class WebDAVModule {
    constructor() {
        this.commands = {};
        this.terminal = null;
        this.config = null;  // { url, username, password }
        this._browsingPath = '/';
        this._STORAGE_KEY = 'webx11_webdav_config';
        // Auto-discover space name from page URL
        this._spaceName = this._detectSpaceName();
        this._autoConfigured = false;
        this._loadConfig();
    }

    _detectSpaceName() {
        try {
            const path = window.location.pathname;
            // /spaces/chatstudio/newos4/ → chatstudio
            const parts = path.split('/').filter(p => p);
            const spacesIdx = parts.indexOf('spaces');
            if (spacesIdx >= 0 && spacesIdx + 1 < parts.length) {
                return parts[spacesIdx + 1];
            }
        } catch (e) {}
        return '';
    }

    requirements() {
        const cfg = localStorage.getItem('webx11_webdav_config');
        if (!cfg) return { met: false, missing: ['WebDAV endpoint not configured. Use webdav-config to set it up.'] };
        try {
            const parsed = JSON.parse(cfg);
            if (!parsed.url) return { met: false, missing: ['WebDAV URL not set'] };
            return { met: true, missing: [] };
        } catch (e) {
            return { met: false, missing: ['WebDAV config corrupted'] };
        }
    }

    getHelpInfo() {
        return {
            'webdav-config': 'webdav-config [url user pass] — Configure WebDAV. No args = auto-detect from current page URL',
            'webdav-status': 'Show current WebDAV configuration status',
            'webdav-ls': 'List files/directories on the WebDAV remote',
            'webdav-push': 'Upload a VFS file to WebDAV',
            'webdav-pull': 'Download a WebDAV file to VFS',
            'webdav-backup': 'Backup entire VFS to WebDAV as a dated JSON snapshot',
            'webdav-restore': 'Restore VFS from a WebDAV backup file',
            'webdav-backup-list': 'List available backup files on WebDAV',
            'webdav-explorer': 'webdav-explorer [path] — Interactive remote file browser',
            'webdav-browser': 'webdav-browser [path] — Visual WebDAV file explorer modal',
        };
    }
    
    _loadConfig() {
        try {
            const saved = localStorage.getItem(this._STORAGE_KEY);
            if (saved) {
                this.config = JSON.parse(saved);
                // Try to get password from SecretVault
                if (window.webx11_secretVault && this.config && this.config.username) {
                    let encryptedPass = window.webx11_secretVault.decrypt('webdav_pass_' + this.config.username);
                    if (encryptedPass !== null && encryptedPass !== undefined) {
                        this.config.password = encryptedPass;
                    } else {
                        // Fallback to old token key
                        encryptedPass = window.webx11_secretVault.decrypt('webdav_token_' + this.config.username);
                        if (encryptedPass !== null && encryptedPass !== undefined) {
                            this.config.password = encryptedPass;
                        }
                    }
                }
            }
        } catch (e) { /* ignore */ }
    }
    
    _saveConfig() {
        try {
            if (this.config) {
                const toStore = {
                    url: this.config.url,
                    username: this.config.username
                };
                // Try SecretVault for encrypted password storage
                if (window.webx11_secretVault && this.config.password) {
                    window.webx11_secretVault.encrypt('webdav_pass_' + this.config.username, this.config.password);
                    // Also store space token
                    if (this._spaceName) {
                        window.webx11_secretVault.encrypt('webdav_token_' + this._spaceName, this.config.password);
                    }
                }
                // Also store in localStorage for backward compat (SecretVault decrypts later)
                // Store only url and username hint in plaintext lS, encrypted password handled above
                localStorage.setItem(this._STORAGE_KEY, JSON.stringify(toStore));
            } else {
                localStorage.removeItem(this._STORAGE_KEY);
            }
        } catch (e) { console.error('WebDAV config save error:', e); }
    }
    
    _getAuthHeader() {
        if (!this.config || !this.config.password) return {};
        const token = btoa(this.config.username + ':' + this.config.password);
        return { 'Authorization': 'Basic ' + token };
    }
    
    async _webdavRequest(method, path, options = {}) {
        if (!this.config || !this.config.url) {
            throw new Error('WebDAV not configured. Use webdav-config first.');
        }
        const baseUrl = this.config.url.replace(/\/+$/, '');
        const urlPath = path ? (path.startsWith('/') ? path : '/' + path) : '/';
        const url = baseUrl + urlPath;
        
        const headers = {
            ...this._getAuthHeader(),
            ...(options.headers || {})
        };
        
        const fetchOpts = {
            method: method,
            headers: headers,
            body: options.body || undefined
        };
        
        const response = await fetch(url, fetchOpts);
        return response;
    }
    
    async _listDir(path) {
        // Try PROPFIND first (works with WebDAV servers), fallback to nginx autoindex
        try {
            const response = await this._webdavRequest('PROPFIND', path, {
                headers: { 'Depth': '1' }
            });
            if (response.ok) {
                const text = await response.text();
                return this._parsePropfind(text);
            }
        } catch (e) { /* PROPFIND failed, try autoindex */ }
        // Fallback: use nginx __list__ endpoint
        return this._listDirViaAutoIndex(path);
    }

    async _listDirViaAutoIndex(path) {
        const baseUrl = this.config.url.replace(/\/+$/, '') + '/';
        const urlPath = path ? (path.startsWith('/') ? path : '/' + path) : '/';
        // Use __list__ for directory listing
        const listUrl = baseUrl.replace(/\/spaces\/([^/]+)\//, '/spaces/$1/__list__/') + urlPath.replace(/^\//, '');
        try {
            const resp = await fetch(listUrl, { method: 'GET' });
            if (!resp.ok) throw new Error('Autoindex failed: HTTP ' + resp.status);
            const html = await resp.text();
            return this._parseAutoindex(html);
        } catch (e) {
            throw new Error('Cannot list directory: ' + e.message);
        }
    }

