class NeuralVFSModule {
    constructor() {
        this.commands = {};
        this.commandsMeta = {
            'nvfs-index': { argType: 'file' }, 'nvfs-status': { argType: 'none' },
            'nvfs-resolve': { argType: 'file' },
            'nvfs-tree': { argType: 'file' }, 'nvfs-config': { argType: 'file' },
            'nvfs-alias': { argType: 'file' },
            'nvfs-sync': { argType: 'file' },
        };
        this.terminal = null;
        this.index = {};
        this.indexPath = '/.semantic_index/map.json';
        this.hashCachePath = '/.semantic_index/hash_cache.json';
        this._hashCache = {};
        // Configurable display limits
        this._fuzzyLimit = 10;
        this._treeFiles = 5;
        this._treeConcepts = 15;
        this._resolveFiles = 20;
        this._loadConfig();
        // Auto-sync state
        this._dirtyPaths = new Set();
        this._autoSyncTimer = null;
        this._aliasMap = {};
        this._loadAliases();
        // Deep Indexing toggle
        this._deepIndexEnabled = localStorage.getItem('webx11_nvfs_deep') === 'true';
        this._deepModel = localStorage.getItem('webx11_nvfs_deep_model') || 'ministral-3:3b-cloud';
        this._deepIndexing = false;
        this._deepQueue = [];
        this._deepProcessed = 0;
        this._deepTotal = 0;
        // Status bar polling — updates #status-text with indexing indicator
        if (typeof window !== 'undefined') {
            this._statusInterval = setInterval(() => this._updateStatusBar(), 2000);
        }
        // Register as window-level event listener for mutation events from VirtualFS
        if (typeof window !== 'undefined') {
            window.__nvfsMarkDirty = (path) => this.markDirty(path);
        }
    }
    _loadConfig() {
        try { const c = localStorage.getItem('webx11_nvfs_config'); if (c) { const p = JSON.parse(c); if (p.fuzzyLimit) this._fuzzyLimit = p.fuzzyLimit; if (p.treeFiles) this._treeFiles = p.treeFiles; if (p.treeConcepts) this._treeConcepts = p.treeConcepts; if (p.resolveFiles) this._resolveFiles = p.resolveFiles; } } catch (e) {}
    }
    _saveConfig() {
        localStorage.setItem('webx11_nvfs_config', JSON.stringify({ fuzzyLimit: this._fuzzyLimit, treeFiles: this._treeFiles, treeConcepts: this._treeConcepts, resolveFiles: this._resolveFiles }));
    }

    getHelpInfo() {
        return {
            'nvfs-index': 'nvfs-index [--deep] — Scan VFS and build semantic concept index',
            'nvfs-status': 'nvfs-status — Show semantic index stats and last scan time',
            'nvfs-resolve': 'nvfs-resolve <concept> — Find files related to a concept',
            'nvfs-tree': 'nvfs-tree [concept] — Show concept-to-file mapping as a tree',
            'nvfs-config': 'nvfs-config [key] [value] — View or set Neural VFS config (fuzzy-limit, tree-files, tree-concepts, resolve-files, deep-index, deep-model)',
            'nvfs-alias': 'nvfs-alias list|add|remove|clear — Manage concept aliases',
            'nvfs-sync': 'nvfs-sync [--deep] — Incremental background sync (auto-sync dirty files)'
        };
    }

    registerCommands() {
        this.commands['nvfs-index'] = (args) => this.buildIndex(args);
        this.commands['nvfs-status'] = (args) => this.showStatus();
        this.commands['nvfs-resolve'] = (args) => this.resolve(args);
        this.commands['nvfs-tree'] = (args) => this.tree(args);
        this.commands['nvfs-config'] = (args) => this.nvfsConfig(args);
        this.commands['nvfs-alias'] = (args) => this.nvfsAlias(args);
        this.commands['nvfs-sync'] = async (args) => this.nvfsSync(args);
    }

