/**
 * PolicyWise Chat Interface
 * Interactive web chat for the RAG application
 */

class ChatInterface {
    constructor() {
        this.messageInput = document.getElementById('messageInput');
        this.sendButton = document.getElementById('sendButton');
        this.chatForm = document.getElementById('chatForm');
        this.messagesContainer = document.getElementById('messagesContainer');
        this.includeSources = document.getElementById('includeSources');
        this.loadingOverlay = document.getElementById('loadingOverlay');
        this.statusIndicator = document.getElementById('statusIndicator');
        this.charCount = document.getElementById('charCount');
        this.sourcePanel = document.getElementById('sourcePanel');
        this.conversationHistoryPanel = document.getElementById('conversationHistoryPanel');
        this.swipeIndicator = document.getElementById('swipeIndicator');

        // Search and filter elements
        this.searchConversations = document.getElementById('searchConversations');
        this.exportConversationsBtn = document.getElementById('exportConversationsBtn');
        this.importConversations = document.getElementById('importConversations');

        this.messages = []; // Store messages in memory
        this.conversationId = this.loadOrCreateConversation();
        this.isLoading = false;
        this.autoRetryCount = 0;
        this.maxAutoRetries = 3;

        // Track focused elements for keyboard navigation
        this.lastFocusedElement = null;

        // Touch handling for mobile swipe
        this.touchStartX = 0;
        this.touchEndX = 0;

        this.initializeEventListeners();
        this.setupKeyboardNavigation();
        this.setupTouchHandlers();
        this.checkSystemHealth();
        this.loadConversationHistory();
        this.loadQuerySuggestions();
        this.focusInput();
        this.initializeSourcePanel();

        // Setup initial policy suggestion buttons if they exist
        this.setupPolicySuggestionButtons();
    }

    /**
     * Set up keyboard navigation and accessibility
     */
    setupKeyboardNavigation() {
        // Trap focus within modal dialogs
        const handleTabKey = (e, containerElement) => {
            if (e.key !== 'Tab') return;

            const focusableElements = containerElement.querySelectorAll(
                'button, [href], input, select, textarea, [tabindex]:not([tabindex="-1"])'
            );

            const firstElement = focusableElements[0];
            const lastElement = focusableElements[focusableElements.length - 1];

            if (e.shiftKey) {
                if (document.activeElement === firstElement) {
                    e.preventDefault();
                    lastElement.focus();
                }
            } else {
                if (document.activeElement === lastElement) {
                    e.preventDefault();
                    firstElement.focus();
                }
            }
        };

        // Add keyboard event listeners to side panels
        if (this.conversationHistoryPanel) {
            this.conversationHistoryPanel.addEventListener('keydown', (e) => {
                if (e.key === 'Escape') {
                    this.closeConversationPanel();
                } else if (e.key === 'Tab') {
                    handleTabKey(e, this.conversationHistoryPanel);
                }
            });
        }

        if (this.sourcePanel) {
            document.addEventListener('keydown', (e) => {
                if (e.key === 'Escape' && this.sourcePanel.classList.contains('show')) {
                    this.closeSourcePanel();
                } else if (e.key === 'Tab' && this.sourcePanel.classList.contains('show')) {
                    handleTabKey(e, this.sourcePanel);
                }
            });
        }

        // Add keyboard shortcuts
        document.addEventListener('keydown', (e) => {
            // Cmd+/ or Ctrl+/ to focus search
            if ((e.metaKey || e.ctrlKey) && e.key === '/') {
                e.preventDefault();
                this.focusInput();
            }

            // Cmd+Shift+E or Ctrl+Shift+E to export conversations
            if ((e.metaKey || e.ctrlKey) && e.shiftKey && e.key === 'E') {
                e.preventDefault();
                this.exportConversationsToFile();
            }
        });
    }

    /**
     * Set up touch handlers for mobile swipe gestures
     */
    setupTouchHandlers() {
        // Only set up on mobile devices
        if (window.innerWidth <= 768) {
            document.addEventListener('touchstart', (e) => {
                this.touchStartX = e.changedTouches[0].screenX;
            }, { passive: true });

            document.addEventListener('touchend', (e) => {
                this.touchEndX = e.changedTouches[0].screenX;
                this.handleSwipeGesture();
            }, { passive: true });

            // Show swipe indicator occasionally
            setTimeout(() => {
                if (this.swipeIndicator && !this.conversationHistoryPanel.classList.contains('show')) {
                    this.swipeIndicator.style.display = 'flex';
                    setTimeout(() => {
                        this.swipeIndicator.style.display = 'none';
                    }, 3000);
                }
            }, 5000);
        }
    }

    /**
     * Initialize source document panel
     */
    /**
     * Load query suggestions from the server
     */
    async loadQuerySuggestions() {
        const suggestionsContainer = document.getElementById('suggestedQueries');
        if (!suggestionsContainer) return;

        try {
            const response = await fetch('/chat/suggestions');
            const data = await response.json();

            if (response.ok && data.status === 'success' && data.suggestions && data.suggestions.length > 0) {
                suggestionsContainer.innerHTML = '';

                data.suggestions.forEach(suggestion => {
                    const suggestionDiv = document.createElement('div');
                    suggestionDiv.className = 'query-suggestion';

                    const iconSpan = document.createElement('span');
                    iconSpan.className = 'suggestion-icon';
                    iconSpan.innerHTML = `
                        <svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
                            <circle cx="12" cy="12" r="10"></circle>
                            <line x1="12" y1="8" x2="12" y2="12"></line>
                            <line x1="12" y1="16" x2="12" y2="16"></line>
                        </svg>
                    `;

                    const textSpan = document.createElement('span');
                    textSpan.className = 'suggestion-text';
                    textSpan.textContent = suggestion;

                    suggestionDiv.appendChild(iconSpan);
                    suggestionDiv.appendChild(textSpan);

                    // Add click event to populate the input
                    suggestionDiv.addEventListener('click', () => {
                        this.messageInput.value = suggestion;
                        this.updateCharCount();
                        this.autoResizeTextarea();
                        this.updateSendButton();
                        this.focusInput();
                    });

                    suggestionsContainer.appendChild(suggestionDiv);
                });
            }
        } catch (error) {
            console.warn('Failed to load query suggestions:', error);
        }
    }

    initializeSourcePanel() {
        // Create the source panel if it doesn't exist
        if (!this.sourcePanel) {
            const sourcePanelHTML = `
                <div id="sourcePanel" class="side-panel source-document-panel"
                     role="dialog"
                     aria-labelledby="sourcePanelHeader"
                     aria-hidden="true">
                    <div class="panel-header">
                        <h3 id="sourcePanelHeader">Source Document</h3>
                        <button id="closeSourcePanel" class="icon-button" aria-label="Close source document">
                            <svg width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" aria-hidden="true">
                                <line x1="18" y1="6" x2="6" y2="18"></line>
                                <line x1="6" y1="6" x2="18" y2="18"></line>
                            </svg>
                        </button>
                    </div>
                    <div class="panel-body">
                        <div id="sourceContent" class="source-document-content">
                            <!-- Document content will be loaded here -->
                            <p class="sr-only">Document content will be loaded here.</p>
                        </div>
                    </div>
                </div>
            `;

            const tempDiv = document.createElement('div');
            tempDiv.innerHTML = sourcePanelHTML;
            document.body.appendChild(tempDiv.firstElementChild);

            this.sourcePanel = document.getElementById('sourcePanel');

            // Add ESC key handler for accessibility
            this.sourcePanel.addEventListener('keydown', (e) => {
                if (e.key === 'Escape') {
                    this.closeSourcePanel();
                }
            });
        }
    }

    /**
     * Initialize all event listeners
     */
    initializeEventListeners() {
        // Form submission
        this.chatForm.addEventListener('submit', (e) => {
            e.preventDefault();
            this.sendMessage();
        });

