/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2009 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga
    slouken@libsdl.org
*/
#include "SDL_config.h"

/* SVGAlib based SDL video driver implementation.
*/

#include <unistd.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <fcntl.h>

#if defined(__LINUX__)
#include <linux/vt.h>
#elif defined(__FREEBSD__)
#include <sys/consio.h>
#else
#error You must choose your operating system here
#endif
#include <vga.h>
#include <vgamouse.h>
#include <vgakeyboard.h>

#include "SDL_video.h"
#include "SDL_mouse.h"
#include "../SDL_sysvideo.h"
#include "../SDL_pixels_c.h"
#include "../../events/SDL_events_c.h"
#include "SDL_svgavideo.h"
#include "SDL_svgaevents_c.h"
#include "SDL_svgamouse_c.h"

/* Initialization/Query functions */
static int SVGA_VideoInit(_THIS, SDL_PixelFormat * vformat);
static SDL_Rect **SVGA_ListModes(_THIS, SDL_PixelFormat * format,
                                 Uint32 flags);
static SDL_Surface *SVGA_SetVideoMode(_THIS, SDL_Surface * current,
                                      int width, int height, int bpp,
                                      Uint32 flags);
static int SVGA_SetColors(_THIS, int firstcolor, int ncolors,
                          SDL_Color * colors);
static void SVGA_VideoQuit(_THIS);

/* Hardware surface functions */
static int SVGA_AllocHWSurface(_THIS, SDL_Surface * surface);
static int SVGA_LockHWSurface(_THIS, SDL_Surface * surface);
static int SVGA_FlipHWSurface(_THIS, SDL_Surface * surface);
static void SVGA_UnlockHWSurface(_THIS, SDL_Surface * surface);
static void SVGA_FreeHWSurface(_THIS, SDL_Surface * surface);

/* SVGAlib driver bootstrap functions */

static int
SVGA_Available(void)
{
    /* Check to see if we are root and stdin is a virtual console */
    int console;

    /* SVGALib 1.9.x+ doesn't require root (via /dev/svga) */
    int svgalib2 = -1;

    /* See if we are connected to a virtual terminal */
    console = STDIN_FILENO;
#if 0                           /* This is no longer needed, SVGAlib can switch consoles for us */
    if (console >= 0) {
        struct stat sb;
        struct vt_mode dummy;

        if ((fstat(console, &sb) < 0) ||
            (ioctl(console, VT_GETMODE, &dummy) < 0)) {
            console = -1;
        }
    }
#endif /* 0 */

    /* See if SVGAlib 2.0 is available */
    svgalib2 = open("/dev/svga", O_RDONLY);
    if (svgalib2 != -1) {
        close(svgalib2);
    }

    return (((svgalib2 != -1) || (geteuid() == 0)) && (console >= 0));
}

static void
SVGA_DeleteDevice(SDL_VideoDevice * device)
{
    SDL_free(device->hidden);
    SDL_free(device);
}

static SDL_VideoDevice *
SVGA_CreateDevice(int devindex)
{
    SDL_VideoDevice *device;

    /* Initialize all variables that we clean on shutdown */
    device = (SDL_VideoDevice *) SDL_malloc(sizeof(SDL_VideoDevice));
    if (device) {
        SDL_memset(device, 0, (sizeof *device));
        device->hidden = (struct SDL_PrivateVideoData *)
            SDL_malloc((sizeof *device->hidden));
    }
    if ((device == NULL) || (device->hidden == NULL)) {
        SDL_OutOfMemory();
        if (device) {
            SDL_free(device);
        }
        return (0);
    }
    SDL_memset(device->hidden, 0, (sizeof *device->hidden));

    /* Set the function pointers */
    device->VideoInit = SVGA_VideoInit;
    device->ListModes = SVGA_ListModes;
    device->SetVideoMode = SVGA_SetVideoMode;
    device->SetColors = SVGA_SetColors;
    device->UpdateRects = NULL;
    device->VideoQuit = SVGA_VideoQuit;
    device->AllocHWSurface = SVGA_AllocHWSurface;
    device->CheckHWBlit = NULL;
    device->FillHWRect = NULL;
    device->SetHWColorKey = NULL;
    device->SetHWAlpha = NULL;
    device->LockHWSurface = SVGA_LockHWSurface;
    device->UnlockHWSurface = SVGA_UnlockHWSurface;
    device->FlipHWSurface = SVGA_FlipHWSurface;
    device->FreeHWSurface = SVGA_FreeHWSurface;
    device->SetCaption = NULL;
    device->SetIcon = NULL;
    device->IconifyWindow = NULL;
    device->GrabInput = NULL;
    device->GetWMInfo = NULL;
    device->InitOSKeymap = SVGA_InitOSKeymap;
    device->PumpEvents = SVGA_PumpEvents;

