/*  RetroArch - A frontend for libretro.
 *  Copyright (C) 2010-2013 - Hans-Kristian Arntzen
 *  Copyright (C) 2011-2013 - 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/>.
 */

// GLX context.

#include "../../driver.h"
#include "../gfx_context.h"
#include "../gl_common.h"
#include "../gfx_common.h"
#include "x11_common.h"

#include <signal.h>
#include <stdint.h>
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <GL/glx.h>

static Display *g_dpy;
static Window   g_win;
static GLXWindow g_glx_win;
static Colormap g_cmap;
static Atom g_quit_atom;
static bool g_has_focus;
static bool g_true_full;
static unsigned g_screen;

static GLXContext g_ctx;
static GLXFBConfig g_fbc;

static XF86VidModeModeInfo g_desktop_mode;
static bool g_should_reset_mode;

static volatile sig_atomic_t g_quit;
static bool g_inited;
static unsigned g_interval;
static bool g_is_double;

static int (*g_pglSwapInterval)(int);

struct key_bind
{
   unsigned x;
   enum retro_key sk;
};

static unsigned keysym_lut[RETROK_LAST];

static const struct key_bind lut_binds[] = {
   { XK_Left, RETROK_LEFT },
   { XK_Right, RETROK_RIGHT },
   { XK_Up, RETROK_UP },
   { XK_Down, RETROK_DOWN },
   { XK_Return, RETROK_RETURN },
   { XK_Tab, RETROK_TAB },
   { XK_Insert, RETROK_INSERT },
   { XK_Home, RETROK_HOME },
   { XK_End, RETROK_END },
   { XK_Page_Up, RETROK_PAGEUP },
   { XK_Page_Down, RETROK_PAGEDOWN },
   { XK_Delete, RETROK_DELETE },
   { XK_Shift_R, RETROK_RSHIFT },
   { XK_Shift_L, RETROK_LSHIFT },
   { XK_Control_L, RETROK_LCTRL },
   { XK_Alt_L, RETROK_LALT },
   { XK_space, RETROK_SPACE },
   { XK_Escape, RETROK_ESCAPE },
   { XK_BackSpace, RETROK_BACKSPACE },
   { XK_KP_Enter, RETROK_KP_ENTER },
   { XK_KP_Add, RETROK_KP_PLUS },
   { XK_KP_Subtract, RETROK_KP_MINUS },
   { XK_KP_Multiply, RETROK_KP_MULTIPLY },
   { XK_KP_Divide, RETROK_KP_DIVIDE },
   { XK_grave, RETROK_BACKQUOTE },
   { XK_Pause, RETROK_PAUSE },
   { XK_KP_0, RETROK_KP0 },
   { XK_KP_1, RETROK_KP1 },
   { XK_KP_2, RETROK_KP2 },
   { XK_KP_3, RETROK_KP3 },
   { XK_KP_4, RETROK_KP4 },
   { XK_KP_5, RETROK_KP5 },
   { XK_KP_6, RETROK_KP6 },
   { XK_KP_7, RETROK_KP7 },
   { XK_KP_8, RETROK_KP8 },
   { XK_KP_9, RETROK_KP9 },
   { XK_0, RETROK_0 },
   { XK_1, RETROK_1 },
   { XK_2, RETROK_2 },
   { XK_3, RETROK_3 },
   { XK_4, RETROK_4 },
   { XK_5, RETROK_5 },
   { XK_6, RETROK_6 },
   { XK_7, RETROK_7 },
   { XK_8, RETROK_8 },
   { XK_9, RETROK_9 },
   { XK_F1, RETROK_F1 },
   { XK_F2, RETROK_F2 },
   { XK_F3, RETROK_F3 },
   { XK_F4, RETROK_F4 },
   { XK_F5, RETROK_F5 },
   { XK_F6, RETROK_F6 },
   { XK_F7, RETROK_F7 },
   { XK_F8, RETROK_F8 },
   { XK_F9, RETROK_F9 },
   { XK_F10, RETROK_F10 },
   { XK_F11, RETROK_F11 },
   { XK_F12, RETROK_F12 },
   { XK_a, RETROK_a },
   { XK_b, RETROK_b },
   { XK_c, RETROK_c },
   { XK_d, RETROK_d },
   { XK_e, RETROK_e },
   { XK_f, RETROK_f },
   { XK_g, RETROK_g },
   { XK_h, RETROK_h },
   { XK_i, RETROK_i },
   { XK_j, RETROK_j },
   { XK_k, RETROK_k },
   { XK_l, RETROK_l },
   { XK_m, RETROK_m },
   { XK_n, RETROK_n },
   { XK_o, RETROK_o },
   { XK_p, RETROK_p },
   { XK_q, RETROK_q },
   { XK_r, RETROK_r },
   { XK_s, RETROK_s },
   { XK_t, RETROK_t },
   { XK_u, RETROK_u },
   { XK_v, RETROK_v },
   { XK_w, RETROK_w },
   { XK_x, RETROK_x },
   { XK_y, RETROK_y },
   { XK_z, RETROK_z },
};

