#include <winsock2.h>
#include <stdio.h>

int main(void)
{
	WSADATA			wsaData;
	SOCKET			ListeningSocket;
	SOCKET			NewConnection;
	SOCKADDR_IN		ServerAddr;
	int				Port = 5150;
	
	// Initialize Winsock version 2.2
	if (WSAStartup(MAKEWORD(2,2), &wsaData) != 0)
	{
		// MSDN: An application can call the WSAGetLastError() function to determine the
		// extended error code for other Windows sockets functions as is normally
		// done in Windows Sockets even if the WSAStartup function fails or the WSAStartup
		// function was not called to properly initialize Windows Sockets before calling a
		// Windows Sockets function. The WSAGetLastError() function is one of the only functions
		// in the Winsock 2.2 DLL that can be called in the case of a WSAStartup failure
		printf("Server: WSAStartup failed with error %ld\n", WSAGetLastError());
		// Exit with error
		return -1;
	}
	else
	{
		printf("Server: The Winsock dll found!\n");
		printf("Server: The current status is %s.\n", wsaData.szSystemStatus);
	}
	
	if (LOBYTE(wsaData.wVersion) != 2 || HIBYTE(wsaData.wVersion) != 2 )
	{
		//Tell the user that we could not find a usable WinSock DLL
		printf("Server: The dll do not support the Winsock version %u.%u!\n", LOBYTE(wsaData.wVersion),HIBYTE(wsaData.wVersion));
		// Do the clean up
		WSACleanup();
		// and exit with error
		return -1;
	}
	else
	{
		printf("Server: The dll supports the Winsock version %u.%u!\n", LOBYTE(wsaData.wVersion),HIBYTE(wsaData.wVersion));
		printf("Server: The highest version this dll can support is %u.%u\n", LOBYTE(wsaData.wHighVersion), HIBYTE(wsaData.wHighVersion));
	}
	
	// Create a new socket to listen for client connections.
	ListeningSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
	
	// Check for errors to ensure that the socket is a valid socket.
	if (ListeningSocket == INVALID_SOCKET)
	{
		printf("Server: Error at socket(), error code: %ld\n", WSAGetLastError());
		// Clean up
		WSACleanup();
		// and exit with error
		return -1;
	}
	else
		printf("Server: socket() is OK!\n");
	
	// Set up a SOCKADDR_IN structure that will tell bind that we
	// want to listen for connections on all interfaces using port 5150.

	// The IPv4 family
	ServerAddr.sin_family = AF_INET;
	// host-to-network byte order
	ServerAddr.sin_port = htons(Port);
	// Listen on all interface, host-to-network byte order
	ServerAddr.sin_addr.s_addr = htonl(INADDR_ANY);
	
	// Associate the address information with the socket using bind.
	// Call the bind function, passing the created socket and the sockaddr_in
	// structure as parameters. Check for general errors.
	if (bind(ListeningSocket, (SOCKADDR *)&ServerAddr, sizeof(ServerAddr)) == SOCKET_ERROR)
	{
		printf("Server: bind() failed! Error code: %ld.\n", WSAGetLastError());
		// Clos the socket
		closesocket(ListeningSocket);
		// Do the clean up
		WSACleanup();
		// and exit with error
		return -1;
	}
	else
		printf("Server: bind() is OK!\n");
	
	// Listen for client connections. We used a backlog of 5, which
	// is normal for many applications.
	if (listen(ListeningSocket, 5) == SOCKET_ERROR)
	{
		printf("Server: listen(): Error listening on socket %ld.\n", WSAGetLastError());
		// Close the socket
		closesocket(ListeningSocket);
		// Do the clean up
		WSACleanup();
		// Exit with error
		return -1;
	}
	else
		printf("Server: listen() is OK, I'm waiting for connections...\n");
	
	printf("Server: accept() is ready...\n");
	// Accept a new connection when one arrives.
	while(1)
	{
		NewConnection = SOCKET_ERROR;
		while(NewConnection == SOCKET_ERROR)
		{
			NewConnection = accept(ListeningSocket, NULL, NULL);
		}
		
		printf("Server: accept() is OK...\n");
		printf("Server: Client connected, ready for receiving and sending data...\n");
		// Transfer the connected socket to the listening socket
		ListeningSocket = NewConnection;
		break;
	}
	
	// At this point you can do two things with these sockets. Wait
	// for more connections by calling accept again on ListeningSocket
	// and start sending or receiving data on NewConnection (need a loop). We will
	// describe how to send and receive data later in the chapter.
	
	// When you are finished sending and receiving data on the
	// NewConnection socket and are finished accepting new connections
	// on ListeningSocket, you should close the sockets using the
	// closesocket API.
	if(closesocket(NewConnection) != 0)
		printf("Server: Cannot close \"NewConnection\" socket. Error code: %ld\n", WSAGetLastError());
	else
		printf("Server: Closing \"NewConnection\" socket...\n");
	
	// When your application is finished handling the connections, 
	// call WSACleanup.
	if(WSACleanup() != 0)
		printf("Server: WSACleanup() failed! Error code: %ld\n", WSAGetLastError());
	else
		printf("Server: WSACleanup() is OK...\n");
	return 0;
}