/*
  Simple DirectMedia Layer
  Copyright (C) 1997-2023 Sam Lantinga <slouken@libsdl.org>

  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.
*/
#include "../../SDL_internal.h"

#if SDL_VIDEO_DRIVER_WINDOWS && !defined(__XBOXONE__) && !defined(__XBOXSERIES__)

#include "SDL_windowsvideo.h"

#include "../../events/SDL_mouse_c.h"

DWORD SDL_last_warp_time = 0;
HCURSOR SDL_cursor = NULL;
static SDL_Cursor *SDL_blank_cursor = NULL;

static int rawInputEnableCount = 0;

static int ToggleRawInput(SDL_bool enabled)
{
    RAWINPUTDEVICE rawMouse = { 0x01, 0x02, 0, NULL }; /* Mouse: UsagePage = 1, Usage = 2 */

    if (enabled) {
        rawInputEnableCount++;
        if (rawInputEnableCount > 1) {
            return 0; /* already done. */
        }
    } else {
        if (rawInputEnableCount == 0) {
            return 0; /* already done. */
        }
        rawInputEnableCount--;
        if (rawInputEnableCount > 0) {
            return 0; /* not time to disable yet */
        }
    }

    if (!enabled) {
        rawMouse.dwFlags |= RIDEV_REMOVE;
    }

    /* (Un)register raw input for mice */
    if (RegisterRawInputDevices(&rawMouse, 1, sizeof(RAWINPUTDEVICE)) == FALSE) {
        /* Reset the enable count, otherwise subsequent enable calls will
           believe raw input is enabled */
        rawInputEnableCount = 0;

        /* Only return an error when registering. If we unregister and fail,
           then it's probably that we unregistered twice. That's OK. */
        if (enabled) {
            return SDL_Unsupported();
        }
    }
    return 0;
}

static SDL_Cursor *WIN_CreateDefaultCursor()
{
    SDL_Cursor *cursor;

    cursor = SDL_calloc(1, sizeof(*cursor));
    if (cursor) {
        cursor->driverdata = LoadCursor(NULL, IDC_ARROW);
    } else {
        SDL_OutOfMemory();
    }

    return cursor;
}

static SDL_Cursor *WIN_CreateCursor(SDL_Surface *surface, int hot_x, int hot_y)
{
    /* msdn says cursor mask has to be padded out to word alignment. Not sure
        if that means machine word or WORD, but this handles either case. */
    const size_t pad = (sizeof(size_t) * 8); /* 32 or 64, or whatever. */
    SDL_Cursor *cursor;
    HICON hicon;
    HICON hcursor;
    HDC hdc;
    BITMAPV4HEADER bmh;
    LPVOID pixels;
    LPVOID maskbits;
    size_t maskbitslen;
    SDL_bool isstack;
    ICONINFO ii;

    SDL_zero(bmh);
    bmh.bV4Size = sizeof(bmh);
    bmh.bV4Width = surface->w;
    bmh.bV4Height = -surface->h; /* Invert the image */
    bmh.bV4Planes = 1;
    bmh.bV4BitCount = 32;
    bmh.bV4V4Compression = BI_BITFIELDS;
    bmh.bV4AlphaMask = 0xFF000000;
    bmh.bV4RedMask = 0x00FF0000;
    bmh.bV4GreenMask = 0x0000FF00;
    bmh.bV4BlueMask = 0x000000FF;

    maskbitslen = ((surface->w + (pad - (surface->w % pad))) / 8) * surface->h;
    maskbits = SDL_small_alloc(Uint8, maskbitslen, &isstack);
    if (maskbits == NULL) {
        SDL_OutOfMemory();
        return NULL;
    }

    /* AND the cursor against full bits: no change. We already have alpha. */
    SDL_memset(maskbits, 0xFF, maskbitslen);

    hdc = GetDC(NULL);
    SDL_zero(ii);
    ii.fIcon = FALSE;
    ii.xHotspot = (DWORD)hot_x;
    ii.yHotspot = (DWORD)hot_y;
    ii.hbmColor = CreateDIBSection(hdc, (BITMAPINFO *)&bmh, DIB_RGB_COLORS, &pixels, NULL, 0);
    ii.hbmMask = CreateBitmap(surface->w, surface->h, 1, 1, maskbits);
    ReleaseDC(NULL, hdc);
    SDL_small_free(maskbits, isstack);