    device->free = SVGA_DeleteDevice;

    return device;
}

VideoBootStrap SVGALIB_bootstrap = {
    "svgalib", "SVGAlib",
    SVGA_Available, SVGA_CreateDevice
};

static int
SVGA_AddMode(_THIS, int mode, int actually_add)
{
    int i, j;
    vga_modeinfo *modeinfo;

    modeinfo = vga_getmodeinfo(mode);

    i = modeinfo->bytesperpixel - 1;
    if (i < 0) {
        return 0;
    }
    if (actually_add) {
        SDL_Rect saved_rect[2];
        int saved_mode[2];
        int b;

        /* Add the mode, sorted largest to smallest */
        b = 0;
        j = 0;
        while ((SDL_modelist[i][j]->w > modeinfo->width) ||
               (SDL_modelist[i][j]->h > modeinfo->height)) {
            ++j;
        }
        /* Skip modes that are already in our list */
        if ((SDL_modelist[i][j]->w == modeinfo->width) &&
            (SDL_modelist[i][j]->h == modeinfo->height)) {
            return (0);
        }
        /* Insert the new mode */
        saved_rect[b] = *SDL_modelist[i][j];
        saved_mode[b] = SDL_vgamode[i][j];
        SDL_modelist[i][j]->w = modeinfo->width;
        SDL_modelist[i][j]->h = modeinfo->height;
        SDL_vgamode[i][j] = mode;
        /* Everybody scoot down! */
        if (saved_rect[b].w && saved_rect[b].h) {
            for (++j; SDL_modelist[i][j]->w; ++j) {
                saved_rect[!b] = *SDL_modelist[i][j];
                saved_mode[!b] = SDL_vgamode[i][j];
                *SDL_modelist[i][j] = saved_rect[b];
                SDL_vgamode[i][j] = saved_mode[b];
                b = !b;
            }
            *SDL_modelist[i][j] = saved_rect[b];
            SDL_vgamode[i][j] = saved_mode[b];
        }
    } else {
        ++SDL_nummodes[i];
    }
    return (1);
}

static void
SVGA_UpdateVideoInfo(_THIS)
{
    vga_modeinfo *modeinfo;

    this->info.wm_available = 0;
    this->info.hw_available = (banked ? 0 : 1);
    modeinfo = vga_getmodeinfo(vga_getcurrentmode());
    this->info.video_mem = modeinfo->memory;
    /* FIXME: Add hardware accelerated blit information */
#ifdef SVGALIB_DEBUG
    printf("Hardware accelerated blit: %savailable\n",
           modeinfo->haveblit ? "" : "not ");
#endif
}

int
SVGA_VideoInit(_THIS, SDL_PixelFormat * vformat)
{
    int keyboard;
    int i, j;
    int mode, total_modes;

    /* Initialize all variables that we clean on shutdown */
    for (i = 0; i < NUM_MODELISTS; ++i) {
        SDL_nummodes[i] = 0;
        SDL_modelist[i] = NULL;
        SDL_vgamode[i] = NULL;
    }

    /* Initialize the library */
    vga_disabledriverreport();
    if (vga_init() < 0) {
        SDL_SetError("Unable to initialize SVGAlib");
        return (-1);
    }
    vga_setmode(TEXT);

    /* Enable mouse and keyboard support */
    vga_setmousesupport(1);
    keyboard = keyboard_init_return_fd();
    if (keyboard < 0) {
        SDL_SetError("Unable to initialize keyboard");
        return (-1);
    }
    if (SVGA_initkeymaps(keyboard) < 0) {
        return (-1);
    }
    keyboard_seteventhandler(SVGA_keyboardcallback);

    /* Determine the current screen size */
    this->info.current_w = 0;
    this->info.current_h = 0;

    /* Determine the screen depth (use default 8-bit depth) */
    vformat->BitsPerPixel = 8;