    _parseAutoindex(html) {
        const entries = [];
        // Parse nginx autoindex HTML format
        const linkRegex = /<a href="([^"]+)">([^<]+)<\/a>\s+(\d{2}-[A-Za-z]{3}-\d{4}\s+\d{2}:\d{2})\s+([\d\w.-]+)/g;
        let match;
        while ((match = linkRegex.exec(html)) !== null) {
            const href = match[1];
            const name = match[2].replace(/\/$/, '');
            const sizeStr = match[4];
            if (name === '..' || name === '../') continue;
            if (name === '__list__') continue;
            const isDir = href.endsWith('/');
            let size = 0;
            if (!isDir && sizeStr !== '-') {
                size = parseInt(sizeStr) || 0;
            }
            entries.push({
                name: name,
                type: isDir ? 'dir' : 'file',
                size: size,
                href: href
            });
        }
        // Fallback: if regex failed, try simpler parse
        if (entries.length === 0) {
            const simpleRegex = /<a href="([^"]+)">/g;
            const names = [];
            while ((match = simpleRegex.exec(html)) !== null) {
                const href = match[1];
                if (href === '../' || href === '/' || href === './') continue;
                if (href.startsWith('?')) continue;
                names.push(href);
            }
            for (const href of names) {
                const isDir = href.endsWith('/');
                entries.push({
                    name: decodeURIComponent(href.replace(/\/$/, '').split('/').pop() || href),
                    type: isDir ? 'dir' : 'file',
                    size: 0,
                    href: href
                });
            }
        }
        return entries;
    }
    
    _parsePropfind(xml) {
        const parser = new DOMParser();
        const doc = parser.parseFromString(xml, 'text/xml');
        const responses = doc.querySelectorAll('D\\:response, response');
        const entries = [];
        responses.forEach((resp) => {
            const href = (resp.querySelector('D\\:href, href') || {}).textContent || '';
            const isDir = !!((resp.querySelector('D\\:collection, collection') || {}).textContent);
            const getContentLength = (resp.querySelector('D\\:getcontentlength, getcontentlength, lp1\\:getcontentlength') || {}).textContent;
            const size = getContentLength ? parseInt(getContentLength) : 0;
            const displayName = href.split('/').filter(Boolean).pop() || '/';
            if (displayName) {
                entries.push({
                    name: decodeURIComponent(displayName),
                    type: isDir ? 'dir' : 'file',
                    size: size,
                    href: href
                });
            }
        });
        // Remove the root entry (same as first child's dir)
        return entries.filter((e, i) => i > 0 || e.type !== 'dir' || entries.length <= 1);
    }
    
    async _ensureDir(remotePath) {
        // Try MKCOL — ignore 405 (already exists) and 409 (parent missing)
        const response = await this._webdavRequest('MKCOL', remotePath);
        if (response.ok || response.status === 405 || response.status === 301 || response.status === 302) return true;
        if (response.status === 409) {
            // Parent missing — try creating parent recursively
            const parts = remotePath.replace(/\/$/, '').split('/').filter(Boolean);
            if (parts.length > 1) {
                const parent = parts.slice(0, -1).join('/');
                await this._ensureDir(parent);
                // Retry MKCOL
                const retry = await this._webdavRequest('MKCOL', remotePath);
                if (retry.ok || retry.status === 405) return true;
            }
            // Try creating path component by component as a fallback
            let current = '';
            for (const part of parts) {
                current += '/' + part;
                try {
                    const attempt = await this._webdavRequest('MKCOL', current);
                    if (!attempt.ok && attempt.status !== 405) {
                        // Ignore — it likely exists already or we can't create it
                    }
                } catch (e) { /* ignore */ }
            }
            return true;
        }
        return false;
    }
    
    async _deleteFile(remotePath) {
        const resp = await this._webdavRequest('DELETE', remotePath);
        return resp.ok || resp.status === 204 || resp.status === 404;
    }
    
    async _cleanupRetention() {
        // Smart retention: keep newest 10 + 1 per day for last 7 days
        try {
            const entries = await this._listDir('backups');
            const files = entries.filter(e => e.type === 'file' && e.name.endsWith('.json'));
            if (files.length <= 17) return; // 10 newest + 7 daily = 17 max needed
            
            // Sort by date descending (newest first)
            files.sort((a, b) => {
                const da = this._extractDateFromBackup(a.name);
                const db = this._extractDateFromBackup(b.name);
                return db - da;
            });
            
            const keep = new Set();
            
