/*  RetroArch - A frontend for libretro.
 *  Copyright (C) 2016-2017 - Alfred Agrell
 *  Copyright (C) 2011-2017 - Daniel De Matteis
 *
 *  RetroArch is free software: you can redistribute it and/or modify it under the terms
 *  of the GNU General Public License as published by the Free Software Found-
 *  ation, either version 3 of the License, or (at your option) any later version.
 *
 *  RetroArch 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 General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along with RetroArch.
 *  If not, see <http://www.gnu.org/licenses/>.
 */

#define _XOPEN_SOURCE 700 /* TODO: this doesn't really belong here. */

#include <stdlib.h>
#include <string.h>

#include <sys/shm.h>
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <X11/extensions/XShm.h>

#ifdef HAVE_CONFIG_H
#include "../../config.h"
#endif

#ifdef HAVE_MENU
#include "../../menu/menu_driver.h"
#endif

#include "../font_driver.h"

#include "../common/x11_common.h"

typedef struct xshm
{
   Display* display;
   Window wndw;
   
   int width;
   int height;
   
   XShmSegmentInfo shmInfo;
   XImage* image;
   GC gc;
} xshm_t;

static void *xshm_gfx_init(const video_info_t *video,
      const input_driver_t **input, void **input_data)
{
   xshm_t* xshm = (xshm_t*)malloc(sizeof(xshm_t));
   Window parent;
   
   XInitThreads();
   
   xshm->display = XOpenDisplay(NULL);
   
#ifdef RARCH_INTERNAL
   parent = DefaultRootWindow(xshm->display);
#else
   parent = video->parent;
#endif
   XSetWindowAttributes attributes;
   attributes.border_pixel=0;
   xshm->wndw = XCreateWindow(xshm->display, parent,
                              0, 0, video->width, video->height,
                              0, 24, CopyFromParent, NULL, CWBorderPixel, &attributes);
   XSetWindowBackground(xshm->display, xshm->wndw, 0);
   XMapWindow(xshm->display, xshm->wndw);
   
   xshm->shmInfo.shmid = shmget(IPC_PRIVATE, sizeof(uint32_t) * video->width * video->height,
                                IPC_CREAT|0600);
   if (xshm->shmInfo.shmid<0) abort();//seems like an out of memory situation... let's just blow up
   
   xshm->shmInfo.shmaddr = (char*)shmat(xshm->shmInfo.shmid, 0, 0);
   xshm->shmInfo.readOnly = False;
   XShmAttach(xshm->display, &xshm->shmInfo);
   XSync(xshm->display, False);//no idea why this is required, but I get weird errors without it
   xshm->image = XShmCreateImage(xshm->display, NULL, 24, ZPixmap,
                                 xshm->shmInfo.shmaddr, &xshm->shmInfo, video->width, video->height);
   
   xshm->gc = XCreateGC(xshm->display, xshm->wndw, 0, NULL);
   
   xshm->width = video->width;
   xshm->height = video->height;
   
   if (input) *input = NULL;
   if (input_data) *input_data = NULL;
   
   return xshm;
}

static bool xshm_gfx_frame(void *data, const void *frame, unsigned width,
      unsigned height, uint64_t frame_count,
      unsigned pitch, const char *msg, video_frame_info_t *video_info)
{
   xshm_t* xshm = (xshm_t*)data;
   int y;
   
   for (y=0;y<height;y++)
   {
      memcpy((uint8_t*)xshm->shmInfo.shmaddr + sizeof(uint32_t)*xshm->width*y,
            (uint8_t*)frame + pitch*y, pitch);
   }

#ifdef HAVE_MENU
   menu_driver_frame(video_info);
#endif
   
   XShmPutImage(xshm->display, xshm->wndw, xshm->gc, xshm->image,
                0, 0, 0, 0, xshm->width, xshm->height, False);
   XFlush(xshm->display);
   
   return true;
}

static void xshm_gfx_set_nonblock_state(void *data, bool toggle)
{
   
}

static bool xshm_gfx_alive(void *data)
{
   return true;
}

static bool xshm_gfx_focus(void *data)
{
   return true;
}

static bool xshm_gfx_suppress_screensaver(void *data, bool enable)
{
   return false;
}

static void xshm_gfx_free(void *data)
{
   
}

static void xshm_gfx_set_rotation(void *data, unsigned rotation)
{
   
}

static void xshm_gfx_viewport_info(void *data, struct video_viewport *vp)
{
   
}

static bool xshm_gfx_read_viewport(void *data, uint8_t *buffer, bool is_idle)
{
   return false;
}

static void xshm_poke_set_filtering(void *data, unsigned index, bool smooth)
{
   
}

static void xshm_poke_set_aspect_ratio(void *data, unsigned aspect_ratio_idx)
{
   
}

static void xshm_poke_apply_state_changes(void *data)
{
   
}

#ifdef HAVE_MENU
static void xshm_poke_set_texture_frame(void *data, const void *frame, bool rgb32,
      unsigned width, unsigned height, float alpha)
{
   
}

static void xshm_poke_texture_enable(void *data, bool enable, bool full_screen)
{
   
}

static void xshm_poke_set_osd_msg(void *data,
      video_frame_info_t *video_info,
      const char *msg,
      const struct font_params *params, void *font)
{
   
}

static void xshm_show_mouse(void *data, bool state)
{
   
}

static void xshm_grab_mouse_toggle(void *data)
{
   
}
#endif

static video_poke_interface_t xshm_video_poke_interface = {
   NULL,
   NULL,
   NULL,
   xshm_poke_set_filtering,
   NULL, /* get_video_output_size */
   NULL, /* get_video_output_prev */
   NULL, /* get_video_output_next */
   NULL, /* get_current_framebuffer */
   NULL, /* get_proc_address */
   xshm_poke_set_aspect_ratio,
   xshm_poke_apply_state_changes,
#ifdef HAVE_MENU
   xshm_poke_set_texture_frame,
   xshm_poke_texture_enable,
   xshm_poke_set_osd_msg,
   xshm_show_mouse,
   xshm_grab_mouse_toggle,
#else
   NULL,
   NULL,
   NULL,
   NULL,
   NULL,
#endif
   NULL,
};

static void xshm_gfx_poke_interface(void *data, const video_poke_interface_t **iface)
{
   (void)data;
   *iface = &xshm_video_poke_interface;
}

static bool xshm_gfx_set_shader(void *data,
      enum rarch_shader_type type, const char *path)
{
   (void)data;
   (void)type;
   (void)path;

   return false; 
}

video_driver_t video_xshm = {
   xshm_gfx_init,
   xshm_gfx_frame,
   xshm_gfx_set_nonblock_state,
   xshm_gfx_alive,
   xshm_gfx_focus,
   xshm_gfx_suppress_screensaver,
   xshm_gfx_has_windowed,
   xshm_gfx_set_shader,
   xshm_gfx_free,
   "xshm",

   NULL,
   xshm_gfx_set_rotation,
   xshm_gfx_viewport_info,
   xshm_gfx_read_viewport,
   NULL, /* read_frame_raw */
#ifdef HAVE_OVERLAY
    NULL,
#endif
    xshm_gfx_poke_interface
};

