document.addEventListener('DOMContentLoaded', function() {
    // DOM Elements
    const chatWindow = document.getElementById('chatWindow');
    const userInput = document.getElementById('userInput');
    const sendButton = document.getElementById('sendButton');
    const clearButton = document.getElementById('clearButton');
    const clearButtonNav = document.getElementById('clearButtonNav');
    const imageInput = document.getElementById('imageInput');
    const uploadImageButton = document.getElementById('uploadImageButton');
    const imagePreviewArea = document.getElementById('imagePreviewArea');
    const imagePreviewContainer = document.getElementById('imagePreviewContainer');
    const chatHistoryList = document.getElementById('chatHistoryList');
    const saveCurrentChatButton = document.getElementById('saveCurrentChatButton');
    const settingsButton = document.getElementById('settingsButtonNav');
    const toggleNavButton = document.getElementById('toggleNavButton');
    const closeSideNavButton = document.getElementById('closeSideNavButton');
    const sideNav = document.getElementById('sideNav');
    const mainContent = document.querySelector('.main-content');
    const welcomeContainer = document.querySelector('.welcome-container');
    const suggestionBubbles = document.querySelectorAll('.suggestion-bubble');
    
    // Templates
    const loadingTemplate = document.getElementById('loadingTemplate');
    const userMessageTemplate = document.getElementById('userMessageTemplate');
    const userImageMessageTemplate = document.getElementById('userImageMessageTemplate');
    const botMessageTemplate = document.getElementById('botMessageTemplate');
    const errorMessageTemplate = document.getElementById('errorMessageTemplate');
    
    // State variables
    let chatHistory = [];
    let selectedImagesData = []; // Pour stocker plusieurs images
    let conversationStarted = false;
    
    // --- IMAGE HANDLING ---
    
    // Upload image button click
    uploadImageButton.addEventListener('click', function() {
        imageInput.click();
    });
    
    // Image input change - support for multiple images
    imageInput.addEventListener('change', function(e) {
        const files = Array.from(e.target.files);
        if (!files.length) return;
        
        // Clear previous image container
        imagePreviewContainer.innerHTML = '';
        selectedImagesData = [];
        
        // Process each file
        files.forEach(file => {
            // Check file type
            if (!file.type.startsWith('image/')) {
                alert('Veuillez sélectionner uniquement des fichiers image valides.');
                return;
            }
            
            // Check file size (max 5MB)
            if (file.size > 5 * 1024 * 1024) {
                alert('La taille de chaque image ne doit pas dépasser 5 Mo.');
                return;
            }
            
            const reader = new FileReader();
            reader.onload = function(event) {
                // Create preview container
                const previewContainer = document.createElement('div');
                previewContainer.className = 'image-preview-container';
                
                // Create image preview
                const imgPreview = document.createElement('img');
                imgPreview.src = event.target.result;
                imgPreview.alt = 'Image preview';
                previewContainer.appendChild(imgPreview);
                
                // Create remove button
                const removeBtn = document.createElement('button');
                removeBtn.className = 'remove-image-button';
                removeBtn.innerHTML = '<i class="bi bi-x-circle-fill"></i>';
                previewContainer.appendChild(removeBtn);
                
                // Add preview to container
                imagePreviewContainer.appendChild(previewContainer);
                
                // Store image data
                const imageData = event.target.result;
                selectedImagesData.push(imageData);
                
                // Add event listener to remove button
                removeBtn.addEventListener('click', () => {
                    // Remove this specific image
                    const index = selectedImagesData.indexOf(imageData);
                    if (index > -1) {
                        selectedImagesData.splice(index, 1);
                    }
                    previewContainer.remove();
                    
                    // Hide preview area if no images left
                    if (selectedImagesData.length === 0) {
                        imagePreviewArea.classList.add('hidden');
                        imageInput.value = '';
                    }
                });
            };
            reader.readAsDataURL(file);
        });
        
        // Show preview area
        imagePreviewArea.classList.remove('hidden');
        
        // Focus on input for caption
        userInput.focus();
    });
    
    // --- SIDE NAVIGATION HANDLING ---
    
    // Toggle side navigation
    toggleNavButton.addEventListener('click', function() {
        sideNav.classList.add('active');
        document.body.insertAdjacentHTML('beforeend', '<div class="overlay" id="navOverlay"></div>');
        const overlay = document.getElementById('navOverlay');
        overlay.classList.add('active');
        loadChatHistoryList();
        
