/*  RetroArch - A frontend for libretro.
 *  Copyright (C) 2010-2014 - Hans-Kristian Arntzen
 *  Copyright (C) 2011-2017 - Daniel De Matteis
 *  Copyright (C) 2016-2019 - Brad Parker
 *
 *  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/>.
 */

/* We are targeting XRandR 1.2 here. */
#include <math.h>

#include <compat/strl.h>

#include <sys/types.h>
#include <unistd.h>
#include <X11/Xlib.h>

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

#ifdef HAVE_XRANDR
#include <X11/extensions/Xrandr.h>
#include <X11/extensions/randr.h>
#include <X11/extensions/Xrender.h>
#endif

#include "../video_display_server.h"
#include "../common/x11_common.h"
#include "../../configuration.h"
#include "../../retroarch.h"
#include "../video_crt_switch.h" /* needed to set aspect for low res in linux */

#ifdef HAVE_XRANDR
static char xrandr[1024]        = {0};
static char crt_name[16]        = {0};
static int crt_name_id          = 0;
static bool crt_en              = false;
static unsigned crt_id          = 20;
static char orig_output[256]    = {0};
static char old_mode[256]       = {0};
static char new_mode[256]       = {0};
static XRRModeInfo crt_rrmode;
#endif

static bool x11_display_server_using_global_dpy = false;

typedef struct
{
   unsigned opacity;
   bool decorations;
} dispserv_x11_t;

#ifdef HAVE_XRANDR
static Display* x11_display_server_open_display(void)
{
   Display *dpy = g_x11_dpy;

   if (dpy)
      x11_display_server_using_global_dpy = true;
   else
   {
      /* SDL might use X11 but doesn't use g_x11_dpy, so open it manually */
      dpy = XOpenDisplay(0);
      x11_display_server_using_global_dpy = false;
   }

   return dpy;
}
#endif

#ifdef HAVE_XRANDR
static void x11_display_server_close_display(Display *dpy)
{
   if (!dpy || x11_display_server_using_global_dpy || dpy == g_x11_dpy)
      return;

   XCloseDisplay(dpy);
}
#endif

static void* x11_display_server_init(void)
{
   dispserv_x11_t *dispserv = (dispserv_x11_t*)calloc(1, sizeof(*dispserv));

   if (!dispserv)
      return NULL;

   return dispserv;
}

static void x11_display_server_destroy(void *data)
{
   dispserv_x11_t *dispserv = (dispserv_x11_t*)data;

#ifdef HAVE_XRANDR
   if (crt_en)
   {
      snprintf(xrandr, sizeof(xrandr),
            "xrandr --newmode 700x480_59.94 13.849698 700 742 801 867 480 490 496 533 interlace -hsync -vsync");
      system(xrandr);
      snprintf(xrandr, sizeof(xrandr),
            "xrandr --addmode \"%s\" 700x480_59.94",
            orig_output);
      system(xrandr);
      snprintf(xrandr, sizeof(xrandr),
            "xrandr --output \"%s\" --mode 700x480_59.94",
            orig_output);
      system(xrandr);
      snprintf(xrandr, sizeof(xrandr),
            "xrandr --delmode \"%s\" \"%s\"",
            orig_output, old_mode);
      system(xrandr);
      snprintf(xrandr, sizeof(xrandr),
            "xrandr --rmmode \"%s\"",
            old_mode);
      system(xrandr);
   }
#endif

   if (dispserv)
      free(dispserv);
}

static bool x11_display_server_set_window_opacity(void *data, unsigned opacity)
{
   dispserv_x11_t *serv = (dispserv_x11_t*)data;
   Atom net_wm_opacity  = XInternAtom(g_x11_dpy, "_NET_WM_WINDOW_OPACITY", False);
   Atom cardinal        = XInternAtom(g_x11_dpy, "CARDINAL", False);

   serv->opacity        = opacity;

   opacity              = opacity * ((unsigned)-1 / 100.0);

   if (opacity == (unsigned)-1)
      XDeleteProperty(g_x11_dpy, g_x11_win, net_wm_opacity);
   else
      XChangeProperty(g_x11_dpy, g_x11_win, net_wm_opacity, cardinal,
            32, PropModeReplace, (const unsigned char*)&opacity, 1);

   return true;
}

static bool x11_display_server_set_window_decorations(void *data, bool on)
{
   dispserv_x11_t *serv = (dispserv_x11_t*)data;

   if (serv)
      serv->decorations = on;

