/*  RetroArch - A frontend for libretro.
 *  Copyright (C) 2010-2015 - 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 <stdint.h>
#include <stdlib.h>

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

#include <boolean.h>

#include "../input_common.h"
#include "../input_joypad.h"
#include "../input_keymaps.h"

#include "../../driver.h"
#include "../../gfx/video_viewport.h"
#include "../../general.h"

typedef struct x11_input
{
   bool blocked;
   const input_device_driver_t *joypad;

   Display *display;
   Window win;

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

   bool grab_mouse;
} x11_input_t;

const struct rarch_key_map rarch_key_map_x11[] = {
   { XK_BackSpace, RETROK_BACKSPACE },
   { XK_Tab, RETROK_TAB },
   { XK_Clear, RETROK_CLEAR },
   { XK_Return, RETROK_RETURN },
   { XK_Pause, RETROK_PAUSE },
   { XK_Escape, RETROK_ESCAPE },
   { XK_space, RETROK_SPACE },
   { XK_exclam, RETROK_EXCLAIM },
   { XK_quotedbl, RETROK_QUOTEDBL },
   { XK_numbersign, RETROK_HASH },
   { XK_dollar, RETROK_DOLLAR },
   { XK_ampersand, RETROK_AMPERSAND },
   { XK_apostrophe, RETROK_QUOTE },
   { XK_parenleft, RETROK_LEFTPAREN },
   { XK_parenright, RETROK_RIGHTPAREN },
   { XK_asterisk, RETROK_ASTERISK },
   { XK_plus, RETROK_PLUS },
   { XK_comma, RETROK_COMMA },
   { XK_minus, RETROK_MINUS },
   { XK_period, RETROK_PERIOD },
   { XK_slash, RETROK_SLASH },
   { 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_colon, RETROK_COLON },
   { XK_semicolon, RETROK_SEMICOLON },
   { XK_less, RETROK_LESS },
   { XK_equal, RETROK_EQUALS },
   { XK_greater, RETROK_GREATER },
   { XK_question, RETROK_QUESTION },
   { XK_at, RETROK_AT },
   { XK_bracketleft, RETROK_LEFTBRACKET },
   { XK_backslash, RETROK_BACKSLASH },
   { XK_bracketright, RETROK_RIGHTBRACKET },
   { XK_dead_circumflex, RETROK_CARET },
   { XK_underscore, RETROK_UNDERSCORE },
   { XK_grave, RETROK_BACKQUOTE },
   { 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 },
   { XK_Delete, RETROK_DELETE },
   { 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_KP_Decimal, RETROK_KP_PERIOD },
   { XK_KP_Divide, RETROK_KP_DIVIDE },
   { XK_KP_Multiply, RETROK_KP_MULTIPLY },
   { XK_KP_Subtract, RETROK_KP_MINUS },
   { XK_KP_Add, RETROK_KP_PLUS },
   { XK_KP_Enter, RETROK_KP_ENTER },
   { XK_KP_Equal, RETROK_KP_EQUALS },
   { XK_Up, RETROK_UP },
   { XK_Down, RETROK_DOWN },
   { XK_Right, RETROK_RIGHT },
   { XK_Left, RETROK_LEFT },
   { XK_Insert, RETROK_INSERT },
   { XK_Home, RETROK_HOME },
   { XK_End, RETROK_END },
   { XK_Page_Up, RETROK_PAGEUP },
   { XK_Page_Down, RETROK_PAGEDOWN },
   { 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_F13, RETROK_F13 },
   { XK_F14, RETROK_F14 },
   { XK_F15, RETROK_F15 },
   { XK_Num_Lock, RETROK_NUMLOCK },
   { XK_Caps_Lock, RETROK_CAPSLOCK },
   { XK_Scroll_Lock, RETROK_SCROLLOCK },
   { XK_Shift_R, RETROK_RSHIFT },
   { XK_Shift_L, RETROK_LSHIFT },
   { XK_Control_R, RETROK_RCTRL },
   { XK_Control_L, RETROK_LCTRL },
   { XK_Alt_R, RETROK_RALT },
   { XK_Alt_L, RETROK_LALT },
   { XK_Meta_R, RETROK_RMETA },
   { XK_Meta_L, RETROK_LMETA },
   { XK_Super_L, RETROK_LSUPER },
   { XK_Super_R, RETROK_RSUPER },
   { XK_Mode_switch, RETROK_MODE },
   { XK_Multi_key, RETROK_COMPOSE },
   { XK_Help, RETROK_HELP },
   { XK_Print, RETROK_PRINT },
   { XK_Sys_Req, RETROK_SYSREQ },
   { XK_Break, RETROK_BREAK },
   { XK_Menu, RETROK_MENU },
   /*{ ?, RETROK_POWER },*/
   { XK_EuroSign, RETROK_EURO },
   { XK_Undo, RETROK_UNDO },