    // ── Core Index Builder (async, chunked) ──

    async buildIndex(args) {
        const useDeep = this._deepIndexEnabled || (args && args.includes('--deep'));
        const fs = this.terminal.fs;
        if (!fs) return this.terminal.print('VFS not available', 'error');

        this.terminal.print(`🔍 Scanning VFS for semantic concepts${useDeep ? ' (deep mode)' : ''}...`, 'info');

        const start = Date.now();
        let newIndex = {};
        let fileCount = 0;
        let conceptCount = 0;
        let cachedCount = 0;

        // Load previous index and hash cache for incremental diffing
        const prevIndex = fs.fsReadJSON(this.indexPath) || {};
        this._loadHashCache(fs);

        // Collect current file list
        const fileList = [];
        this._collectFiles('/', fs, fileList);

        if (fileList.length === 0) {
            return this.terminal.print('No files found to index', 'warning');
        }

        // Detect deleted files — strip orphaned entries from prevIndex
        const currentPaths = new Set(fileList.map(f => f.path));
        let deletedCount = 0;
        for (const [concept, entries] of Object.entries(prevIndex)) {
            const remaining = entries.filter(e => currentPaths.has(e.path));
            if (remaining.length !== entries.length) deletedCount++;
            if (remaining.length > 0) prevIndex[concept] = remaining;
            else delete prevIndex[concept];
        }

        // Warm start: clone prevIndex and count live paths for stats
        newIndex = JSON.parse(JSON.stringify(prevIndex));
        const livePaths = new Set();
        for (const entries of Object.values(newIndex)) {
            for (const e of entries) livePaths.add(e.path);
        }
        conceptCount = Object.keys(newIndex).length;

        // Chunked async processing — yields to UI between chunks
        const chunkSize = 10;
        let i = 0;
        const processChunk = () => {
            const end = Math.min(i + chunkSize, fileList.length);
            for (let j = i; j < end; j++) {
                const { path, node } = fileList[j];
                fileCount++;
                const content = node.content || '';
                const hash = this._contentHash(content);

                // Skip if hash unchanged — content is same as last scan
                const cached = this._getCached(path, hash);
                if (cached) {
                    cachedCount++;
                    if (!livePaths.has(path)) {
                        // File was in cache but somehow missing from prevIndex
                        this._reindexFile(path, content, newIndex, useDeep);
                    }
                    continue;
                }

                // Changed or new file — extract concepts fresh
                this._reindexFile(path, content, newIndex, useDeep);
                this._hashCache[path] = { hash };
            }
            i = end;
            if (i < fileList.length) {
                const pct = Math.round(i / fileList.length * 100);
                const cMsg = cachedCount > 0 ? ` (${cachedCount} cached)` : '';
                this.terminal.print(`⏳ Indexing... ${pct}% (${i}/${fileList.length} files${cMsg})`, 'info');
                setTimeout(processChunk, 0);
            } else {
                // Also index skills
                this._indexSkills(fs, newIndex);
                this.index = newIndex;
                this.lastScan = new Date().toISOString();
                this.fileCount = fileCount;
                this.conceptCount = Object.keys(newIndex).length;
                this._saveIndex(fs);
                if (fs._clearConceptCache) fs._clearConceptCache();
                const elapsed = ((Date.now() - start) / 1000).toFixed(1);
                const processedMsg = cachedCount > 0 ? ` (${cachedCount} cached, ${fileCount - cachedCount} reindexed)` : '';
                this.terminal.print(`✅ Indexed ${fileCount} files → ${Object.keys(newIndex).length} concepts in ${elapsed}s${processedMsg}`, 'success');
                if (deletedCount > 0) this.terminal.print(`   Purged ${deletedCount} orphaned concepts from deleted files`, 'info');
                this.terminal.print(`   Index saved to ${this.indexPath}`, 'info');
            }
        };
        processChunk();
    }

