#include "alfpriv.h"

#include <shlwapi.h>

static
DWORD ALF_DllGetVersion(const char *dll)
{
    HMODULE hDll = GetModuleHandleA(dll);

    if (hDll) {
        DLLGETVERSIONPROC pDllGetVersion;
        pDllGetVersion = (DLLGETVERSIONPROC)(void*)GetProcAddress(hDll, "DllGetVersion");

        if (pDllGetVersion) {
            DLLVERSIONINFO dvi;
            HRESULT hr;

            ZeroMemory(&dvi, sizeof(dvi));
            dvi.cbSize = sizeof(dvi);

            hr = (*pDllGetVersion)(&dvi);

            if (SUCCEEDED(hr)) {
                return MAKELONG(dvi.dwMinorVersion, dvi.dwMajorVersion);
            }
        }
    }
    return 0;
}

static int WINAPI
ALF_Compat_fallbackGetSystemMetricsForDpi(int nIndex, UINT dpi)
{
    (void)dpi;
    if (!ALF_Compat_IsMinWindowsVersion(4, 0)) {
        // old NT does not support several properties, so we fake them
        switch (nIndex) {
            case SM_CXEDGE:
            case SM_CYEDGE:
                return 2;
        }
    }
    return GetSystemMetrics(nIndex);
}

static BOOL WINAPI
ALF_Compat_fallbackIsAppThemed(void)
{
    return FALSE;
}

static UINT WINAPI
ALF_Compat_fallbackGetDpiForWindow(HWND win)
{
    (void)win;

    UINT dpi = 0;

    HDC hdcScreen = GetDC(NULL);
    if (hdcScreen) {
        dpi = GetDeviceCaps(hdcScreen, LOGPIXELSY);
        ReleaseDC(NULL, hdcScreen);
    }

    if (!dpi) {
        dpi = 96; // FIXME! fallback to default DPI
    }

    return dpi;
}

static BOOL WINAPI
ALF_Compat_fallbackSystemParametersInfoForDpi(UINT uiAction, UINT uiParam, PVOID pvParam, UINT fWinIni, UINT dpi)
{
    (void)dpi;

    // NOTE: we only use SystemParametersInfoForDpi for SPI_GETNONCLIENTMETRICS,
    // therefore we only provide a fallback for that.
    // SystemParametersInfoForDpi only accepts the Vista+ version of NONCLIENTMETRICSW.
    if (uiAction == SPI_GETNONCLIENTMETRICS && uiParam == sizeof(ALF_NONCLIENTMETRICSW_VISTA)) {
        ALF_NONCLIENTMETRICSW_VISTA *ncmw = (ALF_NONCLIENTMETRICSW_VISTA*)pvParam;

        // SystemParametersInfoForDpi is Unicode-only, but
        // we need to provide a fallback even on ANSI systems
#ifdef UNICODE
        SIZE_T s = sizeof(*ncmw);
        if (!ALF_Compat_IsMinWindowsVersion(6, 0)) {
            // pre-vista OS doesn't contain last member
            s -= sizeof(ncmw->iPaddedBorderWidth);
            ncmw->iPaddedBorderWidth = 0;
        }

        ncmw->cbSize = s;
        return SystemParametersInfo(SPI_GETNONCLIENTMETRICS, s, ncmw, fWinIni);
#else
        ALF_NONCLIENTMETRICSA_VISTA ncma;
        ZeroMemory(&ncma, sizeof(ncma));

        SIZE_T s = sizeof(ncma);
        if (!ALF_Compat_IsMinWindowsVersion(6, 0)) {
            // pre-vista OS doesn't contain last member
            s -= sizeof(ncma.iPaddedBorderWidth);
            ncma.iPaddedBorderWidth = 0;
        }

        ncma.cbSize = s;

