/*  RetroArch - A frontend for libretro.
 *  Copyright (C) 2010-2014 - Hans-Kristian Arntzen
 * 
 *  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/>.
 */

#include "input_common.h"

#include "../driver.h"

#include "../boolean.h"
#include "../general.h"
#include <stdint.h>
#include <stdlib.h>

#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <X11/keysym.h>

typedef struct x11_input
{
   const rarch_joypad_driver_t *joypad;

   Display *display;
   Window win;

   char state[32];
   bool mouse_l, mouse_r, mouse_m;
   int mouse_x, mouse_y;
   int mouse_last_x, mouse_last_y;

   bool grab_mouse;
} x11_input_t;

static void *x_input_init(void)
{
   if (driver.display_type != RARCH_DISPLAY_X11)
   {
      RARCH_ERR("Currently active window is not an X11 window. Cannot use this driver.\n");
      return NULL;
   }

   x11_input_t *x11 = (x11_input_t*)calloc(1, sizeof(*x11));
   if (!x11)
      return NULL;

   // Borrow the active X window ...
   x11->display = (Display*)driver.video_display;
   x11->win     = (Window)driver.video_window;

   x11->joypad = input_joypad_init_driver(g_settings.input.joypad_driver);
   input_init_keyboard_lut(rarch_key_map_x11);

   return x11;
}

static bool x_key_pressed(x11_input_t *x11, int key)
{
   if (key >= RETROK_LAST)
      return false;

   unsigned sym = input_translate_rk_to_keysym((enum retro_key)key);
   int keycode = XKeysymToKeycode(x11->display, sym);
   bool ret = x11->state[keycode >> 3] & (1 << (keycode & 7));
   return ret;
}

static bool x_is_pressed(x11_input_t *x11, const struct retro_keybind *binds, unsigned id)
{
   if (id < RARCH_BIND_LIST_END)
   {
      const struct retro_keybind *bind = &binds[id];
      return bind->valid && x_key_pressed(x11, binds[id].key);
   }
   else
      return false;
}

static int16_t x_pressed_analog(x11_input_t *x11, const struct retro_keybind *binds, unsigned index, unsigned id)
{
   unsigned id_minus = 0;
   unsigned id_plus  = 0;
   input_conv_analog_id_to_bind_id(index, id, &id_minus, &id_plus);

   int16_t pressed_minus = x_is_pressed(x11, binds, id_minus) ? -0x7fff : 0;
   int16_t pressed_plus = x_is_pressed(x11, binds, id_plus) ? 0x7fff : 0;
   return pressed_plus + pressed_minus;
}

static bool x_bind_button_pressed(void *data, int key)
{
   x11_input_t *x11 = (x11_input_t*)data;
   return x_is_pressed(x11, g_settings.input.binds[0], key) ||
      input_joypad_pressed(x11->joypad, 0, g_settings.input.binds[0], key);
}

static int16_t x_mouse_state(x11_input_t *x11, unsigned id)
{
   switch (id)
   {
      case RETRO_DEVICE_ID_MOUSE_X:
         return x11->mouse_x - x11->mouse_last_x;
      case RETRO_DEVICE_ID_MOUSE_Y:
         return x11->mouse_y - x11->mouse_last_y;
      case RETRO_DEVICE_ID_MOUSE_LEFT:
         return x11->mouse_l;
      case RETRO_DEVICE_ID_MOUSE_RIGHT:
         return x11->mouse_r;
      default:
         return 0;
   }
}

static int16_t x_pointer_state(x11_input_t *x11, unsigned index, unsigned id, bool screen)
{
   if (index != 0)
      return 0;

   int16_t res_x = 0, res_y = 0, res_screen_x = 0, res_screen_y = 0;
   bool valid = input_translate_coord_viewport(x11->mouse_x, x11->mouse_y,
         &res_x, &res_y, &res_screen_x, &res_screen_y);

   if (!valid)
      return 0;

   if (screen)
   {
      res_x = res_screen_x;
      res_y = res_screen_y;
   }

   bool inside = (res_x >= -0x7fff) && (res_y >= -0x7fff);

   if (!inside)
      return 0;

   switch (id)
   {
      case RETRO_DEVICE_ID_POINTER_X:
         return res_x;
      case RETRO_DEVICE_ID_POINTER_Y:
         return res_y;
      case RETRO_DEVICE_ID_POINTER_PRESSED:
         return x11->mouse_l;
      default:
         return 0;
   }
}