    _reindexFile(path, content, index, useDeep) {
        if (useDeep) {
            // Deep mode: queue for async LLM concept extraction — fast-path filename concepts first
            const fastConcepts = this._extractConcepts(path, '');
            for (const concept of fastConcepts) {
                if (!index[concept]) index[concept] = [];
                const exists = index[concept].some(e => e.path === path);
                if (!exists) index[concept].push({ path, summary: this._summarize(content), source: 'filename' });
            }
            this._deepQueue.push({ path, content });
            if (!this._deepIndexing) {
                this._deepIndexing = true;
                this._processDeepQueue(index).catch(e => console.error('Deep index error:', e));
            }
            return;
        }
        const concepts = this._extractConcepts(path, content);
        // Remove old entries for this path
        for (const entries of Object.values(index)) {
            const idx = entries.findIndex(e => e.path === path);
            if (idx !== -1) entries.splice(idx, 1);
        }
        // Add new entries
        for (const concept of concepts) {
            if (!index[concept]) {
                index[concept] = [];
                this.conceptCount++;
            }
            index[concept].push({ path, summary: this._summarize(content) });
        }
    }

    _collectFiles(path, fs, list) {
        const entries = fs.readDir(path);
        if (!entries) return;
        for (const entry of entries) {
            const fullPath = path === '/' ? '/' + entry.name : path + '/' + entry.name;
            if (entry.type === 'file') {
                if (this._isSystemFile(fullPath)) continue;
                list.push({ path: fullPath, node: { type: 'file', content: fs.readFile(fullPath) || '' } });
            } else if (entry.type === 'dir') {
                this._collectFiles(fullPath, fs, list);
            }
        }
    }

    // ── Resolve ──

    resolve(args) {
        if (!args[0]) return this.terminal.print('Usage: nvfs-resolve <concept>', 'warning');

        const concept = args.join(' ').toLowerCase();

        // Check aliases first
        if (this._aliasMap[concept]) {
            const targets = this._aliasMap[concept];
            this.terminal.print(`🔗 Alias "${concept}" → ${targets.length} target(s):`, 'info');
            for (const t of targets) this.terminal.print(`   ${t}`, 'success');
            return;
        }

        const matches = this.index[concept] || [];

        // Fuzzy fallback — find partial matches
        const fuzzy = Object.keys(this.index).filter(k =>
            k.includes(concept) || concept.includes(k)
        ).filter(k => k !== concept);

        if (matches.length === 0 && fuzzy.length === 0) {
            // Hybrid discovery: fall back to live VFS scan
            const shellResult = this._hybridShellCheck(concept);
            if (shellResult.length > 0) {
                this.terminal.print(`🔍 Index empty for "${concept}" but found ${shellResult.length} file(s) via live scan. Run nvfs-index to refresh.`, 'warning');
                for (const f of shellResult.slice(0, this._resolveFiles)) {
                    this.terminal.print(`   ${f.path}${f.summary ? ' — ' + f.summary : ''}`, 'success');
                }
                if (shellResult.length > this._resolveFiles) {
                    this.terminal.print(`   ... and ${shellResult.length - this._resolveFiles} more`, 'info');
                }
                return;
            }
            return this.terminal.print(`No files found for concept "${concept}"`, 'warning');
        }

        if (matches.length > 0) {
            this.terminal.print(`📂 "${concept}" → ${matches.length} file(s):`, 'info');
            for (const m of matches.slice(0, this._resolveFiles)) {
                this.terminal.print(`   ${m.path}`, 'success');
                if (m.summary) this.terminal.print(`     ${m.summary}`, '')
            }
            if (matches.length > this._resolveFiles) {
                this.terminal.print(`   ... and ${matches.length - this._resolveFiles} more`, 'info');
            }
        }

        if (fuzzy.length > 0) {
            this.terminal.print(`\n🔀 Similar concepts: ${fuzzy.slice(0, this._fuzzyLimit).join(', ')}`, 'info');
        }
    }

    // ── Status ──

    showStatus() {
        const count = Object.keys(this.index).length;
        if (count === 0) {
            // Try loading from VFS
            const fs = this.terminal.fs;
            const saved = fs.fsReadJSON(this.indexPath);
            if (saved) {
                this.index = saved;
                this.lastScan = '(loaded from disk)';
                this.terminal.print(`📖 Loaded index from ${this.indexPath}`, 'info');
            } else {
                return this.terminal.print('No semantic index found. Run nvfs-index first.', 'warning');
            }
        }

        const totalFiles = new Set();
        for (const entries of Object.values(this.index)) {
            for (const e of entries) totalFiles.add(e.path);
        }

        this.terminal.print(`🧠 Neural VFS Index`, 'info');
        this.terminal.print(`   Concepts: ${Object.keys(this.index).length}`, '');
        this.terminal.print(`   Files indexed: ${totalFiles.size}`, '');
        this.terminal.print(`   Last scan: ${this.lastScan || 'never'}`, '');
        this.terminal.print(`   Mode: ${this._deepIndexEnabled ? '🌊 Deep (LLM-assisted)' : '⚡ Fast (metadata-only)'}`, '');

