// Split Screen Document Viewer for Chainlit
(function() {
    'use strict';

    let documentViewer = null;
    let documents = [];
    let activeDocIndex = 0;
    let viewerActive = false;

    // Create the document viewer panel (hidden by default)
    function createDocumentViewer() {
        if (document.getElementById('document-viewer')) {
            return document.getElementById('document-viewer');
        }

        const viewer = document.createElement('div');
        viewer.id = 'document-viewer';
        viewer.className = '';  // Start without 'active' class

        // Create header
        const header = document.createElement('div');
        header.className = 'document-header';
        header.innerHTML = `
            <h3>Document Viewer</h3>
            <div style="display: flex; gap: 10px;">
                <button class="document-pin" title="Pin document">📌 Pin</button>
                <button class="document-close-btn">Close</button>
            </div>
        `;
        viewer.appendChild(header);

        // Create tabs container
        const tabsContainer = document.createElement('div');
        tabsContainer.className = 'document-tabs';
        viewer.appendChild(tabsContainer);

        // Create content area
        const contentArea = document.createElement('div');
        contentArea.id = 'document-content';
        contentArea.innerHTML = `
            <div class="document-empty-state">
                <h4>No Document Selected</h4>
                <p>Click on any document, image, or file in the chat to view it here</p>
            </div>
        `;
        viewer.appendChild(contentArea);

        // Add close functionality
        header.querySelector('.document-close-btn').addEventListener('click', () => {
            hideDocumentViewer();
        });

        // Add pin functionality
        const pinBtn = header.querySelector('.document-pin');
        pinBtn.addEventListener('click', () => {
            pinBtn.classList.toggle('pinned');
            const isPinned = pinBtn.classList.contains('pinned');
            pinBtn.textContent = isPinned ? '📍 Pinned' : '📌 Pin';
        });

        return viewer;
    }

    // Show document viewer
    function showDocumentViewer() {
        if (!documentViewer) {
            documentViewer = createDocumentViewer();
            document.body.appendChild(documentViewer);
        }

        // Add active classes
        documentViewer.classList.add('active');
        document.body.classList.add('document-viewer-active');

        // Adjust main container
        const mainContainer = document.querySelector('#root > div');
        if (mainContainer) {
            mainContainer.classList.add('split-active');
        }

        viewerActive = true;
        console.log('Document viewer shown');
    }

    // Hide document viewer
    function hideDocumentViewer() {
        if (documentViewer) {
            documentViewer.classList.remove('active');
            document.body.classList.remove('document-viewer-active');

            const mainContainer = document.querySelector('#root > div');
            if (mainContainer) {
                mainContainer.classList.remove('split-active');
            }
        }
        viewerActive = false;
        console.log('Document viewer hidden');
    }

    // Display document in viewer
    function displayDocument(content, title = 'Document', type = 'text') {
        console.log('Displaying document:', title, type);

        // Show viewer if not visible
        if (!viewerActive) {
            showDocumentViewer();
        }

        const contentArea = document.getElementById('document-content');
        const tabsContainer = documentViewer.querySelector('.document-tabs');

        // Check if document already exists
        const existingIndex = documents.findIndex(doc => doc.title === title);
        if (existingIndex !== -1) {
            // Switch to existing tab
            activeDocIndex = existingIndex;
            updateTabs();
            displayContent(documents[existingIndex]);
            return;
        }

        // Add to documents array
        const docIndex = documents.length;
        documents.push({ content, title, type });

        // Create tab
        const tab = document.createElement('button');
        tab.className = 'document-tab';
        tab.textContent = title.length > 20 ? title.substring(0, 20) + '...' : title;
        tab.title = title;
        tab.dataset.docIndex = docIndex;

        tab.addEventListener('click', () => {
            activeDocIndex = parseInt(tab.dataset.docIndex);
            updateTabs();
            displayContent(documents[activeDocIndex]);
        });

        // Add close button to tab
        const closeTab = document.createElement('span');
        closeTab.innerHTML = ' ×';
        closeTab.style.cssText = 'margin-left: 8px; font-weight: bold; color: #888;';
        closeTab.onclick = (e) => {
            e.stopPropagation();
            removeDocument(docIndex);
        };
        tab.appendChild(closeTab);

        tabsContainer.appendChild(tab);

        // Display content
        activeDocIndex = docIndex;
        updateTabs();
        displayContent({ content, title, type });
    }