        // Input validation and auto-resize
        this.messageInput.addEventListener('input', () => {
            this.updateCharCount();
            this.autoResizeTextarea();
            this.updateSendButton();
        });

        // Enter key handling (Shift+Enter for new line, Enter to send)
        this.messageInput.addEventListener('keydown', (e) => {
            if (e.key === 'Enter' && !e.shiftKey) {
                e.preventDefault();
                if (!this.isLoading && this.messageInput.value.trim()) {
                    this.sendMessage();
                }
            }
        });

        // Clear welcome message on first input
        this.messageInput.addEventListener('focus', () => {
            this.clearWelcomeMessage();
        }, { once: true });

        // Conversation history panel
        const conversationHistoryBtn = document.getElementById('conversationHistoryBtn');
        const closeConversationsBtn = document.getElementById('closeConversationsBtn');
        const newConversationBtn = document.getElementById('newConversationBtn');

        if (conversationHistoryBtn) {
            conversationHistoryBtn.addEventListener('click', () => {
                this.openConversationPanel();
            });
        }

        if (closeConversationsBtn) {
            closeConversationsBtn.addEventListener('click', () => {
                this.closeConversationPanel();
            });
        }

        if (newConversationBtn) {
            newConversationBtn.addEventListener('click', () => {
                this.startNewConversation();
            });
        }

        // Conversation search functionality
        if (this.searchConversations) {
            this.searchConversations.addEventListener('input', () => {
                this.filterConversations(this.searchConversations.value);
            });
        }

        // Export/Import functionality
        if (this.exportConversationsBtn) {
            this.exportConversationsBtn.addEventListener('click', () => {
                this.exportConversationsToFile();
            });
        }

        if (this.importConversations) {
            this.importConversations.addEventListener('change', (e) => {
                this.importConversationsFromFile(e.target.files[0]);
            });
        }
    }

    /**
     * Handle swipe gestures for mobile
     */
    handleSwipeGesture() {
        const swipeThreshold = 100;

        // Right to left swipe (open conversation panel)
        if (this.touchEndX < this.touchStartX - swipeThreshold) {
            if (!this.conversationHistoryPanel.classList.contains('show')) {
                this.openConversationPanel();
            }
        }

        // Left to right swipe (close conversation panel)
        if (this.touchEndX > this.touchStartX + swipeThreshold) {
            if (this.conversationHistoryPanel.classList.contains('show')) {
                this.closeConversationPanel();
            }
        }
    }

    /**
     * Open conversation panel with focus management
     */
    openConversationPanel() {
        this.updateConversationList();
        this.conversationHistoryPanel.classList.add('show');
        this.conversationHistoryPanel.setAttribute('aria-hidden', 'false');

        // Store last focused element to restore focus when closing
        this.lastFocusedElement = document.activeElement;

        // Focus the close button
        const closeBtn = document.getElementById('closeConversationsBtn');
        if (closeBtn) {
            setTimeout(() => closeBtn.focus(), 100);
        }

        // Hide the swipe indicator
        if (this.swipeIndicator) {
            this.swipeIndicator.style.display = 'none';
        }

        // Add class to the body for potential styling
        document.body.classList.add('panel-open');
    }

    /**
     * Close conversation panel with focus management
     */
    closeConversationPanel() {
        this.conversationHistoryPanel.classList.remove('show');
        this.conversationHistoryPanel.setAttribute('aria-hidden', 'true');

        // Restore focus to previous element
        if (this.lastFocusedElement) {
            this.lastFocusedElement.focus();
        }

        document.body.classList.remove('panel-open');
    }

    /**
     * Close source document panel
     */
    closeSourcePanel() {
        if (this.sourcePanel) {
            this.sourcePanel.classList.remove('show');
            document.body.classList.remove('source-panel-open');

            // Restore focus
            if (this.lastFocusedElement) {
                this.lastFocusedElement.focus();
            }
        }
    }

    /**
     * Update the conversation list in the side panel
     */
    updateConversationList() {
        const conversationList = document.getElementById('conversationList');
        if (!conversationList) return;

        // Clear current list
        conversationList.innerHTML = '';

        // Get conversations from storage
        const conversations = this.getConversationsFromStorage();

        if (conversations.length === 0) {
            const emptyState = document.createElement('div');
            emptyState.className = 'empty-state';
            emptyState.innerHTML = '<p>No conversation history found.</p>';
            conversationList.appendChild(emptyState);
            return;
        }

        // Sort conversations by last updated (newest first)
        conversations.sort((a, b) => {
            const dateA = new Date(a.metadata.last_updated);
            const dateB = new Date(b.metadata.last_updated);
            return dateB - dateA;
        });

        // Add each conversation to the list
        conversations.forEach(conversation => {
            const item = document.createElement('div');
            item.className = 'conversation-item';
            item.setAttribute('role', 'listitem');
            item.setAttribute('tabindex', '0');
            item.setAttribute('aria-label', `${conversation.title || 'Untitled Conversation'}, ${conversation.metadata.message_count} messages, last updated ${this.formatDateTime(conversation.metadata.last_updated)}`);

            if (conversation.id === this.conversationId) {
                item.classList.add('active');
                item.setAttribute('aria-current', 'true');
            }

            const title = document.createElement('h4');
            title.textContent = conversation.title || 'Untitled Conversation';

            const meta = document.createElement('div');
            meta.className = 'conversation-meta';

            const date = new Date(conversation.metadata.last_updated);
            const formattedDate = date.toLocaleDateString(undefined, {
                year: 'numeric',
                month: 'short',
                day: 'numeric'
            });

            meta.textContent = `${conversation.metadata.message_count} messages · ${formattedDate}`;

            const actions = document.createElement('div');
            actions.className = 'conversation-actions';

            const deleteBtn = document.createElement('button');
            deleteBtn.className = 'icon-button small';
            deleteBtn.setAttribute('aria-label', `Delete conversation: ${conversation.title || 'Untitled Conversation'}`);
            deleteBtn.innerHTML = `
                <svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" aria-hidden="true">
                    <path d="M3 6h18"></path>
                    <path d="M19 6v14a2 2 0 0 1-2 2H7a2 2 0 0 1-2-2V6m3 0V4a2 2 0 0 1 2-2h4a2 2 0 0 1 2 2v2"></path>
                </svg>
            `;
            deleteBtn.title = 'Delete conversation';
            deleteBtn.addEventListener('click', (e) => {
                e.stopPropagation();
                this.deleteConversation(conversation.id);
            });

            actions.appendChild(deleteBtn);

            item.appendChild(title);
            item.appendChild(meta);
            item.appendChild(actions);

            // Add click event to load this conversation
            item.addEventListener('click', () => {
                this.loadConversation(conversation.id);
                this.closeConversationPanel();
            });

            // Add keyboard support
            item.addEventListener('keydown', (e) => {
                if (e.key === 'Enter' || e.key === ' ') {
                    e.preventDefault();
                    this.loadConversation(conversation.id);
                    this.closeConversationPanel();
                }
            });

            conversationList.appendChild(item);
        });
    }

    /**
     * Filter conversations based on search query
     */
    filterConversations(query) {
        if (!query) {
            this.updateConversationList();
            return;
        }

        query = query.toLowerCase();
        const conversationList = document.getElementById('conversationList');
        if (!conversationList) return;

        // Clear current list
        conversationList.innerHTML = '';

        // Get conversations from storage
        const conversations = this.getConversationsFromStorage();

        // Filter conversations
        const filteredConversations = conversations.filter(conv => {
            // Search in title
            if (conv.title && conv.title.toLowerCase().includes(query)) {
                return true;
            }

            // Search in messages
            if (conv.messages && conv.messages.some(msg =>
                msg.content && msg.content.toLowerCase().includes(query))) {
                return true;
            }

            return false;
        });

        if (filteredConversations.length === 0) {
            const emptyState = document.createElement('div');
            emptyState.className = 'empty-state';
            emptyState.innerHTML = `<p>No conversations matching "${query}"</p>`;
            conversationList.appendChild(emptyState);
            return;
        }

