', minute: '2-digit' });
        }
        return date.toLocaleDateString([], { month: 'short', day: 'numeric' }) + ' ' +
               date.toLocaleTimeString([], { hour: '2-digit', minute: '2-digit' });
    }

    function formatFileSize(bytes) {
        if (!bytes) return '0 B';
        const k = 1024;
        const sizes = ['B', 'KB', 'MB', 'GB'];
        const i = Math.floor(Math.log(bytes) / Math.log(k));
        return parseFloat((bytes / Math.pow(k, i)).toFixed(1)) + ' ' + sizes[i];
    }

    function autoResize() {
        DOM.messageInput.style.height = 'auto';
        DOM.messageInput.style.height = Math.min(DOM.messageInput.scrollHeight, 120) + 'px';
    }

    // =============================================
    // Initialization
    // =============================================
    async function init() {
        if (State.token) {
            try {
                const res = await fetch(`${API}/api/auth/verify`, {
                    headers: { 'X-Auth-Token': State.token }
                });
                if (res.ok) {
                    const data = await res.json();
                    State.user = data.user;
                    showChat();
                    connectWebSocket();
                    return;
                }
            } catch (e) {}
        }
        showAuth();
    }

    function showAuth() {
        DOM.authScreen.classList.add('active');
        DOM.chatScreen.classList.remove('active');
    }

    function showChat() {
        DOM.authScreen.classList.remove('active');
        DOM.chatScreen.classList.add('active');
        updateHeader();
    }

    function updateHeader() {
        if (State.user) {
            DOM.headerDisplayName.textContent = State.user.display_name;
        }
    }

    // Password visibility toggle
    document.querySelectorAll('.input-toggle').forEach(btn => {
        btn.addEventListener('click', () => {
            const targetId = btn.dataset.toggle;
            const input = document.getElementById(targetId);
            if (input) {
                input.type = input.type === 'password' ? 'text' : 'password';
                const icon = btn.querySelector('i');
                if (icon) icon.className = input.type === 'password' ? 'fas fa-eye' : 'fas fa-eye-slash';
            }
        });
    });

    // Logout button
    document.getElementById('logout-btn').addEventListener('click', async () => {
        if (State.token) {
            await fetch(`${API}/api/auth/logout`, {
                method: 'POST',
                headers: { 'X-Auth-Token': State.token }
            });
        }
        if (State.ws) State.ws.close();
        State.ws = null;
        localStorage.removeItem('token');
        State.token = null;
        State.user = null;
        State.messages.clear();
        State.messageOrder = [];
        State.onlineUsers.clear();
        DOM.messagesList.innerHTML = '';
        DOM.emptyState.style.display = 'flex';
        showAuth();
        updateOnlineBadge();
    });

    // Request notification permission
    if (window.Notification && Notification.permission === 'default') {
        Notification.requestPermission();
    }

    // Expose public methods
    window.InfinityChat = {
        replyTo,
        editMessage,
        deleteMessage
    };

    init();
})();