    // Update active tab styling
    function updateTabs() {
        const tabs = documentViewer.querySelectorAll('.document-tab');
        tabs.forEach((tab, index) => {
            if (parseInt(tab.dataset.docIndex) === activeDocIndex) {
                tab.classList.add('active');
            } else {
                tab.classList.remove('active');
            }
        });
    }

    // Remove document and tab
    function removeDocument(index) {
        documents.splice(index, 1);

        // Rebuild tabs
        const tabsContainer = documentViewer.querySelector('.document-tabs');
        tabsContainer.innerHTML = '';

        documents.forEach((doc, i) => {
            const tab = document.createElement('button');
            tab.className = 'document-tab';
            tab.textContent = doc.title.length > 20 ? doc.title.substring(0, 20) + '...' : doc.title;
            tab.title = doc.title;
            tab.dataset.docIndex = i;

            if (i === activeDocIndex) {
                tab.classList.add('active');
            }

            tab.addEventListener('click', () => {
                activeDocIndex = i;
                updateTabs();
                displayContent(documents[i]);
            });

            const closeTab = document.createElement('span');
            closeTab.innerHTML = ' ×';
            closeTab.style.cssText = 'margin-left: 8px; font-weight: bold; color: #888;';
            closeTab.onclick = (e) => {
                e.stopPropagation();
                removeDocument(i);
            };
            tab.appendChild(closeTab);

            tabsContainer.appendChild(tab);
        });

        // If no documents left, show empty state
        if (documents.length === 0) {
            const contentArea = document.getElementById('document-content');
            contentArea.innerHTML = `
                <div class="document-empty-state">
                    <h4>No Document Selected</h4>
                    <p>Click on any document, image, or file in the chat to view it here</p>
                </div>
            `;
            // Hide viewer if not pinned
            const pinBtn = documentViewer.querySelector('.document-pin');
            if (!pinBtn.classList.contains('pinned')) {
                hideDocumentViewer();
            }
        } else {
            // Adjust active index if needed
            if (activeDocIndex >= documents.length) {
                activeDocIndex = documents.length - 1;
            }
            displayContent(documents[activeDocIndex]);
        }
    }

    // Display content based on type
    function displayContent(doc) {
        const contentArea = document.getElementById('document-content');

        switch (doc.type) {
            case 'image':
                contentArea.innerHTML = `
                    <div class="document-content">
                        <img src="${doc.content}" alt="${doc.title}" class="document-image">
                    </div>
                `;
                break;
            case 'pdf':
                contentArea.innerHTML = `
                    <iframe src="${doc.content}" class="pdf-viewer"></iframe>
                `;
                break;
            case 'code':
                contentArea.innerHTML = `
                    <div class="document-code">
                        <pre><code>${escapeHtml(doc.content)}</code></pre>
                    </div>
                `;
                break;
            case 'html':
                contentArea.innerHTML = `
                    <div class="document-content">
                        ${doc.content}
                    </div>
                `;
                break;
            default:
                contentArea.innerHTML = `
                    <div class="document-content">
                        ${escapeHtml(doc.content)}
                    </div>
                `;
        }
    }

    // Escape HTML for safe display
    function escapeHtml(text) {
        const div = document.createElement('div');
        div.textContent = text;
        return div.innerHTML;
    }

    // Add "View in Document Viewer" buttons to file elements
    function addViewerButtons() {
        console.log('Scanning for file elements to add viewer buttons...');

        // Enhanced file element selectors
        const fileSelectors = [
            '[data-testid*="element"]',
            '[data-testid*="file"]',
            '[data-testid*="pdf"]',
            '.cl-file',
            '.cl-pdf',
            '[class*="file"]',
            '[class*="pdf"]',
            'a[href$=".pdf"]',
            'a[download]',
            'div[class*="MuiPaper-root"]:has(a[download])',
            '.message-content a',
            '[title*=".pdf"]',
            '[title*="PDF"]'
        ];

        let foundElements = 0;

        fileSelectors.forEach(selector => {
            try {
                const elements = document.querySelectorAll(selector);
                elements.forEach(element => {
                    if (element.querySelector('.viewer-button') || element.closest('#document-viewer')) {
                        return; // Already has button or is in viewer
                    }

                    // Skip if element is too small or hidden
                    const rect = element.getBoundingClientRect();
                    if (rect.width < 10 || rect.height < 10) {
                        return;
                    }

                    // Check if element is actually visible
                    const style = window.getComputedStyle(element);
                    if (style.display === 'none' || style.visibility === 'hidden' || style.opacity === '0') {
                        return;
                    }

                    foundElements++;
                    console.log(`Adding viewer button to element:`, element, `(selector: ${selector})`);