        // Staleness check
        if (this.lastScan && this.lastScan !== '(loaded from disk)') {
            const ageMs = Date.now() - new Date(this.lastScan).getTime();
            const ageHours = Math.floor(ageMs / 3600000);
            const ageMinutes = Math.floor((ageMs % 3600000) / 60000);
            if (ageHours >= 1) {
                this.terminal.print(`   Age: ${ageHours}h${ageMinutes > 0 ? ` ${ageMinutes}m` : ''}`, '');
            }
            if (ageHours >= 4) {
                this.terminal.print(`   ⚠️ Index is ${ageHours} hours old — structural changes may be missing. Run nvfs-index to refresh.`, 'warning');
            }
        }

        // Dirty file warning
        if (this._dirtyPaths && this._dirtyPaths.size > 0) {
            this.terminal.print(`   ⚠️ ${this._dirtyPaths.size} file(s) changed since last scan (auto-sync pending)`, 'warning');
        }

        // Alias count
        const aliasCount = Object.keys(this._aliasMap).length;
        if (aliasCount > 0) {
            this.terminal.print(`   Aliases: ${aliasCount}`, '');
        }
    }

    // ── Tree View ──

    tree(args) {
        const concepts = Object.keys(this.index);
        if (concepts.length === 0) {
            return this.terminal.print('No index. Run nvfs-index first.', 'warning');
        }

        const filter = args[0] ? args[0].toLowerCase() : null;
        const filtered = filter ? concepts.filter(c => c.includes(filter)) : concepts;

        this.terminal.print(`🌳 Concept Tree${filter ? ` (filter: "${filter}")` : ''}:`, 'info');
        for (const concept of filtered.slice(0, this._treeConcepts)) {
            this.terminal.print(`  📁 ${concept}`, 'success');
            for (const entry of this.index[concept].slice(0, this._treeFiles)) {
                this.terminal.print(`     └─ ${entry.path}`, '');
            }
            if (this.index[concept].length > this._treeFiles) {
                this.terminal.print(`     └─ ... (+${this.index[concept].length - this._treeFiles} more)`, '');
            }
        }
        if (filtered.length > this._treeConcepts) {
            this.terminal.print(`  ... and ${filtered.length - this._treeConcepts} more concepts`, 'info');
        }
    }

