/*  RetroArch - A frontend for libretro.
 *  Copyright (C) 2010-2014 - Hans-Kristian Arntzen
 *  Copyright (C) 2011-2017 - Daniel De Matteis
 *  Copyright (C) 2014-2015 - Higor Euripedes
 * 
 *  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 <boolean.h>
#include <string/stdstring.h>
#include <libretro.h>

#include "SDL.h"

#include "../input_config.h"
#include "../input_driver.h"
#include "../input_joypad_driver.h"
#include "../input_keymaps.h"
#include "../input_keyboard.h"

#include "../../gfx/video_driver.h"
#include "../../verbosity.h"
#include "../../tasks/tasks_internal.h"

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

   int mouse_x, mouse_y;
   int mouse_abs_x, mouse_abs_y;
   int mouse_l, mouse_r, mouse_m, mouse_wu, mouse_wd, mouse_wl, mouse_wr;
} sdl_input_t;

static void *sdl_input_init(const char *joypad_driver)
{
   sdl_input_t     *sdl = (sdl_input_t*)calloc(1, sizeof(*sdl));
   if (!sdl)
      return NULL;

   input_keymaps_init_keyboard_lut(rarch_key_map_sdl);

   sdl->joypad = input_joypad_init_driver(joypad_driver, sdl);

   RARCH_LOG("[SDL]: Input driver initialized.\n");
   return sdl;
}

static bool sdl_key_pressed(int key)
{
   int num_keys;
   const uint8_t *keymap;
   unsigned sym;

   if (key >= RETROK_LAST)
      return false;

   sym = input_keymaps_translate_rk_to_keysym((enum retro_key)key);

#ifdef HAVE_SDL2
   sym = SDL_GetScancodeFromKey(sym);
   keymap = SDL_GetKeyboardState(&num_keys);
#else
   keymap = SDL_GetKeyState(&num_keys);
#endif
   if (sym >= (unsigned)num_keys)
      return false;

   return keymap[sym];
}

static bool sdl_is_pressed(sdl_input_t *sdl, unsigned port_num, const struct retro_keybind *binds, unsigned key)
{
   if (sdl_key_pressed(binds[key].key))
      return true;
   return false;
}

static int16_t sdl_analog_pressed(sdl_input_t *sdl, 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 (sdl_key_pressed(binds[id_minus].key))
      pressed_minus = -0x7fff;
   if (sdl_key_pressed(binds[id_plus].key))
      pressed_plus  = 0x7fff;

   return pressed_plus + pressed_minus;
}

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

static int16_t sdl_joypad_device_state(sdl_input_t *sdl,
      rarch_joypad_info_t joypad_info,
      const struct retro_keybind **binds_, 
      unsigned port, unsigned id, enum input_device_type *device)
{
   if (id < RARCH_BIND_LIST_END)
   {
      const struct retro_keybind *binds = binds_[port];

      if (sdl_is_pressed(sdl, port, binds, id))
      {
         *device = INPUT_DEVICE_TYPE_KEYBOARD;
         return 1;
      }

      if (input_joypad_pressed(sdl->joypad, joypad_info, 0, binds, id))
      {
         *device = INPUT_DEVICE_TYPE_JOYPAD;
         return 1;
      }
   }
   return 0;
}

static int16_t sdl_analog_device_state(sdl_input_t *sdl,
      rarch_joypad_info_t joypad_info,
      const struct retro_keybind **binds,
      unsigned port_num, unsigned idx, unsigned id)
{
   int16_t ret                = binds[port_num] ? sdl_analog_pressed(sdl, binds[port_num], idx, id) : 0;

   if (!ret && binds[port_num])
      ret = input_joypad_analog(sdl->joypad, joypad_info, port_num, idx, id, binds[port_num]);
   return ret;
}

static int16_t sdl_keyboard_device_state(sdl_input_t *sdl, unsigned id)
{
   return sdl_key_pressed(id);
}

static int16_t sdl_mouse_device_state(sdl_input_t *sdl, unsigned id)
{
   switch (id)
   {
      case RETRO_DEVICE_ID_MOUSE_LEFT:
         return sdl->mouse_l;
      case RETRO_DEVICE_ID_MOUSE_RIGHT:
         return sdl->mouse_r;
      case RETRO_DEVICE_ID_MOUSE_WHEELUP:
         return sdl->mouse_wu;
      case RETRO_DEVICE_ID_MOUSE_WHEELDOWN:
         return sdl->mouse_wd;
      case RETRO_DEVICE_ID_MOUSE_X:
         return sdl->mouse_x;
      case RETRO_DEVICE_ID_MOUSE_Y:
         return sdl->mouse_y;
      case RETRO_DEVICE_ID_MOUSE_MIDDLE:
         return sdl->mouse_m;
   }