static void init_lut(void)
{
   memset(keysym_lut, 0, sizeof(keysym_lut));
   for (unsigned i = 0; i < sizeof(lut_binds) / sizeof(lut_binds[0]); i++)
      keysym_lut[lut_binds[i].sk] = lut_binds[i].x;
}

static void sighandler(int sig)
{
   (void)sig;
   g_quit = 1;
}

static Bool glx_wait_notify(Display *d, XEvent *e, char *arg)
{
   (void)d;
   (void)e;
   return e->type == MapNotify && e->xmap.window == g_win;
}

static void gfx_ctx_get_video_size(unsigned *width, unsigned *height);
static void gfx_ctx_destroy(void);

static void gfx_ctx_swap_interval(unsigned interval)
{
   g_interval = interval;
   if (g_pglSwapInterval)
   {
      RARCH_LOG("[GLX]: glXSwapInterval(%u)\n", g_interval);
      if (g_pglSwapInterval(g_interval) != 0)
         RARCH_WARN("[GLX]: glXSwapInterval() failed.\n");
   }
}

static void gfx_ctx_check_window(bool *quit,
      bool *resize, unsigned *width, unsigned *height, unsigned frame_count)
{
   (void)frame_count;

   unsigned new_width = *width, new_height = *height;
   gfx_ctx_get_video_size(&new_width, &new_height);

   if (new_width != *width || new_height != *height)
   {
      *resize = true;
      *width  = new_width;
      *height = new_height;
   }

   XEvent event;
   while (XPending(g_dpy))
   {
      XNextEvent(g_dpy, &event);
      switch (event.type)
      {
         case ClientMessage:
            if ((Atom)event.xclient.data.l[0] == g_quit_atom)
               g_quit = true;
            break;

         case DestroyNotify:
            g_quit = true;
            break;

         case MapNotify:
            g_has_focus = true;
            break;

         case UnmapNotify:
            g_has_focus = false;
            break;

         case KeyPress:
         case KeyRelease:
            x11_handle_key_event(&event);
            break;
      }
   }

   *quit = g_quit;
}

static void gfx_ctx_swap_buffers(void)
{
   if (g_is_double)
      glXSwapBuffers(g_dpy, g_glx_win);
}

static void gfx_ctx_set_resize(unsigned width, unsigned height)
{
   (void)width;
   (void)height;
}

static void gfx_ctx_update_window_title(bool reset)
{
   if (reset)
      gfx_window_title_reset();

   char buf[128];
   if (gfx_get_fps(buf, sizeof(buf), false))
      XStoreName(g_dpy, g_win, buf);
}

static void gfx_ctx_get_video_size(unsigned *width, unsigned *height)
{
   if (!g_dpy || g_win == None)
   {
      Display *dpy = XOpenDisplay(NULL);
      if (dpy)
      {
         int screen = DefaultScreen(dpy);
         *width  = DisplayWidth(dpy, screen);
         *height = DisplayHeight(dpy, screen);
         XCloseDisplay(dpy);
      }
      else
      {
         *width  = 0;
         *height = 0;
      }
   }
   else
   {
      XWindowAttributes target;
      XGetWindowAttributes(g_dpy, g_win, &target);

      *width  = target.width;
      *height = target.height;
   }
}

static bool gfx_ctx_init(void)
{
   if (g_inited)
      return false;

   XInitThreads();

   static const int visual_attribs[] = {
      GLX_X_RENDERABLE     , True,
      GLX_DRAWABLE_TYPE    , GLX_WINDOW_BIT,
      GLX_RENDER_TYPE      , GLX_RGBA_BIT,
      GLX_DOUBLEBUFFER     , True,
      GLX_RED_SIZE         , 8,
      GLX_GREEN_SIZE       , 8,
      GLX_BLUE_SIZE        , 8,
      GLX_ALPHA_SIZE       , 8,
      GLX_DEPTH_SIZE       , 0,
      GLX_STENCIL_SIZE     , 0,
      None
   };

   GLXFBConfig *fbcs = NULL;

   g_quit = 0;

   init_lut();

   g_dpy = XOpenDisplay(NULL);
   if (!g_dpy)
      goto error;

