/*
 * COPYRIGHT:       See COPYING in the top level directory
 * PROJECT:         ReactOS Display Control Panel
 * FILE:            dll/cpl/desk/screensaver.c
 * PURPOSE:         Screen saver property page
 *
 * PROGRAMMERS:     Trevor McCort (lycan359@gmail.com)
 *                  Ged Murphy (gedmurphy@reactos.org)
 */

#include "desk.h"

#define MAX_SCREENSAVERS 100

typedef struct
{
    BOOL  bIsScreenSaver; /* Is this background a wallpaper */
    TCHAR szFilename[MAX_PATH];
    TCHAR szDisplayName[256];
} ScreenSaverItem;


typedef struct _DATA
{
    ScreenSaverItem     ScreenSaverItems[MAX_SCREENSAVERS];
    PROCESS_INFORMATION PrevWindowPi;
    int                 Selection;
    UINT                ScreenSaverCount;
} DATA, *PDATA;


static LPTSTR
GetCurrentScreenSaverValue(LPTSTR lpValue)
{
    HKEY hKey;
    LPTSTR lpBuf = NULL;
    DWORD BufSize, Type = REG_SZ;
    LONG Ret;

    Ret = RegOpenKeyEx(HKEY_CURRENT_USER,
                       _T("Control Panel\\Desktop"),
                       0,
                       KEY_READ,
                       &hKey);
    if (Ret != ERROR_SUCCESS)
        return NULL;

    Ret = RegQueryValueEx(hKey,
                          lpValue,
                          0,
                          &Type,
                          NULL,
                          &BufSize);
    if (Ret == ERROR_SUCCESS)
    {
        lpBuf = HeapAlloc(GetProcessHeap(),
                          0,
                          BufSize);
        if (lpBuf)
        {
            Ret = RegQueryValueEx(hKey,
                                  lpValue,
                                  0,
                                  &Type,
                                  (LPBYTE)lpBuf,
                                  &BufSize);
            if (Ret != ERROR_SUCCESS)
            {
                HeapFree(GetProcessHeap(), 0, lpBuf);
                lpBuf = NULL;
            }
        }
    }

    RegCloseKey(hKey);

    return lpBuf;
}


static VOID
SelectionChanged(HWND hwndDlg, PDATA pData)
{
    HWND hwndCombo;
    BOOL bEnable;
    INT i;

    hwndCombo = GetDlgItem(hwndDlg, IDC_SCREENS_LIST);

    i = (INT)SendMessage(hwndCombo, CB_GETCURSEL, 0, 0);
    i = (INT)SendMessage(hwndCombo, CB_GETITEMDATA, i, 0);

    pData->Selection = i;

    bEnable = (i != 0);

    EnableWindow(GetDlgItem(hwndDlg, IDC_SCREENS_SETTINGS), bEnable);
    EnableWindow(GetDlgItem(hwndDlg, IDC_SCREENS_TESTSC), bEnable);
    EnableWindow(GetDlgItem(hwndDlg, IDC_SCREENS_USEPASSCHK), bEnable);
    EnableWindow(GetDlgItem(hwndDlg, IDC_SCREENS_TIMEDELAY), bEnable);
    EnableWindow(GetDlgItem(hwndDlg, IDC_SCREENS_TIME), bEnable);
    EnableWindow(GetDlgItem(hwndDlg, IDC_WAITTEXT), bEnable);
    EnableWindow(GetDlgItem(hwndDlg, IDC_MINTEXT), bEnable);
}


static VOID
SetScreenSaverPreviewBox(HWND hwndDlg, PDATA pData)
{
    HWND hPreview = GetDlgItem(hwndDlg, IDC_SCREENS_PREVIEW);
    STARTUPINFO si;
    TCHAR szCmdline[2048];

    /* Kill off the previous preview process */
    if (pData->PrevWindowPi.hProcess)
    {
        TerminateProcess(pData->PrevWindowPi.hProcess, 0);
        CloseHandle(pData->PrevWindowPi.hProcess);
        CloseHandle(pData->PrevWindowPi.hThread);
        pData->PrevWindowPi.hThread = pData->PrevWindowPi.hProcess = NULL;
    }

    if (pData->Selection > 0)
    {
        _stprintf(szCmdline,
                  _T("%s /p %Iu"),
                  pData->ScreenSaverItems[pData->Selection].szFilename,
                  (ULONG_PTR)hPreview);