   return 0;
}

static int16_t sdl_pointer_device_state(sdl_input_t *sdl,
      unsigned idx, unsigned id, bool screen)
{
   struct video_viewport vp;
   bool inside                 = false;
   int16_t res_x               = 0;
   int16_t res_y               = 0;
   int16_t res_screen_x        = 0;
   int16_t res_screen_y        = 0;

   vp.x                        = 0;
   vp.y                        = 0;
   vp.width                    = 0;
   vp.height                   = 0;
   vp.full_width               = 0;
   vp.full_height              = 0;

   if (!(video_driver_translate_coord_viewport_wrap(&vp, sdl->mouse_abs_x, sdl->mouse_abs_y,
         &res_x, &res_y, &res_screen_x, &res_screen_y)))
      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 sdl->mouse_l;
   }

   return 0;
}

static int16_t sdl_lightgun_device_state(sdl_input_t *sdl, unsigned id)
{
   switch (id)
   {
      case RETRO_DEVICE_ID_LIGHTGUN_X:
         return sdl->mouse_x;
      case RETRO_DEVICE_ID_LIGHTGUN_Y:
         return sdl->mouse_y;
      case RETRO_DEVICE_ID_LIGHTGUN_TRIGGER:
         return sdl->mouse_l;
      case RETRO_DEVICE_ID_LIGHTGUN_CURSOR:
         return sdl->mouse_m;
      case RETRO_DEVICE_ID_LIGHTGUN_TURBO:
         return sdl->mouse_r;
      case RETRO_DEVICE_ID_LIGHTGUN_START:
         return sdl->mouse_m && sdl->mouse_r; 
      case RETRO_DEVICE_ID_LIGHTGUN_PAUSE:
         return sdl->mouse_m && sdl->mouse_l; 
   }

   return 0;
}

static int16_t sdl_input_state(void *data_,
      rarch_joypad_info_t joypad_info,
      const struct retro_keybind **binds,
      unsigned port, unsigned device, unsigned idx, unsigned id)
{
   enum input_device_type type = INPUT_DEVICE_TYPE_NONE;
   sdl_input_t *data = (sdl_input_t*)data_;

   switch (device)
   {
      case RETRO_DEVICE_JOYPAD:
         return sdl_joypad_device_state(data, joypad_info, binds, port, id, &type);
      case RETRO_DEVICE_ANALOG:
         return sdl_analog_device_state(data, joypad_info, binds, port, idx, id);
      case RETRO_DEVICE_MOUSE:
         return sdl_mouse_device_state(data, id);
      case RETRO_DEVICE_POINTER:
      case RARCH_DEVICE_POINTER_SCREEN:
         if (idx == 0)
            return sdl_pointer_device_state(data, idx, id, device == RARCH_DEVICE_POINTER_SCREEN);
         break;
      case RETRO_DEVICE_KEYBOARD:
         return sdl_keyboard_device_state(data, id);
      case RETRO_DEVICE_LIGHTGUN:
         return sdl_lightgun_device_state(data, id);
   }

   return 0;
}

static void sdl_input_free(void *data)
{
#ifndef HAVE_SDL2
   SDL_Event event;
#endif
   sdl_input_t *sdl = (sdl_input_t*)data;

   if (!data)
      return;

   /* Flush out all pending events. */
#ifdef HAVE_SDL2
   SDL_FlushEvents(SDL_FIRSTEVENT, SDL_LASTEVENT);
#else
   while (SDL_PollEvent(&event));
#endif

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

   free(data);
}

static void sdl_grab_mouse(void *data, bool state)
{
#ifdef HAVE_SDL2
   struct temp{
      SDL_Window *w;
   };

   if (string_is_not_equal_fast(video_driver_get_ident(), "sdl2", 4))
      return;