    // ── Nvfs Config ──

    nvfsConfig(args) {
        if (args.length === 0) {
            this.terminal.print('=== Neural VFS Config ===', 'info');
            this.terminal.print(`fuzzy-limit: ${this._fuzzyLimit} (default: 10)`, '');
            this.terminal.print(`tree-files: ${this._treeFiles} (default: 5)`, '');
            this.terminal.print(`tree-concepts: ${this._treeConcepts} (default: 15)`, '');
            this.terminal.print(`resolve-files: ${this._resolveFiles} (default: 20)`, '');
            this.terminal.print(`deep-index: ${this._deepIndexEnabled ? 'on' : 'off'} (LLM-assisted concept extraction)`, '');
            this.terminal.print(`deep-model: ${this._deepModel} (model for deep indexing)`, '');
            this.terminal.print('Usage: nvfs-config <key> <value>', 'info');
            this.terminal.print('Keys: fuzzy-limit, tree-files, tree-concepts, resolve-files, deep-index (on|off), deep-model <name>', 'info');
            return;
        }
        const key = args[0];
        if (key === 'deep-index') {
            const val = args[1];
            if (val !== 'on' && val !== 'off') return this.terminal.print('deep-index must be "on" or "off"', 'warning');
            this._deepIndexEnabled = val === 'on';
            localStorage.setItem('webx11_nvfs_deep', this._deepIndexEnabled ? 'true' : 'false');
            // If turning off mid-queue, abort pending deep work
            if (!this._deepIndexEnabled && this._deepIndexing) {
                this._deepQueue = [];
                this._deepIndexing = false;
                this._deepProcessed = 0;
                this._deepTotal = 0;
                this._updateStatusBar();
                this.terminal.print('  Deep index queue aborted', 'warning');
            }
            this.terminal.print(`nvfs-config deep-index set to ${val}`, 'success');
            if (this._deepIndexEnabled) this.terminal.print(`  Deep mode uses ${this._deepModel} for semantic concept extraction`, 'info');
            return;
        }
        if (key === 'deep-model') {
            const val = args.slice(1).join(' ');
            if (!val) return this.terminal.print('Usage: nvfs-config deep-model <model-name>', 'warning');
            this._deepModel = val;
            localStorage.setItem('webx11_nvfs_deep_model', val);
            this.terminal.print(`nvfs-config deep-model set to ${val}`, 'success');
            return;
        }
        const val = parseInt(args[1]);
        if (isNaN(val) || val < 1 || val > 200) return this.terminal.print('Value must be 1-200', 'warning');
        if (key === 'fuzzy-limit') { this._fuzzyLimit = val; }
        else if (key === 'tree-files') { this._treeFiles = val; }
        else if (key === 'tree-concepts') { this._treeConcepts = val; }
        else if (key === 'resolve-files') { this._resolveFiles = val; }
        else { return this.terminal.print(`Unknown key: ${key}. Valid: fuzzy-limit, tree-files, tree-concepts, resolve-files, deep-index (on|off), deep-model <name>`, 'warning'); }
        this._saveConfig();
        this.terminal.print(`nvfs-config ${key} set to ${val}`, 'success');
    }

    // ── Nvfs Alias ──

    nvfsAlias(args) {
        const action = args[0];
        if (!action || action === 'list') {
            const keys = Object.keys(this._aliasMap);
            if (keys.length === 0) return this.terminal.print('No aliases defined. Use nvfs-alias add <name> <target,paths>', 'info');
            this.terminal.print('🔗 Concept Aliases:', 'info');
            for (const [name, targets] of Object.entries(this._aliasMap)) {
                this.terminal.print(`   ${name} → ${targets.join(', ')}`, 'success');
            }
            return;
        }
        if (action === 'add') {
            const name = args[1];
            if (!name || !args[2]) return this.terminal.print('Usage: nvfs-alias add <name> <target1,target2,...>', 'warning');
            const targets = args.slice(2).join(' ').split(',').map(t => t.trim()).filter(Boolean);
            this._aliasMap[name] = targets;
            this._saveAliases();
            this.terminal.print(`Alias "${name}" added (${targets.length} target(s))`, 'success');
            return;
        }
        if (action === 'remove') {
            const name = args[1];
            if (!name || !this._aliasMap[name]) return this.terminal.print('Alias not found', 'warning');
            delete this._aliasMap[name];
            this._saveAliases();
            this.terminal.print(`Alias "${name}" removed`, 'success');
            return;
        }
        if (action === 'clear') {
            this._aliasMap = {};
            this._saveAliases();
            this.terminal.print('All aliases cleared', 'success');
            return;
        }
        this.terminal.print('Usage: nvfs-alias list|add <name> <targets>|remove <name>|clear', 'warning');
    }

    // ── Private Helpers ──

    _walk(path, fs, index, cb) {
        const entries = fs.readDir(path);
        if (!entries) return;
        for (const entry of entries) {
            const fullPath = path === '/' ? '/' + entry.name : path + '/' + entry.name;
            if (entry.type === 'file') {
                cb(fullPath, { type: 'file', content: fs.readFile(fullPath) || '' });
            } else if (entry.type === 'dir') {
                this._walk(fullPath, fs, index, cb);
            }
        }
    }

    _isSystemFile(path) {
        const normalized = path.startsWith('/') ? path : '/' + path;
        const sysPrefixes = ['/.trash', '/.semantic_index', '/.memory_graph', '/_snapshots', '/_sessions', '/logs', '/memory', '/system', '/_mods', '/backups'];
        return sysPrefixes.some(p => normalized.startsWith(p) || path.includes('/node_modules'));
    }