                    // Create viewer button
                    const viewerBtn = document.createElement('button');
                    viewerBtn.className = 'viewer-button';
                    viewerBtn.innerHTML = '👁️ View';
                    viewerBtn.title = 'Open in Document Viewer';

                    // Force button visibility with inline styles
                    viewerBtn.style.cssText = `
                        position: absolute !important;
                        top: 5px !important;
                        right: 5px !important;
                        padding: 6px 12px !important;
                        background: #ff4757 !important;
                        color: white !important;
                        border: none !important;
                        border-radius: 6px !important;
                        font-size: 12px !important;
                        font-weight: 500 !important;
                        cursor: pointer !important;
                        z-index: 9999 !important;
                        display: block !important;
                        visibility: visible !important;
                        opacity: 1 !important;
                        min-width: 60px !important;
                        text-align: center !important;
                        box-shadow: 0 2px 8px rgba(255, 71, 87, 0.3) !important;
                    `;

                    // Position the parent element if needed
                    const computedStyle = window.getComputedStyle(element);
                    if (computedStyle.position === 'static') {
                        element.style.position = 'relative';
                    }

                    viewerBtn.addEventListener('click', (e) => {
                        e.preventDefault();
                        e.stopPropagation();

                        console.log('Viewer button clicked for element:', element);

                        // Find download link or href
                        let link = element.href ||
                                  element.getAttribute('href') ||
                                  element.querySelector('a[href]')?.href ||
                                  element.querySelector('[href]')?.getAttribute('href');

                        let fileName = element.textContent?.trim() ||
                                      element.getAttribute('title') ||
                                      element.querySelector('[title]')?.title ||
                                      element.querySelector('a')?.textContent?.trim() ||
                                      `Document ${documents.length + 1}`;

                        console.log('Found link:', link, 'fileName:', fileName);

                        if (link) {
                            if (link.endsWith('.pdf') || link.includes('pdf') || fileName.toLowerCase().includes('pdf')) {
                                displayDocument(link, fileName, 'pdf');
                            } else if (link.match(/\.(jpg|jpeg|png|gif|webp)$/i)) {
                                displayDocument(link, fileName, 'image');
                            } else {
                                // Try to fetch content
                                fetch(link)
                                    .then(res => res.text())
                                    .then(content => {
                                        const type = link.endsWith('.html') ? 'html' : 'text';
                                        displayDocument(content, fileName, type);
                                    })
                                    .catch(err => {
                                        console.error('Error loading document:', err);
                                        displayDocument('Error loading document content', fileName, 'text');
                                    });
                            }
                        } else {
                            // If no link, display the element's content
                            const content = element.textContent || element.innerHTML;
                            displayDocument(content, fileName, 'html');
                        }
                    });

                    element.appendChild(viewerBtn);
                });
            } catch (error) {
                console.warn(`Error processing selector ${selector}:`, error);
            }
        });

        console.log(`Added viewer buttons to ${foundElements} elements`);
    }

    // Attach click handlers to documents
    function attachDocumentHandlers() {
        document.addEventListener('click', (e) => {
            const target = e.target;

            // Don't process clicks on viewer buttons
            if (target.classList.contains('viewer-button')) {
                return;
            }

            console.log('Click detected on:', target.tagName, target.className, target);

            // Enhanced detection for Chainlit file elements
            const fileSelectors = [
                '[data-testid*="element"]',
                '[data-testid*="file"]',
                '[data-testid*="pdf"]',
                '.cl-file',
                '.cl-pdf',
                '[class*="file"]',
                '[class*="pdf"]',
                'a[href$=".pdf"]',
                'a[download]'
            ];

            let fileElement = null;
            for (const selector of fileSelectors) {
                fileElement = target.closest(selector);
                if (fileElement && !fileElement.closest('#document-viewer')) {
                    break;
                }
            }

            if (fileElement) {
                console.log('File element detected:', fileElement);
                e.preventDefault();
                e.stopPropagation();

