import { Injectable, Logger } from "@nestjs/common";
import { OnEvent } from "@nestjs/event-emitter";
import { PARTICIPANT_EVENTS, ParticipantActivityEvent } from "../events/participant.events";
import { CLParticipantActivityService, ParticipantActivityType } from "../participant-activity.service";

/**
 * Event Listener for Participant Activity Tracking
 * Subscribes to participant activity events and updates last_login timestamps
 *
 * This decouples activity tracking from business logic:
 * - Services emit activity events (don't know about tracking)
 * - This listener reacts to events (updates timestamps)
 * - Clean separation of concerns
 */
@Injectable()
export class ParticipantActivityListener {
  private readonly logger = new Logger(ParticipantActivityListener.name);

  constructor(private readonly activityService: CLParticipantActivityService) {}

  /**
   * Handle participant activity event
   * Updates last_login timestamp whenever participant performs an action
   */
  @OnEvent(PARTICIPANT_EVENTS.ACTIVITY)
  async handleParticipantActivity(event: ParticipantActivityEvent) {
    try {
      this.logger.debug(`Activity event: Participant ${event.participantId} - ${event.activityType}`);

      await this.activityService.updateLastActivity(event.participantId, event.activityType, event.metadata);

      this.logger.debug(`Successfully updated last activity for participant ${event.participantId}`);
    } catch (error) {
      const errorMessage = error instanceof Error ? error.message : String(error);
      const errorStack = error instanceof Error ? error.stack : undefined;
      this.logger.error(`Failed to update last activity: ${errorMessage}`, errorStack);
      // Don't throw - activity tracking should not fail the main operation
    }
  }
}