    _contentHash(str) {
        if (!str) return '';
        let hash = 5381;
        for (let i = 0; i < str.length; i++) {
            hash = ((hash << 5) + hash) + str.charCodeAt(i);
            hash = hash & hash;
        }
        return Math.abs(hash).toString(36).slice(0, 12);
    }

    _loadHashCache(fs) {
        const saved = fs.fsReadJSON(this.hashCachePath);
        if (saved && typeof saved === 'object') this._hashCache = saved;
    }

    _getCached(path, hash) {
        const c = this._hashCache[path];
        if (c && c.hash === hash) return c;
        return null;
    }

    _extractConcepts(path, content) {
        const concepts = new Set();
        const name = path.split('/').pop() || '';
        const nameLower = name.toLowerCase();

        // Extract from filename (split on camelCase, kebab, dots, underscores)
        const words = nameLower
            .replace(/([a-z])([A-Z])/g, '$1 $2')
            .replace(/[-_.]/g, ' ')
            .replace(/\.(md|js|html|json|css|txt|yaml|yml|toml|env|sh)$/i, '')
            .split(/\s+/)
            .filter(w => w.length > 2 && !/^\d+$/.test(w));

        for (const word of words) {
            concepts.add(word);
        }

        // Extract file extension as concept
        const ext = path.split('.').pop();
        if (ext && ['md', 'js', 'html', 'json', 'css'].includes(ext)) {
            concepts.add(ext + '-file');
        }

        // Extract path-level concepts
        const parts = path.split('/').filter(p => p.length > 0);
        for (const part of parts) {
            if (['modules', 'skills', 'core', 'ext', 'backups', 'chat', 'downloads'].includes(part)) {
                concepts.add(part);
            }
        }

        // Extract #tags from content (markdown frontmatter or inline)
        if (content) {
            const tagMatches = content.match(/tags:\s*\[([^\]]+)\]/i) || content.match(/#[a-zA-Z]\w+/g);
            if (tagMatches) {
                const tags = tagMatches[0].replace(/tags:\s*\[/i, '').replace(/\]/, '').split(',').map(t => t.trim().replace(/^#/, '').replace(/"/g, ''));
                for (const tag of tags) {
                    if (tag.length > 2) concepts.add(tag.toLowerCase());
                }
            }

            // Extract first H1/H2 as concept
            const headerMatch = content.match(/^#\s+(.+)/m) || content.match(/^##\s+(.+)/m);
            if (headerMatch) {
                const header = headerMatch[1].toLowerCase().replace(/[^a-z0-9\s]/g, '').trim();
                if (header.length > 3 && header.length < 40) {
                    concepts.add(header);
                }
            }
        }

        return [...concepts];
    }

    _hybridShellCheck(concept) {
        const fs = this.terminal?.fs;
        if (!fs) return [];
        const words = concept.split(/\s+/).filter(w => w.length > 2);
        if (words.length === 0) return [];
        const results = [];
        this._walk('/', fs, {}, (path, node) => {
            if (this._isSystemFile(path)) return;
            const lower = path.toLowerCase();
            if (words.some(w => lower.includes(w))) {
                results.push({ path, summary: this._summarize(node.content || '') });
            }
        });
        return results;
    }

    _summarize(content) {
        if (!content || content.length < 10) return '';
        // Strip YAML frontmatter
        const cleaned = content.replace(/---[\s\S]*?---/, '').trim();
        
        // 1. Try first ## section heading
        const sectionMatch = cleaned.match(/^##\s+(.+)/m);
        if (sectionMatch && sectionMatch[1].trim().length > 5) {
            const s = sectionMatch[1].trim();
            return s.slice(0, 100) + (s.length > 100 ? '...' : '');
        }
        
        // 2. Try first paragraph > 40 chars after frontmatter
        const lines = cleaned.split('\n').filter(l => l.trim().length > 0);
        for (const line of lines) {
            const trimmed = line.trim();
            if (trimmed.length > 40 && !trimmed.startsWith('#') && !trimmed.startsWith('//')) {
                return trimmed.slice(0, 100) + (trimmed.length > 100 ? '...' : '');
            }
        }
        