   // GLX 1.3+ required.
   int major, minor;
   glXQueryVersion(g_dpy, &major, &minor);
   if (major < 1 || (major == 1 && minor < 3))
      goto error;

   int nelements;
   fbcs = glXChooseFBConfig(g_dpy, DefaultScreen(g_dpy),
         visual_attribs, &nelements);

   if (!fbcs)
      goto error;

   if (!nelements)
   {
      XFree(fbcs);
      goto error;
   }

   g_fbc = fbcs[0];
   XFree(fbcs);

   return true;

error:
   gfx_ctx_destroy();
   return false;
}

static bool gfx_ctx_set_video_mode(
      unsigned width, unsigned height,
      bool fullscreen)
{
   struct sigaction sa = {{0}};
   sa.sa_handler = sighandler;
   sa.sa_flags   = SA_RESTART;
   sigemptyset(&sa.sa_mask);
   sigaction(SIGINT, &sa, NULL);
   sigaction(SIGTERM, &sa, NULL);
   int x_off = 0;
   int y_off = 0;

   bool windowed_full = g_settings.video.windowed_fullscreen;
   bool true_full = false;

   XSetWindowAttributes swa = {0};

   XVisualInfo *vi = glXGetVisualFromFBConfig(g_dpy, g_fbc);
   if (!vi)
      goto error;

   swa.colormap = g_cmap = XCreateColormap(g_dpy, RootWindow(g_dpy, vi->screen),
         vi->visual, AllocNone);
   swa.event_mask = StructureNotifyMask | KeyPressMask | KeyReleaseMask;
   swa.override_redirect = fullscreen ? True : False;

   if (fullscreen && !windowed_full)
   {
      if (x11_enter_fullscreen(g_dpy, width, height, &g_desktop_mode))
      {
         g_should_reset_mode = true;
         true_full = true;
      }
      else
         RARCH_ERR("[GLX]: Entering true fullscreen failed. Will attempt windowed mode.\n");
   }

   if (g_settings.video.monitor_index)
      g_screen = g_settings.video.monitor_index - 1;

#ifdef HAVE_XINERAMA
   if (fullscreen || g_screen != 0)
   {
      unsigned new_width  = width;
      unsigned new_height = height;
      if (x11_get_xinerama_coord(g_dpy, g_screen, &x_off, &y_off, &new_width, &new_height))
         RARCH_LOG("[GLX]: Using Xinerama on screen #%u.\n", g_screen);
      else
         RARCH_LOG("[GLX]: Xinerama is not active on screen.\n");

      if (fullscreen)
      {
         width  = new_width;
         height = new_height;
      }
   }
#endif

   RARCH_LOG("[GLX]: X = %d, Y = %d, W = %u, H = %u.\n",
         x_off, y_off, width, height);

   g_win = XCreateWindow(g_dpy, RootWindow(g_dpy, vi->screen),
         x_off, y_off, width, height, 0,
         vi->depth, InputOutput, vi->visual, 
         CWBorderPixel | CWColormap | CWEventMask | (true_full ? CWOverrideRedirect : 0), &swa);
   XSetWindowBackground(g_dpy, g_win, 0);

   g_glx_win = glXCreateWindow(g_dpy, g_fbc, g_win, 0);

   gfx_ctx_update_window_title(true);
   x11_set_window_attr(g_dpy, g_win);

   if (fullscreen)
      x11_hide_mouse(g_dpy, g_win);

   if (true_full)
   {
      RARCH_LOG("[GLX]: Using true fullscreen.\n");
      XMapRaised(g_dpy, g_win);
   }
   else if (fullscreen) // We attempted true fullscreen, but failed. Attempt using windowed fullscreen.
   {
      XMapRaised(g_dpy, g_win);
      RARCH_LOG("[GLX]: Using windowed fullscreen.\n");
      // We have to move the window to the screen we want to go fullscreen on first.
      // x_off and y_off usually get ignored in XCreateWindow().
      x11_move_window(g_dpy, g_win, x_off, y_off, width, height);
      x11_windowed_fullscreen(g_dpy, g_win);
   }
   else
   {
      XMapWindow(g_dpy, g_win);
      // If we want to map the window on a different screen, we'll have to do it by force.
      // Otherwise, we should try to let the window manager sort it out.
      // x_off and y_off usually get ignored in XCreateWindow().
      if (g_screen)
         x11_move_window(g_dpy, g_win, x_off, y_off, width, height);
   }

   XEvent event;
   XIfEvent(g_dpy, &event, glx_wait_notify, NULL);

