document.addEventListener('DOMContentLoaded', () => {
    
    // --- DOM Elements ---
    const chatArea = document.getElementById('chat-area');
    const closeSidebarBtn = document.getElementById('close-sidebar-btn');
    const messageInput = document.getElementById('message-input');
    const sendBtn = document.getElementById('send-btn');
    const newChatBtn = document.getElementById('new-chat-btn');
    const chatMessages = document.getElementById('chat-messages');
    const chatHistoryList = document.getElementById('chat-history-list');
    const menuToggle = document.getElementById('menu-toggle');
    const appContainer = document.getElementById('app-container');
    const chatTitle = document.getElementById('chat-title');
    const imageUploadBtn = document.getElementById('image-upload-btn');
    const imageUploadInput = document.getElementById('image-upload-input');
    const imagePreviewContainer = document.getElementById('image-preview-container');
    const imagePreview = document.getElementById('image-preview');
    const removeImageBtn = document.getElementById('remove-image-btn');

    // Add search and filter elements
    let searchInput, clearAllBtn, userStatsDiv;

    // --- State ---
    let currentChatId = null;
    let currentUserId = null;
    let conversationsCache = {};
    let selectedImageFile = null;
    let imgbbApiKey = '';
    let firebase = null;
    let firebaseDB = null;
    let useFirebase = false;

    // --- User Management ---
    const generateUserFingerprint = () => {
        // Create a device fingerprint based on available browser info
        const canvas = document.createElement('canvas');
        const ctx = canvas.getContext('2d');
        ctx.textBaseline = 'top';
        ctx.font = '14px Arial';
        ctx.fillText('Device fingerprint', 2, 2);
        
        const fingerprint = [
            navigator.userAgent,
            navigator.language,
            navigator.platform,
            navigator.cookieEnabled,
            navigator.doNotTrack,
            screen.width + 'x' + screen.height,
            screen.colorDepth,
            new Date().getTimezoneOffset(),
            canvas.toDataURL(),
            navigator.hardwareConcurrency || 'unknown',
            navigator.deviceMemory || 'unknown'
        ].join('|');
        
        // Create hash
        return hashCode(fingerprint).toString();
    };

    const hashCode = (str) => {
        let hash = 0;
        for (let i = 0; i < str.length; i++) {
            const char = str.charCodeAt(i);
            hash = ((hash << 5) - hash) + char;
            hash = hash & hash; // Convert to 32bit integer
        }
        return Math.abs(hash);
    };

    const initializeUser = async () => {
        // Try to get existing user ID from storage
        let userId = localStorage.getItem('easyfarms_user_id');
        
        if (!userId) {
            // Generate new user ID based on device fingerprint
            const deviceFingerprint = generateUserFingerprint();
            const timestamp = Date.now();
            const randomPart = Math.random().toString(36).substr(2, 8);
            
            userId = `user_${deviceFingerprint}_${timestamp}_${randomPart}`;
            localStorage.setItem('easyfarms_user_id', userId);
            
            console.log('Generated new user ID:', userId);
        } else {
            console.log('Using existing user ID:', userId);
        }
        
        currentUserId = userId;
        
        // Also save to Firebase if available
        if (useFirebase && firebaseDB) {
            try {
                await saveUserData(userId, {
                    created_at: new Date().toISOString(),
                    device_fingerprint: generateUserFingerprint(),
                    last_seen: new Date().toISOString()
                });
            } catch (error) {
                console.error('Failed to save user data to Firebase:', error);
            }
        }
        
        return userId;
    };

    const saveUserData = async (userId, userData) => {
        try {
            if (useFirebase && firebaseDB) {
                const { setDoc, doc } = await import('https://www.gstatic.com/firebasejs/9.0.0/firebase-firestore.js');
                await setDoc(doc(firebaseDB, 'users', userId), {
                    ...userData,
                    updatedAt: new Date().toISOString()
                });
                console.log('User data saved to Firebase:', userId);
            } else {
                // Fallback to localStorage
                const users = JSON.parse(localStorage.getItem('easyfarms_users') || '{}');
                users[userId] = {
                    ...userData,
                    updatedAt: new Date().toISOString()
                };
                localStorage.setItem('easyfarms_users', JSON.stringify(users));
                console.log('User data saved to localStorage:', userId);
            }
        } catch (error) {
            console.error('Failed to save user data:', error);
        }
    };