        if (SystemParametersInfo(SPI_GETNONCLIENTMETRICS, s, &ncma, fWinIni)) {
            ncmw->iBorderWidth = ncma.iBorderWidth;
            ncmw->iScrollWidth = ncma.iScrollWidth;
            ncmw->iScrollHeight = ncma.iScrollHeight;
            ncmw->iCaptionWidth = ncma.iCaptionWidth;
            ncmw->iCaptionHeight = ncma.iCaptionHeight;
            ALF_Compat_LogFontAtoW(&ncma.lfCaptionFont, &ncmw->lfCaptionFont);
            ncmw->iSmCaptionWidth = ncma.iSmCaptionWidth;
            ncmw->iSmCaptionHeight = ncma.iSmCaptionHeight;
            ALF_Compat_LogFontAtoW(&ncma.lfSmCaptionFont, &ncmw->lfSmCaptionFont);
            ncmw->iMenuWidth = ncma.iMenuWidth;
            ncmw->iMenuHeight = ncma.iMenuHeight;
            ALF_Compat_LogFontAtoW(&ncma.lfMenuFont, &ncmw->lfMenuFont);
            ALF_Compat_LogFontAtoW(&ncma.lfStatusFont, &ncmw->lfStatusFont);
            ALF_Compat_LogFontAtoW(&ncma.lfMessageFont, &ncmw->lfMessageFont);
            ncmw->iPaddedBorderWidth = ncma.iPaddedBorderWidth;

            return TRUE;
        }

        return FALSE;
#endif
    }

    return FALSE;
}

static BOOL WINAPI
ALF_Compat_fallbackAdjustWindowRectExForDpi(LPRECT lpRect, DWORD dwStyle, BOOL bMenu, DWORD dwExStyle, UINT dpi)
{
    (void)dpi;

    return AdjustWindowRectEx(lpRect, dwStyle, bMenu, dwExStyle);
}


// FIXME: these support one subclass only, negating the whole point of it

typedef struct {
    ALF_COMPAT_SUBCLASSPROC pfnSubclass;
    UINT_PTR uIdSubclass;
    DWORD_PTR dwRefData;
    UINT runCounter;
    WNDPROC orig;
} ALFWindowSubclassData;

static LRESULT CALLBACK
ALF_Compat_fallbackSubclassProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
    ALFWindowSubclassData *data = (ALFWindowSubclassData *)GetWindowLongPtr(hwnd, GWLP_USERDATA);

    LRESULT ret = 0;

    data->runCounter++;

    if (data->pfnSubclass)
        ret = data->pfnSubclass(hwnd, uMsg, wParam, lParam, data->uIdSubclass, data->dwRefData);
    else
        ret = CallWindowProc(data->orig, hwnd, uMsg, wParam, lParam);

    data->runCounter--;

    if (!data->pfnSubclass && !data->runCounter) {
        SetWindowLongPtr(hwnd, GWLP_USERDATA, 0);
        ALF_Free(data);
    }

    return ret;
}

static BOOL WINAPI
ALF_Compat_fallbackSetWindowSubclass(HWND hwnd, ALF_COMPAT_SUBCLASSPROC pfnSubclass, UINT_PTR uIdSubclass, DWORD_PTR dwRefData)
{
    ALFWindowSubclassData *data = ALF_New(ALFWindowSubclassData, 1);

    data->pfnSubclass = pfnSubclass;
    data->uIdSubclass = uIdSubclass;
    data->dwRefData = dwRefData;
    data->orig = (WNDPROC)GetWindowLongPtr(hwnd, GWLP_WNDPROC);

    SetWindowLongPtr(hwnd, GWLP_USERDATA, (LONG_PTR)data);
    SetWindowLongPtr(hwnd, GWLP_WNDPROC, (LONG_PTR)ALF_Compat_fallbackSubclassProc);

    return TRUE;
}

static LRESULT WINAPI
ALF_Compat_fallbackDefSubclassProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
    ALFWindowSubclassData *data = (ALFWindowSubclassData *)GetWindowLongPtr(hwnd, GWLP_USERDATA);

    return CallWindowProc(data->orig, hwnd, uMsg, wParam, lParam);
}

static BOOL WINAPI
ALF_Compat_fallbackRemoveWindowSubclass(HWND hwnd, ALF_COMPAT_SUBCLASSPROC pfnSubclass, UINT_PTR uIdSubclass)
{
    (void)pfnSubclass;
    (void)uIdSubclass;

