vtorio/app/lib/excel-import/websocket-server.ts

import { WebSocketServer, WebSocket } from 'ws';
import { Server } from 'http';
import { ImportProgress } from './types';

export class ImportProgressServer {
  private wss: WebSocketServer | null = null;
  private clients: Set<WebSocket> = new Set();

  constructor() {
    // Initialize WebSocket server
    this.setupWebSocketServer();
  }

  private setupWebSocketServer() {
    // This will be initialized when the HTTP server is available
    // For now, we'll create a standalone WebSocket server
    this.wss = new WebSocketServer({ port: 8080 });
    
    this.wss.on('connection', (ws: WebSocket) => {
      console.log('New WebSocket connection established');
      this.clients.add(ws);

      ws.on('close', () => {
        console.log('WebSocket connection closed');
        this.clients.delete(ws);
      });

      ws.on('error', (error) => {
        console.error('WebSocket error:', error);
        this.clients.delete(ws);
      });
    });

    console.log('WebSocket server started on port 8080');
  }

  // Alternative method to attach to existing HTTP server
  attachToServer(server: Server) {
    if (this.wss) {
      this.wss.close();
    }

    this.wss = new WebSocketServer({ 
      server, 
      path: '/api/imports/progress' 
    });

    this.wss.on('connection', (ws: WebSocket, request) => {
      console.log('New WebSocket connection on import progress endpoint');
      this.clients.add(ws);

      // Handle specific import ID subscriptions
      const url = new URL(request.url || '', `http://${request.headers.host}`);
      const importId = url.searchParams.get('importId');
      
      if (importId) {
        ws.send(JSON.stringify({
          type: 'connected',
          importId: parseInt(importId),
          message: 'Connected to import progress updates'
        }));
      }

      ws.on('close', () => {
        console.log('WebSocket connection closed');
        this.clients.delete(ws);
      });

      ws.on('error', (error) => {
        console.error('WebSocket error:', error);
        this.clients.delete(ws);
      });
    });
  }

  broadcastProgress(importId: number, progress: ImportProgress) {
    const message = JSON.stringify({
      type: 'progress',
      importId,
      progress
    });

    this.clients.forEach(client => {
      if (client.readyState === WebSocket.OPEN) {
        client.send(message);
      }
    });
  }

  broadcastError(importId: number, error: string) {
    const message = JSON.stringify({
      type: 'error',
      importId,
      error
    });

    this.clients.forEach(client => {
      if (client.readyState === WebSocket.OPEN) {
        client.send(message);
      }
    });
  }

  broadcastComplete(importId: number, result: any) {
    const message = JSON.stringify({
      type: 'complete',
      importId,
      result
    });

    this.clients.forEach(client => {
      if (client.readyState === WebSocket.OPEN) {
        client.send(message);
      }
    });
  }

  close() {
    if (this.wss) {
      this.wss.close();
      this.clients.clear();
    }
  }
}

// Export a singleton instance
export const progressServer = new ImportProgressServer();