import type { udp } from "bun"

const udpServer = await Bun.udpSocket({
  port: 33000,
  socket: {
    data(_socket, _buf, _port, _addr) {
      // todo : Handle Recieved Data
    }
  }
})

export const udpSocketPool = await createUDPSocketPool(5)

type bunUDPSocket = udp.Socket<"buffer">

export function getUDPServerPort() {
  return udpServer.port
}

export class UDPSocketPool {
  freeSockets: Set<bunUDPSocket> = new Set()
  busySockets: Set<bunUDPSocket> = new Set()

  getFreeSocket(): bunUDPSocket {
    const socket = this.freeSockets.values().next().value
    if (socket !== undefined) {
      this.busySockets.add(socket)
      this.freeSockets.delete(socket)
    } else {
      throw Error("Failure: Create udp socket failed")
    }
    return socket
  }

  releaseSocket(socket: any) {
    this.freeSockets.add(socket)
    this.busySockets.delete(socket)
  }

  send(data: udp.Data, port: number, hostname: string) {
    const socket = this.getFreeSocket()
    socket.send(data, port, hostname)
    this.releaseSocket(socket)
  }

}

export async function createUDPSocketPool(depth: number): Promise<UDPSocketPool> {
  const pool = new UDPSocketPool()
  for (var i = 0; i < depth; i++) {
    const socket = await Bun.udpSocket({})
    pool.freeSockets.add(socket)
  }

  return pool
}