    SDL_assert(surface->format->format == SDL_PIXELFORMAT_ARGB8888);
    SDL_assert(surface->pitch == surface->w * 4);
    SDL_memcpy(pixels, surface->pixels, (size_t)surface->h * surface->pitch);

    hicon = CreateIconIndirect(&ii);

    DeleteObject(ii.hbmColor);
    DeleteObject(ii.hbmMask);

    if (!hicon) {
        WIN_SetError("CreateIconIndirect()");
        return NULL;
    }

    /* The cursor returned by CreateIconIndirect does not respect system cursor size
        preference, use CopyImage to duplicate the cursor with desired sizes */
    hcursor = CopyImage(hicon, IMAGE_CURSOR, surface->w, surface->h, 0);
    DestroyIcon(hicon);

    if (!hcursor) {
        WIN_SetError("CopyImage()");
        return NULL;
    }

    cursor = SDL_calloc(1, sizeof(*cursor));
    if (cursor) {
        cursor->driverdata = hcursor;
    } else {
        DestroyIcon(hcursor);
        SDL_OutOfMemory();
    }

    return cursor;
}

static SDL_Cursor *WIN_CreateBlankCursor()
{
    SDL_Cursor *cursor = NULL;
    SDL_Surface *surface = SDL_CreateRGBSurfaceWithFormat(0, 32, 32, 32, SDL_PIXELFORMAT_ARGB8888);
    if (surface) {
        cursor = WIN_CreateCursor(surface, 0, 0);
        SDL_FreeSurface(surface);
    }
    return cursor;
}

static SDL_Cursor *WIN_CreateSystemCursor(SDL_SystemCursor id)
{
    SDL_Cursor *cursor;
    LPCTSTR name;

    switch (id) {
    default:
        SDL_assert(0);
        return NULL;
    case SDL_SYSTEM_CURSOR_ARROW:
        name = IDC_ARROW;
        break;
    case SDL_SYSTEM_CURSOR_IBEAM:
        name = IDC_IBEAM;
        break;
    case SDL_SYSTEM_CURSOR_WAIT:
        name = IDC_WAIT;
        break;
    case SDL_SYSTEM_CURSOR_CROSSHAIR:
        name = IDC_CROSS;
        break;
    case SDL_SYSTEM_CURSOR_WAITARROW:
        name = IDC_WAIT;
        break;
    case SDL_SYSTEM_CURSOR_SIZENWSE:
        name = IDC_SIZENWSE;
        break;
    case SDL_SYSTEM_CURSOR_SIZENESW:
        name = IDC_SIZENESW;
        break;
    case SDL_SYSTEM_CURSOR_SIZEWE:
        name = IDC_SIZEWE;
        break;
    case SDL_SYSTEM_CURSOR_SIZENS:
        name = IDC_SIZENS;
        break;
    case SDL_SYSTEM_CURSOR_SIZEALL:
        name = IDC_SIZEALL;
        break;
    case SDL_SYSTEM_CURSOR_NO:
        name = IDC_NO;
        break;
    case SDL_SYSTEM_CURSOR_HAND:
        name = IDC_HAND;
        break;
    }

    cursor = SDL_calloc(1, sizeof(*cursor));
    if (cursor) {
        HICON hicon;

        hicon = LoadCursor(NULL, name);

        cursor->driverdata = hicon;
    } else {
        SDL_OutOfMemory();
    }

    return cursor;
}

static void WIN_FreeCursor(SDL_Cursor *cursor)
{
    HICON hicon = (HICON)cursor->driverdata;

    DestroyIcon(hicon);
    SDL_free(cursor);
}

static int WIN_ShowCursor(SDL_Cursor *cursor)
{
    if (cursor == NULL) {
        cursor = SDL_blank_cursor;
    }
    if (cursor) {
        SDL_cursor = (HCURSOR)cursor->driverdata;
    } else {
        SDL_cursor = NULL;
    }
    if (SDL_GetMouseFocus() != NULL) {
        SetCursor(SDL_cursor);
    }
    return 0;
}

void WIN_SetCursorPos(int x, int y)
{
    /* We need to jitter the value because otherwise Windows will occasionally inexplicably ignore the SetCursorPos() or SendInput() */
    SetCursorPos(x, y);
    SetCursorPos(x + 1, y);
    SetCursorPos(x, y);