    ALFWindowSubclassData *data = (ALFWindowSubclassData *)GetWindowLongPtr(hwnd, GWLP_USERDATA);

    data->pfnSubclass = 0;
    data->uIdSubclass = 0;
    SetWindowLongPtr(hwnd, GWLP_WNDPROC, (LONG_PTR)data->orig);

    // can't free it while the subclass is running, possibly in a nested SendMessage
    // and wants to call DefSubclassProc
    if (!data->runCounter) {
        SetWindowLongPtr(hwnd, GWLP_USERDATA, 0);
        ALF_Free(data);
    }

    return TRUE;
}

long
ALF_GetAveCharWidth(HDC hdc)
{
    // see: HOWTO: Calculate Dialog Units When Not Using the System Font

    SIZE s;
    GetTextExtentPoint32A(hdc, "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz", 52, &s);

    return (s.cx / 26 + 1) / 2;
}

static HTHEME WINAPI
ALF_Compat_fallbackOpenThemeData(HWND window, LPCWSTR classNames)
{
    (void)window;
    (void)classNames;

    return NULL;
}

static HRESULT WINAPI
ALF_Compat_fallbackCloseThemeData(HTHEME hTheme)
{
    (void)hTheme;

    return S_OK;
}

static BOOL WINAPI
ALF_Compat_fallbackIsThemeBackgroundPartiallyTransparent(HTHEME hTheme, int iPartId, int iStateId)
{
    (void)hTheme; (void)iPartId; (void)iStateId;

    return TRUE;
}

static HRESULT WINAPI
ALF_Compat_fallbackDrawThemeParentBackground(HWND hwnd, HDC hdc, RECT *prc)
{
    HWND parent = GetParent(hwnd);
    if (!parent)
        return E_NOTIMPL;

    RECT rc;
    if (prc) {
        rc = *prc;
    } else {
        GetClientRect(hwnd, &rc);
    }
    MapWindowRect(hwnd, parent, &rc);

    RECT childr;
    GetClientRect(hwnd, &childr);
    MapWindowRect(hwnd, parent, &childr);

    POINT o;
    OffsetViewportOrgEx(hdc, -childr.left, -childr.top, &o);

    HRGN oldClipRgn = CreateRectRgn(0, 0, 0, 0);
    if (!GetClipRgn(hdc, oldClipRgn)) {
        DeleteObject(oldClipRgn);
        oldClipRgn = NULL;
    }

    IntersectClipRect(hdc, rc.left, rc.top, rc.right, rc.bottom);

    SendMessage(parent, WM_ERASEBKGND, (WPARAM)hdc, 0);
    SendMessage(parent, WM_PRINTCLIENT, (WPARAM)hdc, (LPARAM)PRF_CLIENT);

    SelectClipRgn(hdc, oldClipRgn);
    if (oldClipRgn) {
        DeleteObject(oldClipRgn);
    }

    SetViewportOrgEx(hdc, o.x, o.y, NULL);

    return S_OK;
}

static HRESULT WINAPI
ALF_Compat_fallbackDrawThemeBackground(HTHEME hTheme, HDC hdc, int iPartId, int iStateId, const RECT *pRect, const RECT *pClipRect)
{
    (void)hTheme;
    (void)hdc;
    (void)iPartId;
    (void)iStateId;
    (void)pRect;
    (void)pClipRect;

    return E_NOTIMPL;
}

static HRESULT WINAPI
ALF_Compat_fallbackGetThemeBackgroundContentRect(HTHEME hTheme, HDC hdc, int iPartId, int iStateId, const RECT *pBoundingRect, RECT *pContentRect)
{
    (void)hTheme;
    (void)hdc;
    (void)iPartId;
    (void)iStateId;
    (void)pBoundingRect;
    (void)pContentRect;

    return E_NOTIMPL;
}

static HRESULT WINAPI
ALF_Compat_fallbackGetThemeTextExtent(HTHEME hTheme, HDC hdc, int iPartId,
                                      int iStateId, LPCWSTR pszText, int iCharCount,
                                      DWORD dwTextFlags, const RECT *pBoundingRect,
                                      RECT *pExtentRect)
{
    (void)hTheme; (void)hdc; (void)iPartId; (void)iStateId; (void)pszText;
    (void)iCharCount; (void)dwTextFlags; (void)pBoundingRect; (void)pExtentRect;