        // 3. First meaningful sentence (> 30 chars)
        const sentence = cleaned.match(/[^.!?\n]+[.!?]/);
        if (sentence && sentence[0].trim().length > 30) {
            const s = sentence[0].trim();
            return s.slice(0, 100) + (s.length > 100 ? '...' : '');
        }
        
        // 4. Fallback: first line > 20 chars (original behavior)
        const firstLine = lines.find(l => l.trim().length > 20);
        if (firstLine) {
            const tl = firstLine.trim();
            return tl.slice(0, 100) + (tl.length > 100 ? '...' : '');
        }
        return '';
    }

    _indexSkills(fs, index) {
        const skills = fs.readDir('/skills');
        if (!skills) return;
        for (const skill of skills) {
            if (skill.type !== 'file' || !skill.name.endsWith('.md')) continue;
            // Already indexed by _walk — but we add a "skill" tag
            const base = skill.name.replace('.md', '');
            if (!index['skill']) index['skill'] = [];
            index['skill'].push({ path: '/skills/' + skill.name, summary: 'Skill: ' + base });
        }
    }

    _saveIndex(fs) {
        try {
            if (!fs.readDir('/.semantic_index')) {
                fs.mkdirRecursive('/.semantic_index');
            }
            fs.fsWriteJSON(this.indexPath, this.index);
            // Also persist content hash cache for incremental diffing
            fs.fsWriteJSON(this.hashCachePath, this._hashCache);
        } catch (e) {
            console.error('NeuralVFS save error:', e);
        }
    }

    // ── Auto-Sync ──

    markDirty(path) {
        this._dirtyPaths.add(path);
        // Debounced auto-sync: wait 10s after last mutation
        if (this._autoSyncTimer) clearTimeout(this._autoSyncTimer);
        this._autoSyncTimer = setTimeout(() => this._reindexDirtyPaths(), 10000);
    }

    async _reindexDirtyPaths() {
        if (this._dirtyPaths.size === 0) return;
        const fs = this.terminal?.fs;
        if (!fs) { this._dirtyPaths.clear(); return; }

        const start = Date.now();
        let reindexed = 0;
        this._loadHashCache(fs);

        for (const path of [...this._dirtyPaths]) {
            const content = fs.readFile(path);
            if (content !== null) {
                const hash = this._contentHash(content);
                const cached = this._getCached(path, hash);
                if (!cached) {
                    this._reindexFile(path, content, this.index);
                    this._hashCache[path] = { hash };
                    reindexed++;
                }
            } else {
                // File was deleted — remove from index
                for (const entries of Object.values(this.index)) {
                    const idx = entries.findIndex(e => e.path === path);
                    if (idx !== -1) entries.splice(idx, 1);
                }
                delete this._hashCache[path];
            }
        }
        this._dirtyPaths.clear();
        this._autoSyncTimer = null;
        this.lastScan = new Date().toISOString();
        this._saveIndex(fs);
        const elapsed = ((Date.now() - start) / 1000).toFixed(1);
        if (reindexed > 0) {
            this.terminal?.print(`🔄 Auto-sync: re-indexed ${reindexed} changed file(s) in ${elapsed}s`, 'success');
        }
    }

    // ── Aliases ──

    _loadAliases() {
        try { const r = localStorage.getItem('webx11_nvfs_aliases'); if (r) this._aliasMap = JSON.parse(r); } catch (e) {}
    }
    _saveAliases() {
        localStorage.setItem('webx11_nvfs_aliases', JSON.stringify(this._aliasMap));
    }

    // ── Status Bar Polling ──

    _updateStatusBar() {
        if (!this.terminal || !this.terminal.statusBar) return;
        const el = this.terminal.statusBar;
        if (this._deepIndexing) {
            const pct = this._deepTotal > 0 ? Math.round(this._deepProcessed / this._deepTotal * 100) : 0;
            el.textContent = `🧠 Deep Indexing... ${this._deepProcessed}/${this._deepTotal} (${pct}%)`;
            el.style.color = 'var(--accent, #00ff88)';
        } else if (this._autoSyncTimer !== null || this._dirtyPaths.size > 0) {
            el.textContent = `🔄 Auto-sync pending (${this._dirtyPaths.size} dirty)`;
            el.style.color = 'var(--warning, #ffaa00)';
        } else {
            const count = Object.keys(this.index).length;
            el.textContent = `🧠 ${count} concepts${this._deepIndexEnabled ? ' 🌊' : ''}`;
            el.style.color = '';
        }
    }

