/*  RetroArch - A frontend for libretro.
 *  Copyright (C) 2010-2012 - 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 "../driver.h"

#include "../gfx/gfx_context.h"
#include "../boolean.h"
#include "../general.h"
#include <stdint.h>
#include <stdlib.h>
#include "../libretro.h"
#include "rarch_sdl_input.h"

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

static unsigned keysym_lut[RETROK_LAST];
static const struct key_bind lut_binds[] = {
   { SDLK_LEFT, RETROK_LEFT },
   { SDLK_RIGHT, RETROK_RIGHT },
   { SDLK_UP, RETROK_UP },
   { SDLK_DOWN, RETROK_DOWN },
   { SDLK_RETURN, RETROK_RETURN },
   { SDLK_TAB, RETROK_TAB },
   { SDLK_INSERT, RETROK_INSERT },
   { SDLK_DELETE, RETROK_DELETE },
   { SDLK_RSHIFT, RETROK_RSHIFT },
   { SDLK_LSHIFT, RETROK_LSHIFT },
   { SDLK_LCTRL, RETROK_LCTRL },
   { SDLK_END, RETROK_END },
   { SDLK_HOME, RETROK_HOME },
   { SDLK_PAGEDOWN, RETROK_PAGEDOWN },
   { SDLK_PAGEUP, RETROK_PAGEUP },
   { SDLK_LALT, RETROK_LALT },
   { SDLK_SPACE, RETROK_SPACE },
   { SDLK_ESCAPE, RETROK_ESCAPE },
   { SDLK_BACKSPACE, RETROK_BACKSPACE },
   { SDLK_KP_ENTER, RETROK_KP_ENTER },
   { SDLK_KP_PLUS, RETROK_KP_PLUS },
   { SDLK_KP_MINUS, RETROK_KP_MINUS },
   { SDLK_KP_MULTIPLY, RETROK_KP_MULTIPLY },
   { SDLK_KP_DIVIDE, RETROK_KP_DIVIDE },
   { SDLK_BACKQUOTE, RETROK_BACKQUOTE },
   { SDLK_PAUSE, RETROK_PAUSE },
   { SDLK_KP0, RETROK_KP0 },
   { SDLK_KP1, RETROK_KP1 },
   { SDLK_KP2, RETROK_KP2 },
   { SDLK_KP3, RETROK_KP3 },
   { SDLK_KP4, RETROK_KP4 },
   { SDLK_KP5, RETROK_KP5 },
   { SDLK_KP6, RETROK_KP6 },
   { SDLK_KP7, RETROK_KP7 },
   { SDLK_KP8, RETROK_KP8 },
   { SDLK_KP9, RETROK_KP9 },
   { SDLK_0, RETROK_0 },
   { SDLK_1, RETROK_1 },
   { SDLK_2, RETROK_2 },
   { SDLK_3, RETROK_3 },
   { SDLK_4, RETROK_4 },
   { SDLK_5, RETROK_5 },
   { SDLK_6, RETROK_6 },
   { SDLK_7, RETROK_7 },
   { SDLK_8, RETROK_8 },
   { SDLK_9, RETROK_9 },
   { SDLK_F1, RETROK_F1 },
   { SDLK_F2, RETROK_F2 },
   { SDLK_F3, RETROK_F3 },
   { SDLK_F4, RETROK_F4 },
   { SDLK_F5, RETROK_F5 },
   { SDLK_F6, RETROK_F6 },
   { SDLK_F7, RETROK_F7 },
   { SDLK_F8, RETROK_F8 },
   { SDLK_F9, RETROK_F9 },
   { SDLK_F10, RETROK_F10 },
   { SDLK_F11, RETROK_F11 },
   { SDLK_F12, RETROK_F12 },
   { SDLK_a, RETROK_a },
   { SDLK_b, RETROK_b },
   { SDLK_c, RETROK_c },
   { SDLK_d, RETROK_d },
   { SDLK_e, RETROK_e },
   { SDLK_f, RETROK_f },
   { SDLK_g, RETROK_g },
   { SDLK_h, RETROK_h },
   { SDLK_i, RETROK_i },
   { SDLK_j, RETROK_j },
   { SDLK_k, RETROK_k },
   { SDLK_l, RETROK_l },
   { SDLK_m, RETROK_m },
   { SDLK_n, RETROK_n },
   { SDLK_o, RETROK_o },
   { SDLK_p, RETROK_p },
   { SDLK_q, RETROK_q },
   { SDLK_r, RETROK_r },
   { SDLK_s, RETROK_s },
   { SDLK_t, RETROK_t },
   { SDLK_u, RETROK_u },
   { SDLK_v, RETROK_v },
   { SDLK_w, RETROK_w },
   { SDLK_x, RETROK_x },
   { SDLK_y, RETROK_y },
   { SDLK_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].sdl;
}

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

#ifdef HAVE_DINPUT
   sdl->di = sdl_dinput_init();
   if (!sdl->di)
   {
      free(sdl);
      RARCH_ERR("Failed to init SDL/DInput.\n");
      return NULL;
   }
#else
   if (SDL_Init(SDL_INIT_JOYSTICK) < 0)
      return NULL;

   SDL_JoystickEventState(SDL_IGNORE);
   sdl->num_joysticks = SDL_NumJoysticks();

   for (unsigned i = 0; i < MAX_PLAYERS; i++)
   {
      if (g_settings.input.joypad_map[i] < 0)
         continue;

      unsigned port = g_settings.input.joypad_map[i];

      if (sdl->num_joysticks <= port)
         continue;

      sdl->joysticks[i] = SDL_JoystickOpen(port);
      if (!sdl->joysticks[i])
      {
         RARCH_ERR("Couldn't open SDL joystick #%u on SNES port %u\n", port, i + 1);
         free(sdl);
         SDL_QuitSubSystem(SDL_INIT_JOYSTICK);
         return NULL;
      }

