stack/apps/api/src/websocket/websocket.gateway.ts

import {
  WebSocketGateway as WSGateway,
  WebSocketServer,
  OnGatewayConnection,
  OnGatewayDisconnect,
} from '@nestjs/websockets';
import { Logger } from '@nestjs/common';
import { Server, Socket } from 'socket.io';

interface AuthenticatedSocket extends Socket {
  data: {
    userId?: string;
    workspaceId?: string;
  };
}

interface Task {
  id: string;
  workspaceId: string;
  [key: string]: unknown;
}

interface Event {
  id: string;
  workspaceId: string;
  [key: string]: unknown;
}

interface Project {
  id: string;
  workspaceId: string;
  [key: string]: unknown;
}

/**
 * WebSocket Gateway for real-time updates
 * Handles workspace-scoped rooms for broadcasting events
 */
@WSGateway({
  cors: {
    origin: process.env.WEB_URL || 'http://localhost:3000',
    credentials: true,
  },
})
export class WebSocketGateway implements OnGatewayConnection, OnGatewayDisconnect {
  @WebSocketServer()
  server!: Server;

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

  /**
   * Handle client connection
   * Joins client to workspace-specific room
   */
  async handleConnection(client: AuthenticatedSocket): Promise<void> {
    const { userId, workspaceId } = client.data;

    if (!userId || !workspaceId) {
      this.logger.warn(`Client ${client.id} connected without authentication`);
      client.disconnect();
      return;
    }

    const room = this.getWorkspaceRoom(workspaceId);
    await client.join(room);

    this.logger.log(`Client ${client.id} joined room ${room}`);
  }

  /**
   * Handle client disconnect
   * Leaves workspace room
   */
  handleDisconnect(client: AuthenticatedSocket): void {
    const { workspaceId } = client.data;

    if (workspaceId) {
      const room = this.getWorkspaceRoom(workspaceId);
      client.leave(room);
      this.logger.log(`Client ${client.id} left room ${room}`);
    }
  }

  /**
   * Emit task:created event to workspace room
   */
  emitTaskCreated(workspaceId: string, task: Task): void {
    const room = this.getWorkspaceRoom(workspaceId);
    this.server.to(room).emit('task:created', task);
    this.logger.debug(`Emitted task:created to ${room}`);
  }

  /**
   * Emit task:updated event to workspace room
   */
  emitTaskUpdated(workspaceId: string, task: Task): void {
    const room = this.getWorkspaceRoom(workspaceId);
    this.server.to(room).emit('task:updated', task);
    this.logger.debug(`Emitted task:updated to ${room}`);
  }

  /**
   * Emit task:deleted event to workspace room
   */
  emitTaskDeleted(workspaceId: string, taskId: string): void {
    const room = this.getWorkspaceRoom(workspaceId);
    this.server.to(room).emit('task:deleted', { id: taskId });
    this.logger.debug(`Emitted task:deleted to ${room}`);
  }

  /**
   * Emit event:created event to workspace room
   */
  emitEventCreated(workspaceId: string, event: Event): void {
    const room = this.getWorkspaceRoom(workspaceId);
    this.server.to(room).emit('event:created', event);
    this.logger.debug(`Emitted event:created to ${room}`);
  }

  /**
   * Emit event:updated event to workspace room
   */
  emitEventUpdated(workspaceId: string, event: Event): void {
    const room = this.getWorkspaceRoom(workspaceId);
    this.server.to(room).emit('event:updated', event);
    this.logger.debug(`Emitted event:updated to ${room}`);
  }

  /**
   * Emit event:deleted event to workspace room
   */
  emitEventDeleted(workspaceId: string, eventId: string): void {
    const room = this.getWorkspaceRoom(workspaceId);
    this.server.to(room).emit('event:deleted', { id: eventId });
    this.logger.debug(`Emitted event:deleted to ${room}`);
  }

  /**
   * Emit project:created event to workspace room
   */
  emitProjectCreated(workspaceId: string, project: Project): void {
    const room = this.getWorkspaceRoom(workspaceId);
    this.server.to(room).emit('project:created', project);
    this.logger.debug(`Emitted project:created to ${room}`);
  }

  /**
   * Emit project:updated event to workspace room
   */
  emitProjectUpdated(workspaceId: string, project: Project): void {
    const room = this.getWorkspaceRoom(workspaceId);
    this.server.to(room).emit('project:updated', project);
    this.logger.debug(`Emitted project:updated to ${room}`);
  }

  /**
   * Emit project:deleted event to workspace room
   */
  emitProjectDeleted(workspaceId: string, projectId: string): void {
    const room = this.getWorkspaceRoom(workspaceId);
    this.server.to(room).emit('project:deleted', { id: projectId });
    this.logger.debug(`Emitted project:deleted to ${room}`);
  }

  /**
   * Get workspace room name
   */
  private getWorkspaceRoom(workspaceId: string): string {
    return `workspace:${workspaceId}`;
  }
}