#include<windows.h>
#include<winsock.h>
#include<string.h>

#define SOCK_DATA_ARRIVAL (WM_USER + 1)


#define BUTTON_LISTEN 1
#define BUTTON_CONNECT 2
#define BUTTON_CLOSE 3
#define BUTTON_SEND 4

#define EDIT_LISTEN 5
#define EDIT_SEND 6

int Port = 5553;
SOCKET sock_listen, sock_s;
SOCKADDR_IN my_addr, remote_addr;
WSADATA wsData;


LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
HINSTANCE hInst;

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, PSTR lpCmdLine, int ShowCmd)
{
	TCHAR appname[] = "App";
	MSG msg;
	HWND hwnd;
	WNDCLASS wclass;

	wclass.style = CS_HREDRAW | CS_VREDRAW;
	wclass.lpfnWndProc = WndProc;
	wclass.cbClsExtra = 0;
	wclass.cbWndExtra = 0;
	wclass.hInstance = hInstance;
	wclass.hIcon = LoadIcon(NULL, IDI_APPLICATION);
	wclass.hCursor = LoadCursor(NULL, IDC_ARROW);
	wclass.hbrBackground = (HBRUSH)GetStockObject(LTGRAY_BRUSH);
	wclass.lpszMenuName = NULL;
	wclass.lpszClassName = appname;

	if(!(RegisterClass(&wclass)))
	{
		MessageBox(NULL, "RegisterClass(*WNDCLASS) Failed.", "Error", NULL);
		return 0;
	}

	hInst = hInstance;

	hwnd = CreateWindowEx(
		NULL,
		appname,
		"Window Title",
		WS_OVERLAPPED | WS_SYSMENU | WS_MINIMIZEBOX,
		0,
		0,
		275,
		255,
		NULL,
		NULL,
		hInstance,
		NULL);

	ShowWindow(hwnd, ShowCmd);
	UpdateWindow(hwnd);

	WSAAsyncSelect(sock_listen, hwnd, SOCK_DATA_ARRIVAL, FD_ACCEPT|FD_READ|FD_CONNECT);
	WSAAsyncSelect(sock_s, hwnd, SOCK_DATA_ARRIVAL, FD_ACCEPT|FD_READ|FD_CONNECT);

	while(GetMessage(&msg, 0, 0, 0))
	{
		TranslateMessage(&msg);
		DispatchMessage(&msg);
	}

	WSACleanup();

	return msg.wParam;
}

LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
	static int xClient, yClient,
		cxChar, cxCaps, cyChar;

	static bool isserver;

	HDC hdc;
	PAINTSTRUCT ps;
	TEXTMETRIC tm;

	switch(message)
	{
	case WM_CREATE:
		{
			hdc = GetDC(hwnd);
			GetTextMetrics(hdc, &tm);
			cxChar = tm.tmAveCharWidth;
			cxCaps = (tm.tmPitchAndFamily & 1 ? 3 : 2) * cxChar / 2;
			cyChar = tm.tmHeight + tm.tmExternalLeading;


			CreateWindowEx(
				NULL,
				"BUTTON",
				"Listen",
				WS_CHILD | WS_VISIBLE | BS_PUSHBUTTON,
				10,
				10,
				75,
				30,
				hwnd,
				(HMENU) BUTTON_LISTEN,
				hInst,
				NULL);

			CreateWindowEx(
				NULL,
				"BUTTON",
				"Connect",
				WS_CHILD | WS_VISIBLE | BS_PUSHBUTTON,
				95,
				10,
				75,
				30,
				hwnd,
				(HMENU) BUTTON_CONNECT,
				hInst,
				NULL);

			CreateWindowEx(
				NULL,
				"BUTTON",
				"Close",
				WS_CHILD | WS_VISIBLE | BS_PUSHBUTTON,
				180,
				10,
				75,
				30,
				hwnd,
				(HMENU) BUTTON_CLOSE,
				hInst,
				NULL);

			CreateWindowEx(
				NULL,
				"EDIT",
				"Listen Text",
				WS_CHILD | WS_VISIBLE | WS_BORDER | WS_VSCROLL | ES_MULTILINE,
				10,
				50,
				245,
				100,
				hwnd,
				(HMENU) EDIT_LISTEN,
				hInst,
				NULL);

			CreateWindowEx(
				NULL,
				"EDIT",
				"Send Text",
				WS_CHILD | WS_VISIBLE | WS_BORDER | ES_MULTILINE | ES_AUTOHSCROLL,
				10,
				160,
				245,
				20,
				hwnd,
				(HMENU) EDIT_SEND,
				hInst,
				NULL);