    return E_NOTIMPL;
}

static HRESULT WINAPI
ALF_Compat_fallbackDrawThemeText(HTHEME hTheme, HDC hdc, int iPartId, int iStateId,
                                 LPCWSTR pszText, int iCharCount, DWORD dwTextFlags,
                                 DWORD dwTextFlags2, const RECT *pRect)
{
    (void)hTheme; (void)hdc; (void)iPartId; (void)iStateId; (void)pszText;
    (void)iCharCount; (void)dwTextFlags; (void)dwTextFlags2; (void)pRect;

    return E_NOTIMPL;
}

static BOOL WINAPI
ALF_Compat_fallbackTrackMouseEvent(LPTRACKMOUSEEVENT tme)
{
    (void)tme;

    return FALSE;
}

static HRESULT WINAPI
ALF_Compat_fallbackBufferedPaintInit(void)
{
    return E_NOTIMPL;
}

static HRESULT WINAPI
ALF_Compat_fallbackBufferedPaintUnInit(void)
{
    return E_NOTIMPL;
}

static ALF_Compat_HANIMATIONBUFFER WINAPI
ALF_Compat_fallbackBeginBufferedAnimation(HWND hwnd, HDC hdcTarget,
                                          const RECT *prcTarget, DWORD dwFormat,
                                          ALF_Compat_BP_PAINTPARAMS *pPaintParams,
                                          ALF_Compat_BP_ANIMATIONPARAMS *pAnimationParams,
                                          HDC *phdcFrom, HDC *phdcTo)
{
    (void)hwnd; (void)hdcTarget; (void)prcTarget; (void)dwFormat;
    (void)pPaintParams; (void)pAnimationParams; (void)phdcFrom; (void)phdcTo;

    return NULL;
}

static HRESULT WINAPI
ALF_Compat_fallbackEndBufferedAnimation(ALF_Compat_HANIMATIONBUFFER hbpAnimation, BOOL fUpdateTarget)
{
    (void)hbpAnimation; (void)fUpdateTarget;

    return E_NOTIMPL;
}

static BOOL WINAPI
ALF_Compat_fallbackBufferedPaintRenderAnimation(HWND hwnd, HDC hdc)
{
    (void)hwnd; (void)hdc;

    return FALSE;
}

static HRESULT WINAPI
ALF_Compat_fallbackGetThemeTransitionDuration(HTHEME hTheme,
                                              int    iPartId,
                                              int    iStateIdFrom,
                                              int    iStateIdTo,
                                              int    iPropId,
                                              DWORD  *pdwDuration)
{
    (void)hTheme; (void)iPartId; (void)iStateIdFrom; (void)iStateIdTo; (void)iPropId; (void)pdwDuration;

    return E_NOTIMPL;
}

#define LOAD_FUNC(dll, name) do { \
        if (_alf_dll_##dll) \
            *((FARPROC*)&ALF_Compat_##name) = GetProcAddress(_alf_dll_##dll, #name); \
        else \
            ALF_Compat_##name = NULL; \
        \
        if (!ALF_Compat_##name) \
            ALF_Compat_##name = ALF_Compat_fallback##name; \
    } while (0)

#define UNLOAD_FUNC(name) do { ALF_Compat_##name = NULL; } while (0)

static HMODULE _alf_dll_uxtheme  = NULL;
static HMODULE _alf_dll_user32   = NULL;
static HMODULE _alf_dll_comctl32 = NULL;

void ALF_LoadCompatFunctions(void)
{
    if (ALF_Compat_IsWinNT()) // don't attempt to load uxtheme.dll on non-NT platforms (ugly error on Win32s)
        _alf_dll_uxtheme  = LoadLibraryA("uxtheme.dll");

    _alf_dll_user32   = LoadLibraryA("user32.dll");
    _alf_dll_comctl32 = LoadLibraryA("comctl32.dll");


    if (ALF_DllGetVersion("comctl32.dll") >= 0x60000)
        LOAD_FUNC(uxtheme, IsAppThemed);
    else
        ALF_Compat_IsAppThemed = ALF_Compat_fallbackIsAppThemed;