            // Always keep newest 10
            for (let i = 0; i < Math.min(10, files.length); i++) keep.add(files[i].name);
            
            // Keep 1 per day for last 7 days (outside the newest 10)
            const dayMap = new Map(); // YYYY-MM-DD -> first backup of that day
            for (let i = 10; i < files.length; i++) {
                const f = files[i];
                const day = this._extractDayString(f.name);
                if (!dayMap.has(day)) dayMap.set(day, f);
            }
            // Get last 7 unique days
            const sortedDays = Array.from(dayMap.keys()).sort().slice(-7);
            for (const day of sortedDays) keep.add(dayMap.get(day).name);
            
            // Delete the rest
            let deleted = 0;
            for (const f of files) {
                if (!keep.has(f.name)) {
                    const ok = await this._deleteFile('backups/' + f.name);
                    if (ok) deleted++;
                }
            }
            if (deleted > 0) {
                this.terminal.print(`Retention cleanup: removed ${deleted} old backup(s)`, 'info');
            }
        } catch (e) {
            this.terminal.print('Retention cleanup skipped: ' + e.message, 'info');
        }
    }
    
    _extractDateFromBackup(name) {
        // Match YYYY-MM-DD_HHMMSS in filename
        const m = name.match(/(\d{4})-(\d{2})-(\d{2})_(\d{2})(\d{2})(\d{2})/);
        if (!m) return 0;
        return new Date(`${m[1]}-${m[2]}-${m[3]}T${m[4]}:${m[5]}:${m[6]}`).getTime();
    }
    
    _extractDayString(name) {
        const m = name.match(/(\d{4}-\d{2}-\d{2})_/);
        return m ? m[1] : '';
    }
    
    registerCommands() {
        const self = this;
        
        // --- webdav-config: set WebDAV endpoint and credentials ---
        this.commands['webdav-config'] = async (args) => {
            // No args: auto-detect space name and try to configure from token
            if (!args || args.length === 0) {
                const spaceName = self._spaceName;
                if (!spaceName) {
                    self.terminal.print('Could not detect space name from URL.', 'warning');
                    self.terminal.print('Usage: webdav-config <url> [username] [password]', 'info');
                    return;
                }

                // Auto-configure URL from space name
                const autoUrl = 'https://webx11.duckdns.org/spaces/' + spaceName + '/';
                let token = null;

                // Check SecretVault first
                if (window.webx11_secretVault) {
                    token = window.webx11_secretVault.decrypt('webdav_token_' + spaceName);
                }

                // Fallback to localStorage
                if (!token) {
                    token = localStorage.getItem('webx11_spaces_' + spaceName);
                }

                // Fallback: fetch .token directly from server
                if (!token) {
                    try {
                        const tokenResp = await fetch('/spaces/' + spaceName + '/.token');
                        if (tokenResp.ok) {
                            token = (await tokenResp.text()).trim();
                            // Cache in SecretVault for future use
                            if (window.webx11_secretVault) {
                                window.webx11_secretVault.encrypt('webdav_token_' + spaceName, token);
                            }
                        }
                    } catch (e) { /* .token not accessible */ }
                }

                if (token) {
                    self.config = {
                        url: autoUrl,
                        username: spaceName,
                        password: token
                    };
                    self._saveConfig();
                    self._autoConfigured = true;
                    self.terminal.print('Auto-configured WebDAV for space: ' + spaceName, 'success');
                    try {
                        const resp = await self._webdavRequest('OPTIONS', '/');
                        self.terminal.print('Connected: ' + resp.status + ' ' + resp.statusText, 'success');
                        self.terminal.print('WebDAV configured: ' + self.config.url, 'success');
                    } catch (e) {
                        self.terminal.print('Connection test failed: ' + e.message, 'warning');
                        self.terminal.print('Config saved but connection may need CORS or network access.', 'warning');
                    }
                } else {
                    self.terminal.print('No WebDAV token found for space: ' + spaceName, 'warning');
                    self.terminal.print('Get your token from /spaces/' + spaceName + '/.token or the dashboard.', 'info');
                    self.terminal.print('Auto-setting URL: ' + autoUrl, 'info');
                    self.terminal.print('Then configure with: webdav-config ' + autoUrl + ' ' + spaceName + ' <your-token>', 'info');
                    // At minimum set the URL
                    self.config = {
                        url: autoUrl,
                        username: spaceName,
                        password: ''
                    };
                    self._saveConfig();
                    self._autoConfigured = true;
                }
                return;
            }

            // Legacy 1-3 arg behavior
            self.config = {
                url: args[0],
                username: args[1] || (self.config ? self.config.username : ''),
                password: args[2] || (self.config ? self.config.password : '')
            };
            self._saveConfig();
            self.terminal.print('Testing WebDAV connection...', 'info');
            try {
                const resp = await self._webdavRequest('OPTIONS', '/');
                self.terminal.print('Connected: ' + resp.status + ' ' + resp.statusText, 'success');
                self.terminal.print('WebDAV configured: ' + self.config.url, 'success');
            } catch (e) {
                self.terminal.print('Connection test failed: ' + e.message, 'warning');
                self.terminal.print('Config saved but connection may need CORS or network access.', 'warning');
            }
        };
        
