#include "alfpriv.h"

#include <shlwapi.h>

#if defined(_MSC_VER) && defined(_M_IX86)

#   pragma warning(push)
#   pragma warning(disable:4035)

    // HACK: inline assembly for MSVC 6
    // TODO: add version detection to use intrinsic on newer MSVC versions

    static inline LONG
    ALF_Compat_InterlockedIncrement(LONG volatile *addend)
    {
        __asm {
            mov         eax,1
            mov         edx,addend
            lock xadd   [edx],eax
        }
    }
#   ifdef InterlockedIncrement
#       undef InterlockedIncrement
#   endif
#   define InterlockedIncrement(d) ALF_Compat_InterlockedIncrement(d)

    static inline LONG
    ALF_Compat_InterlockedCompareExchange(volatile LONG *destination, LONG exchange, LONG comparand)
    {
        __asm {
            mov             eax,comparand
            mov             ecx,exchange
            mov             edx,destination
            lock cmpxchg    [edx],ecx
        }
    }

#   ifdef InterlockedCompareExchange
#       undef InterlockedCompareExchange
#   endif
#   define InterlockedCompareExchange(d,e,c) ALF_Compat_InterlockedCompareExchange(d,e,c)

    static inline PVOID
    ALF_Compat_InterlockedCompareExchangePointer(PVOID volatile *destination, PVOID exchange, PVOID comparand)
    {
        return (void*)InterlockedCompareExchange((LONG volatile *)destination, (LONG)exchange, (LONG)comparand);
    }

#   ifdef InterlockedCompareExchangePointer
#       undef InterlockedCompareExchangePointer
#   endif
#   define InterlockedCompareExchangePointer(d,e,c) ALF_Compat_InterlockedCompareExchangePointer(d,e,c)

#   pragma warning(pop)
#endif

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 (LOBYTE(LOWORD(GetVersion())) < 4) {
        // 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;

    return SystemParametersInfo(uiAction, uiParam, pvParam, fWinIni);
}

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;
}

void
ALF_UniqueCounterValue(LONG_PTR *pCounterId, LONG_PTR *pCounterValue)
{
    static LONG counter = 0;

    LONG r = InterlockedIncrement(&counter);
    *pCounterId    = (LONG_PTR)&counter;
    *pCounterValue = r;
}

static BOOL WINAPI
ALF_Compat_loadIsAppThemed(void)
{
    HMODULE hUxTheme = GetModuleHandleA("uxtheme.dll");
    FARPROC p = GetProcAddress(hUxTheme, "IsAppThemed");

    if (!p || ALF_DllGetVersion("comctl32.dll") < 0x60000)
        p = (FARPROC)ALF_Compat_fallbackIsAppThemed;

    InterlockedCompareExchangePointer((void**)&ALF_Compat_IsAppThemed, (void*)p, (void*)ALF_Compat_loadIsAppThemed);

    return ALF_Compat_IsAppThemed();
}

static UINT WINAPI
ALF_Compat_loadGetDpiForWindow(HWND window)
{
    FARPROC p = GetProcAddress(GetModuleHandleA("user32.dll"), "GetDpiForWindow");

    if (!p)
        p = (FARPROC)(void*)ALF_Compat_fallbackGetDpiForWindow;

    InterlockedCompareExchangePointer((void**)&ALF_Compat_GetDpiForWindow, (void*)p, (void*)ALF_Compat_loadGetDpiForWindow);

    return ALF_Compat_GetDpiForWindow(window);
}

static BOOL WINAPI
ALF_Compat_loadAdjustWindowRectExForDpi(LPRECT lpRect, DWORD dwStyle, BOOL bMenu, DWORD dwExStyle, UINT dpi)
{
    FARPROC p = GetProcAddress(GetModuleHandleA("user32.dll"), "AdjustWindowRectExForDpi");

    if (!p)
        p = (FARPROC)(void*)ALF_Compat_fallbackAdjustWindowRectExForDpi;

    InterlockedCompareExchangePointer((void**)&ALF_Compat_AdjustWindowRectExForDpi, (void*)p, (void*)ALF_Compat_loadAdjustWindowRectExForDpi);

    return ALF_Compat_AdjustWindowRectExForDpi(lpRect, dwStyle, bMenu, dwExStyle, dpi);
}

static int WINAPI
ALF_Compat_loadGetSystemMetricsForDpi(int nIndex, UINT dpi)
{
    void *p = (void*)GetProcAddress(GetModuleHandleA("user32.dll"), "GetSystemMetricsForDpi");

    if (!p)
        p = (void*)ALF_Compat_fallbackGetSystemMetricsForDpi;