    // --- Firebase Configuration ---
    const initializeFirebase = async () => {
        try {
            if (typeof firebase !== 'undefined' && window.firebaseConfig) {
                const { initializeApp } = await import('https://www.gstatic.com/firebasejs/9.0.0/firebase-app.js');
                const { getFirestore, collection, doc, setDoc, getDoc, getDocs, deleteDoc } = await import('https://www.gstatic.com/firebasejs/9.0.0/firebase-firestore.js');
                
                const app = initializeApp(window.firebaseConfig);
                firebaseDB = getFirestore(app);
                useFirebase = true;
                
                console.log('Firebase initialized successfully');
                return { setDoc, getDoc, getDocs, deleteDoc, collection, doc };
            } else {
                console.log('Firebase not configured, using localStorage');
                return null;
            }
        } catch (error) {
            console.error('Firebase initialization failed, falling back to localStorage:', error);
            return null;
        }
    };

    // --- Storage Management with User Isolation ---
    const saveSessionData = async (chatId, data) => {
        try {
            if (useFirebase && firebaseDB) {
                const { setDoc, doc } = await import('https://www.gstatic.com/firebasejs/9.0.0/firebase-firestore.js');
                await setDoc(doc(firebaseDB, 'user_sessions', `${currentUserId}_${chatId}`), {
                    ...data,
                    userId: currentUserId,
                    chatId: chatId,
                    updatedAt: new Date().toISOString()
                });
                console.log('Session saved to Firebase:', chatId, 'for user:', currentUserId);
            } else {
                // Fallback to localStorage with user isolation
                const userSessions = JSON.parse(localStorage.getItem(`easyfarms_sessions_${currentUserId}`) || '{}');
                userSessions[chatId] = {
                    ...data,
                    userId: currentUserId,
                    updatedAt: new Date().toISOString()
                };
                localStorage.setItem(`easyfarms_sessions_${currentUserId}`, JSON.stringify(userSessions));
                console.log('Session saved to localStorage:', chatId, 'for user:', currentUserId);
            }
        } catch (error) {
            console.error('Failed to save session data:', error);
            // Fallback to localStorage
            const userSessions = JSON.parse(localStorage.getItem(`easyfarms_sessions_${currentUserId}`) || '{}');
            userSessions[chatId] = data;
            localStorage.setItem(`easyfarms_sessions_${currentUserId}`, JSON.stringify(userSessions));
        }
    };

    const loadSessionData = async (chatId) => {
        try {
            if (useFirebase && firebaseDB) {
                const { getDoc, doc } = await import('https://www.gstatic.com/firebasejs/9.0.0/firebase-firestore.js');
                const docRef = doc(firebaseDB, 'user_sessions', `${currentUserId}_${chatId}`);
                const docSnap = await getDoc(docRef);
                if (docSnap.exists()) {
                    console.log('Session loaded from Firebase:', chatId);
                    return docSnap.data();
                }
            } else {
                // Fallback to localStorage
                const userSessions = JSON.parse(localStorage.getItem(`easyfarms_sessions_${currentUserId}`) || '{}');
                if (userSessions[chatId]) {
                    console.log('Session loaded from localStorage:', chatId);
                    return userSessions[chatId];
                }
            }
            return null;
        } catch (error) {
            console.error('Failed to load session data:', error);
            // Fallback to localStorage
            const userSessions = JSON.parse(localStorage.getItem(`easyfarms_sessions_${currentUserId}`) || '{}');
            return userSessions[chatId] || null;
        }
    };

    const loadAllSessions = async () => {
        try {
            if (useFirebase && firebaseDB) {
                const { getDocs, collection, query, where } = await import('https://www.gstatic.com/firebasejs/9.0.0/firebase-firestore.js');
                const q = query(collection(firebaseDB, 'user_sessions'), where('userId', '==', currentUserId));
                const querySnapshot = await getDocs(q);
                const sessions = {};
                querySnapshot.forEach((doc) => {
                    const data = doc.data();
                    sessions[data.chatId] = data;
                });
                console.log('All sessions loaded from Firebase for user:', currentUserId);
                return sessions;
            } else {
                // Fallback to localStorage
                const sessions = JSON.parse(localStorage.getItem(`easyfarms_sessions_${currentUserId}`) || '{}');
                console.log('All sessions loaded from localStorage for user:', currentUserId);
                return sessions;
            }
        } catch (error) {
            console.error('Failed to load all sessions:', error);
            // Fallback to localStorage
            return JSON.parse(localStorage.getItem(`easyfarms_sessions_${currentUserId}`) || '{}');
        }
    };

    const deleteSessionData = async (chatId) => {
        try {
            if (useFirebase && firebaseDB) {
                const { deleteDoc, doc } = await import('https://www.gstatic.com/firebasejs/9.0.0/firebase-firestore.js');
                await deleteDoc(doc(firebaseDB, 'user_sessions', `${currentUserId}_${chatId}`));
                console.log('Session deleted from Firebase:', chatId);
            } else {
                // Fallback to localStorage
                const userSessions = JSON.parse(localStorage.getItem(`easyfarms_sessions_${currentUserId}`) || '{}');
                delete userSessions[chatId];
                localStorage.setItem(`easyfarms_sessions_${currentUserId}`, JSON.stringify(userSessions));
                console.log('Session deleted from localStorage:', chatId);
            }
        } catch (error) {
            console.error('Failed to delete session data:', error);
        }
    };