        // --- webdav-status: show current WebDAV config ---
        this.commands['webdav-status'] = () => {
            if (!self.config || !self.config.url) {
                self.terminal.print('WebDAV not configured. Use webdav-config <url> [username] [password]', 'warning');
                return;
            }
            self.terminal.print('WebDAV Status:', 'text-muted');
            self.terminal.print('  URL: ' + self.config.url);
            self.terminal.print('  User: ' + (self.config.username || '(none)'));
            self.terminal.print('  Password: ' + (self.config.password ? '**** (' + self.config.password.length + ' chars)' : '(none)'));
            self.terminal.print('  Space detected: ' + (self._spaceName || '(none)'));
            if (self._autoConfigured) {
                self.terminal.print('  Auto-configured: yes', 'success');
            }
        };
        
        // --- webdav-ls: list remote directory ---
        this.commands['webdav-ls'] = async (args) => {
            const remotePath = args[0] || '/';
            try {
                const entries = await self._listDir(remotePath);
                if (entries.length === 0) {
                    self.terminal.print('(empty)', 'info');
                    return;
                }
                entries.forEach(e => {
                    const icon = e.type === 'dir' ? '📁' : '📄';
                    const sizeStr = e.type === 'file' ? ' (' + self._formatSize(e.size) + ')' : '/';
                    self.terminal.print(icon + ' ' + e.name + (e.type === 'dir' ? '/' : '') + (e.type === 'file' ? sizeStr : ''));
                });
                self.terminal.print(entries.length + ' item(s)', 'text-muted');
            } catch (e) {
                self.terminal.print('Failed to list: ' + e.message, 'error');
            }
        };
        
        // --- webdav-push: upload a VFS file to WebDAV ---
        this.commands['webdav-push'] = async (args) => {
            if (!args[0]) {
                self.terminal.print('Usage: webdav-push <vfs-path> [remote-path]', 'warning');
                return;
            }
            const vfsPath = args[0];
            const remotePath = args[1] || vfsPath;
            const content = self.terminal.fs.readFile(vfsPath);
            if (content === null) {
                self.terminal.print('File not found in VFS: ' + vfsPath, 'error');
                return;
            }
            try {
                // Ensure remote dir exists
                const parts = remotePath.replace(/\/$/, '').split('/').filter(Boolean);
                if (parts.length > 1) {
                    const parent = parts.slice(0, -1).join('/');
                    await self._ensureDir(parent);
                }
                const resp = await self._webdavRequest('PUT', remotePath, {
                    body: content,
                    headers: { 'Content-Type': 'text/plain' }
                });
                if (resp.ok || resp.status === 201 || resp.status === 204) {
                    self.terminal.print('Pushed: ' + vfsPath + ' → ' + remotePath, 'success');
                } else {
                    self.terminal.print('Push failed: HTTP ' + resp.status, 'error');
                }
            } catch (e) {
                self.terminal.print('Push error: ' + e.message, 'error');
            }
        };
        
        // --- webdav-pull: download a WebDAV file to VFS ---
        this.commands['webdav-pull'] = async (args) => {
            if (!args[0]) {
                self.terminal.print('Usage: webdav-pull <remote-path> [vfs-path]', 'warning');
                return;
            }
            const remotePath = args[0];
            const vfsPath = args[1] || remotePath.split('/').pop();
            try {
                const resp = await self._webdavRequest('GET', remotePath);
                if (!resp.ok) throw new Error('HTTP ' + resp.status);
                const content = await resp.text();
                self.terminal.fs.writeFile(vfsPath, content);
                self.terminal.print('Pulled: ' + remotePath + ' → ' + vfsPath + ' (' + content.length + ' bytes)', 'success');
            } catch (e) {
                self.terminal.print('Pull error: ' + e.message, 'error');
            }
        };
        
        // --- webdav-backup: backup entire VFS to WebDAV ---
        this.commands['webdav-backup'] = async (args) => {
            // Parse flags
            let encryptPass = null;
            let nameIdx = 0;
            for (let i = 0; i < args.length; i++) {
                if (args[i] === '--encrypt' || args[i] === '-e') {
                    encryptPass = args[i + 1];
                    i++;
                } else if (!args[i].startsWith('-')) {
                    nameIdx = i;
                }
            }
            const name = (args[nameIdx] || 'backup').replace(/[^a-zA-Z0-9_-]/g, '_');
            const now = new Date();
            const dateStr = now.getFullYear() + '-' +
                String(now.getMonth() + 1).padStart(2, '0') + '-' +
                String(now.getDate()).padStart(2, '0') + '_' +
                String(now.getHours()).padStart(2, '0') +
                String(now.getMinutes()).padStart(2, '0') +
                String(now.getSeconds()).padStart(2, '0');
            let filename = name + '-' + dateStr + '.json';
            let remotePath = 'backups/' + filename;
            