        // Sort and display filtered conversations
        filteredConversations.sort((a, b) => {
            const dateA = new Date(a.metadata.last_updated);
            const dateB = new Date(b.metadata.last_updated);
            return dateB - dateA;
        });

        // Add each filtered conversation to the list
        filteredConversations.forEach(conversation => {
            const item = document.createElement('div');
            item.className = 'conversation-item';
            item.setAttribute('role', 'listitem');
            item.setAttribute('tabindex', '0');

            if (conversation.id === this.conversationId) {
                item.classList.add('active');
                item.setAttribute('aria-current', 'true');
            }

            const title = document.createElement('h4');
            title.textContent = conversation.title || 'Untitled Conversation';

            const meta = document.createElement('div');
            meta.className = 'conversation-meta';

            const date = new Date(conversation.metadata.last_updated);
            const formattedDate = this.formatDateTime(conversation.metadata.last_updated);

            meta.textContent = `${conversation.metadata.message_count} messages · ${formattedDate}`;

            item.appendChild(title);
            item.appendChild(meta);

            // Add click event to load this conversation
            item.addEventListener('click', () => {
                this.loadConversation(conversation.id);
                this.closeConversationPanel();
            });

            // Add keyboard support
            item.addEventListener('keydown', (e) => {
                if (e.key === 'Enter' || e.key === ' ') {
                    e.preventDefault();
                    this.loadConversation(conversation.id);
                    this.closeConversationPanel();
                }
            });

            conversationList.appendChild(item);
        });
    }

    /**
     * Export conversations to a JSON file
     */
    exportConversationsToFile() {
        try {
            const conversations = this.getConversationsFromStorage();
            if (conversations.length === 0) {
                alert('No conversations to export.');
                return;
            }

            const dataStr = JSON.stringify(conversations, null, 2);
            const blob = new Blob([dataStr], { type: 'application/json' });
            const url = URL.createObjectURL(blob);

            const downloadLink = document.createElement('a');
            downloadLink.href = url;
            downloadLink.download = `policywise_conversations_${new Date().toISOString().split('T')[0]}.json`;

            // Append to the document, click it, then remove it
            document.body.appendChild(downloadLink);
            downloadLink.click();
            document.body.removeChild(downloadLink);

            // Clean up the URL
            setTimeout(() => URL.revokeObjectURL(url), 100);

            // Show confirmation
            const statusText = this.statusIndicator.querySelector('.status-text');
            const originalText = statusText.textContent;
            statusText.textContent = 'Conversations exported!';
            setTimeout(() => {
                statusText.textContent = originalText;
            }, 3000);

        } catch (error) {
            console.error('Failed to export conversations:', error);
            alert('Failed to export conversations. Please try again.');
        }
    }

    /**
     * Import conversations from a JSON file
     */
    importConversationsFromFile(file) {
        if (!file) return;

        const reader = new FileReader();
        reader.onload = (event) => {
            try {
                const importedData = JSON.parse(event.target.result);

                if (!Array.isArray(importedData)) {
                    throw new Error('Invalid format: expected an array of conversations');
                }

                // Validate the structure
                const validConversations = importedData.filter(conv => {
                    return (
                        conv.id &&
                        conv.messages &&
                        Array.isArray(conv.messages) &&
                        conv.metadata
                    );
                });

                if (validConversations.length === 0) {
                    throw new Error('No valid conversations found in the file');
                }

                // Merge with existing conversations
                const existingConversations = this.getConversationsFromStorage();
                const existingIds = new Set(existingConversations.map(c => c.id));

                // Add only conversations that don't exist
                const newConversations = validConversations.filter(c => !existingIds.has(c.id));
                const mergedConversations = [...existingConversations, ...newConversations];

                // Save to localStorage
                this.saveConversationsToStorage(mergedConversations);

                // Update UI
                this.updateConversationList();

                // Show confirmation with count of imported conversations
                alert(`Successfully imported ${newConversations.length} conversation(s).`);

            } catch (error) {
                console.error('Failed to import conversations:', error);
                alert(`Failed to import conversations: ${error.message}`);
            }
        };

        reader.readAsText(file);
    }

    /**
     * Start a new conversation
     */
    startNewConversation() {
        // Generate new ID
        this.conversationId = this.generateConversationId();

        // Clear messages
        this.messages = [];
        this.messagesContainer.innerHTML = '';

        // Add welcome message
        this.addWelcomeMessage();

        // Update URL without reloading
        const url = new URL(window.location.href);
        url.searchParams.set('conversation_id', this.conversationId);
        window.history.pushState({}, '', url);

        // Close conversation panel
        document.getElementById('conversationHistoryPanel').classList.remove('show');

        // Focus input
        this.focusInput();
    }

    /**
     * Load a conversation by ID
     */
    loadConversation(conversationId) {
        const conversations = this.getConversationsFromStorage();
        const conversation = conversations.find(c => c.id === conversationId);

        if (conversation) {
            // Update current conversation ID
            this.conversationId = conversationId;

            // Update URL without reloading
            const url = new URL(window.location.href);
            url.searchParams.set('conversation_id', this.conversationId);
            window.history.pushState({}, '', url);

            // Clear current messages
            this.messages = [];
            this.messagesContainer.innerHTML = '';

            // Load messages
            conversation.messages.forEach(msg => {
                this.addMessage(msg.content, msg.sender, msg.metadata, false);
            });

            // Add messages to memory
            this.messages = [...conversation.messages];

            // Update conversation metadata
            conversation.metadata.last_accessed = new Date().toISOString();
            this.saveConversationsToStorage(conversations);

            // Focus input
            this.focusInput();
        }
    }

    /**
     * Delete a conversation by ID
     */
    deleteConversation(conversationId) {
        if (confirm('Are you sure you want to delete this conversation? This cannot be undone.')) {
            const conversations = this.getConversationsFromStorage();
            const updatedConversations = conversations.filter(c => c.id !== conversationId);
            this.saveConversationsToStorage(updatedConversations);

            // If we deleted the current conversation, start a new one
            if (conversationId === this.conversationId) {
                this.startNewConversation();
            }

            // Update the conversation list
            this.updateConversationList();
        }
    }

    /**
     * Add welcome message to the UI
     */
    addWelcomeMessage() {
        const welcomeDiv = document.createElement('div');
        welcomeDiv.className = 'welcome-message';
        welcomeDiv.innerHTML = `
            <div class="welcome-icon">🤖</div>
            <h2>Welcome to PolicyWise!</h2>
            <p>I'm here to help you find information about company policies and procedures. Ask me anything about:</p>
            <div class="policy-topics" role="group" aria-label="Suggested policy topics">
                <button class="policy-suggestion-btn" data-topic="Remote work policies">Remote work policies</button>
                <button class="policy-suggestion-btn" data-topic="PTO and leave policies">PTO and leave policies</button>
                <button class="policy-suggestion-btn" data-topic="Expense reimbursement">Expense reimbursement</button>
                <button class="policy-suggestion-btn" data-topic="Information security">Information security</button>
                <button class="policy-suggestion-btn" data-topic="Employee benefits">Employee benefits</button>
                <button class="policy-suggestion-btn" data-topic="And much more...">And much more...</button>
            </div>
        `;
        this.messagesContainer.appendChild(welcomeDiv);

        // Add click event listeners to policy suggestion buttons
        this.setupPolicySuggestionButtons();
    }

    /**
     * Setup click handlers for policy suggestion buttons
     */
    setupPolicySuggestionButtons() {
        const suggestionButtons = this.messagesContainer.querySelectorAll('.policy-suggestion-btn');
        suggestionButtons.forEach(button => {
            button.addEventListener('click', () => {
                const topic = button.getAttribute('data-topic');
                if (topic && topic !== "And much more...") {
                    const prompt = `Tell me about ${topic.toLowerCase()}`;
                    this.messageInput.value = prompt;
                    this.sendMessage();
                }
            });

