rwadurian/backend/services/wallet-service/src/infrastructure/kafka/event-publisher.service.ts

119 lines
3.4 KiB
TypeScript

/**
* Kafka Event Publisher Service for Wallet Service
*
* Publishes domain events to Kafka for cross-service communication.
* Used to notify blockchain-service about withdrawal requests.
*/
import { Injectable, Logger, OnModuleInit, OnModuleDestroy } from '@nestjs/common';
import { ConfigService } from '@nestjs/config';
import { Kafka, Producer, logLevel } from 'kafkajs';
export interface EventPayload {
eventId?: string;
eventType: string;
occurredAt?: Date;
payload: { [key: string]: unknown };
}
@Injectable()
export class EventPublisherService implements OnModuleInit, OnModuleDestroy {
private readonly logger = new Logger(EventPublisherService.name);
private kafka: Kafka;
private producer: Producer;
private isConnected = false;
constructor(private readonly configService: ConfigService) {}
async onModuleInit() {
const brokers = this.configService.get<string>('KAFKA_BROKERS')?.split(',') || ['localhost:9092'];
const clientId = this.configService.get<string>('KAFKA_CLIENT_ID') || 'wallet-service';
this.logger.log(`[INIT] Event Publisher initializing...`);
this.logger.log(`[INIT] ClientId: ${clientId}`);
this.logger.log(`[INIT] Brokers: ${brokers.join(', ')}`);
this.kafka = new Kafka({
clientId,
brokers,
logLevel: logLevel.WARN,
retry: {
initialRetryTime: 100,
retries: 8,
},
});
this.producer = this.kafka.producer();
try {
await this.producer.connect();
this.isConnected = true;
this.logger.log(`[CONNECT] Kafka producer connected successfully`);
} catch (error) {
this.logger.error(`[ERROR] Failed to connect Kafka producer`, error);
}
}
async onModuleDestroy() {
if (this.isConnected) {
await this.producer.disconnect();
this.logger.log('Kafka producer disconnected');
}
}
/**
* Publish an event to Kafka
*/
async publish(event: EventPayload): Promise<void> {
if (!this.isConnected) {
this.logger.warn(`[PUBLISH] Kafka not connected, skipping event: ${event.eventType}`);
return;
}
const topic = this.getTopicForEvent(event.eventType);
const eventId = event.eventId || this.generateEventId();
const occurredAt = event.occurredAt || new Date();
const message = {
key: eventId,
value: JSON.stringify({
eventId,
eventType: event.eventType,
occurredAt: occurredAt.toISOString(),
payload: event.payload,
}),
headers: {
eventType: event.eventType,
source: 'wallet-service',
},
};
try {
await this.producer.send({
topic,
messages: [message],
});
this.logger.log(`[PUBLISH] Published event: ${event.eventType} to topic: ${topic}`);
} catch (error) {
this.logger.error(`[ERROR] Failed to publish event: ${event.eventType}`, error);
throw error;
}
}
private getTopicForEvent(eventType: string): string {
const topicMap: Record<string, string> = {
'wallet.withdrawal.requested': 'wallet.withdrawals',
'wallet.withdrawal.completed': 'wallet.withdrawals',
'wallet.withdrawal.failed': 'wallet.withdrawals',
// ACK events - 确认消息
'wallet.deposit.credited': 'wallet.acks',
};
return topicMap[eventType] || 'wallet.events';
}
private generateEventId(): string {
return `${Date.now()}-${Math.random().toString(36).substring(2, 9)}`;
}
}