    // --- Initialization ---
    const init = async () => {
        if (!messageInput || !sendBtn || !imageUploadBtn || !imagePreviewContainer) {
            console.error("Critical UI elements not found. Check HTML IDs.");
            return;
        }

        // Initialize Firebase
        firebase = await initializeFirebase();
        
        // Initialize user
        await initializeUser();

        await fetchConfig();
        await loadCachedSessions();
        await renderChatHistoryFromAPI();
        setupSearchAndFilter();
        setupUserStats();

        // Event Listeners
        sendBtn.addEventListener('click', sendMessage);
        messageInput.addEventListener('keydown', e => { 
            if (e.key === 'Enter' && !e.shiftKey) { 
                e.preventDefault(); 
                sendMessage(); 
            } 
        });
        
        imageUploadBtn.addEventListener('click', () => imageUploadInput.click());
        imageUploadInput.addEventListener('change', handleImageSelect);
        removeImageBtn.addEventListener('click', removeSelectedImage);

        // Sidebar Listeners
        newChatBtn.addEventListener('click', () => { startNewChat(); closeSidebar(); });
        menuToggle.addEventListener('click', (event) => {
            event.stopPropagation();
            appContainer.classList.toggle('sidebar-visible');
        });
        closeSidebarBtn.addEventListener('click', (event) => {
            event.stopPropagation();
            closeSidebar();
        });
        chatArea.addEventListener('click', () => {
            if (appContainer.classList.contains('sidebar-visible')) {
                closeSidebar();
            }
        });

        // Update last seen periodically
        setInterval(updateLastSeen, 30000); // Every 30 seconds

        console.log('EasyFarms Chat initialized with user authentication for user:', currentUserId);
    };

    const fetchConfig = async () => {
        try {
            const response = await fetch('/config');
            const config = await response.json();
            imgbbApiKey = config.imgbb_api_key;
            if (!imgbbApiKey) { 
                console.error("ImgBB API Key is missing."); 
            }
        } catch (error) { 
            console.error('Failed to fetch config:', error); 
        }
    };

    const setupUserStats = () => {
        // Create user stats div
        if (!userStatsDiv) {
            userStatsDiv = document.createElement('div');
            userStatsDiv.className = 'user-stats';
            userStatsDiv.style.cssText = `
                padding: 10px;
                margin: 10px 0;
                background: #f8f9fa;
                border-radius: 4px;
                font-size: 12px;
                color: #666;
                border-top: 1px solid #eee;
            `;
            
            // Insert at the bottom of sidebar
            chatHistoryList.parentNode.appendChild(userStatsDiv);
        }
        
        updateUserStats();
    };

    const updateUserStats = async () => {
        try {
            const response = await fetch(`/users/${currentUserId}/stats`);
            if (response.ok) {
                const stats = await response.json();
                userStatsDiv.innerHTML = `
                    <div><strong>Your Stats</strong></div>
                    <div>Chats: ${stats.total_sessions || 0}</div>
                    <div>Messages: ${stats.total_messages || 0}</div>
                    <div>Recent: ${stats.recent_sessions_24h || 0}</div>
                `;
            }
        } catch (error) {
            console.error('Failed to update user stats:', error);
            // Show basic local stats
            const sessions = await loadAllSessions();
            const sessionCount = Object.keys(sessions).length;
            userStatsDiv.innerHTML = `
                <div><strong>Local Stats</strong></div>
                <div>Chats: ${sessionCount}</div>
                <div>User: ${currentUserId.substr(0, 12)}...</div>
            `;
        }
    };

    const updateLastSeen = async () => {
        try {
            await saveUserData(currentUserId, {
                last_seen: new Date().toISOString()
            });
        } catch (error) {
            console.error('Failed to update last seen:', error);
        }
    };

    const setupSearchAndFilter = () => {
        // Create search input if it doesn't exist
        if (!searchInput) {
            searchInput = document.createElement('input');
            searchInput.type = 'text';
            searchInput.placeholder = 'Search chats...';
            searchInput.className = 'search-input';
            searchInput.style.cssText = `
                width: 100%;
                padding: 8px;
                margin: 10px 0;
                border: 1px solid #ddd;
                border-radius: 4px;
                font-size: 14px;
            `;
            