            try {
                await self._ensureDir('backups');
                // Build structured export: root + currentPath + aliases + moduleRegistry
                const exportData = {
                    type: 'webx11-backup',
                    version: 2,
                    savedAt: new Date().toISOString(),
                    root: self.terminal.fs.root,
                    currentPath: self.terminal.fs.currentPath,
                    aliases: self.terminal.moduleManager.aliases || {},
                    moduleRegistry: self.terminal.moduleManager.moduleRegistry || []
                };
                const serialized = JSON.stringify(exportData, null, 2);
                // Gzip payload
                let payload = serialized;
                let isGzipped = false;
                if (typeof CompressionStream !== 'undefined') {
                    try {
                        const blob = new Blob([serialized]);
                        const stream = blob.stream().pipeThrough(new CompressionStream('gzip'));
                        const resp = new Response(stream);
                        const buf = await resp.arrayBuffer();
                        payload = new Uint8Array(buf);
                        isGzipped = true;
                    } catch (e) { /* fallback to plain */ }
                }
                // Encrypt if requested
                if (encryptPass) {
                    if (!isGzipped) {
                        self.terminal.print('Encryption requires gzip compression. CompressionStream unavailable — aborting.', 'error');
                        return;
                    }
                    const wrapper = await self._encryptPayload(payload, encryptPass);
                    payload = JSON.stringify(wrapper);
                    filename = name + '-' + dateStr + '.json.enc';
                    remotePath = 'backups/' + filename;
                }
                const resp = await self._webdavRequest('PUT', remotePath, {
                    body: payload,
                    headers: { 'Content-Type': encryptPass ? 'application/json' : (isGzipped ? 'application/gzip' : 'application/json') }
                });
                if (resp.ok || resp.status === 201 || resp.status === 204) {
                    const sizeStr = isGzipped ? self._formatSize(serialized.length) + ' → ' + self._formatSize(typeof payload === 'string' ? payload.length : payload.length) : self._formatSize(serialized.length);
                    const encMark = encryptPass ? ' [🔒 encrypted]' : '';
                    self.terminal.print('Backup saved: ' + remotePath + ' (' + sizeStr + ')' + encMark, 'success');
                    // Run retention cleanup in background
                    self._cleanupRetention().catch(() => {});
                } else {
                    self.terminal.print('Backup failed: HTTP ' + resp.status, 'error');
                }
            } catch (e) {
                self.terminal.print('Backup error: ' + e.message, 'error');
            }
        };
        
        // --- webdav-restore: restore VFS from a WebDAV backup ---
        this.commands['webdav-restore'] = async (args) => {
            if (!args[0]) {
                self.terminal.print('Usage: webdav-restore <backup-filename> [--passphrase <phrase>]', 'warning');
                self.terminal.print('  Use webdav-ls backups/ to see available backups', 'info');
                return;
            }
            let remotePath = args[0];
            let passphrase = null;
            for (let i = 1; i < args.length; i++) {
                if (args[i] === '--passphrase' || args[i] === '-p') passphrase = args[i + 1];
            }
            if (!remotePath.startsWith('backups/') && !remotePath.startsWith('/backups/')) {
                remotePath = 'backups/' + remotePath;
            }
            try {
                const resp = await self._webdavRequest('GET', remotePath);
                if (!resp.ok) throw new Error('HTTP ' + resp.status);
                // Read raw bytes first (resp.text() corrupts gzip binary)
                const arrayBuf = await resp.arrayBuffer();
                const bytes = new Uint8Array(arrayBuf);
                let text;
                // Detect gzip by magic bytes 0x1f 0x8b
                if (bytes.length > 2 && bytes[0] === 0x1f && bytes[1] === 0x8b) {
                    self.terminal.print('Detected gzip-compressed backup, decompressing...', 'info');
                    try {
                        const blob = new Blob([bytes]);
                        const stream = blob.stream().pipeThrough(new DecompressionStream('gzip'));
                        const decompressed = await new Response(stream).text();
                        text = decompressed;
                    } catch (e) {
                        throw new Error('Gzip decompression failed: ' + e.message);
                    }
                } else {
                    text = new TextDecoder().decode(bytes);
                }
                // Detect encrypted wrapper
                let isEncrypted = false;
                let wrapper = null;
                try {
                    wrapper = JSON.parse(text);
                    if (wrapper && wrapper._encrypted) isEncrypted = true;
                } catch (e) { /* not JSON wrapper */ }
                let content = text;
                if (isEncrypted) {
                    if (!passphrase) {
                        self.terminal.print('🔒 This backup is encrypted. Run: webdav-restore ' + args[0] + ' --passphrase <your-phrase>', 'warning');
                        return;
                    }
                    self.terminal.print('Decrypting backup...', 'info');
                    const decryptedU8 = await self._decryptPayload(wrapper, passphrase);
                    content = new TextDecoder().decode(decryptedU8);
                }
                const data = JSON.parse(content);
                if (!data || !data.type) {
                    self.terminal.print('Invalid backup file (not a valid VFS export)', 'error');
                    return;
                }
                if (self.terminal.fs.restoreFromExport(data)) {
                    self.terminal.updatePrompt();
                    self.terminal.print('VFS restored from: ' + remotePath, 'success');
                    self.terminal.executeCommand('ls');
                } else {
                    self.terminal.print('Failed to restore VFS from backup', 'error');
                }
            } catch (e) {
                self.terminal.print('Restore error: ' + e.message, 'error');
            }
        };
        