   /* First member of sdl2_video_t is the window */
   SDL_SetWindowGrab(((struct temp*)video_driver_get_ptr(false))->w,
         state ? SDL_TRUE : SDL_FALSE);
#endif
}

static bool sdl_set_rumble(void *data, unsigned port,
      enum retro_rumble_effect effect, uint16_t strength)
{
   sdl_input_t *sdl = (sdl_input_t*)data;
   if (!sdl)
      return false;
   return input_joypad_set_rumble(sdl->joypad, port, effect, strength);
}

static const input_device_driver_t *sdl_get_joypad_driver(void *data)
{
   sdl_input_t *sdl = (sdl_input_t*)data;
   if (!sdl)
      return NULL;
   return sdl->joypad;
}

static void sdl_poll_mouse(sdl_input_t *sdl)
{
   Uint8 btn = SDL_GetRelativeMouseState(&sdl->mouse_x, &sdl->mouse_y);

   SDL_GetMouseState(&sdl->mouse_abs_x, &sdl->mouse_abs_y);

   sdl->mouse_l  = (SDL_BUTTON(SDL_BUTTON_LEFT)      & btn) ? 1 : 0;
   sdl->mouse_r  = (SDL_BUTTON(SDL_BUTTON_RIGHT)     & btn) ? 1 : 0;
   sdl->mouse_m  = (SDL_BUTTON(SDL_BUTTON_MIDDLE)    & btn) ? 1 : 0;
#ifndef HAVE_SDL2
   sdl->mouse_wu = (SDL_BUTTON(SDL_BUTTON_WHEELUP)   & btn) ? 1 : 0;
   sdl->mouse_wd = (SDL_BUTTON(SDL_BUTTON_WHEELDOWN) & btn) ? 1 : 0;
#endif
}

static void sdl_input_poll(void *data)
{
   sdl_input_t *sdl = (sdl_input_t*)data;
   SDL_Event event;

   SDL_PumpEvents();

   if (sdl->joypad)
      sdl->joypad->poll();
   sdl_poll_mouse(sdl);

#ifdef HAVE_SDL2
   while (SDL_PeepEvents(&event, 1, SDL_GETEVENT, SDL_KEYDOWN, SDL_MOUSEWHEEL) > 0)
#else
   while (SDL_PeepEvents(&event, 1, SDL_GETEVENT, SDL_KEYEVENTMASK) > 0)
#endif
   {
      if (event.type == SDL_KEYDOWN || event.type == SDL_KEYUP)
      {
         uint16_t mod = 0;
         unsigned code = input_keymaps_translate_keysym_to_rk(event.key.keysym.sym);

         if (event.key.keysym.mod & KMOD_SHIFT)
            mod |= RETROKMOD_SHIFT;

         if (event.key.keysym.mod & KMOD_CTRL)
            mod |= RETROKMOD_CTRL;

         if (event.key.keysym.mod & KMOD_ALT)
            mod |= RETROKMOD_ALT;

         if (event.key.keysym.mod & KMOD_NUM)
            mod |= RETROKMOD_NUMLOCK;

         if (event.key.keysym.mod & KMOD_CAPS)
            mod |= RETROKMOD_CAPSLOCK;

         input_keyboard_event(event.type == SDL_KEYDOWN, code, code, mod,
               RETRO_DEVICE_KEYBOARD);
      }
#ifdef HAVE_SDL2
      else if (event.type == SDL_MOUSEWHEEL)
      {
         sdl->mouse_wu = event.wheel.y < 0;
         sdl->mouse_wd = event.wheel.y > 0;
         sdl->mouse_wl = event.wheel.x < 0;
         sdl->mouse_wr = event.wheel.x > 0;
         break;
      }
#endif
   }
}

static uint64_t sdl_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 sdl_keyboard_mapping_is_blocked(void *data)
{
   sdl_input_t *sdl = (sdl_input_t*)data;
   if (!sdl)
      return false;
   return sdl->blocked;
}

static void sdl_keyboard_mapping_set_block(void *data, bool value)
{
   sdl_input_t *sdl = (sdl_input_t*)data;
   if (!sdl)
      return;
   sdl->blocked = value;
}

input_driver_t input_sdl = {
   sdl_input_init,
   sdl_input_poll,
   sdl_input_state,
   sdl_input_meta_key_pressed,
   sdl_input_free,
   NULL,
   NULL,
   sdl_get_capabilities,
#ifdef HAVE_SDL2
   "sdl2",
#else
   "sdl",
#endif
   sdl_grab_mouse,
   NULL,
   sdl_set_rumble,
   sdl_get_joypad_driver,
   NULL,
   sdl_keyboard_mapping_is_blocked,
   sdl_keyboard_mapping_set_block,
};