            chatHistoryList.parentNode.insertBefore(searchInput, chatHistoryList);
        }

        // Create clear all button if it doesn't exist
        if (!clearAllBtn) {
            clearAllBtn = document.createElement('button');
            clearAllBtn.textContent = 'Clear All My Chats';
            clearAllBtn.className = 'clear-all-btn';
            clearAllBtn.style.cssText = `
                width: 100%;
                padding: 8px;
                margin: 5px 0;
                background: #ff4444;
                color: white;
                border: none;
                border-radius: 4px;
                cursor: pointer;
                font-size: 12px;
            `;
            
            searchInput.parentNode.insertBefore(clearAllBtn, chatHistoryList);
        }

        // Add event listeners
        searchInput.addEventListener('input', filterChats);
        clearAllBtn.addEventListener('click', confirmClearAllChats);
    };

    const filterChats = () => {
        const searchTerm = searchInput.value.toLowerCase();
        const chatItems = chatHistoryList.querySelectorAll('.chat-history-item');
        
        chatItems.forEach(item => {
            const title = item.textContent.toLowerCase();
            const shouldShow = title.includes(searchTerm);
            item.style.display = shouldShow ? 'block' : 'none';
        });
        
        console.log('Filtered chats with term:', searchTerm);
    };

    const confirmClearAllChats = () => {
        if (confirm('Are you sure you want to delete all your chats? This action cannot be undone.')) {
            clearAllChats();
        }
    };

    const clearAllChats = async () => {
        try {
            // Delete all user chats from backend
            const response = await fetch(`/users/${currentUserId}/chats`, {
                method: 'DELETE'
            });
            
            if (response.ok) {
                console.log('All chats deleted from backend for user:', currentUserId);
            } else {
                console.error('Failed to delete all chats from backend');
            }
            
            // Clear local storage
            const allSessions = await loadAllSessions();
            const chatIds = Object.keys(allSessions);
            
            for (const chatId of chatIds) {
                await deleteSessionData(chatId);
            }
            
            // Clear UI and cache
            conversationsCache = {};
            chatHistoryList.innerHTML = '';
            startNewChat();
            updateUserStats();
            
            console.log('All chats cleared successfully for user:', currentUserId);
        } catch (error) {
            console.error('Failed to clear all chats:', error);
        }
    };

    // --- Core Chat Functions ---
    const sendMessage = async () => {
        const messageText = messageInput.value.trim();
        if (!messageText && !selectedImageFile) return;

        // Display user message immediately
        displayMessage({ 
            role: 'user', 
            content: messageText, 
            imageUrl: selectedImageFile 
        });

        const loadingIndicator = displayMessage({ 
            role: 'assistant', 
            content: 'Thinking...', 
            isLoading: true 
        });

        try {
            let permanentImageUrl = null;
            if (selectedImageFile) { 
                permanentImageUrl = await uploadImageToImgBB(selectedImageFile); 
            }

            // Prepare request data with user ID
            const requestData = {
                query: messageText,
                session_id: currentChatId,
                user_id: currentUserId
            };

            if (permanentImageUrl) {
                requestData.image_url = permanentImageUrl;
            }

            // Send to API endpoint
            const response = await fetch('/chat', {
                method: 'POST',
                headers: {
                    'Content-Type': 'application/json',
                },
                body: JSON.stringify(requestData)
            });

            if (!response.ok) {
                throw new Error(`HTTP error! status: ${response.status}`);
            }

            const data = await response.json();
            console.log('Chat response:', data);

            // Remove loading indicator
            chatMessages.removeChild(loadingIndicator);

            // Display assistant response
            displayMessage({ 
                role: 'assistant', 
                content: data.response,
                message_id: data.assistant_message_id
            });

            // Update cache and UI
            await updateCacheWithNewSystem(
                data.chat_id,
                { 
                    content: messageText, 
                    imageUrl: permanentImageUrl,
                    message_id: data.user_message_id
                },
                { 
                    content: data.response,
                    message_id: data.assistant_message_id
                },
                data.is_new_chat
            );

            // Update stats
            updateUserStats();

        } catch (error) {
            console.error('Error sending message:', error);
            
            // Remove loading indicator and show error
            chatMessages.removeChild(loadingIndicator);
            