static int16_t x_lightgun_state(x11_input_t *x11, unsigned id)
{
   switch (id)
   {
      case RETRO_DEVICE_ID_LIGHTGUN_X:
         return x11->mouse_x - x11->mouse_last_x;
      case RETRO_DEVICE_ID_LIGHTGUN_Y:
         return x11->mouse_y - x11->mouse_last_y;
      case RETRO_DEVICE_ID_LIGHTGUN_TRIGGER:
         return x11->mouse_l;
      case RETRO_DEVICE_ID_LIGHTGUN_CURSOR:
         return x11->mouse_m;
      case RETRO_DEVICE_ID_LIGHTGUN_TURBO:
         return x11->mouse_r;
      case RETRO_DEVICE_ID_LIGHTGUN_START:
         return x11->mouse_m && x11->mouse_r; 
      case RETRO_DEVICE_ID_LIGHTGUN_PAUSE:
         return x11->mouse_m && x11->mouse_l; 
      default:
         return 0;
   }
}

static int16_t x_input_state(void *data, const struct retro_keybind **binds, unsigned port, unsigned device, unsigned index, unsigned id)
{
   x11_input_t *x11 = (x11_input_t*)data;
   int16_t ret;

   switch (device)
   {
      case RETRO_DEVICE_JOYPAD:
         return x_is_pressed(x11, binds[port], id) ||
            input_joypad_pressed(x11->joypad, port, binds[port], id);

      case RETRO_DEVICE_KEYBOARD:
         return x_key_pressed(x11, id);

      case RETRO_DEVICE_ANALOG:
         ret = x_pressed_analog(x11, binds[port], index, id);
         if (!ret)
            ret = input_joypad_analog(x11->joypad, port, index, id, binds[port]);
         return ret;

      case RETRO_DEVICE_MOUSE:
         return x_mouse_state(x11, id);

      case RETRO_DEVICE_POINTER:
      case RARCH_DEVICE_POINTER_SCREEN:
         return x_pointer_state(x11, index, id, device == RARCH_DEVICE_POINTER_SCREEN);

      case RETRO_DEVICE_LIGHTGUN:
         return x_lightgun_state(x11, id);

      default:
         return 0;
   }
}

static void x_input_free(void *data)
{
   x11_input_t *x11 = (x11_input_t*)data;

   if (x11->joypad)
      x11->joypad->destroy();

   free(data);
}

static void x_input_poll_mouse(x11_input_t *x11)
{
   Window root_win, child_win;
   int root_x, root_y, win_x, win_y;
   unsigned mask;

   x11->mouse_last_x = x11->mouse_x;
   x11->mouse_last_y = x11->mouse_y;

   XQueryPointer(x11->display,
            x11->win,
            &root_win, &child_win,
            &root_x, &root_y,
            &win_x, &win_y,
            &mask);

   x11->mouse_x = win_x;
   x11->mouse_y = win_y;
   x11->mouse_l = mask & Button1Mask; 
   x11->mouse_m = mask & Button2Mask; 
   x11->mouse_r = mask & Button3Mask; 

   // Somewhat hacky, but seem to do the job.
   if (x11->grab_mouse && video_focus_func())
   {
      struct rarch_viewport vp = {0};
      video_viewport_info_func(&vp);
      int mid_w = vp.full_width >> 1;
      int mid_h = vp.full_height >> 1;

      if (x11->mouse_x != mid_w || x11->mouse_y != mid_h)
      {
         XWarpPointer(x11->display, None,
               x11->win, 0, 0, 0, 0,
               mid_w, mid_h);
      }
      x11->mouse_last_x = mid_w;
      x11->mouse_last_y = mid_h;
   }
}

static void x_input_poll(void *data)
{
   x11_input_t *x11 = (x11_input_t*)data;

   if (video_focus_func())
      XQueryKeymap(x11->display, x11->state);
   else
      memset(x11->state, 0, sizeof(x11->state));

   x_input_poll_mouse(x11);
   input_joypad_poll(x11->joypad);
}

static void x_grab_mouse(void *data, bool state)
{
   x11_input_t *x11 = (x11_input_t*)data;
   x11->grab_mouse = state;
}

static bool x_set_rumble(void *data, unsigned port, enum retro_rumble_effect effect, uint16_t strength)
{
   x11_input_t *x11 = (x11_input_t*)data;
   return input_joypad_set_rumble(x11->joypad, port, effect, strength);
}

static const rarch_joypad_driver_t *x_get_joypad_driver(void *data)
{
   x11_input_t *x11 = (x11_input_t*)data;
   return x11->joypad;
}

static uint64_t x_input_get_capabilities(void *data)
{
   uint64_t caps = 0;

   caps |= (1 << RETRO_DEVICE_JOYPAD);
   caps |= (1 << RETRO_DEVICE_MOUSE);
   caps |= (1 << RETRO_DEVICE_KEYBOARD);
   caps |= (1 << RETRO_DEVICE_LIGHTGUN);
   caps |= (1 << RETRO_DEVICE_POINTER);
   caps |= (1 << RETRO_DEVICE_ANALOG);

   return caps;
}

const input_driver_t input_x = {
   x_input_init,
   x_input_poll,
   x_input_state,
   x_bind_button_pressed,
   x_input_free,
   NULL,
   NULL,
   x_input_get_capabilities,
   "x",
   x_grab_mouse,
   x_set_rumble,
   x_get_joypad_driver,
};