    /* Flush any mouse motion prior to or associated with this warp */
    SDL_last_warp_time = GetTickCount();
    if (!SDL_last_warp_time) {
        SDL_last_warp_time = 1;
    }
}

static void WIN_WarpMouse(SDL_Window *window, int x, int y)
{
    SDL_WindowData *data = (SDL_WindowData *)window->driverdata;
    HWND hwnd = data->hwnd;
    POINT pt;

    /* Don't warp the mouse while we're doing a modal interaction */
    if (data->in_title_click || data->focus_click_pending) {
        return;
    }

    pt.x = x;
    pt.y = y;
    ClientToScreen(hwnd, &pt);
    WIN_SetCursorPos(pt.x, pt.y);

    /* Send the exact mouse motion associated with this warp */
    SDL_SendMouseMotion(window, SDL_GetMouse()->mouseID, 0, x, y);
}

static int WIN_WarpMouseGlobal(int x, int y)
{
    POINT pt;

    WIN_ScreenPointFromSDL(&x, &y, NULL);
    pt.x = x;
    pt.y = y;
    SetCursorPos(pt.x, pt.y);
    return 0;
}

static int WIN_SetRelativeMouseMode(SDL_bool enabled)
{
    return ToggleRawInput(enabled);
}

static int WIN_CaptureMouse(SDL_Window *window)
{
    if (window) {
        SDL_WindowData *data = (SDL_WindowData *)window->driverdata;
        SetCapture(data->hwnd);
    } else {
        SDL_Window *focus_window = SDL_GetMouseFocus();

        if (focus_window) {
            SDL_WindowData *data = (SDL_WindowData *)focus_window->driverdata;
            if (!data->mouse_tracked) {
                SDL_SetMouseFocus(NULL);
            }
        }
        ReleaseCapture();
    }

    return 0;
}

static Uint32 WIN_GetGlobalMouseState(int *x, int *y)
{
    Uint32 retval = 0;
    POINT pt = { 0, 0 };
    SDL_bool swapButtons = GetSystemMetrics(SM_SWAPBUTTON) != 0;

    GetCursorPos(&pt);
    *x = (int)pt.x;
    *y = (int)pt.y;
    WIN_ScreenPointToSDL(x, y);

    retval |= GetAsyncKeyState(!swapButtons ? VK_LBUTTON : VK_RBUTTON) & 0x8000 ? SDL_BUTTON_LMASK : 0;
    retval |= GetAsyncKeyState(!swapButtons ? VK_RBUTTON : VK_LBUTTON) & 0x8000 ? SDL_BUTTON_RMASK : 0;
    retval |= GetAsyncKeyState(VK_MBUTTON) & 0x8000 ? SDL_BUTTON_MMASK : 0;
    retval |= GetAsyncKeyState(VK_XBUTTON1) & 0x8000 ? SDL_BUTTON_X1MASK : 0;
    retval |= GetAsyncKeyState(VK_XBUTTON2) & 0x8000 ? SDL_BUTTON_X2MASK : 0;

    return retval;
}

void WIN_InitMouse(_THIS)
{
    SDL_Mouse *mouse = SDL_GetMouse();

    mouse->CreateCursor = WIN_CreateCursor;
    mouse->CreateSystemCursor = WIN_CreateSystemCursor;
    mouse->ShowCursor = WIN_ShowCursor;
    mouse->FreeCursor = WIN_FreeCursor;
    mouse->WarpMouse = WIN_WarpMouse;
    mouse->WarpMouseGlobal = WIN_WarpMouseGlobal;
    mouse->SetRelativeMouseMode = WIN_SetRelativeMouseMode;
    mouse->CaptureMouse = WIN_CaptureMouse;
    mouse->GetGlobalMouseState = WIN_GetGlobalMouseState;

    SDL_SetDefaultCursor(WIN_CreateDefaultCursor());

    SDL_blank_cursor = WIN_CreateBlankCursor();