            // Display mock error response (don't save to database)
            displayMessage({ 
                role: 'assistant', 
                content: "I apologize, but I'm having trouble connecting right now. Please check your internet connection and try again. Your chat session is still active.",
                isError: true
            });
        } finally {
            messageInput.value = ''; 
            messageInput.style.height = 'auto'; 
            removeSelectedImage();
        }
    };

    const uploadImageToImgBB = async (imageFile) => {
        if (!imgbbApiKey) throw new Error("ImgBB API Key not configured.");
        
        const formData = new FormData();
        formData.append('image', imageFile);
        formData.append('key', imgbbApiKey);
        
        const response = await fetch('https://api.imgbb.com/1/upload', { 
            method: 'POST', 
            body: formData 
        });
        
        const result = await response.json();
        if (result.success) { 
            return result.data.url; 
        } else { 
            throw new Error(result.error.message || 'Image upload failed.'); 
        }
    };

    // --- Chat Management ---
    const startNewChat = () => {
        currentChatId = null;
        chatMessages.innerHTML = `<div class="welcome-message"><h1>EasyFarms Assistant</h1><p>User: ${currentUserId.substr(0, 16)}...</p></div>`;
        chatTitle.textContent = "New Chat";
        updateActiveChatItem();
        console.log('Started new chat for user:', currentUserId);
    };

    const switchChat = async (chatId) => {
        console.log('Switching to chat:', chatId, 'for user:', currentUserId);
        currentChatId = chatId;
        chatMessages.innerHTML = '';

        // Check cache first
        if (conversationsCache[chatId] && conversationsCache[chatId].messages) {
            conversationsCache[chatId].messages.forEach(displayMessage);
            chatTitle.textContent = conversationsCache[chatId].title || "Chat";
        } else {
            // Load from API
            const loading = displayMessage({ 
                role: 'assistant', 
                content: 'Loading chat history...', 
                isLoading: true 
            });
            
            try {
                const response = await fetch(`/chat/${chatId}/messages?user_id=${currentUserId}`);
                
                if (!response.ok) {
                    throw new Error(`HTTP error! status: ${response.status}`);
                }
                
                const messages = await response.json();
                console.log('Loaded messages for chat:', chatId, messages);
                
                // Update cache
                if (!conversationsCache[chatId]) conversationsCache[chatId] = {};
                conversationsCache[chatId].messages = messages;
                
                // Save to storage
                await saveSessionData(chatId, conversationsCache[chatId]);
                
                // Remove loading and display messages
                chatMessages.removeChild(loading);
                messages.forEach(displayMessage);
                
                // Set title from first user message or use cached title
                const sessionData = await loadSessionData(chatId);
                chatTitle.textContent = sessionData?.title || conversationsCache[chatId]?.title || "Chat";
                
            } catch (error) {
                console.error('Failed to load chat history:', error);
                chatMessages.removeChild(loading);
                displayMessage({ 
                    role: 'assistant', 
                    content: "Failed to load chat history. Please try again.",
                    isError: true
                });
            }
        }
        
        updateActiveChatItem();
        closeSidebar();
    };

    const deleteChat = async (chatId, chatItem) => {
        if (!confirm('Are you sure you want to delete this chat?')) return;
        
        try {
            // Delete from backend
            const response = await fetch(`/chat/${chatId}?user_id=${currentUserId}`, {
                method: 'DELETE'
            });
            
            if (response.ok) {
                console.log('Chat deleted from backend:', chatId);
            } else {
                console.error('Failed to delete chat from backend:', chatId);
            }
            
            // Delete from storage
            await deleteSessionData(chatId);
            
            // Remove from cache
            delete conversationsCache[chatId];
            
            // Remove from UI
            chatItem.remove();
            
            // If this was the current chat, start a new one
            if (currentChatId === chatId) {
                startNewChat();
            }
            
            console.log('Chat deleted successfully:', chatId);
            updateUserStats();
            
        } catch (error) {
            console.error('Error deleting chat:', error);
            alert('Failed to delete chat. Please try again.');
        }
    };

    const updateCacheWithNewSystem = async (chatId, userTurn, assistantTurn, isNewChat) => {
        const previousChatId = currentChatId;
        currentChatId = chatId;
        
        if (isNewChat || !conversationsCache[chatId]) {
            const title = (userTurn.content || "Image Query").substring(0, 30) + '...';
            conversationsCache[chatId] = { 
                title, 
                messages: [],
                created_at: new Date().toISOString(),
                user_id: currentUserId
            };
            
            // Add to UI
            const item = createChatHistoryItem(chatId, title);
            chatHistoryList.prepend(item);
            
            console.log('Created new chat:', chatId, 'for user:', currentUserId);
        }
        
        // Create message objects with IDs
        const userMessage = { 
            role: 'user', 
            content: userTurn.content,
            message_id: userTurn.message_id,
            timestamp: new Date().toISOString()
        };
        if (userTurn.imageUrl) userMessage.imageUrl = userTurn.imageUrl;
        
        const assistantMessage = { 
            role: 'assistant', 
            content: assistantTurn.content,
            message_id: assistantTurn.message_id,
            timestamp: new Date().toISOString()
        };
        