        ZeroMemory(&si, sizeof(si));
        si.cb = sizeof(si);
        ZeroMemory(&pData->PrevWindowPi, sizeof(pData->PrevWindowPi));

        if (!CreateProcess(NULL,
                           szCmdline,
                           NULL,
                           NULL,
                           FALSE,
                           0,
                           NULL,
                           NULL,
                           &si,
                           &pData->PrevWindowPi))
        {
            pData->PrevWindowPi.hThread = pData->PrevWindowPi.hProcess = NULL;
        }
    }
}

static BOOL
WaitForSettingsDialog(HWND hwndDlg,
                      HANDLE hProcess)
{
    DWORD dwResult;
    MSG msg;

    while (TRUE)
    {
        dwResult = MsgWaitForMultipleObjects(1,
                                             &hProcess,
                                             FALSE,
                                             INFINITE,
                                             QS_ALLINPUT);
        if (dwResult == WAIT_OBJECT_0 + 1)
        {
            if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE))
            {
                if (msg.message == WM_QUIT)
                {
                    return FALSE;
                }
                if (IsDialogMessage(hwndDlg, &msg))
                {
                    TranslateMessage(&msg);
                    DispatchMessage(&msg);
                }
            }
            else
            {
                return FALSE;
            }
        }
        else if (dwResult == WAIT_OBJECT_0)
        {
            return TRUE;
        }
        else
        {
            return FALSE;
        }
    }
}


static VOID
ScreensaverConfig(HWND hwndDlg, PDATA pData)
{
    /*
     * /c:<hwnd>  Run configuration, hwnd is handle of calling window
     */

    TCHAR szCmdline[2048];
    STARTUPINFO si;
    PROCESS_INFORMATION pi;

    if (pData->Selection < 1)
        return;

    _stprintf(szCmdline,
              _T("%s /c:%Iu"),
              pData->ScreenSaverItems[pData->Selection].szFilename,
              (ULONG_PTR)hwndDlg);

    ZeroMemory(&si, sizeof(si));
    si.cb = sizeof(si);
    ZeroMemory(&pi, sizeof(pi));
    if (CreateProcess(NULL,
                     szCmdline,
                     NULL,
                     NULL,
                     FALSE,
                     0,
                     NULL,
                     NULL,
                     &si,
                     &pi))
    {
        /* Kill off the previous preview process */
        if (pData->PrevWindowPi.hProcess)
        {
            TerminateProcess(pData->PrevWindowPi.hProcess, 0);
            CloseHandle(pData->PrevWindowPi.hProcess);
            CloseHandle(pData->PrevWindowPi.hThread);
            pData->PrevWindowPi.hThread = pData->PrevWindowPi.hProcess = NULL;
        }

        if (WaitForSettingsDialog(hwndDlg, pi.hProcess))
            SetScreenSaverPreviewBox(hwndDlg, pData);
    }
}


static VOID
ScreensaverPreview(HWND hwndDlg, PDATA pData)
{
    /*
       /s         Run normal
    */

    TCHAR szCmdline[2048];
    STARTUPINFO si;
    PROCESS_INFORMATION pi;

    if (pData->Selection < 1)
        return;

    /* Kill off the previous preview process */
    if (pData->PrevWindowPi.hProcess)
    {
        TerminateProcess(pData->PrevWindowPi.hProcess, 0);
        CloseHandle(pData->PrevWindowPi.hProcess);
        CloseHandle(pData->PrevWindowPi.hThread);
        pData->PrevWindowPi.hThread = pData->PrevWindowPi.hProcess = NULL;
    }

    _stprintf(szCmdline,
              _T("%s /s"),
              pData->ScreenSaverItems[pData->Selection].szFilename);