			CreateWindowEx(
				NULL,
				"BUTTON",
				"Send",
				WS_CHILD | WS_VISIBLE | BS_PUSHBUTTON,
				180,
				190,
				75,
				30,
				hwnd,
				(HMENU) BUTTON_SEND,
				hInst,
				NULL);

			return 0;
		}
	case WM_COMMAND:
		{
			switch(HIWORD(wParam))
			{
			case BN_CLICKED:
				{
					switch(LOWORD(wParam))
					{
					case BUTTON_LISTEN:
						{
							WSAStartup(MAKEWORD(1,1), &wsData);

							isserver = true;

							sock_listen = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);

							if(sock_listen == SOCKET_ERROR)
							{
								MessageBox(hwnd, "socket() failed.", "server", MB_OK);
								return 0;
							}

							my_addr.sin_family = AF_INET;
							my_addr.sin_port = htons(Port);
							my_addr.sin_addr.s_addr = htonl(INADDR_ANY);

							if((bind(sock_listen, (struct sockaddr *) &my_addr, sizeof(my_addr))) == SOCKET_ERROR)
							{
								MessageBox(hwnd, "bind() failed.", "server", MB_OK);
								return 0;
							}

							if((listen(sock_listen, 10)) == SOCKET_ERROR)
							{
								MessageBox(hwnd, "listen() failed.", "server", MB_OK);
								return 0;
							}

							MessageBox(hwnd, "listening for connections.", "server", MB_OK);

							return 0;
						}
					case BUTTON_CONNECT:
						{
							WSAStartup(MAKEWORD(1,1), &wsData);

							isserver = false;
							char szAddress[64] = "127.0.0.1";
							char iAddressLen = strlen(szAddress);

							sock_s = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);

							if(sock_s == SOCKET_ERROR)
							{
								MessageBox(hwnd, "socket() failed.", "client", MB_OK);
								return 0;
							}

							remote_addr.sin_family = AF_INET;
							remote_addr.sin_port = htons(Port);
							remote_addr.sin_addr.s_addr = inet_addr(szAddress);

							if((connect(sock_s, (struct sockaddr *) &remote_addr, sizeof(remote_addr))) == SOCKET_ERROR)
							{
								MessageBox(hwnd, "connect() failed.", "client", MB_OK);
								return 0;
							}

							MessageBox(hwnd, "connect?", "", NULL);

							return 0;
						}
					case BUTTON_CLOSE:
						{
							closesocket(sock_s);
							closesocket(sock_listen);
							WSACleanup();
							return 0;
						}
					case BUTTON_SEND:
						{
							char szSendBuffer[512];

							GetDlgItemText(hwnd, EDIT_SEND, szSendBuffer, 512);

							if((send(sock_s, szSendBuffer, strlen(szSendBuffer), 0)) == SOCKET_ERROR)
							{
								MessageBox(hwnd, "send() failed.", (isserver == true) ? "server" : "client", MB_OK);
								return 0;
							}

							send(sock_s, szSendBuffer, strlen(szSendBuffer), 0);

							return 0;
						}
					}
				}
			}
			return 0;
		}
	case SOCK_DATA_ARRIVAL:
		{
			switch(LOWORD(lParam))
			{
			case FD_READ:
				{
					int ret;
					char szBuffer[512];
					
					ret = recv(sock_s, szBuffer, sizeof(szBuffer), 0);

					if(ret == SOCKET_ERROR)
					{
						MessageBox(hwnd, "recv() failed.", (isserver == true) ? "server" : "client", MB_OK);
						return 0;
					}

					szBuffer[ret] = '\0';

					SetDlgItemText(hwnd, EDIT_LISTEN, szBuffer);

					return 0;
				}
			case FD_ACCEPT:
				{
					int len;
					len = sizeof(remote_addr);
					sock_s = accept(sock_listen, (struct sockaddr *) &remote_addr, &len);

					MessageBox(hwnd, "connection received.", "server", NULL);
					return 0;
				}
			case FD_CONNECT:
				{
					MessageBox(hwnd, "socket connected.", (isserver == true) ? "server" : "client", NULL);
					return 0;
				}
			}
		}
	case WM_PAINT:
		{
			hdc = BeginPaint(hwnd, &ps);
			EndPaint(hwnd, &ps);
			return 0;
		}
	case WM_SIZE:
		{
			xClient = LOWORD(lParam);
			yClient = HIWORD(lParam);
			return 0;
		}
	case WM_DESTROY:
		{
			PostQuitMessage(0);
			return 0;
		}
	}

	return DefWindowProc(hwnd, message, wParam, lParam);
}

case FD_READ:
{
	char szRead[1024];
	int ReadLen = recv(sock_s, szRead, sizeof(szRead), 0);

	szRead[ReadLen] = '\0';
					
	SetDlgItemText(hwnd, EDIT_LISTEN, szRead);

	break;
}