        // Add to cache
        conversationsCache[chatId].messages.push(userMessage, assistantMessage);
        conversationsCache[chatId].updated_at = new Date().toISOString();
        conversationsCache[chatId].user_id = currentUserId;
        
        // Save to storage
        await saveSessionData(chatId, conversationsCache[chatId]);
        
        updateActiveChatItem();
        chatTitle.textContent = conversationsCache[chatId].title;
        
        console.log('Updated cache for chat:', chatId, 'user:', currentUserId);
    };

    const createChatHistoryItem = (chatId, title) => {
        const item = document.createElement('div');
        item.className = 'chat-history-item';
        item.dataset.sessionId = chatId;
        
        // Create title element
        const titleElement = document.createElement('span');
        titleElement.textContent = title;
        titleElement.className = 'chat-title';
        
        // Create delete button
        const deleteBtn = document.createElement('button');
        deleteBtn.innerHTML = '×';
        deleteBtn.className = 'delete-chat-btn';
        deleteBtn.style.cssText = `
            float: right;
            background: none;
            border: none;
            color: #999;
            cursor: pointer;
            font-size: 18px;
            padding: 0;
            width: 20px;
            height: 20px;
            line-height: 18px;
        `;
        deleteBtn.title = 'Delete chat';
        
        // Add event listeners
        titleElement.addEventListener('click', () => switchChat(chatId));
        deleteBtn.addEventListener('click', (e) => {
            e.stopPropagation();
            deleteChat(chatId, item);
        });
        
        item.appendChild(titleElement);
        item.appendChild(deleteBtn);
        
        return item;
    };

    const loadCachedSessions = async () => {
        try {
            conversationsCache = await loadAllSessions();
            console.log('Loaded cached sessions for user:', currentUserId, 'Count:', Object.keys(conversationsCache).length);
        } catch (error) {
            console.error('Failed to load cached sessions:', error);
            conversationsCache = {};
        }
    };

    const displayMessage = (message) => {
        const { role, content, imageUrl, isLoading, isError, message_id } = message;
        const sender = role || message.sender;
        const messageDiv = document.createElement('div');
        messageDiv.classList.add('message', `${sender}-message`);
        
        if (message_id) {
            messageDiv.dataset.messageId = message_id;
            console.log('Displayed message with ID:', message_id);
        }
        
        let htmlContent = '';
        const imageSrc = (typeof imageUrl === 'object' && imageUrl instanceof File) 
            ? URL.createObjectURL(imageUrl) 
            : imageUrl;
            
        if (imageSrc) { 
            htmlContent += `<img src="${imageSrc}" alt="User upload" class="user-upload">`; 
        }
        if (content) { 
            htmlContent += marked.parse(content); 
        }
        
        messageDiv.innerHTML = htmlContent || (isLoading ? '...' : '');
        
        if (isLoading) messageDiv.classList.add('loading');
        if (isError) messageDiv.classList.add('error');
        
        chatMessages.appendChild(messageDiv);
        chatMessages.scrollTop = chatMessages.scrollHeight;
        
        return messageDiv;
    };

    // --- Image Preview Handling ---
    const handleImageSelect = (event) => {
        const file = event.target.files[0];
        if (file) {
            selectedImageFile = file;
            imagePreview.src = URL.createObjectURL(file);
            imagePreviewContainer.style.display = 'block';
            console.log('Image selected:', file.name);
        }
    };

    const removeSelectedImage = () => {
        selectedImageFile = null;
        imageUploadInput.value = '';
        imagePreviewContainer.style.display = 'none';
        imagePreview.src = '#';
        console.log('Image removed');
    };

    // --- API Integration ---
    const renderChatHistoryFromAPI = async () => {
        try {
            const response = await fetch(`/chats?user_id=${currentUserId}`);
            
            if (!response.ok) {
                throw new Error(`HTTP error! status: ${response.status}`);
            }
            
            const sessions = await response.json();
            console.log('Loaded chat sessions from API for user:', currentUserId, sessions.length);
            
            chatHistoryList.innerHTML = '';
            
