MCP Vibe Coding Knowledge Graph

import { logger } from '../utils/logger.js'; import fs from 'fs/promises'; import path from 'path'; import { EventEmitter } from 'events'; /** * CONTEXT: Mock Kuzu client for development and testing when Kuzu is not available * REASON: Allows CLI testing and development without Kuzu installation issues * CHANGE: Mock implementation that simulates Kuzu behavior for demonstration * PREVENTION: Blocking development due to native library issues */ export class MockKuzuClient extends EventEmitter { constructor(config) { super(); this.config = { databasePath: '.kg-context/knowledge-graph.kuzu', maxRetries: 3, retryDelay: 1000, healthCheckInterval: 30000, backupInterval: 86400000, queryTimeout: 30000, ...config }; this.database = null; this.connection = null; this.isConnected = false; this.connectionAttempts = 0; this.lastHealthCheck = null; this.metrics = { queries: 0, errors: 0, avgQueryTime: 0, totalQueryTime: 0 }; // Mock data storage this.mockData = { CodeEntity: [], Pattern: [], Rule: [], Standard: [], Decision: [] }; // Graceful shutdown handling process.on('SIGINT', () => this.gracefulShutdown()); process.on('SIGTERM', () => this.gracefulShutdown()); } async connect() { const startTime = Date.now(); try { logger.info('Connecting to Mock Kuzu database', { path: this.config.databasePath, attempt: this.connectionAttempts + 1 }); // Ensure database directory exists await this.ensureDatabaseDirectory(); // Simulate connection delay await this.delay(100); this.isConnected = true; this.connectionAttempts = 0; this.lastHealthCheck = Date.now(); const connectionTime = Date.now() - startTime; logger.info('Mock Kuzu database connection established', { connectionTime: `${connectionTime}ms`, databasePath: this.config.databasePath }); this.emit('connected'); } catch (error) { this.connectionAttempts++; logger.error('Mock Kuzu connection failed', { error: error.message, attempt: this.connectionAttempts, maxRetries: this.config.maxRetries }); this.emit('error', error); throw new Error(`Failed to connect to Mock Kuzu: ${error.message}`); } } async ensureDatabaseDirectory() { try { const dbDir = path.dirname(this.config.databasePath); const kgContextDir = path.resolve(dbDir); // Create main .kg-context directory await fs.mkdir(kgContextDir, { recursive: true }); // Create subdirectory structure const subdirs = ['backups', 'exports', 'imports', 'logs', 'cache', 'temp']; for (const subdir of subdirs) { const subdirPath = path.join(kgContextDir, subdir); await fs.mkdir(subdirPath, { recursive: true }); // Create .gitkeep files to preserve directories in git const gitkeepPath = path.join(subdirPath, '.gitkeep'); await fs.writeFile(gitkeepPath, '# Keep this directory in git\n', { flag: 'wx' }).catch(() => {}); } logger.info('Mock Knowledge graph context directory initialized', { path: kgContextDir, subdirs: subdirs.length }); } catch (error) { logger.error('Database directory setup failed', { error: error.message }); throw new Error(`Database directory setup failed: ${error.message}`); } } async query(cypherQuery, params = {}, options = {}) { if (!this.isConnected) { throw new Error('Database not connected'); } const startTime = Date.now(); const queryId = this.generateQueryId(); try { logger.debug('Executing mock query', { queryId, query: cypherQuery.substring(0, 100) + '...', params }); // Simulate query execution delay await this.delay(Math.random() * 50 + 10); // Mock query responses let results = []; if (cypherQuery.includes('RETURN 1 as test')) { results = [{ test: 1 }]; } else if (cypherQuery.includes('MATCH (e:CodeEntity)')) { results = this.mockData.CodeEntity.map(e => ({ e })); } else if (cypherQuery.includes('MATCH (p:Pattern)')) { results = this.mockData.Pattern.map(p => ({ p })); } else if (cypherQuery.includes('count(')) { const match = cypherQuery.match(/MATCH \((\w+):(\w+)\)/); if (match) { const [, variable, nodeType] = match; const count = this.mockData[nodeType]?.length || 0; results = [{ count }]; } } // Update metrics const queryTime = Date.now() - startTime; this.updateMetrics(queryTime, true); logger.debug('Mock query executed successfully', { queryId, duration: `${queryTime}ms`, rowCount: results.length }); return results; } catch (error) { const queryTime = Date.now() - startTime; this.updateMetrics(queryTime, false); logger.error('Mock query execution failed', { queryId, error: error.message, duration: `${queryTime}ms`, query: cypherQuery.substring(0, 200) }); this.emit('queryError', { queryId, error, query: cypherQuery }); throw new Error(`Mock query execution failed: ${error.message}`); } } async createNode(label, properties) { try { if (!properties.id) { throw new Error('Node ID is required'); } const nodeProps = { ...properties, lastModified: Date.now() }; // Store in mock data if (!this.mockData[label]) { this.mockData[label] = []; } // Remove existing node with same ID this.mockData[label] = this.mockData[label].filter(n => n.id !== properties.id); // Add new node this.mockData[label].push(nodeProps); logger.debug('Mock node created', { label, id: properties.id }); this.emit('nodeCreated', { label, properties }); return nodeProps; } catch (error) { logger.error('Failed to create mock node', { label, id: properties.id, error: error.message }); throw error; } } async createRelationship(fromId, relationshipType, toId, properties = {}) { try { if (!fromId || !toId) { throw new Error('Both fromId and toId are required'); } const relProps = { ...properties, timestamp: Date.now(), fromId, toId, type: relationshipType }; // Store relationship in mock data if (!this.mockData.relationships) { this.mockData.relationships = []; } this.mockData.relationships.push(relProps); logger.debug('Mock relationship created', { from: fromId, to: toId, type: relationshipType }); this.emit('relationshipCreated', { fromId, toId, relationshipType, properties }); return relProps; } catch (error) { logger.error('Failed to create mock relationship', { from: fromId, to: toId, type: relationshipType, error: error.message }); throw error; } } async getHealthMetrics() { try { const stats = { isConnected: this.isConnected, uptime: Date.now() - (this.lastHealthCheck || Date.now()), metrics: { ...this.metrics }, databasePath: this.config.databasePath, mode: 'mock' }; // Get table counts from mock data stats.tableCounts = { codeEntities: this.mockData.CodeEntity?.length || 0, patterns: this.mockData.Pattern?.length || 0, rules: this.mockData.Rule?.length || 0, standards: this.mockData.Standard?.length || 0, decisions: this.mockData.Decision?.length || 0 }; return stats; } catch (error) { logger.error('Failed to get mock health metrics', { error: error.message }); return { isConnected: false, error: error.message, metrics: this.metrics, mode: 'mock' }; } } updateMetrics(queryTime, success) { this.metrics.queries++; this.metrics.totalQueryTime += queryTime; this.metrics.avgQueryTime = this.metrics.totalQueryTime / this.metrics.queries; if (!success) { this.metrics.errors++; } } generateQueryId() { return `q_${Date.now()}_${Math.random().toString(36).substr(2, 9)}`; } delay(ms) { return new Promise(resolve => setTimeout(resolve, ms)); } async gracefulShutdown() { logger.info('Initiating mock graceful shutdown'); try { this.isConnected = false; this.emit('disconnected'); logger.info('Mock graceful shutdown completed'); } catch (error) { logger.error('Error during mock graceful shutdown', { error: error.message }); } } async close() { await this.gracefulShutdown(); } }