document.addEventListener('DOMContentLoaded', () => {
    const fileList = document.getElementById('file-list');
    const backBtn = document.getElementById('back-btn');
    const forwardBtn = document.getElementById('forward-btn');
    const upBtn = document.getElementById('up-btn');
    const addressInput = document.getElementById('address-input');
    const searchInput = document.getElementById('search-input');
    const statusText = document.getElementById('status-text');

    let history = ['/'];
    let historyIndex = 0;
    let forwardStack = [];
    let selectedIndex = -1;
    let currentItems = [];

    function getCurrentPath() {
        return history[historyIndex];
    }

    function setAddressBar() {
        let p = getCurrentPath();
        addressInput.value = p === '/' ? 'Computer' : p;
    }

    function updateSelection() {
        const items = fileList.querySelectorAll('.file-item');
        items.forEach((item, index) => {
            item.classList.toggle('focused', index === selectedIndex);
        });
    }

    function selectItem(index) {
        const items = fileList.querySelectorAll('.file-item');
        if (index >= 0 && index < items.length) {
            selectedIndex = index;
            updateSelection();
            // Scroll into view
            items[selectedIndex].scrollIntoView({ block: 'nearest' });
            
            // Update status
            if (currentItems[selectedIndex]) {
                const item = currentItems[selectedIndex];
                statusText.textContent = `Selected: ${item.name} (${item.isDir ? 'Folder' : 'File'})`;
            }
        }
    }

    function openSelectedItem() {
        if (selectedIndex >= 0 && selectedIndex < currentItems.length) {
            const item = currentItems[selectedIndex];
            if (item.isDir) {
                let cur = getCurrentPath();
                let next = cur.endsWith('/') ? cur + item.name : cur + '/' + item.name;
                history = history.slice(0, historyIndex + 1);
                history.push(next);
                historyIndex++;
                forwardStack = [];
                selectedIndex = -1;
                fetchFiles();
            } else {
                // Download file
                let cur = getCurrentPath();
                let filePath = cur.endsWith('/') ? cur + item.name : cur + '/' + item.name;
                window.location.href = `/api/download?path=${encodeURIComponent(filePath)}`;
            }
        }
    }

    function fetchFiles(searchTerm = '') {
        setAddressBar();
        statusText.textContent = 'Loading...';
        let path = getCurrentPath();
        let url = `/api/list-isos?path=${encodeURIComponent(path)}`;
        if (searchTerm) {
            url += `&search=${encodeURIComponent(searchTerm)}`;
        }
        fetch(url)
            .then(res => {
                if (!res.ok) throw new Error('Failed to fetch file list');
                return res.json();
            })
            .then(items => {
                fileList.innerHTML = '';
                currentItems = [];
                selectedIndex = -1;
                if (!items.length) {
                    fileList.innerHTML = '<div class="file-item" style="grid-column: 1 / -1; text-align: center; color: #888;">No files or folders found.</div>';
                    statusText.textContent = 'No items found';
                    return;
                }
                currentItems = items;
                items.forEach((item, index) => {
                    const div = document.createElement('div');
                    div.className = 'file-item';
                    div.dataset.index = index;
                    
                    // Icon
                    const icon = document.createElement('img');
                    icon.className = 'icon';
                    icon.src = item.isDir ? 'data:image/svg+xml;base64,PHN2ZyB3aWR0aD0iMTYiIGhlaWdodD0iMTYiIHZpZXdCb3g9IjAgMCAxNiAxNiIgZmlsbD0ibm9uZSIgeG1sbnM9Imh0dHA6Ly93d3cudzMub3JnLzIwMDAvc3ZnIj4KPHBhdGggZD0iTTIgM0MxLjQ0NzcyIDMgMSAzLjQ0NzcyIDEgNFYxMkMxIDEyLjU1MjMgMS40NDc3MiAxMyAyIDEzSDE0QzE0LjU1MjMgMTMgMTUgMTIuNTUyMyAxNSAxMlY2QzE1IDUuNDQ3NzIgMTQuNTUyMyA1IDE0IDVIOEw2IDNIMloiIGZpbGw9IiNGRkQ3MDAiLz4KPC9zdmc+' : 'data:image/svg+xml;base64,PHN2ZyB3aWR0aD0iMTYiIGhlaWdodD0iMTYiIHZpZXdCb3g9IjAgMCAxNiAxNiIgZmlsbD0ibm9uZSIgeG1sbnM9Imh0dHA6Ly93d3cudzMub3JnLzIwMDAvc3ZnIj4KPHBhdGggZD0iTTMgM0MyLjQ0NzcyIDMgMiAzLjQ0NzcyIDIgNFYxMkMyIDEyLjU1MjMgMi40NDc3MiAxMyAzIDEzSDEzQzEzLjU1MjMgMTMgMTQgMTIuNTUyMyAxNCAxMlY0QzE0IDMuNDQ3NzIgMTMuNTUyMyAzIDEzIDNIM1oiIGZpbGw9IiM4ODg4ODgiLz4KPC9zdmc+';
                    icon.onerror = () => icon.style.display = 'none';
                    div.appendChild(icon);
                    