        // Close side nav when clicking overlay
        overlay.addEventListener('click', closeSideNav);
    });
    
    // Close side navigation
    closeSideNavButton.addEventListener('click', closeSideNav);
    
    function closeSideNav() {
        sideNav.classList.remove('active');
        const overlay = document.getElementById('navOverlay');
        if (overlay) {
            overlay.remove();
        }
    }
    
    // Clear chat from nav button
    if (clearButtonNav) {
        clearButtonNav.addEventListener('click', function() {
            clearChat(true); // With confirmation
            closeSideNav();
        });
    }
    
    // Settings button in side nav
    if (settingsButtonNav) {
        settingsButtonNav.addEventListener('click', function() {
            alert('Fonctionnalité en cours de développement');
            closeSideNav();
        });
    }
    
    // Load chat history list
    function loadChatHistoryList() {
        fetch('/api/load-chats')
            .then(response => response.json())
            .then(data => {
                if (data.error) {
                    chatHistoryList.innerHTML = `<div class="empty-state">${data.error}</div>`;
                    return;
                }
                
                if (!data.chats || data.chats.length === 0) {
                    chatHistoryList.innerHTML = '<div class="empty-state">Aucune conversation sauvegardée</div>';
                    return;
                }
                
                // Create history items
                let historyHTML = '';
                data.chats.forEach(chat => {
                    // Format timestamp (YYYYMMDD_HHMMSS to readable format)
                    const timestamp = chat.timestamp;
                    const year = timestamp.substring(0, 4);
                    const month = timestamp.substring(4, 6);
                    const day = timestamp.substring(6, 8);
                    const hour = timestamp.substring(9, 11);
                    const minute = timestamp.substring(11, 13);
                    const formattedDate = `${day}/${month}/${year} ${hour}:${minute}`;
                    
                    historyHTML += `
                        <div class="chat-history-item" data-filename="${chat.filename}">
                            <div class="icon"><i class="bi bi-chat-dots"></i></div>
                            <div class="details">
                                <div>Conversation</div>
                                <div class="timestamp">${formattedDate}</div>
                            </div>
                        </div>
                    `;
                });
                
                chatHistoryList.innerHTML = historyHTML;
                
                // Add click event to history items
                const historyItems = chatHistoryList.querySelectorAll('.chat-history-item');
                historyItems.forEach(item => {
                    item.addEventListener('click', function() {
                        const filename = this.getAttribute('data-filename');
                        loadChatHistory(filename);
                        toggleHistoryDropdown();
                    });
                });
            })
            .catch(error => {
                console.error('Error loading chat history:', error);
                chatHistoryList.innerHTML = '<div class="empty-state">Erreur lors du chargement de l\'historique</div>';
            });
    }
    
    // Load specific chat history
    function loadChatHistory(filename) {
        fetch(`/api/load-chat/${filename}`)
            .then(response => response.json())
            .then(data => {
                if (data.error) {
                    alert(data.error);
                    return;
                }
                
                if (data.history) {
                    // Clear current chat
                    clearChat(false); // No confirmation needed
                    
                    // Load history
                    chatHistory = data.history;
                    
                    // Display messages
                    data.history.forEach(msg => {
                        if (msg.sender === 'user') {
                            const messageElement = userMessageTemplate.content.cloneNode(true);
                            messageElement.querySelector('p').textContent = msg.text;
                            chatWindow.appendChild(messageElement);
                        } else {
                            const messageElement = botMessageTemplate.content.cloneNode(true);
                            const messageParagraph = messageElement.querySelector('p');
                            
                            if (window.marked) {
                                messageParagraph.innerHTML = marked.parse(msg.text);
                            } else {
                                messageParagraph.textContent = msg.text;
                            }
                            
                            chatWindow.appendChild(messageElement);
                            
                            if (window.Prism) {
                                const codeBlocks = messageParagraph.querySelectorAll('pre code');
                                codeBlocks.forEach(block => {
                                    Prism.highlightElement(block);
                                });
                            }
                        }
                    });
                    
                    // Scroll to bottom
                    scrollToBottom();
                }
            })
            .catch(error => {
                console.error('Error loading chat:', error);
                alert('Erreur lors du chargement de la conversation.');
            });
    }
    