    LOAD_FUNC(user32, GetDpiForWindow);
    LOAD_FUNC(user32, AdjustWindowRectExForDpi);
    LOAD_FUNC(user32, GetSystemMetricsForDpi);

    *((FARPROC*)&ALF_Compat_SetWindowSubclass) = GetProcAddress(_alf_dll_comctl32, "SetWindowSubclass");
    if (!ALF_Compat_SetWindowSubclass)
        *((FARPROC*)&ALF_Compat_SetWindowSubclass) = GetProcAddress(_alf_dll_comctl32, (char*)410);
    if (!ALF_Compat_SetWindowSubclass)
        ALF_Compat_SetWindowSubclass = ALF_Compat_fallbackSetWindowSubclass;

    *((FARPROC*)&ALF_Compat_DefSubclassProc) = GetProcAddress(_alf_dll_comctl32, "DefSubclassProc");
    if (!ALF_Compat_DefSubclassProc)
        *((FARPROC*)&ALF_Compat_DefSubclassProc) = GetProcAddress(_alf_dll_comctl32, (char*)413);
    if (!ALF_Compat_DefSubclassProc)
        ALF_Compat_DefSubclassProc = ALF_Compat_fallbackDefSubclassProc;

    *((FARPROC*)&ALF_Compat_RemoveWindowSubclass) = GetProcAddress(_alf_dll_comctl32, "RemoveWindowSubclass");
    if (!ALF_Compat_RemoveWindowSubclass)
        *((FARPROC*)&ALF_Compat_RemoveWindowSubclass) = GetProcAddress(_alf_dll_comctl32, (char*)412);
    if (!ALF_Compat_RemoveWindowSubclass)
        ALF_Compat_RemoveWindowSubclass = ALF_Compat_fallbackRemoveWindowSubclass;

    LOAD_FUNC(user32, SystemParametersInfoForDpi);

    *((FARPROC*)&ALF_Compat_TrackMouseEvent) = GetProcAddress(_alf_dll_comctl32, "_TrackMouseEvent");
    if (!ALF_Compat_TrackMouseEvent)
        ALF_Compat_TrackMouseEvent = ALF_Compat_fallbackTrackMouseEvent;

    LOAD_FUNC(uxtheme, OpenThemeData);
    LOAD_FUNC(uxtheme, CloseThemeData);
    LOAD_FUNC(uxtheme, IsThemeBackgroundPartiallyTransparent);
    LOAD_FUNC(uxtheme, DrawThemeParentBackground);
    LOAD_FUNC(uxtheme, DrawThemeBackground);
    LOAD_FUNC(uxtheme, GetThemeBackgroundContentRect);
    LOAD_FUNC(uxtheme, GetThemeTextExtent);
    LOAD_FUNC(uxtheme, DrawThemeText);
    LOAD_FUNC(uxtheme, BufferedPaintInit);
    LOAD_FUNC(uxtheme, BufferedPaintUnInit);
    LOAD_FUNC(uxtheme, BeginBufferedAnimation);
    LOAD_FUNC(uxtheme, EndBufferedAnimation);
    LOAD_FUNC(uxtheme, BufferedPaintRenderAnimation);
    LOAD_FUNC(uxtheme, GetThemeTransitionDuration);
}

void ALF_UnloadCompatFunctions(void)
{
    UNLOAD_FUNC(IsAppThemed);
    UNLOAD_FUNC(GetDpiForWindow);
    UNLOAD_FUNC(AdjustWindowRectExForDpi);
    UNLOAD_FUNC(GetSystemMetricsForDpi);
    UNLOAD_FUNC(SetWindowSubclass);
    UNLOAD_FUNC(DefSubclassProc);
    UNLOAD_FUNC(RemoveWindowSubclass);
    UNLOAD_FUNC(SystemParametersInfoForDpi);
    UNLOAD_FUNC(TrackMouseEvent);
    UNLOAD_FUNC(OpenThemeData);
    UNLOAD_FUNC(CloseThemeData);
    UNLOAD_FUNC(IsThemeBackgroundPartiallyTransparent);
    UNLOAD_FUNC(DrawThemeParentBackground);
    UNLOAD_FUNC(DrawThemeBackground);
    UNLOAD_FUNC(GetThemeBackgroundContentRect);
    UNLOAD_FUNC(GetThemeTextExtent);
    UNLOAD_FUNC(DrawThemeText);
    UNLOAD_FUNC(BufferedPaintInit);
    UNLOAD_FUNC(BufferedPaintUnInit);
    UNLOAD_FUNC(BeginBufferedAnimation);
    UNLOAD_FUNC(EndBufferedAnimation);
    UNLOAD_FUNC(BufferedPaintRenderAnimation);
    UNLOAD_FUNC(GetThemeTransitionDuration);