                    // Name (show relative path if searching)
                    const nameSpan = document.createElement('span');
                    nameSpan.className = 'file-name';
                    if (searchTerm && item.path) {
                        nameSpan.textContent = item.path;
                    } else {
                        nameSpan.textContent = item.name;
                    }
                    div.appendChild(nameSpan);
                    
                    // Type
                    const typeSpan = document.createElement('span');
                    typeSpan.className = 'file-type';
                    typeSpan.textContent = item.isDir ? 'Folder' : 'File';
                    div.appendChild(typeSpan);
                    
                    // Size
                    const sizeSpan = document.createElement('span');
                    sizeSpan.className = 'file-size';
                    sizeSpan.textContent = item.isDir ? '' : '-';
                    div.appendChild(sizeSpan);
                    
                    // Date Modified
                    const dateSpan = document.createElement('span');
                    dateSpan.className = 'file-date';
                    dateSpan.textContent = '';
                    div.appendChild(dateSpan);
                    
                    // Action
                    const actionDiv = document.createElement('div');
                    if (!item.isDir) {
                        const dlBtn = document.createElement('button');
                        dlBtn.className = 'download-btn';
                        dlBtn.textContent = 'Download';
                        dlBtn.onclick = (e) => {
                            e.stopPropagation();
                            let cur = getCurrentPath();
                            let filePath = cur.endsWith('/') ? cur + item.name : cur + '/' + item.name;
                            window.location.href = `/api/download?path=${encodeURIComponent(filePath)}`;
                        };
                        actionDiv.appendChild(dlBtn);
                    }
                    div.appendChild(actionDiv);
                    
                    // Click handlers
                    div.onclick = () => {
                        selectItem(index);
                        if (item.isDir) {
                            setTimeout(() => openSelectedItem(), 200);
                        }
                    };
                    
                    fileList.appendChild(div);
                });
                
                statusText.textContent = `${items.length} item${items.length !== 1 ? 's' : ''}`;
                
                // Update button states
                backBtn.disabled = historyIndex <= 0;
                forwardBtn.disabled = historyIndex >= history.length - 1;
                upBtn.disabled = getCurrentPath() === '/';
            })
            .catch(err => {
                fileList.innerHTML = `<div class="file-item" style="grid-column: 1 / -1; text-align: center; color: #d9534f;">${err.message}</div>`;
                statusText.textContent = 'Error loading files';
            });
    }

    // Navigation event handlers
    backBtn.addEventListener('click', () => {
        if (historyIndex > 0) {
            historyIndex--;
            selectedIndex = -1;
            fetchFiles();
        }
    });

    forwardBtn.addEventListener('click', () => {
        if (historyIndex < history.length - 1) {
            historyIndex++;
            selectedIndex = -1;
            fetchFiles();
        }
    });

    upBtn.addEventListener('click', () => {
        let cur = getCurrentPath();
        if (cur === '/' || cur === '') return;
        let parts = cur.split('/').filter(Boolean);
        parts.pop();
        let upPath = '/' + parts.join('/');
        if (upPath === '') upPath = '/';
        history = history.slice(0, historyIndex + 1);
        history.push(upPath);
        historyIndex++;
        selectedIndex = -1;
        fetchFiles();
    });

    addressInput.addEventListener('click', () => {
        addressInput.select();
    });

    searchInput.addEventListener('input', (e) => {
        selectedIndex = -1;
        fetchFiles(e.target.value);
    });

    // Keyboard navigation
    document.addEventListener('keydown', (e) => {
        if (e.target.tagName === 'INPUT') return;
        
        switch(e.key) {
            case 'ArrowUp':
                e.preventDefault();
                if (selectedIndex > 0) {
                    selectItem(selectedIndex - 1);
                } else if (currentItems.length > 0) {
                    selectItem(currentItems.length - 1);
                }
                break;
                
            case 'ArrowDown':
                e.preventDefault();
                if (selectedIndex < currentItems.length - 1) {
                    selectItem(selectedIndex + 1);
                } else if (currentItems.length > 0) {
                    selectItem(0);
                }
                break;
                
            case 'Enter':
                e.preventDefault();
                openSelectedItem();
                break;
                
            case 'Escape':
                e.preventDefault();
                selectedIndex = -1;
                updateSelection();
                statusText.textContent = `${currentItems.length} item${currentItems.length !== 1 ? 's' : ''}`;
                break;
                
            case 'Backspace':
                e.preventDefault();
                upBtn.click();
                break;
                
            case 'F5':
                e.preventDefault();
                selectedIndex = -1;
                fetchFiles(searchInput.value);
                break;
                
            case '/':
                e.preventDefault();
                searchInput.focus();
                break;
        }
    });

    // Initial load
    fetchFiles();
});