            // Add keyboard support
            button.addEventListener('keydown', (e) => {
                if (e.key === 'Enter' || e.key === ' ') {
                    e.preventDefault();
                    button.click();
                }
            });
        });
    }

    /**
     * Generate a unique conversation ID
     */
    generateConversationId() {
        return 'conv_' + Date.now() + '_' + Math.random().toString(36).substr(2, 9);
    }

    /**
     * Load existing conversation or create new one
     */
    loadOrCreateConversation() {
        // Check URL parameters for conversation ID
        const urlParams = new URLSearchParams(window.location.search);
        const conversationId = urlParams.get('conversation_id');

        if (conversationId) {
            // If this conversation exists in localStorage, use it
            const conversations = this.getConversationsFromStorage();
            if (conversations.some(conv => conv.id === conversationId)) {
                return conversationId;
            }
        }

        // Otherwise generate a new ID
        return this.generateConversationId();
    }

    /**
     * Load conversation history from localStorage
     */
    loadConversationHistory() {
        const conversations = this.getConversationsFromStorage();
        const conversation = conversations.find(conv => conv.id === this.conversationId);

        if (conversation && conversation.messages && conversation.messages.length > 0) {
            // Clear welcome message if we're loading history
            this.clearWelcomeMessage();

            // Load messages
            conversation.messages.forEach(msg => {
                this.addMessage(msg.content, msg.sender, msg.metadata, false);
            });

            // Update conversation metadata
            conversation.metadata.last_accessed = new Date().toISOString();
            this.saveConversationsToStorage(conversations);
        }
    }

    /**
     * Get conversations from localStorage
     */
    getConversationsFromStorage() {
        try {
            return JSON.parse(localStorage.getItem('policywise_conversations') || '[]');
        } catch (e) {
            console.error('Failed to parse conversations from localStorage:', e);
            return [];
        }
    }

    /**
     * Save conversations to localStorage
     */
    saveConversationsToStorage(conversations) {
        try {
            localStorage.setItem('policywise_conversations', JSON.stringify(conversations));
        } catch (e) {
            console.error('Failed to save conversations to localStorage:', e);
        }
    }

    /**
     * Save current conversation to localStorage
     */
    saveCurrentConversation() {
        const conversations = this.getConversationsFromStorage();
        const now = new Date().toISOString();

        // Find existing conversation or create new one
        let conversation = conversations.find(conv => conv.id === this.conversationId);

        if (!conversation) {
            // Create new conversation
            conversation = {
                id: this.conversationId,
                title: this.getConversationTitle(),
                messages: this.messages,
                metadata: {
                    created_at: now,
                    last_updated: now,
                    last_accessed: now,
                    message_count: this.messages.length
                }
            };
            conversations.push(conversation);
        } else {
            // Update existing conversation
            conversation.messages = this.messages;
            conversation.title = this.getConversationTitle();
            conversation.metadata.last_updated = now;
            conversation.metadata.message_count = this.messages.length;
        }

        this.saveConversationsToStorage(conversations);
    }

    /**
     * Generate a title for the conversation based on first user message
     */
    getConversationTitle() {
        const firstUserMessage = this.messages.find(msg => msg.sender === 'user');
        if (firstUserMessage) {
            // Truncate to reasonable title length
            const title = firstUserMessage.content.trim();
            return title.length > 50 ? title.substring(0, 50) + '...' : title;
        }
        return 'New Conversation';
    }

    /**
     * Update character count and styling
     */
    updateCharCount() {
        const count = this.messageInput.value.length;
        this.charCount.textContent = count;

        const counter = this.charCount.parentElement;
        counter.classList.remove('warning', 'error');

        if (count > 900) {
            counter.classList.add('error');
        } else if (count > 800) {
            counter.classList.add('warning');
        }
    }

    /**
     * Auto-resize textarea based on content
     */
    autoResizeTextarea() {
        this.messageInput.style.height = 'auto';
        this.messageInput.style.height = Math.min(this.messageInput.scrollHeight, 120) + 'px';
    }

    /**
     * Update send button state
     */
    updateSendButton() {
        const hasText = this.messageInput.value.trim().length > 0;
        this.sendButton.disabled = !hasText || this.isLoading;
    }

    /**
     * Focus the input field
     */
    focusInput() {
        this.messageInput.focus();
    }

    /**
     * Check system health status
     */
    async checkSystemHealth() {
        try {
            const response = await fetch('/chat/health');
            const data = await response.json();

            if (data.status === 'healthy') {
                this.updateStatus('Ready', 'ready');
            } else {
                this.updateStatus('Degraded', 'warning');
            }
        } catch (error) {
            console.warn('Health check failed:', error);
            this.updateStatus('Offline', 'error');
        }
    }

    /**
     * Update status indicator
     */
    updateStatus(text, type) {
        const statusText = this.statusIndicator.querySelector('.status-text');
        const statusDot = this.statusIndicator.querySelector('.status-dot');

        statusText.textContent = text;

        // Remove existing status classes
        statusDot.classList.remove('ready', 'warning', 'error', 'loading');
        statusDot.classList.add(type);
    }

    /**
     * Clear the welcome message
     */
    clearWelcomeMessage() {
        const welcomeMessage = this.messagesContainer.querySelector('.welcome-message');
        if (welcomeMessage) {
            welcomeMessage.style.display = 'none';
        }
    }

    /**
     * Send a message to the chat API
     */
    async sendMessage() {
        const message = this.messageInput.value.trim();
        if (!message || this.isLoading) return;

        // Add user message to chat
        this.addMessage(message, 'user');

        // Clear input and reset
        this.messageInput.value = '';
        this.updateCharCount();
        this.autoResizeTextarea();
        this.updateSendButton();

        // Send the message to the API
        await this.sendMessageToAPI(message);
    }

    /**
     * Send a message to the chat API with enhanced error handling
     */
    async sendMessageToAPI(message) {
        if (this.isLoading) return;

        // Show loading state
        this.setLoading(true);

        try {
            const requestData = {
                message: message,
                conversation_id: this.conversationId,
                include_sources: this.includeSources.checked,
                include_debug: false // Set to true for debugging
            };

            // Set timeout for the request (30 seconds)
            const controller = new AbortController();
            const timeoutId = setTimeout(() => controller.abort(), 30000);

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

            clearTimeout(timeoutId);

            const data = await response.json();

            if (response.ok && data.status === 'success') {
                // Reset auto retry count on success
                this.autoRetryCount = 0;

                this.addMessage(data.answer || data.response, 'assistant', {
                    sources: data.sources,
                    citations: data.citations,
                    confidence: data.confidence,
                    processing_time: data.processing_time_ms,
                    timestamp: new Date().toISOString()
                });
            } else {
                // Handle API error
                const errorInfo = {
                    status: response.status,
                    message: data.message || 'Unknown error'
                };

                let errorMessage = 'An error occurred while processing your request.';
                let canRetry = true;

                // Customize message based on status code
                if (response.status === 400) {
                    errorMessage = 'Invalid request. Please modify your query and try again.';
                    canRetry = false;
                } else if (response.status === 401 || response.status === 403) {
                    errorMessage = 'You are not authorized to perform this action.';
                    canRetry = false;
                } else if (response.status === 404) {
                    errorMessage = 'The requested resource could not be found.';
                } else if (response.status === 429) {
                    errorMessage = 'You\'ve sent too many requests. Please wait a moment and try again.';
                    canRetry = true;
                } else if (response.status >= 500) {
                    errorMessage = 'The server encountered an error. We\'ll automatically retry shortly.';
                    canRetry = true;
                }

                if (data.message) {
                    errorMessage += ` Details: ${data.message}`;
                }

                this.addErrorMessage(errorMessage, errorInfo, canRetry);
            }

        } catch (error) {
            console.error('Chat request failed:', error);

            const errorInfo = {
                code: error.name,
                message: error.message
            };

            let errorMessage = 'Failed to connect to the server.';

            if (error.name === 'AbortError') {
                errorMessage = 'The request took too long and was cancelled. The server might be experiencing high load.';
            } else if (error.name === 'TypeError' && error.message.includes('NetworkError')) {
                errorMessage = 'Network error. Please check your internet connection and try again.';
            } else if (error.name === 'SyntaxError') {
                errorMessage = 'Received an invalid response from the server.';
            }

            this.addErrorMessage(errorMessage, errorInfo, true);
        } finally {
            this.setLoading(false);
            this.focusInput();
        }
    }