    ZeroMemory(&si, sizeof(si));
    si.cb = sizeof(si);
    ZeroMemory(&pi, sizeof(pi));
    if (CreateProcess(NULL,
                     szCmdline,
                     NULL,
                     NULL,
                     FALSE,
                     0,
                     NULL,
                     NULL,
                     &si,
                     &pi))
    {
        WaitForSingleObject(pi.hProcess, INFINITE);
        CloseHandle(pi.hProcess);
        CloseHandle(pi.hThread);
    }
}


static VOID
CheckRegScreenSaverIsSecure(HWND hwndDlg)
{
    HKEY hKey;
    TCHAR szBuffer[2];
    DWORD bufferSize = sizeof(szBuffer);
    DWORD varType = REG_SZ;
    LONG result;

    if (RegOpenKeyEx(HKEY_CURRENT_USER,
                     _T("Control Panel\\Desktop"),
                     0,
                     KEY_ALL_ACCESS,
                     &hKey) == ERROR_SUCCESS)
    {
        result = RegQueryValueEx(hKey,
                                _T("ScreenSaverIsSecure"),
                                0,
                                &varType,
                                (LPBYTE)szBuffer,
                                &bufferSize);
        RegCloseKey(hKey);

        if (result == ERROR_SUCCESS)
        {
            if (_ttoi(szBuffer) == 1)
            {
                SendDlgItemMessage(hwndDlg,
                                   IDC_SCREENS_USEPASSCHK,
                                   BM_SETCHECK,
                                   (WPARAM)BST_CHECKED,
                                   0);
                return;
            }
        }

        SendDlgItemMessage(hwndDlg,
                           IDC_SCREENS_USEPASSCHK,
                           BM_SETCHECK,
                           (WPARAM)BST_UNCHECKED,
                           0);
    }
}


static VOID
SearchScreenSavers(HWND hwndScreenSavers,
                   LPCTSTR pszSearchPath,
                   PDATA pData)
{
    WIN32_FIND_DATA  fd;
    TCHAR            szSearchPath[MAX_PATH];
    HANDLE           hFind;
    ScreenSaverItem *ScreenSaverItem;
    HANDLE           hModule;
    UINT             i, ScreenSaverCount;
    HRESULT hr;

    ScreenSaverCount = pData->ScreenSaverCount;

    hr = StringCbCopy(szSearchPath, sizeof(szSearchPath), pszSearchPath);
    if (FAILED(hr))
        return;
    hr = StringCbCat(szSearchPath, sizeof(szSearchPath), TEXT("\\*.scr"));
    if (FAILED(hr))
        return;

    hFind = FindFirstFile(szSearchPath, &fd);

    if (hFind == INVALID_HANDLE_VALUE)
        return;

    while (ScreenSaverCount < MAX_SCREENSAVERS)
    {
        /* Don't add any hidden screensavers */
        if ((fd.dwFileAttributes & FILE_ATTRIBUTE_HIDDEN) == 0)
        {
            TCHAR filename[MAX_PATH];

            hr = StringCbCopy(filename, sizeof(filename), pszSearchPath);
            if (FAILED(hr))
            {
                FindClose(hFind);
                return;
            }
            hr = StringCbCat(filename, sizeof(filename), _T("\\"));
            if (FAILED(hr))
            {
                FindClose(hFind);
                return;
            }
            hr = StringCbCat(filename, sizeof(filename), fd.cFileName);
            if (FAILED(hr))
            {
                FindClose(hFind);
                return;
            }

            ScreenSaverItem = pData->ScreenSaverItems + ScreenSaverCount;

            ScreenSaverItem->bIsScreenSaver = TRUE;

            hModule = LoadLibraryEx(filename,
                                    NULL,
                                    DONT_RESOLVE_DLL_REFERENCES | LOAD_LIBRARY_AS_DATAFILE);
            if (hModule)
            {
                if (0 == LoadString(hModule,
                          1,
                          ScreenSaverItem->szDisplayName,
                          sizeof(ScreenSaverItem->szDisplayName) / sizeof(TCHAR)))
                {
                    // If the string does not exists, copy the name of the file
                    hr = StringCbCopy(ScreenSaverItem->szDisplayName, sizeof(ScreenSaverItem->szDisplayName), fd.cFileName);
                    if (FAILED(hr))
                    {
                        FreeLibrary(hModule);
                        FindClose(hFind);
                        return;
                    }
                    ScreenSaverItem->szDisplayName[_tcslen(fd.cFileName)-4] = '\0';
                }
                FreeLibrary(hModule);
            }
            else
            {
                hr = StringCbCopy(ScreenSaverItem->szDisplayName, sizeof(ScreenSaverItem->szDisplayName), _T("Unknown"));
                if (FAILED(hr))
                {
                    FindClose(hFind);
                    return;
                }
            }