   /* menu_setting performs a reinit instead to properly apply
    * decoration changes */

   return true;
}

#ifdef HAVE_XRANDR
static bool x11_display_server_set_resolution(void *data,
      unsigned width, unsigned height, int int_hz, float hz, int center, int monitor_index, int xoffset)
{
   int screen;
   Window window;
   XRRScreenResources  *res = NULL;
   Display *dpy             = NULL;
   int i                    = 0;
   int hfp                  = 0;
   int hsp                  = 0;
   int hbp                  = 0;
   int vfp                  = 0;
   int vsp                  = 0;
   int vbp                  = 0;
   int hmax                 = 0;
   int vmax                 = 0;
   int x_offset             = center;
   int pdefault             = 8;
   int pwidth               = 0;
   float roundw             = 0.0f;
   float pixel_clock        = 0;

   crt_en = true;
   crt_name_id += 1;
   snprintf(crt_name, sizeof(crt_name), "CRT%d", crt_name_id);
   snprintf(old_mode, sizeof(old_mode), "%s", new_mode);

   dpy = XOpenDisplay(0);
   screen = DefaultScreen(dpy);
   window = RootWindow(dpy, screen);

   /* set core refresh from hz */
   video_monitor_set_refresh_rate(hz);

   /* following code is the mode line generator */
   if (width < 700)
   {
      hfp    = (width * 1.033);
      hbp  = width * 1.225;
   }else {
      hfp  = (width * 1.033) + (width / 112);
      hbp  = (width * 1.225) + (width /58);
      xoffset = xoffset*2;
   }
   
   hsp    = (width * 1.117) - (xoffset*4);

   hmax = hbp;

   if (height < 241)
      vmax = 261;
   if (height < 241 && hz > 56 && hz < 58)
      vmax = 280;
   if (height < 241 && hz < 55)
      vmax = 313;
   if (height > 250 && height < 260 && hz > 54)
      vmax = 296;
   if (height > 250 && height < 260 && hz > 52 && hz < 54)
      vmax = 285;
   if (height > 250 && height < 260 && hz < 52)
      vmax = 313;
   if (height > 260 && height < 300)
      vmax = 318;
   if (height > 400 && hz > 56)
      vmax = 533;
   if (height > 520 && hz < 57)
      vmax = 580;
   if (height > 300 && hz < 56)
      vmax = 615;
   if (height > 500 && hz < 56)
      vmax = 624;
   if (height > 300)
      pdefault = pdefault * 2;

   vfp = height + ((vmax - height) / 2) - pdefault;

   if (height < 300)
      vsp = vfp + 3; /* needs to be 3 for progressive */
   if (height > 300)
      vsp = vfp + 6; /* needs to be 6 for interlaced */

   vbp = vmax;

   if (height < 300)
      pixel_clock = (hmax * vmax * hz) / 1000000;
   if (height > 300)
      pixel_clock = ((hmax * vmax * hz) / 1000000) / 2;
   /* above code is the modeline generator */

   /* create interlaced newmode from modline variables */
   if (height < 300)
   {
      snprintf(xrandr, sizeof(xrandr),
            "xrandr --newmode \"%s_%dx%d_%0.2f\" %f %d %d %d %d %d %d %d %d -hsync -vsync",
            crt_name, width, height, hz, pixel_clock, width, hfp, hsp, hbp, height, vfp, vsp, vbp);
      system(xrandr);
   }

   /* create interlaced newmode from modline variables */
   if (height > 300)
   {
      snprintf(xrandr, sizeof(xrandr),
            "xrandr --newmode \"%s_%dx%d_%0.2f\" %f %d %d %d %d %d %d %d %d interlace -hsync -vsync",
            crt_name, width, height, hz, pixel_clock, width, hfp, hsp, hbp, height, vfp, vsp, vbp);
      system(xrandr);
   }

   /* variable for new mode */
   snprintf(new_mode, sizeof(new_mode), "%s_%dx%d_%0.2f", crt_name, width, height, hz);

   /* need to run loops for DVI0 - DVI-2 and VGA0 - VGA-2 outputs to
    * add and delete modes */
   crt_rrmode.id = crt_id;
   crt_rrmode.width = width;
   crt_rrmode.height = height;
   crt_rrmode.dotClock = pixel_clock;
   crt_rrmode.hSyncStart = hfp;
   crt_rrmode.hSyncEnd = hsp;
   crt_rrmode.hTotal = hmax;
   crt_rrmode.hSkew = 0;
   crt_rrmode.vSyncStart = vfp;
   crt_rrmode.vSyncEnd = vsp;
   crt_rrmode.vTotal = vmax;
   crt_rrmode.name = new_mode;
   crt_rrmode.nameLength = sizeof(new_mode);
   crt_rrmode.modeFlags = 0;

   res = XRRGetScreenResources(dpy, window);

   if (monitor_index == 0)
   {
      for (i = 0; i < res->noutput; i++)
      {
         XRROutputInfo *outputs = XRRGetOutputInfo(dpy, res, res->outputs[i]);