    /**
     * Set loading state
     */
    setLoading(loading) {
        this.isLoading = loading;

        if (loading) {
            this.loadingOverlay.classList.remove('hidden');
            this.updateStatus('Processing...', 'loading');
        } else {
            this.loadingOverlay.classList.add('hidden');
            this.updateStatus('Ready', 'ready');
        }

        this.updateSendButton();
    }

    /**
     * Add a message to the chat interface
     */
    addMessage(text, sender, metadata = {}, save = true) {
        const messageId = 'msg_' + Date.now() + '_' + Math.random().toString(36).substr(2, 9);
        const timestamp = metadata.timestamp || new Date().toISOString();

        // Create message element
        const messageDiv = document.createElement('div');
        messageDiv.className = `message message-${sender}`;
        messageDiv.dataset.messageId = messageId;

        // Add header with timestamp
        const messageHeader = document.createElement('div');
        messageHeader.className = 'message-header';

        const senderLabel = document.createElement('span');
        senderLabel.className = 'sender-label';
        senderLabel.textContent = sender === 'user' ? 'You' : 'PolicyWise';

        const timestampSpan = document.createElement('span');
        timestampSpan.className = 'message-timestamp';
        timestampSpan.setAttribute('aria-label', `Sent ${this.formatDateTime(timestamp)}`);
        timestampSpan.textContent = this.formatDateTime(timestamp);

        messageHeader.appendChild(senderLabel);
        messageHeader.appendChild(timestampSpan);
        messageDiv.appendChild(messageHeader);

        const contentDiv = document.createElement('div');
        contentDiv.className = 'message-content';

        const textDiv = document.createElement('div');
        textDiv.className = 'message-text';

        // Format assistant responses with markdown rendering for better readability
        if (sender === 'assistant') {
            textDiv.innerHTML = this.formatMarkdown(text);
        } else {
            textDiv.textContent = text;
        }

        contentDiv.appendChild(textDiv);

        // Add sources and citations for assistant messages
        if (sender === 'assistant' && metadata.sources && this.includeSources.checked) {
            this.addSourcesToMessage(contentDiv, metadata);
        }

        // Add confidence score for assistant messages
        if (sender === 'assistant' && metadata.confidence !== undefined) {
            this.addConfidenceScore(contentDiv, metadata.confidence);
        }

        // Add feedback controls for assistant messages
        if (sender === 'assistant' && save) {
            this.addFeedbackControls(contentDiv, messageId);
        }

        messageDiv.appendChild(contentDiv);
        this.messagesContainer.appendChild(messageDiv);

        // Store message in memory
        if (save) {
            this.messages.push({
                id: messageId,
                sender,
                content: text,
                timestamp,
                metadata: {...metadata}
            });

            // Save to localStorage
            this.saveCurrentConversation();
        }

        // Scroll to bottom
        this.scrollToBottom();
    }

    /**
     * Add feedback controls to assistant messages
     */
    addFeedbackControls(contentDiv, messageId) {
        const feedbackDiv = document.createElement('div');
        feedbackDiv.className = 'message-feedback';

        const helpfulBtn = document.createElement('button');
        helpfulBtn.className = 'feedback-btn';
        helpfulBtn.title = 'Helpful';
        helpfulBtn.innerHTML = `
            <svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
                <path d="M14 9V5a3 3 0 0 0-3-3l-4 9v11h11.28a2 2 0 0 0 2-1.7l1.38-9a2 2 0 0 0-2-2.3zM7 22H4a2 2 0 0 1-2-2v-7a2 2 0 0 1 2-2h3"></path>
            </svg>
            <span>Helpful</span>
        `;

        const unhelpfulBtn = document.createElement('button');
        unhelpfulBtn.className = 'feedback-btn';
        unhelpfulBtn.title = 'Not helpful';
        unhelpfulBtn.innerHTML = `
            <svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
                <path d="M10 15v4a3 3 0 0 0 3 3l4-9V2H5.72a2 2 0 0 0-2 1.7l-1.38 9a2 2 0 0 0 2 2.3zm7-13h2.67A2.31 2.31 0 0 1 22 4v7a2.31 2.31 0 0 1-2.33 2H17"></path>
            </svg>
            <span>Not helpful</span>
        `;

        // Add event listeners
        helpfulBtn.addEventListener('click', () => {
            this.submitFeedback(messageId, true);
            feedbackDiv.innerHTML = '<div class="feedback-thanks">Thanks for your feedback!</div>';
        });

        unhelpfulBtn.addEventListener('click', () => {
            this.submitFeedback(messageId, false);

            // Replace with detailed feedback form
            feedbackDiv.innerHTML = `
                <div class="feedback-form">
                    <p>What was the issue with this response?</p>
                    <select id="feedback-reason-${messageId}" class="feedback-select">
                        <option value="inaccurate">Information is inaccurate</option>
                        <option value="incomplete">Information is incomplete</option>
                        <option value="irrelevant">Response is irrelevant</option>
                        <option value="sources">Sources are missing or incorrect</option>
                        <option value="other">Other issue</option>
                    </select>
                    <textarea id="feedback-detail-${messageId}" class="feedback-textarea"
                        placeholder="Optional: Provide more details about the issue"></textarea>
                    <div class="feedback-actions">
                        <button class="primary-button submit-feedback-btn">Submit</button>
                    </div>
                </div>
            `;

            // Add event listener to the new submit button
            const submitBtn = feedbackDiv.querySelector('.submit-feedback-btn');
            submitBtn.addEventListener('click', () => {
                const reason = document.getElementById(`feedback-reason-${messageId}`).value;
                const detail = document.getElementById(`feedback-detail-${messageId}`).value;

                this.submitDetailedFeedback(messageId, reason, detail);
                feedbackDiv.innerHTML = '<div class="feedback-thanks">Thanks for your detailed feedback!</div>';
            });
        });

        feedbackDiv.appendChild(helpfulBtn);
        feedbackDiv.appendChild(unhelpfulBtn);

        contentDiv.appendChild(feedbackDiv);
    }

    /**
     * Add sources and citations to a message
     */
    addSourcesToMessage(contentDiv, metadata) {
        if (!metadata.sources || metadata.sources.length === 0) return;

        const sourcesDiv = document.createElement('div');
        sourcesDiv.className = 'message-sources';
        sourcesDiv.setAttribute('aria-label', 'Source documents');

        const headerDiv = document.createElement('div');
        headerDiv.className = 'sources-header';
        headerDiv.textContent = 'Sources:';
        sourcesDiv.appendChild(headerDiv);

        metadata.sources.forEach(source => {
            const citationDiv = document.createElement('div');
            citationDiv.className = 'source-citation';

            const iconSvg = document.createElement('svg');
            iconSvg.className = 'source-icon';
            iconSvg.innerHTML = '<path d="M14 2H6a2 2 0 0 0-2 2v16a2 2 0 0 0 2 2h12a2 2 0 0 0 2-2V8z"></path><polyline points="14,2 14,8 20,8"></polyline><line x1="16" y1="13" x2="8" y2="13"></line><line x1="16" y1="17" x2="8" y2="17"></line><polyline points="10,9 9,9 8,9"></polyline>';
            iconSvg.setAttribute('width', '16');
            iconSvg.setAttribute('height', '16');
            iconSvg.setAttribute('viewBox', '0 0 24 24');
            iconSvg.setAttribute('fill', 'none');
            iconSvg.setAttribute('stroke', 'currentColor');
            iconSvg.setAttribute('stroke-width', '2');
            iconSvg.setAttribute('aria-hidden', 'true');

            const textSpan = document.createElement('span');
            textSpan.textContent = source.document || source.title || source.chunk_id || 'Unknown source';