        // --- webdav-backup-list: list available backups ---
        this.commands['webdav-backup-list'] = async () => {
            try {
                const entries = await self._listDir('backups');
                if (entries.length === 0) {
                    self.terminal.print('No backups found', 'info');
                    return;
                }
                self.terminal.print('Available backups:', 'text-muted');
                entries.forEach(e => {
                    if (e.type === 'file') {
                        self.terminal.print('  ' + e.name + '  (' + self._formatSize(e.size) + ')');
                    }
                });
            } catch (e) {
                self.terminal.print('Failed to list backups: ' + e.message, 'info');
                self.terminal.print('  (backups directory may not exist yet — run webdav-backup first)', 'info');
            }
        };

        // --- webdav-browser: visual modal file browser ---
        this.commands['webdav-browser'] = async (args) => {
            const startPath = args[0] || self._browsingPath || '/';
            await self.openWebdavBrowser(startPath);
        };

        // --- webdav-explorer: interactive file browser via WebDAV ---
        this.commands['webdav-explorer'] = async (args) => {
            const startPath = args[0] || '/';
            try {
                const entries = await self._listDir(startPath);
                self.terminal.print('📁 WebDAV: ' + startPath, 'info');
                if (entries.length === 0) {
                    self.terminal.print('(empty)', 'info');
                    return;
                }
                entries.forEach(e => {
                    const icon = e.type === 'dir' ? '📁' : '📄';
                    const size = e.type === 'file' ? ' (' + self._formatSize(e.size) + ')' : '/';
                    self.terminal.print(icon + ' ' + e.name + (e.type === 'dir' ? '/' : '') + size);
                });
                self.terminal.print('---');
                self.terminal.print('↳ Navigate: webdav-explorer <dir> | Pull: webdav-pull <file>', 'text-muted');
                self.terminal.print(entries.length + ' item(s)', 'text-muted');
            } catch (e) {
                self.terminal.print('WebDAV error: ' + e.message, 'error');
            }
        };
    }

    /* ── Visual WebDAV Browser Modal ── */

    async openWebdavBrowser(path) {
        if (!this.config || !this.config.url) {
            if (this.terminal) this.terminal.print('WebDAV not configured. Use webdav-config first.', 'warning');
            return;
        }
        this._browsingPath = path;
        const self = this;

        // Remove existing modal if any
        const existing = document.getElementById('webdav-browser-modal');
        if (existing) existing.remove();

        // Fetch listing
        let entries = [];
        let errorMsg = '';
        try {
            entries = await this._listDir(path);
        } catch (e) {
            errorMsg = e.message;
        }

        // Build modal
        const overlay = document.createElement('div');
        overlay.id = 'webdav-browser-modal';
        overlay.className = 'modal-overlay';
        overlay.style.cssText = 'display:flex; justify-content:center; align-items:center; z-index:999;';
        overlay.onclick = function(e) { if (e.target === this) self.closeWebdavBrowser(); };

        const content = document.createElement('div');
        content.className = 'modal-content';
        content.style.cssText = 'max-width:650px; max-height:80vh; width:92%;';

        // Header
        const header = document.createElement('div');
        header.className = 'modal-header';
        header.innerHTML = '<span>📁 WebDAV Browser</span><span style="cursor:pointer" onclick="var m=document.getElementById(\'webdav-browser-modal\');if(m)m.remove();var t=window.webx11;if(t&&t.inputField)t.inputField.focus();">✕</span>';
        content.appendChild(header);

        // Body
        const body = document.createElement('div');
        body.className = 'modal-body';
        body.style.cssText = 'padding:8px; overflow-y:auto; flex-grow:1;';

        if (errorMsg) {
            const errDiv = document.createElement('div');
            errDiv.style.cssText = 'color:var(--error-color); padding:16px; text-align:center;';
            errDiv.textContent = '❌ ' + errorMsg;
            body.appendChild(errDiv);
        } else if (entries.length === 0) {
            const emptyDiv = document.createElement('div');
            emptyDiv.className = 'text-center';
            emptyDiv.style.cssText = 'padding:20px; color:var(--text-muted);';
            emptyDiv.textContent = '(empty) — upload files using the button below';
            body.appendChild(emptyDiv);
        } else {
            // Sort: dirs first, then files, alphabetically
            entries.sort(function(a, b) {
                if (a.type !== b.type) return a.type === 'dir' ? -1 : 1;
                return a.name.localeCompare(b.name);
            });

            var frag = document.createDocumentFragment();
            entries.forEach(function(entry) {
                var item = document.createElement('div');
                item.className = entry.type === 'dir' ? 'file-item dir' : 'file-item';
                item.style.cssText = 'display:flex; justify-content:space-between; align-items:center; padding:8px; border-bottom:1px solid #111; cursor:pointer; min-height:36px;';
                item.onmouseover = function() { this.style.background = 'var(--bg-tertiary)'; };
                item.onmouseout = function() { this.style.background = ''; };

                var nameSpan = document.createElement('span');
                var icon = entry.type === 'dir' ? '📁' : '📄';
                nameSpan.textContent = icon + ' ' + entry.name + (entry.type === 'dir' ? '/' : '');

                var sizeSpan = document.createElement('span');
                sizeSpan.style.cssText = 'font-size:0.8em; color:var(--text-muted);';
                if (entry.type === 'file') {
                    sizeSpan.textContent = self._formatSize(entry.size);
                }

                item.appendChild(nameSpan);
                item.appendChild(sizeSpan);

                if (entry.type === 'dir') {
                    item.onclick = function() { self.openWebdavBrowser(entry.href); };
                } else {
                    item.onclick = function() { self.previewWebdavFile(entry); };
                    // Right-click or context menu could download — but for simplicity, long tap or regular click previews
                    // Double-click to download
                    item.ondblclick = function() { self.downloadFromWebdav(entry); };
                }
                frag.appendChild(item);
            });
            body.appendChild(frag);
        }

        content.appendChild(body);