         if (outputs->connection == RR_Connected)
         {
            snprintf(orig_output, sizeof(orig_output), "%s", outputs->name);

            snprintf(xrandr, sizeof(xrandr),
                  "xrandr --addmode \"%s\" \"%s\"",
                  outputs->name, new_mode);
            system(xrandr);
            snprintf(xrandr, sizeof(xrandr),
                  "xrandr --output \"%s\" --mode \"%s\"",
                  outputs->name, new_mode);
            system(xrandr);
            snprintf(xrandr, sizeof(xrandr),
                  "xrandr --delmode \"%s\" \"%s\"",
                  outputs->name, old_mode);
            system(xrandr);
            snprintf(xrandr, sizeof(xrandr),
                  "xrandr --rmmode \"%s\"",
                  old_mode);
            system(xrandr);
         }
      }
   }
   else if (monitor_index > 0)
   {
      XRROutputInfo *outputs = XRRGetOutputInfo(dpy, res, res->outputs[monitor_index]);

      if (outputs->connection == RR_Connected)
      {
         snprintf(orig_output, sizeof(orig_output), "%s", outputs->name);

         snprintf(xrandr, sizeof(xrandr),
               "xrandr --addmode \"%s\" \"%s\"",
               outputs->name, new_mode);
         system(xrandr);
         snprintf(xrandr, sizeof(xrandr),
               "xrandr --output \"%s\" --mode \"%s\"",
               outputs->name, new_mode);
         system(xrandr);
         snprintf(xrandr, sizeof(xrandr),
               "xrandr --delmode \"%s\" \"%s\"",
               outputs->name, old_mode);
         system(xrandr);
         snprintf(xrandr, sizeof(xrandr),
               "xrandr --rmmode \"%s\"",
               old_mode);
         system(xrandr);
      }
   }
   return true;
}
#endif

const char *x11_display_server_get_output_options(void *data)
{
#ifdef HAVE_XRANDR
   Display *dpy;
   XRRScreenResources *res;
   XRROutputInfo *info;
   Window root;
   int i;
   static char s[PATH_MAX_LENGTH];

   if (!(dpy = XOpenDisplay(0)))
      return NULL;

   root = RootWindow(dpy, DefaultScreen(dpy));

   if (!(res = XRRGetScreenResources(dpy, root)))
      return NULL;

   for (i = 0; i < res->noutput; i++)
   {
      if (!(info = XRRGetOutputInfo(dpy, res, res->outputs[i])))
         return NULL;

      strlcat(s, info->name, sizeof(s));
      if ((i+1) < res->noutput)
         strlcat(s, "|", sizeof(s));
   }

   return s;
#else
   /* TODO/FIXME - hardcoded for now; list should be built up dynamically later */
   return "HDMI-0|HDMI-1|HDMI-2|HDMI-3|DVI-0|DVI-1|DVI-2|DVI-3|VGA-0|VGA-1|VGA-2|VGA-3|Config";
#endif
}

#ifdef HAVE_XRANDR
static void x11_display_server_set_screen_orientation(enum rotation rotation)
{
   int i, j;
   XRRScreenResources *screen;
   /* switched to using XOpenDisplay() due to deinit order issue with g_x11_dpy when restoring original rotation on exit */
   Display *dpy = XOpenDisplay(0);
   XRRScreenConfiguration *config = XRRGetScreenInfo(dpy, DefaultRootWindow(dpy));
   double dpi = (25.4 * DisplayHeight(dpy, DefaultScreen(dpy))) / DisplayHeightMM(dpy, DefaultScreen(dpy));

   XGrabServer(dpy);

   screen = XRRGetScreenResources(dpy, DefaultRootWindow(dpy));

   for (i = 0; i < screen->noutput; i++)
   {
      XRROutputInfo *info = XRRGetOutputInfo(dpy, screen, screen->outputs[i]);

      if (info->connection != RR_Connected)
      {
         XRRFreeOutputInfo(info);
         continue;
      }

      for (j = 0; j < info->ncrtc; j++)
      {
         XRRCrtcInfo *crtc = XRRGetCrtcInfo(dpy, screen, screen->crtcs[j]);
         Rotation new_rotation = RR_Rotate_0;

         if (crtc->width == 0 || crtc->height == 0)
         {
            XRRFreeCrtcInfo(crtc);
            continue;
         }

         switch (rotation)
         {
            case ORIENTATION_NORMAL:
            default:
               if (crtc->rotations & RR_Rotate_0)
                  new_rotation = RR_Rotate_0;
               break;
            case ORIENTATION_VERTICAL:
               if (crtc->rotations & RR_Rotate_270)
                  new_rotation = RR_Rotate_270;
               break;
            case ORIENTATION_FLIPPED:
               if (crtc->rotations & RR_Rotate_180)
                  new_rotation = RR_Rotate_180;
               break;
            case ORIENTATION_FLIPPED_ROTATED:
               if (crtc->rotations & RR_Rotate_90)
                  new_rotation = RR_Rotate_90;
               break;
         }

