// Legacy WebSocket upgrade routing — to be replaced in T-1.5/T-1.6.
import type { IncomingMessage } from "node:http";
import type { Socket } from "node:net";

// Lightweight ws server interface (compatible with the ws package without types)
interface WsServer {
  handleUpgrade(
    request: IncomingMessage,
    socket: Socket,
    head: Buffer,
    cb: (ws: unknown) => void,
  ): void;
  emit(event: string, ...args: unknown[]): void;
}

/**
 * Route WebSocket upgrade requests to the legacy server.
 * In Phase 2 this will dispatch to topic/session-specific handlers.
 */
export function handleUpgrade(
  wss: WsServer,
  request: IncomingMessage,
  socket: Socket,
  head: Buffer,
): void {
  // T-1.5/T-1.6: inspect URL to route to stream/input/session handlers.
  // For now, delegate everything to the legacy WebSocket server.
  wss.handleUpgrade(request, socket, head, (ws) => {
    wss.emit("connection", ws, request);
  });
}