    FreeLibrary(_alf_dll_uxtheme);
    FreeLibrary(_alf_dll_user32);
    FreeLibrary(_alf_dll_comctl32);
}

#undef LOAD_FUNC
#undef UNLOAD_FUNC

BOOL (WINAPI *ALF_Compat_IsAppThemed)(void) = NULL;
UINT (WINAPI *ALF_Compat_GetDpiForWindow)(HWND /*window*/) = NULL;
BOOL (WINAPI *ALF_Compat_AdjustWindowRectExForDpi)(LPRECT,DWORD,BOOL,DWORD,UINT) = NULL;
int (WINAPI *ALF_Compat_GetSystemMetricsForDpi)(int,  UINT) = NULL;
BOOL (WINAPI *ALF_Compat_SetWindowSubclass)(HWND, ALF_COMPAT_SUBCLASSPROC, UINT_PTR, DWORD_PTR) = NULL;
LRESULT (WINAPI *ALF_Compat_DefSubclassProc)(HWND, UINT, WPARAM, LPARAM) = NULL;
BOOL (WINAPI *ALF_Compat_RemoveWindowSubclass)(HWND, ALF_COMPAT_SUBCLASSPROC, UINT_PTR) = NULL;
BOOL (WINAPI *ALF_Compat_SystemParametersInfoForDpi)(UINT,UINT,PVOID,UINT,UINT) = NULL;

HTHEME (WINAPI *ALF_Compat_OpenThemeData)(HWND, LPCWSTR) = NULL;
HRESULT (WINAPI *ALF_Compat_CloseThemeData)(HTHEME) = NULL;
BOOL (WINAPI *ALF_Compat_IsThemeBackgroundPartiallyTransparent)(HTHEME,int,int) = NULL;
HRESULT (WINAPI *ALF_Compat_DrawThemeParentBackground)(HWND,HDC,RECT *) = NULL;
HRESULT (WINAPI *ALF_Compat_DrawThemeBackground)(HTHEME, HDC, int, int, const RECT *, const RECT *) = NULL;
HRESULT (WINAPI *ALF_Compat_GetThemeBackgroundContentRect)(HTHEME,HDC,int,int,const RECT *,RECT *) = NULL;
HRESULT (WINAPI *ALF_Compat_GetThemeTextExtent)(HTHEME,HDC,int,int,LPCWSTR,int,DWORD,const RECT *, RECT *) = NULL;
HRESULT (WINAPI *ALF_Compat_DrawThemeText)(HTHEME,HDC,int,int,LPCWSTR,int,DWORD,DWORD,const RECT *) = NULL;
BOOL (WINAPI *ALF_Compat_TrackMouseEvent)(LPTRACKMOUSEEVENT tme) = NULL;
HRESULT (WINAPI *ALF_Compat_BufferedPaintInit)(void) = NULL;
HRESULT (WINAPI *ALF_Compat_BufferedPaintUnInit)(void) = NULL;
ALF_Compat_HANIMATIONBUFFER (WINAPI *ALF_Compat_BeginBufferedAnimation)(HWND,HDC,const RECT *,DWORD,ALF_Compat_BP_PAINTPARAMS *,ALF_Compat_BP_ANIMATIONPARAMS *,HDC *,HDC *) = NULL;
HRESULT (WINAPI *ALF_Compat_EndBufferedAnimation)(ALF_Compat_HANIMATIONBUFFER,BOOL) = NULL;
BOOL (WINAPI *ALF_Compat_BufferedPaintRenderAnimation)(HWND,HDC) = NULL;
HRESULT (WINAPI *ALF_Compat_GetThemeTransitionDuration)(HTHEME,int,int,int,int,DWORD*) = NULL;