         XRRSetCrtcConfig(dpy, screen, screen->crtcs[j], CurrentTime, 0, 0, None, RR_Rotate_0, NULL, 0);

         if ((crtc->rotation & RR_Rotate_0 || crtc->rotation & RR_Rotate_180) && (rotation == ORIENTATION_VERTICAL || rotation == ORIENTATION_FLIPPED_ROTATED))
         {
            unsigned width = crtc->width;
            crtc->width = crtc->height;
            crtc->height = width;
         }
         else if ((crtc->rotation & RR_Rotate_90 || crtc->rotation & RR_Rotate_270) && (rotation == ORIENTATION_NORMAL || rotation == ORIENTATION_FLIPPED))
         {
            unsigned width = crtc->width;
            crtc->width = crtc->height;
            crtc->height = width;
         }

         crtc->rotation = new_rotation;

         XRRSetScreenSize(dpy, DefaultRootWindow(dpy), crtc->width, crtc->height, (25.4 * crtc->width) / dpi, (25.4 * crtc->height) / dpi);

         XRRSetCrtcConfig(dpy, screen, screen->crtcs[j], CurrentTime, crtc->x, crtc->y, crtc->mode, crtc->rotation, crtc->outputs, crtc->noutput);

         XRRFreeCrtcInfo(crtc);
      }

      XRRFreeOutputInfo(info);
   }

   XRRFreeScreenResources(screen);

   XUngrabServer(dpy);
   XSync(dpy, False);
   XRRFreeScreenConfigInfo(config);
   XCloseDisplay(dpy);
}

static enum rotation x11_display_server_get_screen_orientation(void)
{
   int i, j;
   Display *dpy = x11_display_server_open_display();
   XRRScreenResources *screen = XRRGetScreenResources(dpy, DefaultRootWindow(dpy));
   XRRScreenConfiguration *config = XRRGetScreenInfo(dpy, DefaultRootWindow(dpy));
   enum rotation rotation = ORIENTATION_NORMAL;

   for (i = 0; i < screen->noutput; i++)
   {
      XRROutputInfo *info = XRRGetOutputInfo(dpy, screen, screen->outputs[i]);

      if (info->connection != RR_Connected)
      {
         XRRFreeOutputInfo(info);
         continue;
      }

      for (j = 0; j < info->ncrtc; j++)
      {
         XRRCrtcInfo *crtc = XRRGetCrtcInfo(dpy, screen, screen->crtcs[j]);

         if (crtc->width == 0 || crtc->height == 0)
         {
            XRRFreeCrtcInfo(crtc);
            continue;
         }

         switch (crtc->rotation)
         {
            case RR_Rotate_0:
            default:
               rotation = ORIENTATION_NORMAL;
               break;
            case RR_Rotate_270:
               rotation = ORIENTATION_VERTICAL;
               break;
            case RR_Rotate_180:
               rotation = ORIENTATION_FLIPPED;
               break;
            case RR_Rotate_90:
               rotation = ORIENTATION_FLIPPED_ROTATED;
               break;
         }

         XRRFreeCrtcInfo(crtc);
      }

      XRRFreeOutputInfo(info);
   }

   XRRFreeScreenResources(screen);
   XRRFreeScreenConfigInfo(config);

   x11_display_server_close_display(dpy);

   return rotation;
}
#endif

static uint32_t x11_display_server_get_flags(void *data)
{
   uint32_t             flags   = 0;

#ifdef HAVE_XRANDR
   BIT32_SET(flags, DISPSERV_CTX_CRT_SWITCHRES);
#endif

   return flags;
}

const video_display_server_t dispserv_x11 = {
   x11_display_server_init,
   x11_display_server_destroy,
   x11_display_server_set_window_opacity,
   NULL, /* set_window_progress */
   x11_display_server_set_window_decorations,
#ifdef HAVE_XRANDR
   x11_display_server_set_resolution,
#else
   NULL, /* set_resolution */
#endif
   NULL, /* get_resolution_list */
   x11_display_server_get_output_options,
#ifdef HAVE_XRANDR
   x11_display_server_set_screen_orientation,
   x11_display_server_get_screen_orientation,
#else
   NULL, /* set_screen_orientation */
   NULL, /* get_screen_orientation */
#endif
   x11_display_server_get_flags,
   "x11"
};