    // Save current chat
    saveCurrentChatButton.addEventListener('click', function() {
        if (chatHistory.length <= 1) {
            alert('Aucune conversation à sauvegarder. Veuillez d\'abord discuter avec le chatbot.');
            return;
        }
        
        fetch('/api/save-chat', {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json'
            },
            body: JSON.stringify({
                history: chatHistory
            })
        })
        .then(response => response.json())
        .then(data => {
            if (data.error) {
                alert(data.error);
            } else {
                alert('Conversation sauvegardée avec succès !');
                loadChatHistoryList();
            }
        })
        .catch(error => {
            console.error('Error saving chat:', error);
            alert('Erreur lors de la sauvegarde de la conversation.');
        });
    });
    
    // --- TEXT INPUT HANDLING ---
    
    // Auto-resize textarea based on content
    userInput.addEventListener('input', function() {
        this.style.height = 'auto';
        this.style.height = (this.scrollHeight) + 'px';
        // Reset height if empty
        if (this.value === '') {
            this.style.height = '';
        }
    });
    
    // Send message when Enter key is pressed (without shift)
    userInput.addEventListener('keydown', function(e) {
        if (e.key === 'Enter' && !e.shiftKey) {
            e.preventDefault();
            sendMessage();
        }
    });
    
    // Send message when send button is clicked
    sendButton.addEventListener('click', sendMessage);
    
    // Clear chat history when clear button is clicked
    if (clearButton) {
        clearButton.addEventListener('click', function() {
            clearChat(true); // With confirmation
        });
    }
    
    // --- CHAT FUNCTIONS ---
    
    // Function to clear the chat history
    function clearChat(withConfirmation = true) {
        if (!withConfirmation || (chatHistory.length > 0 && confirm('Êtes-vous sûr de vouloir effacer toute la conversation ?'))) {
            // Clear the chat window except for the welcome message
            while (chatWindow.childElementCount > 1) {
                chatWindow.removeChild(chatWindow.lastChild);
            }
            
            // Reset chat history but keep the welcome message
            const welcomeMsg = chatHistory[0];
            chatHistory = welcomeMsg ? [welcomeMsg] : [];
            
            // Focus on input field
            userInput.focus();
        }
    }
    
    // Function to send message
    function sendMessage() {
        const message = userInput.value.trim();
        
        // Require either text or images
        if (message === '' && selectedImagesData.length === 0) return;
        
        if (selectedImagesData.length > 0) {
            // Add user message with images to UI
            addUserImageMessage(message, selectedImagesData[0]); // Pour l'instant afficher seulement la première image dans l'UI
        } else {
            // Add user text message to UI
            addUserMessage(message);
        }
        
        // Clear input field and reset height
        userInput.value = '';
        userInput.style.height = '';
        
        // Show loading indicator
        const loadingElement = addLoadingIndicator();
        
        // Send message to API
        sendToAPI(message, loadingElement, selectedImagesData.length > 0 ? selectedImagesData[0] : null);
        
        // Clear image previews if any
        if (selectedImagesData.length > 0) {
            imagePreviewContainer.innerHTML = '';
            imagePreviewArea.classList.add('hidden');
            selectedImagesData = [];
            imageInput.value = '';
        }
    }
    
    // Add user message to chat window
    function addUserMessage(message) {
        // Hide welcome container if visible (first message)
        if (!conversationStarted && welcomeContainer) {
            welcomeContainer.style.display = 'none';
            conversationStarted = true;
        }
        
        const messageElement = userMessageTemplate.content.cloneNode(true);
        messageElement.querySelector('p').textContent = message;
        chatWindow.appendChild(messageElement);
        
        // Add to chat history
        chatHistory.push({
            sender: 'user',
            text: message
        });
        
        // Scroll to bottom
        scrollToBottom();
    }
    
    // Add user message with image to chat window
    function addUserImageMessage(message, imageData) {
        // Hide welcome container if visible (first message)
        if (!conversationStarted && welcomeContainer) {
            welcomeContainer.style.display = 'none';
            conversationStarted = true;
        }
        
        const messageElement = userImageMessageTemplate.content.cloneNode(true);
        
        // Set image source
        const imageElement = messageElement.querySelector('.chat-image');
        imageElement.src = imageData;
        
        // Set message text if any
        const textElement = messageElement.querySelector('p');
        if (message) {
            textElement.textContent = message;
        } else {
            textElement.style.display = 'none'; // Hide text element if no message
        }
        
        chatWindow.appendChild(messageElement);
        
        // Add to chat history (we don't add the image to history, just the text)
        chatHistory.push({
            sender: 'user',
            text: message || 'Image envoyée'  // Default text if no message provided
        });
        