            hr = StringCbCopy(ScreenSaverItem->szFilename, sizeof(ScreenSaverItem->szFilename), filename);
            if (FAILED(hr))
            {
                FindClose(hFind);
                return;
            }

            i = SendMessage(hwndScreenSavers,
                            CB_ADDSTRING,
                            0,
                            (LPARAM)ScreenSaverItem->szDisplayName);

            SendMessage(hwndScreenSavers,
                        CB_SETITEMDATA,
                        i,
                        (LPARAM)ScreenSaverCount);

            ScreenSaverCount++;
        }

        if (!FindNextFile(hFind, &fd))
            break;
    }

    FindClose(hFind);

    pData->ScreenSaverCount = ScreenSaverCount;
}


static VOID
AddScreenSavers(HWND hwndDlg, PDATA pData)
{
    HWND hwndScreenSavers = GetDlgItem(hwndDlg, IDC_SCREENS_LIST);
    TCHAR szSearchPath[MAX_PATH];
    TCHAR szLocalPath[MAX_PATH];
    INT i;
    ScreenSaverItem *ScreenSaverItem = NULL;
    LPTSTR lpBackSlash;

    /* Add the "None" item */
    ScreenSaverItem = pData->ScreenSaverItems;

    ScreenSaverItem->bIsScreenSaver = FALSE;

    LoadString(hApplet,
               IDS_NONE,
               ScreenSaverItem->szDisplayName,
               sizeof(ScreenSaverItem->szDisplayName) / sizeof(TCHAR));

    i = SendMessage(hwndScreenSavers,
                    CB_ADDSTRING,
                    0,
                    (LPARAM)ScreenSaverItem->szDisplayName);

    SendMessage(hwndScreenSavers,
                CB_SETITEMDATA,
                i,
                (LPARAM)0);

    // Initialize number of items into the list
    pData->ScreenSaverCount = 1;

    // Add all the screensavers where the applet is stored.
    GetModuleFileName(hApplet, szLocalPath, MAX_PATH);
    lpBackSlash = _tcsrchr(szLocalPath, _T('\\'));
    if (lpBackSlash != NULL)
    {
        *lpBackSlash = '\0';
        SearchScreenSavers(hwndScreenSavers, szLocalPath, pData);
    }

    // Add all the screensavers in the C:\ReactOS\System32 directory.
    GetSystemDirectory(szSearchPath, MAX_PATH);
    if (lpBackSlash != NULL && _tcsicmp(szSearchPath, szLocalPath) != 0)
        SearchScreenSavers(hwndScreenSavers, szSearchPath, pData);

    // Add all the screensavers in the C:\ReactOS directory.
    GetWindowsDirectory(szSearchPath, MAX_PATH);
    if (lpBackSlash != NULL && _tcsicmp(szSearchPath, szLocalPath) != 0)
        SearchScreenSavers(hwndScreenSavers, szSearchPath, pData);
}


static VOID
SetScreenSaver(HWND hwndDlg, PDATA pData)
{
    HKEY regKey;
    BOOL DeleteMode = FALSE;

    DBG_UNREFERENCED_LOCAL_VARIABLE(DeleteMode);

    if (RegOpenKeyEx(HKEY_CURRENT_USER,
                     _T("Control Panel\\Desktop"),
                     0,
                     KEY_ALL_ACCESS,
                     &regKey) == ERROR_SUCCESS)
    {
        INT Time;
        BOOL bRet;
        TCHAR Sec;
        UINT Ret;