            // Sort by updated_at (most recent first)
            sessions.sort((a, b) => new Date(b.updated_at) - new Date(a.updated_at));
            
            sessions.forEach(session => {
                // Update cache
                if (!conversationsCache[session.session_id]) {
                    conversationsCache[session.session_id] = {};
                }
                conversationsCache[session.session_id].title = session.title;
                conversationsCache[session.session_id].message_count = session.message_count;
                conversationsCache[session.session_id].created_at = session.created_at;
                conversationsCache[session.session_id].updated_at = session.updated_at;
                conversationsCache[session.session_id].user_id = currentUserId;
                
                // Create UI item
                const item = createChatHistoryItem(session.session_id, session.title);
                chatHistoryList.appendChild(item);
            });
            
            // Save updated cache
            for (const [chatId, data] of Object.entries(conversationsCache)) {
                if (data.user_id === currentUserId) {
                    await saveSessionData(chatId, data);
                }
            }
            
            updateActiveChatItem();
            updateUserStats();
            
        } catch (error) { 
            console.error("Failed to render chat history from API:", error); 
            
            // Fallback to local cache
            console.log('Falling back to local cache for user:', currentUserId);
            for (const [chatId, data] of Object.entries(conversationsCache)) {
                if (data.title && data.user_id === currentUserId) {
                    const item = createChatHistoryItem(chatId, data.title);
                    chatHistoryList.appendChild(item);
                }
            }
        }
    };

    const updateActiveChatItem = () => {
        document.querySelectorAll('.chat-history-item').forEach(item => {
            item.classList.toggle('active', item.dataset.sessionId === currentChatId);
        });
    };

    const closeSidebar = () => appContainer.classList.remove('sidebar-visible');

    // --- User Account Management ---
    const exportUserData = async () => {
        try {
            const response = await fetch(`/users/${currentUserId}/export`);
            if (response.ok) {
                const userData = await response.json();
                const dataStr = JSON.stringify(userData, null, 2);
                const dataUri = 'data:application/json;charset=utf-8,'+ encodeURIComponent(dataStr);
                
                const exportFileDefaultName = `easyfarms_data_${currentUserId.substr(0, 8)}_${new Date().toISOString().split('T')[0]}.json`;
                
                const linkElement = document.createElement('a');
                linkElement.setAttribute('href', dataUri);
                linkElement.setAttribute('download', exportFileDefaultName);
                linkElement.click();
                
                console.log('User data exported successfully');
            } else {
                throw new Error('Export failed');
            }
        } catch (error) {
            console.error('Failed to export user data:', error);
            alert('Failed to export data. Please try again.');
        }
    };

    const deleteUserAccount = async () => {
        if (!confirm('Are you sure you want to delete your account? This will permanently delete all your chats and data.')) {
            return;
        }
        
        if (!confirm('This action cannot be undone. Type "DELETE" to confirm:') || 
            prompt('Type "DELETE" to confirm account deletion:') !== 'DELETE') {
            return;
        }
        
        try {
            const response = await fetch(`/users/${currentUserId}`, {
                method: 'DELETE'
            });
            
            if (response.ok) {
                // Clear all local data
                localStorage.removeItem('easyfarms_user_id');
                localStorage.removeItem(`easyfarms_sessions_${currentUserId}`);
                localStorage.removeItem(`easyfarms_users`);
                
                // Clear Firebase data if applicable
                if (useFirebase && firebaseDB) {
                    try {
                        const { deleteDoc, doc, collection, getDocs, query, where } = await import('https://www.gstatic.com/firebasejs/9.0.0/firebase-firestore.js');
                        
                        // Delete user document
                        await deleteDoc(doc(firebaseDB, 'users', currentUserId));
                        
                        // Delete user sessions
                        const q = query(collection(firebaseDB, 'user_sessions'), where('userId', '==', currentUserId));
                        const querySnapshot = await getDocs(q);
                        querySnapshot.forEach(async (doc) => {
                            await deleteDoc(doc.ref);
                        });
                        
                    } catch (firebaseError) {
                        console.error('Failed to clean Firebase data:', firebaseError);
                    }
                }
                
                alert('Account deleted successfully. Refreshing page...');
                location.reload();
                
            } else {
                throw new Error('Account deletion failed');
            }
            
        } catch (error) {
            console.error('Failed to delete account:', error);
            alert('Failed to delete account. Please try again.');
        }
    };

    const createUserMenu = () => {
        // Create user menu button
        const userMenuBtn = document.createElement('button');
        userMenuBtn.innerHTML = '⚙️';
        userMenuBtn.title = 'User Settings';
        userMenuBtn.style.cssText = `
            position: fixed;
            top: 10px;
            right: 10px;
            background: #007bff;
            color: white;
            border: none;
            border-radius: 50%;
            width: 40px;
            height: 40px;
            cursor: pointer;
            font-size: 16px;
            z-index: 1000;
        `;
        