            // Make the source citation clickable to view the full document
            if (source.id) {
                citationDiv.classList.add('clickable');
                citationDiv.setAttribute('role', 'button');
                citationDiv.setAttribute('tabindex', '0');
                citationDiv.setAttribute('aria-label', `View source: ${source.document || source.title || 'Source Document'}`);
                citationDiv.title = 'Click to view full source document';
                citationDiv.dataset.sourceId = source.id;

                // Add click event
                citationDiv.addEventListener('click', () => {
                    this.showSourceDocument(source.id, source.document || source.title || 'Source Document');
                });

                // Add keyboard support
                citationDiv.addEventListener('keydown', (e) => {
                    if (e.key === 'Enter' || e.key === ' ') {
                        e.preventDefault();
                        this.showSourceDocument(source.id, source.document || source.title || 'Source Document');
                    }
                });
            }

            citationDiv.appendChild(iconSvg);
            citationDiv.appendChild(textSpan);
            sourcesDiv.appendChild(citationDiv);
        });

        contentDiv.appendChild(sourcesDiv);
    }

    /**
     * Show the full source document in a side panel
     */
    async showSourceDocument(sourceId, title) {
        // Get source panel elements
        let sourcePanel = document.getElementById('sourcePanel');
        if (!sourcePanel) {
            this.initializeSourcePanel();
            sourcePanel = document.getElementById('sourcePanel');
            if (!sourcePanel) {
                console.error('Failed to create source panel');
                return;
            }
        }

        const sourceContent = document.getElementById('sourceContent');
        const closeBtn = document.getElementById('closeSourcePanel');

        // Store last focused element for accessibility
        this.lastFocusedElement = document.activeElement;

        // Clear existing content
        sourceContent.innerHTML = '<div class="loading-spinner" role="status" aria-label="Loading source document"></div><p>Loading source document...</p>';

        // Show the panel
        sourcePanel.classList.add('show');
        sourcePanel.setAttribute('aria-hidden', 'false');
        document.body.classList.add('source-panel-open');

        // Set up close button
        if (closeBtn) {
            closeBtn.addEventListener('click', () => {
                this.closeSourcePanel();
            }, { once: true });

            // Focus the close button for keyboard accessibility
            setTimeout(() => closeBtn.focus(), 100);
        }

        try {
            // Set timeout for the request (15 seconds)
            const controller = new AbortController();
            const timeoutId = setTimeout(() => controller.abort(), 15000);

            // Fetch source document content
            const response = await fetch(`/chat/source/${sourceId}`, {
                signal: controller.signal
            });

            clearTimeout(timeoutId);
            const data = await response.json();

            if (response.ok && data.status === 'success') {
                // Create content elements
                const documentTitle = data.metadata?.filename || data.metadata?.title || title;
                const contentHTML = `
                    <h3 id="sourceTitle">${documentTitle}</h3>
                    <div class="metadata" aria-label="Document metadata">
                        ${data.metadata?.last_updated ?
                            `<div class="metadata-item"><span>Last Updated:</span> ${data.metadata.last_updated}</div>` : ''}
                        ${data.metadata?.author ?
                            `<div class="metadata-item"><span>Author:</span> ${data.metadata.author}</div>` : ''}
                        ${data.metadata?.department ?
                            `<div class="metadata-item"><span>Department:</span> ${data.metadata.department}</div>` : ''}
                    </div>
                    <div class="document-content" tabindex="0">
                        ${this.formatDocumentContent(data.content)}
                    </div>
                `;

                sourceContent.innerHTML = contentHTML;

                // Update ARIA labels
                sourcePanel.setAttribute('aria-label', `Source document: ${documentTitle}`);

                // Make content keyboard navigable
                const docContent = sourceContent.querySelector('.document-content');
                if (docContent) {
                    docContent.addEventListener('keydown', (e) => {
                        const scrollAmount = 100;
                        if (e.key === 'ArrowDown') {
                            e.preventDefault();
                            docContent.scrollTop += scrollAmount;
                        } else if (e.key === 'ArrowUp') {
                            e.preventDefault();
                            docContent.scrollTop -= scrollAmount;
                        }
                    });
                }
            } else {
                // Show error with retry button
                this.renderSourceError(data.message || 'Failed to load document', sourceId, title, sourceContent);
            }
        } catch (error) {
            console.error('Failed to fetch source document:', error);

            let errorMessage = 'Failed to load the source document.';
            if (error.name === 'AbortError') {
                errorMessage = 'The request took too long and was cancelled.';
            } else if (error.name === 'TypeError' && error.message.includes('NetworkError')) {
                errorMessage = 'Network error. Please check your internet connection.';
            }

            this.renderSourceError(`${errorMessage} Please try again later.`, sourceId, title, sourceContent);
        }
    }

    /**
     * Escape HTML characters to prevent XSS
     */
    escapeHtml(text) {
        const div = document.createElement('div');
        div.textContent = text;
        return div.innerHTML;
    }

    /**
     * Format markdown text for better readability in chat responses
     * Safely converts markdown to HTML while preventing XSS attacks
     */
    formatMarkdown(text) {
        if (!text) return '';

        // First escape ALL HTML to prevent XSS - this is critical for security
        let escapedText = this.escapeHtml(text);

        // Now safely convert markdown formatting to HTML
        // Process line by line to maintain proper structure
        const lines = escapedText.split('\n');
        const processedLines = [];
        let inList = false;
        let listType = '';

        for (let i = 0; i < lines.length; i++) {
            let line = lines[i];
            const trimmedLine = line.trim();

            // Skip empty lines for now - we'll handle them in paragraph processing
            if (!trimmedLine) {
                processedLines.push('');
                continue;
            }

            // Process headers (must be at start of line) - check from least to most specific
            if (trimmedLine.match(/^# (.+)$/)) {
                if (inList) {
                    processedLines.push(`</${listType}>`);
                    inList = false;
                    listType = '';
                }
                const headerText = trimmedLine.replace(/^# /, '');
                processedLines.push(`<h1>${headerText}</h1>`);
                continue;
            } else if (trimmedLine.match(/^## (.+)$/)) {
                if (inList) {
                    processedLines.push(`</${listType}>`);
                    inList = false;
                    listType = '';
                }
                const headerText = trimmedLine.replace(/^## /, '');
                processedLines.push(`<h2>${headerText}</h2>`);
                continue;
            } else if (trimmedLine.match(/^### (.+)$/)) {
                if (inList) {
                    processedLines.push(`</${listType}>`);
                    inList = false;
                    listType = '';
                }
                const headerText = trimmedLine.replace(/^### /, '');
                processedLines.push(`<h3>${headerText}</h3>`);
                continue;
            }

            // Process list items
            const bulletMatch = trimmedLine.match(/^[-*+]\s+(.+)$/);
            const numberMatch = trimmedLine.match(/^\d+\.\s+(.+)$/);

            if (bulletMatch) {
                if (!inList || listType !== 'ul') {
                    if (inList) processedLines.push(`</${listType}>`);
                    processedLines.push('<ul>');
                    inList = true;
                    listType = 'ul';
                }
                let listContent = bulletMatch[1];
                // Apply inline formatting to list content
                listContent = this.applyInlineFormatting(listContent);
                processedLines.push(`<li>${listContent}</li>`);
                continue;
            } else if (numberMatch) {
                if (!inList || listType !== 'ol') {
                    if (inList) processedLines.push(`</${listType}>`);
                    processedLines.push('<ol>');
                    inList = true;
                    listType = 'ol';
                }
                let listContent = numberMatch[1];
                // Apply inline formatting to list content
                listContent = this.applyInlineFormatting(listContent);
                processedLines.push(`<li>${listContent}</li>`);
                continue;
            }