        // Scroll to bottom
        scrollToBottom();
    }
    
    // Add bot message to chat window with markdown support
    function addBotMessage(message) {
        // Hide welcome container if visible (first message)
        if (!conversationStarted && welcomeContainer) {
            welcomeContainer.style.display = 'none';
            conversationStarted = true;
        }
        
        const messageElement = botMessageTemplate.content.cloneNode(true);
        const messageParagraph = messageElement.querySelector('p');
        
        // Use the marked library to parse Markdown if available
        if (window.marked) {
            messageParagraph.innerHTML = marked.parse(message);
        } else {
            messageParagraph.textContent = message;
        }
        
        chatWindow.appendChild(messageElement);
        
        // Add syntax highlighting to code blocks if Prism is available
        if (window.Prism) {
            const codeBlocks = messageParagraph.querySelectorAll('pre code');
            codeBlocks.forEach(block => {
                Prism.highlightElement(block);
            });
        }
        
        // Add to chat history
        chatHistory.push({
            sender: 'bot',
            text: message
        });
        
        // Scroll to bottom
        scrollToBottom();
    }
    
    // Add loading indicator to chat window
    function addLoadingIndicator() {
        const loadingElement = loadingTemplate.content.cloneNode(true);
        chatWindow.appendChild(loadingElement);
        
        // Scroll to bottom
        scrollToBottom();
        
        // Return the loading element so it can be removed later
        return chatWindow.lastElementChild;
    }
    
    // Add error message to chat window
    function addErrorMessage(error, retryMessage, retryImage) {
        const errorElement = errorMessageTemplate.content.cloneNode(true);
        errorElement.querySelector('p').textContent = error;
        
        // Add retry functionality if a message to retry is provided
        if (retryMessage || retryImage) {
            const retryButton = errorElement.querySelector('.retry-button');
            retryButton.addEventListener('click', function() {
                // Remove the error message
                this.closest('.message-container').remove();
                
                // Show loading indicator
                const loadingElement = addLoadingIndicator();
                
                // Retry sending the message
                sendToAPI(retryMessage, loadingElement, retryImage);
            });
        } else {
            // Hide retry button if no retry message
            errorElement.querySelector('.retry-button').style.display = 'none';
        }
        
        chatWindow.appendChild(errorElement);
        
        // Scroll to bottom
        scrollToBottom();
    }
    
    // Send message to API
    function sendToAPI(message, loadingElement, imageData = null) {
        // Disable input while processing
        userInput.disabled = true;
        sendButton.disabled = true;
        uploadImageButton.disabled = true;
        if (clearButton) clearButton.disabled = true;
        
        // Prepare request data
        const requestData = {
            message: message,
            history: chatHistory
        };
        
        // Add image data if provided
        if (imageData) {
            requestData.image = imageData;
        }
        
        fetch('/api/chat', {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json'
            },
            body: JSON.stringify(requestData)
        })
        .then(response => {
            if (!response.ok) {
                throw new Error(`Server responded with status: ${response.status}`);
            }
            return response.json();
        })
        .then(data => {
            // Remove loading indicator
            if (loadingElement) {
                loadingElement.remove();
            }
            
            // Check for error
            if (data.error) {
                addErrorMessage(data.error, message, imageData);
            } else {
                // Add bot response
                addBotMessage(data.response);
            }
        })
        .catch(error => {
            console.error('Error:', error);
            
            // Remove loading indicator
            if (loadingElement) {
                loadingElement.remove();
            }
            
            // Add error message
            addErrorMessage('Désolé, il y a eu un problème de connexion avec le serveur. Veuillez réessayer.', message, imageData);
        })
        .finally(() => {
            // Re-enable input
            userInput.disabled = false;
            sendButton.disabled = false;
            uploadImageButton.disabled = false;
            if (clearButton) clearButton.disabled = false;
            userInput.focus();
        });
    }
    
    // Scroll chat window to bottom
    function scrollToBottom() {
        chatWindow.scrollTop = chatWindow.scrollHeight;
    }
    
    // Setup suggestion bubbles click handlers
    if (suggestionBubbles) {
        suggestionBubbles.forEach(bubble => {
            bubble.addEventListener('click', function() {
                const prompt = this.getAttribute('data-prompt');
                if (prompt) {
                    userInput.value = prompt;
                    sendMessage();
                }
            });
        });
    }
    
    // Initial focus on input field
    userInput.focus();
});