        /* Set the screensaver */
        if (pData->ScreenSaverItems[pData->Selection].bIsScreenSaver)
        {
            SIZE_T Length = _tcslen(pData->ScreenSaverItems[pData->Selection].szFilename) * sizeof(TCHAR);
            RegSetValueEx(regKey,
                          _T("SCRNSAVE.EXE"),
                          0,
                          REG_SZ,
                          (PBYTE)pData->ScreenSaverItems[pData->Selection].szFilename,
                          (DWORD)Length);

            SystemParametersInfo(SPI_SETSCREENSAVEACTIVE, TRUE, 0, SPIF_UPDATEINIFILE);
        }
        else
        {
            /* Windows deletes the value if no screensaver is set */
            RegDeleteValue(regKey, _T("SCRNSAVE.EXE"));
            DeleteMode = TRUE;

            SystemParametersInfo(SPI_SETSCREENSAVEACTIVE, FALSE, 0, SPIF_UPDATEINIFILE);
        }

        /* Set the secure value */
        Ret = SendDlgItemMessage(hwndDlg,
                                 IDC_SCREENS_USEPASSCHK,
                                 BM_GETCHECK,
                                 0,
                                 0);
        Sec = (Ret == BST_CHECKED) ? _T('1') : _T('0');
        RegSetValueEx(regKey,
                      _T("ScreenSaverIsSecure"),
                      0,
                      REG_SZ,
                      (PBYTE)&Sec,
                      sizeof(TCHAR));

        /* Set the screensaver time delay */
        Time = GetDlgItemInt(hwndDlg,
                             IDC_SCREENS_TIMEDELAY,
                             &bRet,
                             FALSE);
        if (Time == 0)
            Time = 60;
        else
            Time *= 60;

        SystemParametersInfoW(SPI_SETSCREENSAVETIMEOUT, Time, 0, SPIF_SENDCHANGE | SPIF_UPDATEINIFILE);

        RegCloseKey(regKey);
    }
}


static BOOL
OnInitDialog(HWND hwndDlg, PDATA pData)
{
    LPTSTR lpCurSs;
    HWND hwndSSCombo = GetDlgItem(hwndDlg, IDC_SCREENS_LIST);
    INT Num;

    pData = HeapAlloc(GetProcessHeap(),
                            HEAP_ZERO_MEMORY,
                            sizeof(DATA));
    if (!pData)
    {
        EndDialog(hwndDlg, -1);
        return FALSE;
    }

    SetWindowLongPtr(hwndDlg,
                     DWLP_USER,
                     (LONG_PTR)pData);

    pData->Selection = -1;

    SendDlgItemMessage(hwndDlg,
                       IDC_SCREENS_TIME,
                       UDM_SETRANGE,
                       0,
                       MAKELONG
                       ((short) 240, (short) 1));

    AddScreenSavers(hwndDlg,
                    pData);

    CheckRegScreenSaverIsSecure(hwndDlg);

    /* Set the current screensaver in the combo box */
    lpCurSs = GetCurrentScreenSaverValue(_T("SCRNSAVE.EXE"));
    if (lpCurSs)
    {
        BOOL bFound = FALSE;
        INT i;

        for (i = 0; i < MAX_SCREENSAVERS; i++)
        {
            if (!_tcscmp(lpCurSs, pData->ScreenSaverItems[i].szFilename))
            {
                bFound = TRUE;
                break;
            }
        }

        if (bFound)
        {
            Num = SendMessage(hwndSSCombo,
                              CB_FINDSTRINGEXACT,
                              -1,
                              (LPARAM)pData->ScreenSaverItems[i].szDisplayName);
            if (Num != CB_ERR)
                SendMessage(hwndSSCombo,
                            CB_SETCURSEL,
                            Num,
                            0);
        }
        else
        {
            SendMessage(hwndSSCombo,
                        CB_SETCURSEL,
                        0,
                        0);
        }

        HeapFree(GetProcessHeap(),
                 0,
                 lpCurSs);
    }
    else
    {
        /* Set screensaver to (none) */
        SendMessage(hwndSSCombo,
                    CB_SETCURSEL,
                    0,
                    0);
    }

    /* Set the current timeout */
    lpCurSs = GetCurrentScreenSaverValue(_T("ScreenSaveTimeOut"));
    if (lpCurSs)
    {
        UINT Time = _ttoi(lpCurSs);

