SAP OData to MCP Server

import { getDestination, HttpDestination } from '@sap-cloud-sdk/connectivity'; import xsenv from '@sap/xsenv'; import { Logger } from '../utils/logger.js'; import { Config } from '../utils/config.js'; export class DestinationService { private config: Config; private vcapServices!: Record<string, unknown>; constructor( private logger: Logger, config?: Config ) { this.config = config || new Config(); } async initialize(): Promise<void> { try { // Load VCAP services xsenv.loadEnv(); this.vcapServices = xsenv.getServices({ destination: { label: 'destination' }, connectivity: { label: 'connectivity' }, xsuaa: { label: 'xsuaa' } }); this.logger.info('Destination service initialized successfully'); } catch (error) { this.logger.error('Failed to initialize destination service:', error); throw error; } } /** * Get destination for API discovery (uses technical user) */ async getDiscoveryDestination(): Promise<HttpDestination> { const destinationName = this.config.get('sap.discoveryDestinationName', this.config.get('sap.destinationName', 'SAP_SYSTEM')); this.logger.debug(`Fetching discovery destination: ${destinationName}`); return this.getDestination(destinationName, undefined); } /** * Get destination for API execution (uses JWT token if provided) */ async getExecutionDestination(jwtToken?: string): Promise<HttpDestination> { const destinationName = this.config.get('sap.executionDestinationName', this.config.get('sap.destinationName', 'SAP_SYSTEM')); this.logger.debug(`Fetching execution destination: ${destinationName}`); return this.getDestination(destinationName, jwtToken); } /** * Legacy method for backward compatibility */ async getSAPDestination(): Promise<HttpDestination> { return this.getDiscoveryDestination(); } /** * Internal method to get destination with optional JWT */ private async getDestination(destinationName: string, jwtToken?: string): Promise<HttpDestination> { this.logger.debug(`Fetching destination: ${destinationName} ${jwtToken ? 'with JWT' : 'without JWT'}`); try { // First try environment variables (for local development) const envDestinations = process.env.destinations; if (envDestinations) { const destinations = JSON.parse(envDestinations); const envDest = destinations.find((d: Record<string, unknown>) => d.name === destinationName); if (envDest) { this.logger.info(`Successfully retrieved destination '${destinationName}' from environment variable.`); return { url: envDest.url, username: envDest.username, password: envDest.password, authentication: 'BasicAuthentication' } as HttpDestination; } } } catch (envError) { this.logger.debug('Failed to load from environment destinations:', envError); } try { // Use SAP Cloud SDK getDestination with optional JWT const destination = await getDestination({ destinationName, jwt: jwtToken || this.getJWT() }); if (!destination) { throw new Error(`Destination '${destinationName}' not found in environment variables or BTP destination service`); } this.logger.info(`Successfully retrieved destination: ${destinationName}`); return destination as HttpDestination; } catch (error) { this.logger.error('Failed to get SAP destination:', error); throw error; } } private getJWT(): string | undefined { // In a real application, this would extract JWT from the current request // For technical user scenario, this might not be needed return process.env.USER_JWT || undefined; } getDestinationCredentials() { return (this.vcapServices?.destination as { credentials?: unknown })?.credentials; } getConnectivityCredentials() { return (this.vcapServices?.connectivity as { credentials?: unknown })?.credentials; } getXSUAACredentials() { return (this.vcapServices?.xsuaa as { credentials?: unknown })?.credentials; } }