package server

import (
	"net"
)

type IPv4TransparentListener struct {
	listener *net.TCPListener
}

type IPv4TransparentConnection struct {
	conn *net.TCPConn
	remoteAddr *net.TCPAddr
}

func NewIPv4TransparentListener(addr string) (*IPv4TransparentListener, error) {
	tcpaddr, err := net.ResolveTCPAddr("tcp4", addr)
	if err != nil {
		return nil, err
	}
	listener, err := net.ListenTCP("tcp4", tcpaddr)
	if err != nil {
		return nil, err
	}
	return &IPv4TransparentListener{listener: listener}, nil
}

func (l *IPv4TransparentListener) Close() error {
	return l.listener.Close()
}

func (l *IPv4TransparentListener) Accept() (*IPv4TransparentConnection, error) {
	conn, err := l.listener.AcceptTCP()
	if err != nil {
		return nil, err
	}
	fd := GetFDFromTCPConn(conn)
	remoteAddr := GetAddr4FromFD(fd)
	return &IPv4TransparentConnection{conn: conn, remoteAddr: remoteAddr}, nil
}

func (c *IPv4TransparentConnection) TCPConn() *net.TCPConn {
	return c.conn
}

func (c *IPv4TransparentConnection) RealAddr() *net.TCPAddr {
	return c.remoteAddr
}