    /* Enumerate the available fullscreen modes */
    total_modes = 0;
    for (mode = vga_lastmodenumber(); mode; --mode) {
        if (vga_hasmode(mode)) {
            if (SVGA_AddMode(this, mode, 0)) {
                ++total_modes;
            }
        }
    }
    if (SVGA_AddMode(this, G320x200x256, 0))
        ++total_modes;
    if (total_modes == 0) {
        SDL_SetError("No linear video modes available");
        return (-1);
    }
    for (i = 0; i < NUM_MODELISTS; ++i) {
        SDL_vgamode[i] = (int *) SDL_malloc(SDL_nummodes[i] * sizeof(int));
        if (SDL_vgamode[i] == NULL) {
            SDL_OutOfMemory();
            return (-1);
        }
        SDL_modelist[i] = (SDL_Rect **)
            SDL_malloc((SDL_nummodes[i] + 1) * sizeof(SDL_Rect *));
        if (SDL_modelist[i] == NULL) {
            SDL_OutOfMemory();
            return (-1);
        }
        for (j = 0; j < SDL_nummodes[i]; ++j) {
            SDL_modelist[i][j] = (SDL_Rect *) SDL_malloc(sizeof(SDL_Rect));
            if (SDL_modelist[i][j] == NULL) {
                SDL_OutOfMemory();
                return (-1);
            }
            SDL_memset(SDL_modelist[i][j], 0, sizeof(SDL_Rect));
        }
        SDL_modelist[i][j] = NULL;
    }
    for (mode = vga_lastmodenumber(); mode; --mode) {
        if (vga_hasmode(mode)) {
            SVGA_AddMode(this, mode, 1);
        }
    }
    SVGA_AddMode(this, G320x200x256, 1);

    /* Free extra (duplicated) modes */
    for (i = 0; i < NUM_MODELISTS; ++i) {
        j = 0;
        while (SDL_modelist[i][j] && SDL_modelist[i][j]->w) {
            j++;
        }
        while (SDL_modelist[i][j]) {
            SDL_free(SDL_modelist[i][j]);
            SDL_modelist[i][j] = NULL;
            j++;
        }
    }

    /* Fill in our hardware acceleration capabilities */
    SVGA_UpdateVideoInfo(this);

    /* We're done! */
    return (0);
}

SDL_Rect **
SVGA_ListModes(_THIS, SDL_PixelFormat * format, Uint32 flags)
{
    return (SDL_modelist[((format->BitsPerPixel + 7) / 8) - 1]);
}

/* Various screen update functions available */
static void SVGA_DirectUpdate(_THIS, int numrects, SDL_Rect * rects);
static void SVGA_BankedUpdate(_THIS, int numrects, SDL_Rect * rects);

SDL_Surface *
SVGA_SetVideoMode(_THIS, SDL_Surface * current,
                  int width, int height, int bpp, Uint32 flags)
{
    int mode;
    int vgamode;
    vga_modeinfo *modeinfo;
    int screenpage_len;

    /* Free old pixels if we were in banked mode */
    if (banked && current->pixels) {
        free(current->pixels);
        current->pixels = NULL;
    }

    /* Try to set the requested linear video mode */
    bpp = (bpp + 7) / 8 - 1;
    for (mode = 0; SDL_modelist[bpp][mode]; ++mode) {
        if ((SDL_modelist[bpp][mode]->w == width) &&
            (SDL_modelist[bpp][mode]->h == height)) {
            break;
        }
    }
    if (SDL_modelist[bpp][mode] == NULL) {
        SDL_SetError("Couldn't find requested mode in list");
        return (NULL);
    }
    vgamode = SDL_vgamode[bpp][mode];
    vga_setmode(vgamode);
    vga_setpage(0);

    if ((vga_setlinearaddressing() < 0) && (vgamode != G320x200x256)) {
        banked = 1;
    } else {
        banked = 0;
    }

    modeinfo = vga_getmodeinfo(SDL_vgamode[bpp][mode]);

    /* Update hardware acceleration info */
    SVGA_UpdateVideoInfo(this);

    /* Allocate the new pixel format for the screen */
    bpp = (bpp + 1) * 8;
    if ((bpp == 16) && (modeinfo->colors == 32768)) {
        bpp = 15;
    }
    if (!SDL_ReallocFormat(current, bpp, 0, 0, 0, 0)) {
        return (NULL);
    }

    /* Set up the new mode framebuffer */
    current->flags = SDL_FULLSCREEN;
    if (!banked) {
        current->flags |= SDL_HWSURFACE;
    }
    if (bpp == 8) {
        /* FIXME: What about DirectColor? */
        current->flags |= SDL_HWPALETTE;
    }
    current->w = width;
    current->h = height;
    current->pitch = modeinfo->linewidth;
    if (banked) {
        current->pixels = SDL_malloc(current->h * current->pitch);
        if (!current->pixels) {
            SDL_OutOfMemory();
            return (NULL);
        }
    } else {
        current->pixels = vga_getgraphmem();
    }

    /* set double-buffering */
    if ((flags & SDL_DOUBLEBUF) && !banked) {
        /* length of one screen page in bytes */
        screenpage_len = current->h * modeinfo->linewidth;

        /* if start address should be aligned */
        if (modeinfo->linewidth_unit) {
            if (screenpage_len % modeinfo->linewidth_unit) {
                screenpage_len +=
                    modeinfo->linewidth_unit -
                    (screenpage_len % modeinfo->linewidth_unit);
            }
        }