            // Close any open list for regular text
            if (inList) {
                processedLines.push(`</${listType}>`);
                inList = false;
                listType = '';
            }

            // Apply inline formatting (bold, italic) to regular text
            line = this.applyInlineFormatting(trimmedLine);
            processedLines.push(line);
        }

        // Close any remaining open list
        if (inList) {
            processedLines.push(`</${listType}>`);
        }

        // Convert to paragraph structure
        const content = processedLines.join('\n');
        return this.convertToParagraphs(content);
    }

    /**
     * Apply inline formatting (bold, italic) to text that's already HTML-escaped
     */
    applyInlineFormatting(text) {
        // First handle bold formatting (**text**) and replace with a placeholder
        const boldPlaceholder = '___BOLD_PLACEHOLDER___';
        const boldMatches = [];
        text = text.replace(/\*\*([^*]+)\*\*/g, (match, content) => {
            boldMatches.push(`<strong>${content}</strong>`);
            return `${boldPlaceholder}${boldMatches.length - 1}${boldPlaceholder}`;
        });

        // Now handle italic formatting (*text*) - won't conflict with bold placeholders
        text = text.replace(/\*([^*]+)\*/g, '<em>$1</em>');

        // Restore bold formatting
        const restoreRegex = new RegExp(`${boldPlaceholder}(\\d+)${boldPlaceholder}`, 'g');
        text = text.replace(restoreRegex, (match, index) => boldMatches[parseInt(index)]);

        return text;
    }

    /**
     * Convert processed lines to proper paragraph structure
     */
    convertToParagraphs(content) {
        // Split by double line breaks for paragraphs
        const sections = content.split('\n\n');
        const formattedSections = [];

        for (const section of sections) {
            const trimmed = section.trim();
            if (!trimmed) continue;

            // Check if this section contains only block elements (headers, lists)
            if (trimmed.match(/^<(h[1-6]|ul|ol)/)) {
                formattedSections.push(trimmed);
            } else {
                // Regular text content - wrap in paragraph and handle line breaks
                const withBreaks = trimmed.replace(/\n/g, '<br>');
                formattedSections.push(`<p>${withBreaks}</p>`);
            }
        }

        return formattedSections.join('\n');
    }

    /**
     * Render error message with retry functionality for source documents
     */
    renderSourceError(message, sourceId, title, sourceContent) {
        const errorHtml = `
            <div class="error-message" role="alert">
                <strong>Error loading source document</strong>
                <p>${this.escapeHtml(message)}</p>
                <button class="retry-button" id="retrySourceLoad" aria-label="Retry loading the source document">
                    <svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" aria-hidden="true">
                        <polyline points="23 4 23 10 17 10"></polyline>
                        <polyline points="1 20 1 14 7 14"></polyline>
                        <path d="M3.51 9a9 9 0 0 1 14.85-3.36L23 10M1 14l4.64 4.36A9 9 0 0 0 20.49 15"></path>
                    </svg>
                    Retry
                </button>
            </div>
        `;

        sourceContent.innerHTML = errorHtml;

        // Add retry functionality
        document.getElementById('retrySourceLoad')?.addEventListener('click', () => {
            this.showSourceDocument(sourceId, title);
        });
    }

    /**
     * Format document content for display
     */
    formatDocumentContent(content) {
        if (!content) return '<p>No content available</p>';

        // First escape HTML to prevent XSS
        const escapedContent = this.escapeHtml(content);

        // Check if content is markdown and convert if needed
        if (content.includes('#') || content.includes('*')) {
            // Simple markdown formatting on escaped content
            return escapedContent
                .replace(/^# (.+)$/gm, '<h1>$1</h1>')
                .replace(/^## (.+)$/gm, '<h2>$1</h2>')
                .replace(/^### (.+)$/gm, '<h3>$1</h3>')
                .replace(/\*\*(.+?)\*\*/g, '<strong>$1</strong>')
                .replace(/\*(.+?)\*/g, '<em>$1</em>')
                .replace(/\n\n/g, '</p><p>')
                .replace(/\n/g, '<br>')
                .replace(/^(.+)$/gm, function(match) {
                    if (!match.startsWith('<')) return '<p>' + match + '</p>';
                    return match;
                });
        }

        // If not markdown, wrap escaped content in paragraphs
        return '<p>' + escapedContent + '</p>';
    }

    /**
     * Add confidence score visualization
     */
    addConfidenceScore(contentDiv, confidence) {
        const confidenceDiv = document.createElement('div');
        confidenceDiv.className = 'confidence-score';

        const labelSpan = document.createElement('span');
        labelSpan.textContent = `Confidence: ${Math.round(confidence * 100)}%`;

        const barDiv = document.createElement('div');
        barDiv.className = 'confidence-bar';

        const fillDiv = document.createElement('div');
        fillDiv.className = 'confidence-fill';
        fillDiv.style.width = `${confidence * 100}%`;

        barDiv.appendChild(fillDiv);
        confidenceDiv.appendChild(labelSpan);
        confidenceDiv.appendChild(barDiv);
        contentDiv.appendChild(confidenceDiv);
    }

    /**
     * Add an error message to the chat with retry options
     */
    addErrorMessage(errorText, error = null, canRetry = true) {
        const messageId = 'msg_' + Date.now() + '_' + Math.random().toString(36).substr(2, 9);
        const timestamp = new Date().toISOString();

        const messageDiv = document.createElement('div');
        messageDiv.className = 'message message-assistant';
        messageDiv.dataset.messageId = messageId;

        // Add header with timestamp
        const messageHeader = document.createElement('div');
        messageHeader.className = 'message-header';

        const senderLabel = document.createElement('span');
        senderLabel.className = 'sender-label';
        senderLabel.textContent = 'System';

        const timestampSpan = document.createElement('span');
        timestampSpan.className = 'message-timestamp';
        timestampSpan.textContent = this.formatDateTime(timestamp);

        messageHeader.appendChild(senderLabel);
        messageHeader.appendChild(timestampSpan);
        messageDiv.appendChild(messageHeader);

        const contentDiv = document.createElement('div');
        contentDiv.className = 'message-content error-message';

        const strongElement = document.createElement('strong');
        strongElement.textContent = 'Error:';
        strongElement.setAttribute('aria-hidden', 'true');

        const textSpan = document.createElement('span');
        textSpan.textContent = ` ${errorText}`;
        textSpan.setAttribute('role', 'alert');

        contentDiv.appendChild(strongElement);
        contentDiv.appendChild(textSpan);

        // Add retry button if applicable
        if (canRetry) {
            const retryButton = document.createElement('button');
            retryButton.className = 'retry-button';
            retryButton.innerHTML = `
                <svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" aria-hidden="true">
                    <polyline points="23 4 23 10 17 10"></polyline>
                    <polyline points="1 20 1 14 7 14"></polyline>
                    <path d="M3.51 9a9 9 0 0 1 14.85-3.36L23 10M1 14l4.64 4.36A9 9 0 0 0 20.49 15"></path>
                </svg>
                Retry
            `;
            retryButton.setAttribute('aria-label', 'Retry sending your last message');

            retryButton.addEventListener('click', () => {
                // Remove the error message
                messageDiv.remove();

                // Retry the last user message
                this.retryLastMessage();
            });

            contentDiv.appendChild(retryButton);
        }

        // Add more detailed error info if available
        if (error && (error.status || error.code)) {
            const detailsDiv = document.createElement('div');
            detailsDiv.className = 'error-details';

            let detailsText = '';
            if (error.status) detailsText += `Status code: ${error.status}. `;
            if (error.code) detailsText += `Error code: ${error.code}. `;
            if (error.message) detailsText += error.message;

            detailsDiv.textContent = detailsText;
            contentDiv.appendChild(detailsDiv);
        }

        messageDiv.appendChild(contentDiv);
        this.messagesContainer.appendChild(messageDiv);