        Time /= 60;

        SendDlgItemMessage(hwndDlg,
                           IDC_SCREENS_TIME,
                           UDM_SETPOS32,
                           0,
                           Time);

        HeapFree(GetProcessHeap(),
                 0,
                 lpCurSs);

    }

    SelectionChanged(hwndDlg,
                     pData);

    return TRUE;
}


INT_PTR CALLBACK
ScreenSaverPageProc(HWND hwndDlg,
                    UINT uMsg,
                    WPARAM wParam,
                    LPARAM lParam)
{
    PDATA pData;

    pData = (PDATA)GetWindowLongPtr(hwndDlg, DWLP_USER);

    switch (uMsg)
    {
        case WM_INITDIALOG:
        {
            OnInitDialog(hwndDlg, pData);
            break;
        }

        case WM_DESTROY:
        {
            if (pData->PrevWindowPi.hProcess)
            {
                TerminateProcess(pData->PrevWindowPi.hProcess, 0);
                CloseHandle(pData->PrevWindowPi.hProcess);
                CloseHandle(pData->PrevWindowPi.hThread);
            }
            HeapFree(GetProcessHeap(),
                     0,
                     pData);
            break;
        }

        case WM_ENDSESSION:
        {
            SetScreenSaverPreviewBox(hwndDlg,
                                     pData);
            break;
        }

        case WM_COMMAND:
        {
            DWORD controlId = LOWORD(wParam);
            DWORD command   = HIWORD(wParam);

            switch (controlId)
            {
                case IDC_SCREENS_LIST:
                {
                    if (HIWORD(wParam) == CBN_SELCHANGE)
                    {
                        SelectionChanged(hwndDlg, pData);
                        SetScreenSaverPreviewBox(hwndDlg, pData);
                        PropSheet_Changed(GetParent(hwndDlg), hwndDlg);
                    }
                    break;
                }

                case IDC_SCREENS_TIMEDELAY:
                {
                    if (command == EN_CHANGE)
                        PropSheet_Changed(GetParent(hwndDlg), hwndDlg);
                    break;
                }

                case IDC_SCREENS_POWER_BUTTON: // Start Powercfg.Cpl
                {
                    if (command == BN_CLICKED)
                        WinExec("rundll32 shell32.dll,Control_RunDLL powercfg.cpl",SW_SHOWNORMAL);
                    break;
                }

                case IDC_SCREENS_TESTSC: // Screensaver Preview
                {
                    if (command == BN_CLICKED)
                    {
                        ScreensaverPreview(hwndDlg, pData);
                        SetScreenSaverPreviewBox(hwndDlg, pData);
                    }
                    break;
                }

                case IDC_SCREENS_SETTINGS: // Screensaver Settings
                {
                    if (command == BN_CLICKED)
                        ScreensaverConfig(hwndDlg, pData);
                    break;
                }

                case IDC_SCREENS_USEPASSCHK: // Screensaver Is Secure
                {
                    if (command == BN_CLICKED)
                    {
                        PropSheet_Changed(GetParent(hwndDlg), hwndDlg);
                    }
                    break;
                }
            }
            break;
        }

        case WM_NOTIFY:
        {
            LPNMHDR lpnm = (LPNMHDR)lParam;

            switch(lpnm->code)
            {
                case PSN_APPLY:
                {
                    SetScreenSaver(hwndDlg, pData);
                    return TRUE;
                }

                case PSN_SETACTIVE:
                {
                    /* Enable screensaver preview support */
                    SetScreenSaverPreviewBox(hwndDlg, pData);
                    break;
                }

                case PSN_KILLACTIVE:
                {
                    /* Kill running preview screensaver */
                    if (pData->PrevWindowPi.hProcess)
                    {
                        TerminateProcess(pData->PrevWindowPi.hProcess, 0);
                        CloseHandle(pData->PrevWindowPi.hProcess);
                        CloseHandle(pData->PrevWindowPi.hThread);
                        pData->PrevWindowPi.hThread = pData->PrevWindowPi.hProcess = NULL;
                    }
                    break;
                }
            }
        }
        break;
    }

    return FALSE;
}