        /* if we heve enough videomemory =  ak je dost videopamete  */
        if (modeinfo->memory > (screenpage_len * 2 / 1024)) {
            current->flags |= SDL_DOUBLEBUF;
            flip_page = 0;
            flip_offset[0] = 0;
            flip_offset[1] = screenpage_len;
            flip_address[0] = vga_getgraphmem();
            flip_address[1] = flip_address[0] + screenpage_len;
            SVGA_FlipHWSurface(this, current);
        }
    }

    /* Set the blit function */
    if (banked) {
        this->UpdateRects = SVGA_BankedUpdate;
    } else {
        this->UpdateRects = SVGA_DirectUpdate;
    }

    /* Set up the mouse handler again (buggy SVGAlib 1.40) */
    mouse_seteventhandler(SVGA_mousecallback);

    /* We're done */
    return (current);
}

/* We don't actually allow hardware surfaces other than the main one */
static int
SVGA_AllocHWSurface(_THIS, SDL_Surface * surface)
{
    return (-1);
}

static void
SVGA_FreeHWSurface(_THIS, SDL_Surface * surface)
{
    return;
}

/* We need to wait for vertical retrace on page flipped displays */
static int
SVGA_LockHWSurface(_THIS, SDL_Surface * surface)
{
    /* The waiting is done in SVGA_FlipHWSurface() */
    return (0);
}

static void
SVGA_UnlockHWSurface(_THIS, SDL_Surface * surface)
{
    return;
}

static int
SVGA_FlipHWSurface(_THIS, SDL_Surface * surface)
{
    if (!banked) {
        vga_setdisplaystart(flip_offset[flip_page]);
        flip_page = !flip_page;
        surface->pixels = flip_address[flip_page];
        vga_waitretrace();
    }
    return (0);
}

static void
SVGA_DirectUpdate(_THIS, int numrects, SDL_Rect * rects)
{
    return;
}

static void
SVGA_BankedUpdate(_THIS, int numrects, SDL_Rect * rects)
{
    int i, j;
    SDL_Rect *rect;
    int page, vp;
    int x, y, w, h;
    unsigned char *src;
    unsigned char *dst;
    int bpp = this->screen->format->BytesPerPixel;
    int pitch = this->screen->pitch;

    dst = vga_getgraphmem();
    for (i = 0; i < numrects; ++i) {
        rect = &rects[i];
        x = rect->x;
        y = rect->y;
        w = rect->w * bpp;
        h = rect->h;

        vp = y * pitch + x * bpp;
        src = (unsigned char *) this->screen->pixels + vp;
        page = vp >> 16;
        vp &= 0xffff;
        vga_setpage(page);
        for (j = 0; j < h; j++) {
            if (vp + w > 0x10000) {
                if (vp >= 0x10000) {
                    page++;
                    vga_setpage(page);
                    vp &= 0xffff;
                } else {
                    SDL_memcpy(dst + vp, src, 0x10000 - vp);
                    page++;
                    vga_setpage(page);
                    SDL_memcpy(dst, src + 0x10000 - vp, (vp + w) & 0xffff);
                    vp = (vp + pitch) & 0xffff;
                    src += pitch;
                    continue;
                }
            }
            SDL_memcpy(dst + vp, src, w);
            src += pitch;
            vp += pitch;
        }
    }
}

int
SVGA_SetColors(_THIS, int firstcolor, int ncolors, SDL_Color * colors)
{
    int i;

    for (i = 0; i < ncolors; i++) {
        vga_setpalette(firstcolor + i,
                       colors[i].r >> 2, colors[i].g >> 2, colors[i].b >> 2);
    }
    return (1);
}

/* Note:  If we are terminated, this could be called in the middle of
   another SDL video routine -- notably UpdateRects.
*/
void
SVGA_VideoQuit(_THIS)
{
    int i, j;

    /* Reset the console video mode */
    if (this->screen && (this->screen->w && this->screen->h)) {
        vga_setmode(TEXT);
    }
    keyboard_close();

    /* Free video mode lists */
    for (i = 0; i < NUM_MODELISTS; ++i) {
        if (SDL_modelist[i] != NULL) {
            for (j = 0; SDL_modelist[i][j]; ++j)
                SDL_free(SDL_modelist[i][j]);
            SDL_free(SDL_modelist[i]);
            SDL_modelist[i] = NULL;
        }
        if (SDL_vgamode[i] != NULL) {
            SDL_free(SDL_vgamode[i]);
            SDL_vgamode[i] = NULL;
        }
    }
    if (this->screen) {
        if (banked && this->screen->pixels) {
            SDL_free(this->screen->pixels);
        }
        this->screen->pixels = NULL;
    }
}

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