        // Footer with breadcrumb + buttons
        const footer = document.createElement('div');
        footer.className = 'modal-footer';
        footer.style.cssText = 'display:flex; justify-content:space-between; align-items:center; gap:6px; flex-wrap:wrap; padding:8px 10px;';

        // Breadcrumb
        var breadDiv = document.createElement('div');
        breadDiv.style.cssText = 'font-size:0.8em; color:var(--info-color); overflow:hidden; text-overflow:ellipsis; white-space:nowrap; flex:1; min-width:0;';
        var cleanPath = path.replace(/\/+$/, '') || '/';
        var parts = cleanPath.split('/').filter(Boolean);
        var breadHtml = '📁 <span style="cursor:pointer;text-decoration:underline;" onclick="var m=document.getElementById(\'webdav-browser-modal\');if(m)m.__nav(\'/\');return false;">/</span>';
        var cumulative = '';
        for (var i = 0; i < parts.length; i++) {
            cumulative += '/' + parts[i];
            var seg = parts[i];
            breadHtml += '<span style="cursor:pointer;text-decoration:underline;" onclick="var m=document.getElementById(\'webdav-browser-modal\');if(m)m.__nav(\'' + cumulative.replace(/'/g, "\\'") + '/\');return false;">' + seg + '</span>';
            if (i < parts.length - 1) breadHtml += ' ▸ ';
        }
        breadDiv.innerHTML = breadHtml;
        // Attach nav function to modal element for breadcrumb clicks
        overlay.__nav = function(p) { self.openWebdavBrowser(p); };

        // Button group
        var btnGroup = document.createElement('div');
        btnGroup.style.cssText = 'display:flex; gap:4px; flex-shrink:0;';

        var uploadBtn = document.createElement('button');
        uploadBtn.className = 'btn';
        uploadBtn.textContent = '⬆ Upload';
        uploadBtn.onclick = function() { self.uploadToWebdav(path); };

        var refreshBtn = document.createElement('button');
        refreshBtn.className = 'btn';
        refreshBtn.textContent = '🔄';
        refreshBtn.title = 'Refresh';
        refreshBtn.onclick = function() { self.openWebdavBrowser(path); };

        var closeBtn = document.createElement('button');
        closeBtn.className = 'btn';
        closeBtn.textContent = 'Close';
        closeBtn.onclick = function() { self.closeWebdavBrowser(); };

        btnGroup.appendChild(uploadBtn);
        btnGroup.appendChild(refreshBtn);
        btnGroup.appendChild(closeBtn);

        footer.appendChild(breadDiv);
        footer.appendChild(btnGroup);
        content.appendChild(footer);

        overlay.appendChild(content);
        document.body.appendChild(overlay);

        this.terminal.print('📂 Opened WebDAV browser: ' + path, 'info');
    }

    closeWebdavBrowser() {
        var modal = document.getElementById('webdav-browser-modal');
        if (modal) modal.remove();
        if (this.terminal && this.terminal.inputField) this.terminal.inputField.focus();
        this.terminal.print('WebDAV browser closed', 'text-muted');
    }

    async previewWebdavFile(entry) {
        try {
            var resp = await this._webdavRequest('GET', entry.href);
            if (!resp.ok) { this.terminal.print('Failed to fetch: HTTP ' + resp.status, 'error'); return; }
            var content = await resp.text();
            var isHtml = entry.name.match(/\.html?$/i);
            var isImage = entry.name.match(/\.(png|jpg|jpeg|gif|svg|webp)$/i);
            var size = content.length;

            if (size > 512000 && !isHtml && !isImage) {
                // Large non-html file — offer download instead
                this.terminal.print(entry.name + ' is ' + this._formatSize(size) + ' — double-click to download instead of preview.', 'warning');
                this.terminal.print('--- ' + entry.name + ' (first 2000 chars) ---');
                this.terminal.print(content.substring(0, 2000));
                if (content.length > 2000) this.terminal.print('...(truncated ' + this._formatSize(size) + ' total)');
                return;
            }

            if (isImage) {
                var dataUrl = 'data:image/' + (entry.name.split('.').pop()) + ';base64,' + btoa(unescape(encodeURIComponent(content)));
                // Use preview modal
                var previewTitle = document.getElementById('preview-title');
                var previewIframe = document.getElementById('preview-iframe');
                if (previewTitle && previewIframe) {
                    previewTitle.textContent = '🖼 ' + entry.name;
                    previewIframe.srcdoc = '<img src="' + dataUrl + '" style="max-width:100%; max-height:100%; display:block; margin:auto; background:var(--bg-color);">';
                    document.getElementById('preview-modal').style.display = 'flex';
                    return;
                }
            }

            if (isHtml) {
                var previewTitle = document.getElementById('preview-title');
                var previewIframe = document.getElementById('preview-iframe');
                if (previewTitle && previewIframe) {
                    previewTitle.textContent = '📄 ' + entry.name;
                    previewIframe.srcdoc = content;
                    document.getElementById('preview-modal').style.display = 'flex';
                    return;
                }
            }

