import {
  WebSocketGateway,
  WebSocketServer,
  OnGatewayConnection,
  OnGatewayDisconnect,
  SubscribeMessage,
} from '@nestjs/websockets';
import { Logger } from '@nestjs/common';
import { Server, Socket } from 'socket.io';
import {
  WS_EVENTS,
  JobProgressEvent,
  JobCompletedEvent,
  JobFailedEvent,
  SegmentEvent,
  VersionEvent,
  ProjectStatusEvent,
} from './ws-events';

/**
 * SkriptAI WebSocket Gateway
 *
 * Socket.IO gateway for real-time notifications.
 * Clients join project-specific rooms to receive updates.
 *
 * TR: Gerçek zamanlı bildirimler için Socket.IO gateway.
 * İstemciler proje odalarına katılarak güncellemeler alır.
 */
@WebSocketGateway({
  namespace: '/skriptai',
  cors: {
    origin: '*',
    credentials: true,
  },
})
export class SkriptaiGateway
  implements OnGatewayConnection, OnGatewayDisconnect
{
  @WebSocketServer()
  server: Server;

  private readonly logger = new Logger(SkriptaiGateway.name);

  handleConnection(client: Socket) {
    this.logger.log(`Client connected: ${client.id}`);
  }

  handleDisconnect(client: Socket) {
    this.logger.log(`Client disconnected: ${client.id}`);
  }

  /**
   * Client joins a project room to receive project-specific events
   */
  @SubscribeMessage('join:project')
  handleJoinProject(client: Socket, projectId: string) {
    const room = `project:${projectId}`;
    client.join(room);
    this.logger.debug(`Client ${client.id} joined room ${room}`);
    return { status: 'ok', room };
  }

  /**
   * Client leaves a project room
   */
  @SubscribeMessage('leave:project')
  handleLeaveProject(client: Socket, projectId: string) {
    const room = `project:${projectId}`;
    client.leave(room);
    this.logger.debug(`Client ${client.id} left room ${room}`);
    return { status: 'ok' };
  }

  // ========== EMIT METHODS (called by processors/services) ==========

  /**
   * Emit job progress to all clients in the project room
   */
  emitJobProgress(event: JobProgressEvent) {
    const room = `project:${event.projectId}`;
    this.server.to(room).emit(WS_EVENTS.JOB_PROGRESS, event);
  }

  /**
   * Emit job completed
   */
  emitJobCompleted(event: JobCompletedEvent) {
    const room = `project:${event.projectId}`;
    this.server.to(room).emit(WS_EVENTS.JOB_COMPLETED, event);
  }

  /**
   * Emit job failed
   */
  emitJobFailed(event: JobFailedEvent) {
    const room = `project:${event.projectId}`;
    this.server.to(room).emit(WS_EVENTS.JOB_FAILED, event);
  }

  /**
   * Emit segment generated/updated
   */
  emitSegmentEvent(eventName: string, event: SegmentEvent) {
    const room = `project:${event.projectId}`;
    this.server.to(room).emit(eventName, event);
  }

  /**
   * Emit version created/restored
   */
  emitVersionEvent(eventName: string, event: VersionEvent) {
    const room = `project:${event.projectId}`;
    this.server.to(room).emit(eventName, event);
  }

  /**
   * Emit project status change
   */
  emitProjectStatusChanged(event: ProjectStatusEvent) {
    const room = `project:${event.projectId}`;
    this.server.to(room).emit(WS_EVENTS.PROJECT_STATUS_CHANGED, event);
  }
}