graphzep/src/drivers/rdf-driver-simple.ts

GraphZep: A temporal knowledge graph memory system for AI agents based on the Zep paper

import { BaseGraphDriver } from './driver.js';
import { GraphProvider } from '../types/index.js';

export interface RDFDriverConfig {
  uri?: string;
  username?: string;
  password?: string;
  database?: string;
  inMemory?: boolean;
  sparqlEndpoint?: string;
  customOntologyPath?: string;
  cacheSize?: number;
  batchSize?: number;
}

export interface RDFTriple {
  subject: string;
  predicate: string;
  object: string | { value: string; type: string; datatype?: string; language?: string };
}

export class SimplifiedRDFDriver extends BaseGraphDriver {
  provider = GraphProvider.RDF;
  
  private triples: RDFTriple[] = [];
  private config: RDFDriverConfig;
  private isConnected = false;
  
  constructor(config: RDFDriverConfig = {}) {
    super(
      config.uri || 'memory://graphzep',
      config.username || '',
      config.password || '',
      config.database || 'default'
    );
    
    this.config = {
      inMemory: true,
      cacheSize: 10000,
      batchSize: 1000,
      ...config
    };
  }
  
  async connect(): Promise<void> {
    this.isConnected = true;
  }
  
  async close(): Promise<void> {
    this.isConnected = false;
  }
  
  async createIndexes(): Promise<void> {
    // No-op for simplified implementation
  }
  
  async executeQuery<T = any>(query: string, _params?: Record<string, any>): Promise<T> {
    if (!this.isConnected) {
      throw new Error('RDF driver not connected');
    }
    
    // Simplified SPARQL simulation - in real implementation would use proper SPARQL engine
    console.log('Executing SPARQL query:', query);
    
    // Return mock results for demo
    return [] as any;
  }
  
  /**
   * Add RDF triples to the store
   */
  async addTriples(triples: RDFTriple[]): Promise<void> {
    this.triples.push(...triples);
  }
  
  /**
   * Get all stored triples
   */
  getTriples(): RDFTriple[] {
    return [...this.triples];
  }
  
  /**
   * Clear all triples
   */
  clearTriples(): void {
    this.triples = [];
  }
  
  /**
   * Serialize to basic formats
   */
  async serialize(format: 'turtle' | 'rdf-xml' | 'json-ld' | 'n-triples' = 'turtle'): Promise<string> {
    switch (format) {
      case 'turtle':
        return this.serializeToTurtle();
      case 'json-ld':
        return this.serializeToJsonLD();
      default:
        return this.serializeToTurtle();
    }
  }
  
  private serializeToTurtle(): string {
    const prefixes = [
      '@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .',
      '@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .',
      '@prefix owl: <http://www.w3.org/2002/07/owl#> .',
      '@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .',
      '@prefix zep: <http://graphzep.ai/ontology#> .',
      '@prefix zepmem: <http://graphzep.ai/memory#> .',
      '@prefix zepent: <http://graphzep.ai/entity#> .',
      ''
    ].join('\n');
    
    const tripleStrings = this.triples.map(triple => {
      const object = typeof triple.object === 'string' 
        ? `<${triple.object}>`
        : `"${triple.object.value}"`;
      
      return `<${triple.subject}> <${triple.predicate}> ${object} .`;
    });
    
    return prefixes + tripleStrings.join('\n');
  }
  
  private serializeToJsonLD(): string {
    const context = {
      '@context': {
        'rdf': 'http://www.w3.org/1999/02/22-rdf-syntax-ns#',
        'rdfs': 'http://www.w3.org/2000/01/rdf-schema#',
        'owl': 'http://www.w3.org/2002/07/owl#',
        'xsd': 'http://www.w3.org/2001/XMLSchema#',
        'zep': 'http://graphzep.ai/ontology#',
        'zepmem': 'http://graphzep.ai/memory#',
        'zepent': 'http://graphzep.ai/entity#'
      }
    };
    
    const graph = this.triples.map(triple => ({
      '@id': triple.subject,
      [triple.predicate]: typeof triple.object === 'string' 
        ? { '@id': triple.object }
        : { '@value': triple.object.value, '@type': triple.object.datatype }
    }));
    
    return JSON.stringify({ ...context, '@graph': graph }, null, 2);
  }
  
  /**
   * Execute basic SPARQL-like queries
   */
  async executeSPARQL(query: string): Promise<any[]> {
    console.log('SPARQL Query:', query);
    
    // Simple pattern matching for demo
    if (query.includes('SELECT')) {
      return this.triples.map((triple, index) => ({
        subject: triple.subject,
        predicate: triple.predicate,
        object: triple.object,
        index
      }));
    }
    
    return [];
  }
}