   XSetInputFocus(g_dpy, g_win, RevertToNone, CurrentTime);

   g_ctx = glXCreateNewContext(g_dpy, g_fbc, GLX_RGBA_TYPE, 0, True);
   if (!g_ctx)
   {
      RARCH_ERR("[GLX]: Failed to create new context.\n");
      goto error;
   }

   glXMakeContextCurrent(g_dpy, g_glx_win, g_glx_win, g_ctx);
   XSync(g_dpy, False);

   g_quit_atom = XInternAtom(g_dpy, "WM_DELETE_WINDOW", False);
   if (g_quit_atom)
      XSetWMProtocols(g_dpy, g_win, &g_quit_atom, 1);

   int val;
   glXGetConfig(g_dpy, vi, GLX_DOUBLEBUFFER, &val);
   g_is_double = val;
   if (g_is_double)
   {
      if (!g_pglSwapInterval)
         g_pglSwapInterval = (int (*)(int))glXGetProcAddress((const GLubyte*)"glXSwapInterval");
      if (!g_pglSwapInterval)
         g_pglSwapInterval = (int (*)(int))glXGetProcAddress((const GLubyte*)"glXSwapIntervalMESA");
      if (!g_pglSwapInterval)
         g_pglSwapInterval = (int (*)(int))glXGetProcAddress((const GLubyte*)"glXSwapIntervalSGI");
      if (!g_pglSwapInterval)
         RARCH_WARN("[GLX]: Cannot find swap interval call.\n");
   }
   else
      RARCH_WARN("[GLX]: Context is not double buffered!.\n");

   gfx_ctx_swap_interval(g_interval);

   XFree(vi);
   g_has_focus = true;
   g_inited    = true;

   driver.display_type  = RARCH_DISPLAY_X11;
   driver.video_display = (uintptr_t)g_dpy;
   driver.video_window  = (uintptr_t)g_win;
   g_true_full = true_full;

   return true;

error:
   if (vi)
      XFree(vi);

   gfx_ctx_destroy();
   return false;
}

static void gfx_ctx_destroy(void)
{
   if (g_dpy && g_ctx)
   {
      glXMakeContextCurrent(g_dpy, None, None, NULL);
      glXDestroyContext(g_dpy, g_ctx);
      g_ctx = NULL;
   }

   if (g_win)
   {
      glXDestroyWindow(g_dpy, g_glx_win);
      g_glx_win = 0;

      // Save last used monitor for later.
#ifdef HAVE_XINERAMA
      XWindowAttributes target;
      Window child;

      int x = 0, y = 0;
      XGetWindowAttributes(g_dpy, g_win, &target);
      XTranslateCoordinates(g_dpy, g_win, DefaultRootWindow(g_dpy),
            target.x, target.y, &x, &y, &child);

      g_screen = x11_get_xinerama_monitor(g_dpy, x, y,
            target.width, target.height);

      RARCH_LOG("[GLX]: Saved monitor #%u.\n", g_screen);
#endif

      XUnmapWindow(g_dpy, g_win);
      XDestroyWindow(g_dpy, g_win);
      g_win = None;
   }

   if (g_cmap)
   {
      XFreeColormap(g_dpy, g_cmap);
      g_cmap = None;
   }

   if (g_should_reset_mode)
   {
      x11_exit_fullscreen(g_dpy, &g_desktop_mode);
      g_should_reset_mode = false;
   }

   if (g_dpy)
   {
      XCloseDisplay(g_dpy);
      g_dpy = NULL;
   }

   g_inited = false;
}

static void gfx_ctx_input_driver(const input_driver_t **input, void **input_data)
{
   void *xinput = input_x.init();
   *input       = xinput ? &input_x : NULL;
   *input_data  = xinput;
}

static bool gfx_ctx_has_focus(void)
{
   if (!g_inited)
      return false;

   Window win;
   int rev;
   XGetInputFocus(g_dpy, &win, &rev);

   return (win == g_win && g_has_focus) || g_true_full;
}

static gfx_ctx_proc_t gfx_ctx_get_proc_address(const char *symbol)
{
   return glXGetProcAddress((const GLubyte*)symbol);
}

static bool gfx_ctx_bind_api(enum gfx_ctx_api api)
{
   return api == GFX_CTX_OPENGL_API;
}

static bool gfx_ctx_init_egl_image_buffer(const video_info_t *video)
{
   return false;
}

static bool gfx_ctx_write_egl_image(const void *frame, unsigned width, unsigned height, unsigned pitch, bool rgb32, unsigned index, void **image_handle)
{
   return false;
}

const gfx_ctx_driver_t gfx_ctx_glx = {
   gfx_ctx_init,
   gfx_ctx_destroy,
   gfx_ctx_bind_api,
   gfx_ctx_swap_interval,
   gfx_ctx_set_video_mode,
   gfx_ctx_get_video_size,
   NULL,
   gfx_ctx_update_window_title,
   gfx_ctx_check_window,
   gfx_ctx_set_resize,
   gfx_ctx_has_focus,
   gfx_ctx_swap_buffers,
   gfx_ctx_input_driver,
   gfx_ctx_get_proc_address,
   gfx_ctx_init_egl_image_buffer,
   gfx_ctx_write_egl_image,
   NULL,
   "glx",
};