#include once "win/winsock2.bi"

Type SOCKET As Ulongint

Const PORT = 12321
Const BUFFER_SIZE = 1024
Dim Shared As SOCKET sock

Sub clientHandler(Byval clientSocket As SOCKET)
    Dim As String linea
    Dim As ZString * BUFFER_SIZE buffer
    Dim As Integer bytesReceived

    Do
        bytesReceived = recv(clientSocket, @buffer, BUFFER_SIZE-1, 0)
        If bytesReceived <= 0 Then Exit Do

        buffer[bytesReceived] = 0
        linea = *Cast(ZString Ptr, @buffer)
        Print "Received: "; linea

        send(clientSocket, Strptr(linea), Len(linea), 0)
    Loop

    closesocket(clientSocket)
End Sub

Sub server()
    Dim As sockaddr_in addr
    With addr
        .sin_family = AF_INET
        .sin_port = htons(PORT)
        .sin_addr.s_addr = INADDR_ANY
    End With

    sock = WSASocket(AF_INET, SOCK_STREAM, IPPROTO_TCP, NULL, 0, 0)
    If sock = INVALID_SOCKET Then
        Print "Failed to create socket"
        Exit Sub
    End If

    If bind(sock, Cast(sockaddr Ptr, @addr), Sizeof(sockaddr_in)) = SOCKET_ERROR Then
        Print "Bind failed"
        closesocket(sock)
        Exit Sub
    End If

    If listen(sock, SOMAXCONN) = SOCKET_ERROR Then
        Print "Listen failed"
        closesocket(sock)
        Exit Sub
    End If

    Print "Server running on port "; PORT

    Do
        Dim As sockaddr_in clientAddr
        Dim As Long clientAddrLen = Sizeof(sockaddr_in)
        Dim As SOCKET clientSocket = accept(sock, Cast(sockaddr Ptr, @clientAddr), @clientAddrLen)

        If clientSocket <> INVALID_SOCKET Then
            Print "Connection from "; *inet_ntoa(clientAddr.sin_addr)
            clientHandler(clientSocket)
        End If
    Loop
End Sub

' Initialize Winsock
Dim As WSADATA wsaData
If WSAStartup(MAKEWORD(2, 2), @wsaData) Then
    Print "Winsock initialization failed"
    End 1
End If

' Run server
server()

' Cleanup on exit
closesocket(sock)
WSACleanup()