   { 0, RETROK_UNKNOWN },
};

static void *x_input_init(void)
{
   driver_t *driver     = driver_get_ptr();
   settings_t *settings = config_get_ptr();
   x11_input_t *x11;

   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 = (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(settings->input.joypad_driver, x11);
   input_keymaps_init_keyboard_lut(rarch_key_map_x11);

   return x11;
}

static bool x_key_pressed(x11_input_t *x11, int key)
{
   unsigned sym;
   int keycode;
   bool ret;

   if (key >= RETROK_LAST)
      return false;

   sym     = input_keymaps_translate_rk_to_keysym((enum retro_key)key);
   keycode = XKeysymToKeycode(x11->display, sym);
   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);
   }

   return false;
}

static int16_t x_pressed_analog(x11_input_t *x11,
      const struct retro_keybind *binds, unsigned idx, unsigned id)
{
   int16_t pressed_minus = 0, pressed_plus = 0;
   unsigned id_minus = 0;
   unsigned id_plus  = 0;

   input_conv_analog_id_to_bind_id(idx, id, &id_minus, &id_plus);

   if (x_is_pressed(x11, binds, id_minus))
      pressed_minus = -0x7fff;
   if (x_is_pressed(x11, binds, id_plus))
      pressed_plus  =  0x7fff;

   return pressed_plus + pressed_minus;
}

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

static bool x_input_meta_key_pressed(void *data, int key)
{
   return false;
}

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;
      case RETRO_DEVICE_ID_MOUSE_WHEELUP:
         {
            int16_t ret = x11->mouse_wu;
            x11->mouse_wu = 0;
            return ret;
         }
      case RETRO_DEVICE_ID_MOUSE_WHEELDOWN:
         {
            int16_t ret = x11->mouse_wd;
            x11->mouse_wd = 0;
            return ret;
         }
      case RETRO_DEVICE_ID_MOUSE_MIDDLE:
         return x11->mouse_m;
   }

   return 0;
}

static int16_t x_pointer_state(x11_input_t *x11,
      unsigned idx, unsigned id, bool screen)
{
   int16_t res_x = 0, res_y = 0, res_screen_x = 0, res_screen_y = 0;
   bool valid, inside;

   if (idx != 0)
      return 0;

   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;
   }

   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;
   }

   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; 
   }

   return 0;
}

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

   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], idx, id);
         if (!ret)
            ret = input_joypad_analog(x11->joypad, port, idx,
                  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, idx, id,
               device == RARCH_DEVICE_POINTER_SCREEN);

      case RETRO_DEVICE_LIGHTGUN:
         return x_lightgun_state(x11, id);
   }

   return 0;
}

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

   if (!x11)
      return;

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

   free(x11);
}

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

   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_driver_focus())
   {
      int mid_w, mid_h;
      struct video_viewport vp = {0};

      video_driver_viewport_info(&vp);

      mid_w = vp.full_width >> 1;
      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;
   }
}

void x_input_poll_wheel(void *data, XButtonEvent *event, bool latch)
{
   x11_input_t *x11 = (x11_input_t*)data;

   if (!x11)
      return;

   switch (event->button)
   {
      case 4:
         x11->mouse_wu = 1;
         break;
      case 5:
         x11->mouse_wd = 1;
         break;
   }
}

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

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

   x_input_poll_mouse(x11);

   if (x11->joypad)
      x11->joypad->poll();
}

static void x_grab_mouse(void *data, bool state)
{
   x11_input_t *x11 = (x11_input_t*)data;
   if (x11)
      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;
   if (!x11)
      return false;
   return input_joypad_set_rumble(x11->joypad, port, effect, strength);
}

static const input_device_driver_t *x_get_joypad_driver(void *data)
{
   x11_input_t *x11 = (x11_input_t*)data;

   if (!x11)
      return NULL;
   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;
}

static bool x_keyboard_mapping_is_blocked(void *data)
{
   x11_input_t *x11 = (x11_input_t*)data;
   if (!x11)
      return false;
   return x11->blocked;
}

static void x_keyboard_mapping_set_block(void *data, bool value)
{
   x11_input_t *x11 = (x11_input_t*)data;
   if (!x11)
      return;
   x11->blocked = value;
}

input_driver_t input_x = {
   x_input_init,
   x_input_poll,
   x_input_state,
   x_input_key_pressed,
   x_input_meta_key_pressed,
   x_input_free,
   NULL,
   NULL,
   x_input_get_capabilities,
   "x",
   x_grab_mouse,
   NULL,
   x_set_rumble,
   x_get_joypad_driver,
   x_keyboard_mapping_is_blocked,
   x_keyboard_mapping_set_block,
};