            // Text file — print to terminal
            this.terminal.print('--- ' + entry.name + ' (' + this._formatSize(size) + ') ---', 'info');
            this.terminal.print(content);
            this.terminal.print('--- End: ' + entry.name + ' ---', 'text-muted');
        } catch (e) {
            this.terminal.print('Preview error: ' + e.message, 'error');
        }
    }

    uploadToWebdav(currentPath) {
        var self = this;
        var input = document.createElement('input');
        input.type = 'file';
        input.onchange = async function(e) {
            var file = e.target.files[0];
            if (!file) return;
            var reader = new FileReader();
            reader.onload = async function(evt) {
                var basePath = currentPath.replace(/\/+$/, '');
                var remotePath = basePath + '/' + file.name;
                var parentDir = remotePath.split('/').slice(0, -1).join('/');
                try {
                    await self._ensureDir(parentDir);
                    var resp = await self._webdavRequest('PUT', remotePath, {
                        body: evt.target.result,
                        headers: { 'Content-Type': 'application/octet-stream' }
                    });
                    if (resp.ok || resp.status === 201 || resp.status === 204) {
                        self.terminal.print('⬆ Uploaded: ' + file.name + ' (' + self._formatSize(file.size) + ')', 'success');
                        self.openWebdavBrowser(currentPath);
                    } else {
                        self.terminal.print('Upload failed: HTTP ' + resp.status, 'error');
                    }
                } catch (e) {
                    self.terminal.print('Upload error: ' + e.message, 'error');
                }
            };
            reader.readAsText(file);
        };
        input.click();
    }

    async downloadFromWebdav(entry) {
        try {
            var resp = await this._webdavRequest('GET', entry.href);
            if (!resp.ok) { this.terminal.print('Download failed: HTTP ' + resp.status, 'error'); return; }
            var content = await resp.text();
            var blob = new Blob([content], { type: 'application/octet-stream' });
            var url = URL.createObjectURL(blob);
            var a = document.createElement('a');
            a.href = url;
            a.download = entry.name;
            a.style.display = 'none';
            document.body.appendChild(a);
            a.click();
            setTimeout(function() {
                document.body.removeChild(a);
                URL.revokeObjectURL(url);
            }, 200);
            this.terminal.print('⬇ Downloaded: ' + entry.name + ' (' + this._formatSize(content.length) + ')', 'success');
        } catch (e) {
            this.terminal.print('Download error: ' + e.message, 'error');
        }
    }

    /* ── Encryption helpers (AES-GCM for backups) ── */
    _u8ToBase64(u8) {
        let s = '';
        for (let i = 0; i < u8.length; i++) s += String.fromCharCode(u8[i]);
        return btoa(s);
    }
    _base64ToU8(b64) {
        const s = atob(b64);
        const u8 = new Uint8Array(s.length);
        for (let i = 0; i < s.length; i++) u8[i] = s.charCodeAt(i);
        return u8;
    }
    async _deriveKey(passphrase, salt) {
        const enc = new TextEncoder();
        const keyMaterial = await crypto.subtle.importKey('raw', enc.encode(passphrase), 'PBKDF2', false, ['deriveKey']);
        return crypto.subtle.deriveKey(
            { name: 'PBKDF2', salt: salt, iterations: 100000, hash: 'SHA-256' },
            keyMaterial, { name: 'AES-GCM', length: 256 }, false, ['encrypt', 'decrypt']
        );
    }
    async _encryptPayload(gzipU8, passphrase) {
        const salt = crypto.getRandomValues(new Uint8Array(16));
        const iv = crypto.getRandomValues(new Uint8Array(12));
        const key = await this._deriveKey(passphrase, salt);
        const ciphertext = await crypto.subtle.encrypt({ name: 'AES-GCM', iv }, key, gzipU8);
        return {
            _encrypted: true,
            salt: this._u8ToBase64(salt),
            iv: this._u8ToBase64(iv),
            iterations: 100000,
            cipher: this._u8ToBase64(new Uint8Array(ciphertext))
        };
    }
    async _decryptPayload(wrapper, passphrase) {
        const salt = this._base64ToU8(wrapper.salt);
        const iv = this._base64ToU8(wrapper.iv);
        const key = await this._deriveKey(passphrase, salt);
        const ciphertext = this._base64ToU8(wrapper.cipher);
        const decrypted = await crypto.subtle.decrypt({ name: 'AES-GCM', iv }, key, ciphertext);
        return new Uint8Array(decrypted);
    }

    _formatSize(bytes) {
        if (bytes < 1024) return bytes + ' B';
        if (bytes < 1024 * 1024) return (bytes / 1024).toFixed(1) + ' KB';
        return (bytes / (1024 * 1024)).toFixed(1) + ' MB';
    }
}