    WIN_UpdateMouseSystemScale();
}

void WIN_QuitMouse(_THIS)
{
    if (rawInputEnableCount) { /* force RAWINPUT off here. */
        rawInputEnableCount = 1;
        ToggleRawInput(SDL_FALSE);
    }

    if (SDL_blank_cursor) {
        WIN_FreeCursor(SDL_blank_cursor);
        SDL_blank_cursor = NULL;
    }
}

/* For a great description of how the enhanced mouse curve works, see:
 * https://superuser.com/questions/278362/windows-mouse-acceleration-curve-smoothmousexcurve-and-smoothmouseycurve
 * http://www.esreality.com/?a=post&id=1846538/
 */
static SDL_bool LoadFiveFixedPointFloats(const BYTE *bytes, float *values)
{
    int i;

    for (i = 0; i < 5; ++i) {
        float fraction = (float)((Uint16)bytes[1] << 8 | bytes[0]) / 65535.0f;
        float value = (float)(((Uint16)bytes[3] << 8) | bytes[2]) + fraction;
        *values++ = value;
        bytes += 8;
    }
    return SDL_TRUE;
}

static void WIN_SetEnhancedMouseScale(int mouse_speed)
{
    float scale = (float)mouse_speed / 10.0f;
    HKEY hKey;
    DWORD dwType = REG_BINARY;
    BYTE value[40];
    DWORD length = sizeof(value);
    int i;
    float xpoints[5];
    float ypoints[5];
    float scale_points[10];
    const int dpi = 96; // FIXME, how do we handle different monitors with different DPI?
    const float display_factor = 3.5f * (150.0f / dpi);

    if (RegOpenKeyExW(HKEY_CURRENT_USER, L"Control Panel\\Mouse", 0, KEY_READ, &hKey) == ERROR_SUCCESS) {
        if (RegQueryValueExW(hKey, L"SmoothMouseXCurve", 0, &dwType, value, &length) == ERROR_SUCCESS &&
            LoadFiveFixedPointFloats(value, xpoints) &&
            RegQueryValueExW(hKey, L"SmoothMouseYCurve", 0, &dwType, value, &length) == ERROR_SUCCESS &&
            LoadFiveFixedPointFloats(value, ypoints)) {
            for (i = 0; i < 5; ++i) {
                float gain;
                if (xpoints[i] > 0.0f) {
                    gain = (ypoints[i] / xpoints[i]) * scale;
                } else {
                    gain = 0.0f;
                }
                scale_points[i * 2] = xpoints[i];
                scale_points[i * 2 + 1] = gain / display_factor;
                // SDL_Log("Point %d = %f,%f\n", i, scale_points[i * 2], scale_points[i * 2 + 1]);
            }
            SDL_SetMouseSystemScale(SDL_arraysize(scale_points), scale_points);
        }
        RegCloseKey(hKey);
    }
}

static void WIN_SetLinearMouseScale(int mouse_speed)
{
    static float mouse_speed_scale[] = {
        0.0f,
        1 / 32.0f,
        1 / 16.0f,
        1 / 8.0f,
        2 / 8.0f,
        3 / 8.0f,
        4 / 8.0f,
        5 / 8.0f,
        6 / 8.0f,
        7 / 8.0f,
        1.0f,
        1.25f,
        1.5f,
        1.75f,
        2.0f,
        2.25f,
        2.5f,
        2.75f,
        3.0f,
        3.25f,
        3.5f
    };

    if (mouse_speed > 0 && mouse_speed < SDL_arraysize(mouse_speed_scale)) {
        SDL_SetMouseSystemScale(1, &mouse_speed_scale[mouse_speed]);
    }
}

void WIN_UpdateMouseSystemScale()
{
    int mouse_speed;
    int params[3] = { 0, 0, 0 };

    if (SystemParametersInfo(SPI_GETMOUSESPEED, 0, &mouse_speed, 0) &&
        SystemParametersInfo(SPI_GETMOUSE, 0, params, 0)) {
        if (params[2]) {
            WIN_SetEnhancedMouseScale(mouse_speed);
        } else {
            WIN_SetLinearMouseScale(mouse_speed);
        }
    }
}

#endif /* SDL_VIDEO_DRIVER_WINDOWS */

/* vi: set ts=4 sw=4 expandtab: */