    // ── Deep Indexing (LLM-assisted) ──

    _parseLLMConcepts(llmResponse) {
        // LLM returns markdown bullet list: "- concept: description"
        const concepts = [];
        if (!llmResponse) return concepts;
        const lines = llmResponse.split('\n');
        for (const line of lines) {
            const trimmed = line.replace(/^[-*\s]+/, '').trim();
            if (!trimmed) continue;
            // Split on first colon or comma or dash
            const colonIdx = trimmed.indexOf(':');
            const commaIdx = trimmed.indexOf(',');
            const delimIdx = colonIdx > 0 ? colonIdx : (commaIdx > 0 ? commaIdx : -1);
            const concept = delimIdx > 0 ? trimmed.slice(0, delimIdx).trim().toLowerCase() : trimmed.toLowerCase();
            if (concept && concept.length > 2 && concept.length < 60) {
                concepts.push(concept);
            }
        }
        return [...new Set(concepts)];
    }

    async _callLLM(prompt, context) {
        const om = this.terminal?.ollamaManager;
        if (!om || !om.connected) return null;
        const fullPrompt = `Extract 2-5 key searchable concepts from this file. Return one per line as lowercase keywords (1-3 words).

File: ${context.path}
Content:
${context.content.slice(0, 2000)}

Concepts:`;
        try {
            const result = await om._chatWithProvider(om.currentProvider, fullPrompt, this._deepModel);
            return result;
        } catch (e) {
            console.warn('LLM concept extraction failed:', e);
            return null;
        }
    }

    async _processDeepQueue(index) {
        this._deepProcessed = 0;
        this._deepTotal = this._deepQueue.length;
        const batchSize = 3;
        const results = [];

        while (this._deepQueue.length > 0) {
            const batch = this._deepQueue.splice(0, batchSize);
            for (const item of batch) {
                const context = { path: item.path, content: item.content };
                const llmResponse = await this._callLLM('', context);
                if (llmResponse) {
                    const concepts = this._parseLLMConcepts(llmResponse);
                    results.push({ path: item.path, concepts });
                    for (const concept of concepts) {
                        if (!index[concept]) index[concept] = [];
                        const exists = index[concept].some(e => e.path === item.path);
                        if (!exists) index[concept].push({
                            path: item.path,
                            summary: this._summarize(item.content),
                            source: 'llm'
                        });
                    }
                }
                this._deepProcessed++;
                // Update status bar live
                this._updateStatusBar();
            }
            // Yield to UI between batches
            await new Promise(r => setTimeout(r, 50));
        }

        this._deepIndexing = false;
        this._deepQueue = [];
        this._deepProcessed = 0;
        this._deepTotal = 0;
        this._updateStatusBar();

        if (results.length > 0) {
            const llmConcepts = results.reduce((s, r) => s + r.concepts.length, 0);
            this.terminal?.print(`🧠 Deep pass complete: ${llmConcepts} LLM-generated concepts across ${results.length} files`, 'success');
        }
    }

    // ── Nvfs Sync (incremental background) ──

    async nvfsSync(args) {
        const useDeep = args && args.includes('--deep');
        if (this._dirtyPaths.size === 0) {
            this.terminal.print('No dirty files to sync', 'info');
            return;
        }
        this.terminal.print(`🔄 Syncing ${this._dirtyPaths.size} dirty file(s)${useDeep ? ' (deep mode)' : ''}...`, 'info');
        const fs = this.terminal?.fs;
        if (!fs) return;
        await this._reindexDirtyPaths();
        // After reindex, if deep mode, queue remaining queued items for LLM processing
        if (useDeep && this._deepQueue.length > 0) {
            this._deepIndexing = true;
            await this._processDeepQueue(this.index);
        }
    }
}

// Required for module system
if (typeof window !== 'undefined') {
    window.NeuralVFSModule = NeuralVFSModule;
}