                // Try to find the download link within the element
                const downloadLink = fileElement.href ||
                                   fileElement.querySelector('a[href]')?.href ||
                                   fileElement.querySelector('[href]')?.getAttribute('href');

                if (downloadLink) {
                    const fileName = fileElement.textContent ||
                                   fileElement.querySelector('[title]')?.title ||
                                   fileElement.getAttribute('title') ||
                                   'Document ' + (documents.length + 1);

                    console.log('Opening document:', fileName, downloadLink);

                    if (downloadLink.endsWith('.pdf')) {
                        displayDocument(downloadLink, fileName, 'pdf');
                    } else {
                        // Try to fetch and display content
                        fetch(downloadLink)
                            .then(res => res.text())
                            .then(content => {
                                const type = downloadLink.endsWith('.html') ? 'html' : 'text';
                                displayDocument(content, fileName, type);
                            })
                            .catch(err => {
                                console.error('Error loading document:', err);
                                displayDocument('Error loading document content', fileName, 'text');
                            });
                    }
                }
                return;
            }

            // Check for images
            if (target.tagName === 'IMG' && target.src && !target.closest('#document-viewer')) {
                e.preventDefault();
                e.stopPropagation();
                const title = target.alt || 'Image ' + (documents.length + 1);
                displayDocument(target.src, title, 'image');
                return;
            }

            // Check for code blocks
            const codeBlock = target.closest('pre');
            if (codeBlock && !codeBlock.closest('#document-viewer')) {
                e.preventDefault();
                e.stopPropagation();
                const content = codeBlock.textContent;
                const title = 'Code Block ' + (documents.length + 1);
                displayDocument(content, title, 'code');
                return;
            }
        }, true);
    }

    // Periodically scan for new file elements and add viewer buttons
    function scanForNewElements() {
        addViewerButtons();
    }

    // Initialize when DOM is ready
    function initialize() {
        console.log('Initializing Chainlit Split Screen Document Viewer');

        // Add a global helper function to manually open documents
        window.openInDocumentViewer = function(url, title, type = 'pdf') {
            console.log('Manual document viewer open called:', url, title, type);
            displayDocument(url, title, type);
        };

        // Create viewer but keep it hidden
        documentViewer = createDocumentViewer();
        document.body.appendChild(documentViewer);

        // Attach handlers
        attachDocumentHandlers();

        // Add initial viewer buttons
        addViewerButtons();

        // Scan for new elements periodically (more frequently for better responsiveness)
        setInterval(scanForNewElements, 1000);

        // Also scan when new messages are added
        const observer = new MutationObserver((mutations) => {
            let shouldScan = false;
            mutations.forEach((mutation) => {
                if (mutation.type === 'childList' && mutation.addedNodes.length > 0) {
                    mutation.addedNodes.forEach((node) => {
                        if (node.nodeType === Node.ELEMENT_NODE) {
                            // Check if new element contains file-like content
                            if (node.querySelector && (
                                node.querySelector('a[download]') ||
                                node.querySelector('[class*="file"]') ||
                                node.querySelector('[data-testid*="file"]') ||
                                node.textContent?.toLowerCase().includes('pdf')
                            )) {
                                shouldScan = true;
                            }
                        }
                    });
                }
            });
            if (shouldScan) {
                console.log('New content detected, scanning for file elements...');
                setTimeout(addViewerButtons, 500); // Small delay to let DOM settle
            }
        });

        observer.observe(document.body, {
            childList: true,
            subtree: true
        });

        // Add mobile toggle button if needed
        if (window.innerWidth <= 768) {
            const toggleBtn = document.createElement('button');
            toggleBtn.className = 'mobile-doc-toggle';
            toggleBtn.innerHTML = '📄';
            toggleBtn.style.display = viewerActive ? 'flex' : 'none';
            toggleBtn.addEventListener('click', () => {
                if (viewerActive) {
                    hideDocumentViewer();
                    toggleBtn.style.display = 'none';
                } else {
                    showDocumentViewer();
                }
            });
            document.body.appendChild(toggleBtn);
        }

        console.log('Document Viewer initialized (hidden by default)');
    }

    // Wait for DOM to be ready
    if (document.readyState === 'loading') {
        document.addEventListener('DOMContentLoaded', initialize);
    } else {
        // Delay initialization to ensure Chainlit is fully loaded
        setTimeout(initialize, 1000);

        // Additional initialization after a longer delay
        setTimeout(() => {
            console.log('Additional document viewer initialization...');
            addViewerButtons();

            // Force scan every few seconds in case elements are missed
            setInterval(() => {
                console.log('Force scanning for new elements...');
                addViewerButtons();
            }, 3000);
        }, 3000);
    }

    // Export functions for external use
    window.ChainlitDocumentViewer = {
        displayDocument,
        showDocumentViewer,
        hideDocumentViewer,
        addViewerButtons,
        openInDocumentViewer: function(url, title, type = 'pdf') {
            displayDocument(url, title, type);
        }
    };
})();