    InterlockedCompareExchangePointer((void**)&ALF_Compat_GetSystemMetricsForDpi, p, (void*)ALF_Compat_loadGetSystemMetricsForDpi);

    return ALF_Compat_GetSystemMetricsForDpi(nIndex, dpi);
}

static BOOL WINAPI
ALF_Compat_loadSetWindowSubclass(HWND hwnd, ALF_COMPAT_SUBCLASSPROC pfnSubclass, UINT_PTR uIdSubclass, DWORD_PTR dwRefData)
{
    HMODULE comctl32 = GetModuleHandleA("comctl32.dll");

    void *p = (void*)GetProcAddress(comctl32, "SetWindowSubclass");
    if (!p) {
        p = (void*)GetProcAddress(comctl32, (char*)410);
        if (!p) {
            p = (void*)ALF_Compat_fallbackSetWindowSubclass;
        }
    }

    InterlockedCompareExchangePointer((void**)&ALF_Compat_SetWindowSubclass, p, (void*)ALF_Compat_loadSetWindowSubclass);

    return ALF_Compat_SetWindowSubclass(hwnd, pfnSubclass, uIdSubclass, dwRefData);
}

static BOOL WINAPI
ALF_Compat_loadRemoveWindowSubclass(HWND hwnd, ALF_COMPAT_SUBCLASSPROC pfnSubclass, UINT_PTR uIdSubclass)
{
    HMODULE comctl32 = GetModuleHandleA("comctl32.dll");

    void *p = (void*)GetProcAddress(comctl32, "RemoveWindowSubclass");
    if (!p) {
        p = (void*)GetProcAddress(comctl32, (char*)412);
        if (!p) {
            p = (void*)ALF_Compat_fallbackRemoveWindowSubclass;
        }
    }

    InterlockedCompareExchangePointer((void**)&ALF_Compat_RemoveWindowSubclass, p, (void*)ALF_Compat_loadRemoveWindowSubclass);

    return ALF_Compat_RemoveWindowSubclass(hwnd, pfnSubclass, uIdSubclass);
}

static LRESULT WINAPI
ALF_Compat_loadDefSubclassProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
    HMODULE comctl32 = GetModuleHandleA("comctl32.dll");

    void *p = (void*)GetProcAddress(comctl32, "DefSubclassProc");
    if (!p) {
        p = (void*)GetProcAddress(comctl32, (char*)413);
        if (!p) {
            p = (void*)ALF_Compat_fallbackDefSubclassProc;
        }
    }

    InterlockedCompareExchangePointer((void**)&ALF_Compat_DefSubclassProc, p, (void*)ALF_Compat_loadDefSubclassProc);

    return ALF_Compat_DefSubclassProc(hwnd, uMsg, wParam, lParam);
}

static BOOL WINAPI
ALF_Compat_loadSystemParametersInfoForDpi(UINT uiAction, UINT uiParam, PVOID pvParam, UINT fWinIni, UINT dpi)
{
    void *p = (void*)GetProcAddress(GetModuleHandleA("user32.dll"), "SystemParametersInfoForDpi");
    if (!p)
        p = (void*)ALF_Compat_fallbackSystemParametersInfoForDpi;

    InterlockedCompareExchangePointer((void**)&ALF_Compat_SystemParametersInfoForDpi, p, (void*)ALF_Compat_loadSystemParametersInfoForDpi);

    return ALF_Compat_SystemParametersInfoForDpi(uiAction, uiParam, pvParam, fWinIni, dpi);
}


BOOL (WINAPI *ALF_Compat_IsAppThemed)(void) = ALF_Compat_loadIsAppThemed;
UINT (WINAPI *ALF_Compat_GetDpiForWindow)(HWND /*window*/) = ALF_Compat_loadGetDpiForWindow;
BOOL (WINAPI *ALF_Compat_AdjustWindowRectExForDpi)(LPRECT,DWORD,BOOL,DWORD,UINT) = ALF_Compat_loadAdjustWindowRectExForDpi;
int (WINAPI *ALF_Compat_GetSystemMetricsForDpi)(int,  UINT) = ALF_Compat_loadGetSystemMetricsForDpi;
BOOL (WINAPI *ALF_Compat_SetWindowSubclass)(HWND, ALF_COMPAT_SUBCLASSPROC, UINT_PTR, DWORD_PTR) = ALF_Compat_loadSetWindowSubclass;
LRESULT (WINAPI *ALF_Compat_DefSubclassProc)(HWND, UINT, WPARAM, LPARAM) = ALF_Compat_loadDefSubclassProc;
BOOL (WINAPI *ALF_Compat_RemoveWindowSubclass)(HWND, ALF_COMPAT_SUBCLASSPROC, UINT_PTR) = ALF_Compat_loadRemoveWindowSubclass;

// FIXME! do Unicode properly for SystemParametersInfoForDpi
#ifdef UNICODE
BOOL (WINAPI *ALF_Compat_SystemParametersInfoForDpi)(UINT,UINT,PVOID,UINT,UINT) = ALF_Compat_loadSystemParametersInfoForDpi;
#else
BOOL (WINAPI *ALF_Compat_SystemParametersInfoForDpi)(UINT,UINT,PVOID,UINT,UINT) = ALF_Compat_fallbackSystemParametersInfoForDpi;
#endif