        // Store in messages array
        this.messages.push({
            id: messageId,
            sender: 'system',
            content: errorText,
            timestamp,
            metadata: { error: true }
        });

        // Save to localStorage
        this.saveCurrentConversation();

        this.scrollToBottom();

        // Auto retry for server errors (5xx) if retry count is under the limit
        if (error && error.status && error.status >= 500 && this.autoRetryCount < this.maxAutoRetries) {
            this.autoRetryCount++;

            // Show auto-retry status
            const retryStatus = document.createElement('div');
            retryStatus.className = 'auto-retry-status';
            retryStatus.innerHTML = `
                <svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" aria-hidden="true">
                    <circle cx="12" cy="12" r="10"></circle>
                    <polyline points="12 6 12 12 16 14"></polyline>
                </svg>
                Retrying in <span class="retry-countdown">5</span> seconds...
            `;
            contentDiv.appendChild(retryStatus);

            // Countdown timer
            const countdownEl = retryStatus.querySelector('.retry-countdown');
            let countdown = 5;

            const countdownInterval = setInterval(() => {
                countdown--;
                if (countdownEl) countdownEl.textContent = countdown.toString();

                if (countdown <= 0) {
                    clearInterval(countdownInterval);
                    messageDiv.remove();
                    this.retryLastMessage();
                }
            }, 1000);
        }
    }

    /**
     * Retry sending the last user message
     */
    retryLastMessage() {
        // Find the last user message
        const lastUserMessage = [...this.messages].reverse().find(msg => msg.sender === 'user');

        if (lastUserMessage) {
            // Reset auto retry count if this is a manual retry
            this.autoRetryCount = 0;

            // Resend the message
            this.sendMessageToAPI(lastUserMessage.content);
        } else {
            this.addErrorMessage("Couldn't find a previous message to retry.", null, false);
        }
    }

    /**
     * Submit simple feedback (helpful/not helpful)
     */
    submitFeedback(messageId, isHelpful) {
        const message = this.messages.find(msg => msg.id === messageId);
        if (!message) return;

        // Update message with feedback
        message.feedback = {
            rating: isHelpful ? 5 : 1,
            timestamp: new Date().toISOString()
        };

        // Save to localStorage
        this.saveCurrentConversation();

        // Send to server if available
        this.sendFeedbackToServer(messageId, isHelpful);
    }

    /**
     * Submit detailed feedback
     */
    submitDetailedFeedback(messageId, reason, detail) {
        const message = this.messages.find(msg => msg.id === messageId);
        if (!message) return;

        // Update message with detailed feedback
        message.feedback = {
            rating: 1, // Not helpful
            reason: reason,
            detail: detail,
            timestamp: new Date().toISOString()
        };

        // Save to localStorage
        this.saveCurrentConversation();

        // Send to server if available
        this.sendDetailedFeedbackToServer(messageId, reason, detail);
    }

    /**
     * Send feedback to server
     */
    sendFeedbackToServer(messageId, isHelpful) {
        try {
            const feedback = {
                feedback_id: 'feedback_' + Date.now(),
                conversation_id: this.conversationId,
                message_id: messageId,
                feedback_type: 'response_rating',
                rating: isHelpful ? 5 : 1,
                timestamp: new Date().toISOString()
            };

            fetch('/chat/feedback', {
                method: 'POST',
                headers: {
                    'Content-Type': 'application/json'
                },
                body: JSON.stringify(feedback)
            })
            .then(response => {
                if (!response.ok) {
                    console.warn('Failed to send feedback to server:', response.status);
                }
            })
            .catch(error => {
                console.warn('Error sending feedback to server:', error);
            });
        } catch (error) {
            console.warn('Error preparing feedback:', error);
        }
    }

    /**
     * Send detailed feedback to server
     */
    sendDetailedFeedbackToServer(messageId, reason, detail) {
        try {
            const feedback = {
                feedback_id: 'feedback_' + Date.now(),
                conversation_id: this.conversationId,
                message_id: messageId,
                feedback_type: 'detailed',
                rating: 1,
                reason: reason,
                comment: detail,
                timestamp: new Date().toISOString()
            };

            fetch('/chat/feedback', {
                method: 'POST',
                headers: {
                    'Content-Type': 'application/json'
                },
                body: JSON.stringify(feedback)
            })
            .then(response => {
                if (!response.ok) {
                    console.warn('Failed to send detailed feedback to server:', response.status);
                }
            })
            .catch(error => {
                console.warn('Error sending detailed feedback to server:', error);
            });
        } catch (error) {
            console.warn('Error preparing detailed feedback:', error);
        }
    }

    /**
     * Scroll to the bottom of the messages container
     */
    scrollToBottom() {
        this.messagesContainer.scrollTop = this.messagesContainer.scrollHeight;
    }

    /**
     * Format ISO datetime string to a user-friendly format
     */
    formatDateTime(isoString) {
        try {
            const date = new Date(isoString);

            // For messages from today, just show the time
            const today = new Date();
            if (date.toDateString() === today.toDateString()) {
                return date.toLocaleTimeString([], { hour: '2-digit', minute: '2-digit' });
            }

            // For messages from this year, show month, day and time
            if (date.getFullYear() === today.getFullYear()) {
                return date.toLocaleDateString([], { month: 'short', day: 'numeric' }) +
                       ' at ' + date.toLocaleTimeString([], { hour: '2-digit', minute: '2-digit' });
            }

            // For older messages, show full date
            return date.toLocaleDateString([], { year: 'numeric', month: 'short', day: 'numeric' }) +
                   ' at ' + date.toLocaleTimeString([], { hour: '2-digit', minute: '2-digit' });
        } catch (e) {
            console.warn('Invalid timestamp format:', isoString);
            return 'Unknown time';
        }
    }
}

// CSS for additional status states
const additionalStyles = `
.status-dot.loading {
    background: #f59e0b;
}

.status-dot.warning {
    background: #f59e0b;
}

.status-dot.error {
    background: #ef4444;
}

.status-dot.ready {
    background: #10b981;
}

/* Source document panel styles */
.source-document-panel {
    position: fixed;
    top: 0;
    right: -500px;
    width: 450px;
    max-width: 90vw;
    height: 100vh;
    background: white;
    box-shadow: -2px 0 10px rgba(0, 0, 0, 0.1);
    z-index: 101;
    transition: right 0.3s ease;
    display: flex;
    flex-direction: column;
}

.source-document-panel.show {
    right: 0;
}

.source-document-content {
    padding: 1rem;
    overflow-y: auto;
}

.source-document-content h1 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: #1e293b;
}

.source-document-content h2 {
    font-size: 1.25rem;
    margin: 1.5rem 0 0.75rem 0;
    color: #1e293b;
}

.source-document-content h3 {
    font-size: 1.125rem;
    margin: 1.25rem 0 0.5rem 0;
    color: #1e293b;
}

.source-document-content p {
    margin: 0.75rem 0;
    color: #4b5563;
    line-height: 1.6;
}

.source-document-content .metadata {
    margin: 1rem 0;
    padding: 0.75rem;
    background: #f1f5f9;
    border-radius: 6px;
    font-size: 0.875rem;
    color: #64748b;
}

.source-document-content .metadata-item {
    margin: 0.25rem 0;
}

.source-document-content .metadata-item span {
    font-weight: 600;
}

.source-citation.clickable {
    cursor: pointer;
    transition: background-color 0.2s;
}

.source-citation.clickable:hover {
    background: #e2e8f0;
}
`;

// Add additional styles to document
const styleSheet = document.createElement('style');
styleSheet.textContent = additionalStyles;
document.head.appendChild(styleSheet);

// Initialize the chat interface when the DOM is loaded
document.addEventListener('DOMContentLoaded', () => {
    new ChatInterface();
});

// Service worker registration for potential offline functionality
if ('serviceWorker' in navigator) {
    window.addEventListener('load', () => {
        // Optional: register a service worker for offline functionality
        // navigator.serviceWorker.register('/sw.js').catch(console.warn);
    });
}