        // Create user menu dropdown
        const userMenu = document.createElement('div');
        userMenu.style.cssText = `
            position: fixed;
            top: 55px;
            right: 10px;
            background: white;
            border: 1px solid #ddd;
            border-radius: 4px;
            padding: 10px;
            box-shadow: 0 2px 10px rgba(0,0,0,0.1);
            display: none;
            z-index: 1001;
            min-width: 200px;
        `;
        
        userMenu.innerHTML = `
            <div style="margin-bottom: 10px; font-weight: bold;">User Settings</div>
            <div style="margin-bottom: 5px; font-size: 12px; color: #666;">ID: ${currentUserId.substr(0, 16)}...</div>
            <button id="export-data-btn" style="width: 100%; margin: 5px 0; padding: 5px; background: #28a745; color: white; border: none; border-radius: 3px; cursor: pointer;">Export My Data</button>
            <button id="delete-account-btn" style="width: 100%; margin: 5px 0; padding: 5px; background: #dc3545; color: white; border: none; border-radius: 3px; cursor: pointer;">Delete Account</button>
        `;
        
        document.body.appendChild(userMenuBtn);
        document.body.appendChild(userMenu);
        
        // Toggle menu
        userMenuBtn.addEventListener('click', (e) => {
            e.stopPropagation();
            userMenu.style.display = userMenu.style.display === 'none' ? 'block' : 'none';
        });
        
        // Close menu when clicking outside
        document.addEventListener('click', () => {
            userMenu.style.display = 'none';
        });
        
        // Menu actions
        document.getElementById('export-data-btn').addEventListener('click', exportUserData);
        document.getElementById('delete-account-btn').addEventListener('click', deleteUserAccount);
    };

    // --- Enhanced Error Handling ---
    window.addEventListener('unhandledrejection', (event) => {
        console.error('Unhandled promise rejection:', event.reason);
        // Don't show error to user for now, just log it
    });

    window.addEventListener('error', (event) => {
        console.error('Global error:', event.error);
        // Don't show error to user for now, just log it
    });

    // --- Session Recovery ---
    const attemptSessionRecovery = async () => {
        try {
            // Try to recover any unsaved messages
            const unsavedMessages = localStorage.getItem(`unsaved_messages_${currentUserId}`);
            if (unsavedMessages) {
                const messages = JSON.parse(unsavedMessages);
                console.log('Found unsaved messages, attempting recovery:', messages);
                
                // Display recovered messages
                messages.forEach(msg => {
                    displayMessage({
                        role: msg.role,
                        content: `[RECOVERED] ${msg.content}`,
                        isError: true
                    });
                });
                
                // Clear unsaved messages
                localStorage.removeItem(`unsaved_messages_${currentUserId}`);
            }
        } catch (error) {
            console.error('Session recovery failed:', error);
        }
    };

    const saveUnsavedMessage = (role, content) => {
        try {
            const unsavedMessages = JSON.parse(localStorage.getItem(`unsaved_messages_${currentUserId}`) || '[]');
            unsavedMessages.push({
                role,
                content,
                timestamp: new Date().toISOString()
            });
            
            // Keep only last 5 unsaved messages
            if (unsavedMessages.length > 5) {
                unsavedMessages.splice(0, unsavedMessages.length - 5);
            }
            
            localStorage.setItem(`unsaved_messages_${currentUserId}`, JSON.stringify(unsavedMessages));
        } catch (error) {
            console.error('Failed to save unsaved message:', error);
        }
    };

    // --- Performance Monitoring ---
    const logPerformance = () => {
        if (performance && performance.timing) {
            const perfData = performance.timing;
            const loadTime = perfData.loadEventEnd - perfData.navigationStart;
            console.log(`Page load time: ${loadTime}ms`);
            
            // Log to backend if needed
            // fetch('/analytics/performance', {
            //     method: 'POST',
            //     body: JSON.stringify({ user_id: currentUserId, load_time: loadTime })
            // });
        }
    };

    // --- Initialize Everything ---
    // Add user menu after initialization
    const setupUserInterface = () => {
        createUserMenu();
        attemptSessionRecovery();
        logPerformance();
    };

    // Start the Application
    init().then(() => {
        setupUserInterface();
        console.log('EasyFarms Chat fully initialized for user:', currentUserId);
    }).catch((error) => {
        console.error('Failed to initialize application:', error);
        document.body.innerHTML = `
            <div style="padding: 20px; text-align: center;">
                <h2>Failed to Load EasyFarms Chat</h2>
                <p>Please refresh the page and try again.</p>
                <p style="color: #666; font-size: 12px;">Error: ${error.message}</p>
            </div>
        `;
    });

});