      RARCH_LOG("Opened Joystick: %s (#%u) on port %u\n", 
            SDL_JoystickName(port), port, i + 1);

      sdl->num_axes[i] = SDL_JoystickNumAxes(sdl->joysticks[i]);
      sdl->num_buttons[i] = SDL_JoystickNumButtons(sdl->joysticks[i]);
      sdl->num_hats[i] = SDL_JoystickNumHats(sdl->joysticks[i]);
      RARCH_LOG("Joypad has: %u axes, %u buttons, %u hats.\n",
            sdl->num_axes[i], sdl->num_buttons[i], sdl->num_hats[i]);
   }
#endif

   sdl->use_keyboard = true;
   return sdl;
}

static bool sdl_key_pressed(int key)
{
   return key < RETROK_LAST && gfx_ctx_key_pressed(keysym_lut[key]);
}

#ifndef HAVE_DINPUT
static bool sdl_joykey_pressed(sdl_input_t *sdl, int port_num, uint16_t joykey)
{
   if (joykey == NO_BTN)
      return false;

   // Check hat.
   if (GET_HAT_DIR(joykey))
   {
      uint16_t hat = GET_HAT(joykey);
      if (hat >= sdl->num_hats[port_num])
         return false;

      Uint8 dir = SDL_JoystickGetHat(sdl->joysticks[port_num], hat);
      switch (GET_HAT_DIR(joykey))
      {
         case HAT_UP_MASK:
            return dir & SDL_HAT_UP;
         case HAT_DOWN_MASK:
            return dir & SDL_HAT_DOWN;
         case HAT_LEFT_MASK:
            return dir & SDL_HAT_LEFT;
         case HAT_RIGHT_MASK:
            return dir & SDL_HAT_RIGHT;
         default:
            return false;
      }
   }
   else // Check the button
   {
      if (joykey < sdl->num_buttons[port_num] && SDL_JoystickGetButton(sdl->joysticks[port_num], joykey))
         return true;

      return false;
   }
}

static int16_t sdl_axis_analog(sdl_input_t *sdl, unsigned port_num, uint32_t joyaxis)
{
   if (joyaxis == AXIS_NONE)
      return 0;

   Sint16 val = 0;
   if (AXIS_NEG_GET(joyaxis) < sdl->num_axes[port_num])
   {
      val = SDL_JoystickGetAxis(sdl->joysticks[port_num], AXIS_NEG_GET(joyaxis));

      if (val > 0)
         val = 0;
      else if (val < -0x8000) // -0x8000 can cause trouble if we later abs() it.
         val = -0x7fff;
   }
   else if (AXIS_POS_GET(joyaxis) < sdl->num_axes[port_num])
   {
      val = SDL_JoystickGetAxis(sdl->joysticks[port_num], AXIS_POS_GET(joyaxis));

      if (val < 0)
         val = 0;
   }

   return val;
}

static bool sdl_axis_pressed(sdl_input_t *sdl, unsigned port_num, uint32_t joyaxis)
{
   int16_t val = sdl_axis_analog(sdl, port_num, joyaxis);

   float scaled = (float)abs(val) / 0x8000;
   return scaled > g_settings.input.axis_threshold;
}
#endif

static bool sdl_is_pressed(sdl_input_t *sdl, unsigned port_num, const struct retro_keybind *key)
{
   if (sdl->use_keyboard && sdl_key_pressed(key->key))
      return true;

#ifdef HAVE_DINPUT
   return sdl_dinput_pressed(sdl->di, port_num, key);
#else
   if (sdl->joysticks[port_num] == NULL)
      return false;
   if (sdl_joykey_pressed(sdl, port_num, key->joykey))
      return true;
   if (sdl_axis_pressed(sdl, port_num, key->joyaxis))
      return true;
#endif

   return false;
}

static bool sdl_bind_button_pressed(void *data, int key)
{
   const struct retro_keybind *binds = g_settings.input.binds[0];
   if (key >= 0 && key < RARCH_BIND_LIST_END)
   {
      const struct retro_keybind *bind = &binds[key];
      return sdl_is_pressed((sdl_input_t*)data, 0, bind);
   }
   else
      return false;
}

static int16_t sdl_joypad_device_state(sdl_input_t *sdl, const struct retro_keybind **binds_, 
      unsigned port_num, unsigned id)
{
   const struct retro_keybind *binds = binds_[port_num];
   if (id < RARCH_BIND_LIST_END)
   {
      const struct retro_keybind *bind = &binds[id];
      return bind->valid ? (sdl_is_pressed(sdl, port_num, bind) ? 1 : 0) : 0;
   }
   else
      return 0;
}

static void conv_analog_id_to_bind_id(unsigned index, unsigned id,
      unsigned *id_minus, unsigned *id_plus)
{
   switch ((index << 1) | id)
   {
      case (RETRO_DEVICE_INDEX_ANALOG_LEFT << 1) | RETRO_DEVICE_ID_ANALOG_X:
         *id_minus = RARCH_ANALOG_LEFT_X_MINUS;
         *id_plus  = RARCH_ANALOG_LEFT_X_PLUS;
         break;

      case (RETRO_DEVICE_INDEX_ANALOG_LEFT << 1) | RETRO_DEVICE_ID_ANALOG_Y:
         *id_minus = RARCH_ANALOG_LEFT_Y_MINUS;
         *id_plus  = RARCH_ANALOG_LEFT_Y_PLUS;
         break;

      case (RETRO_DEVICE_INDEX_ANALOG_RIGHT << 1) | RETRO_DEVICE_ID_ANALOG_X:
         *id_minus = RARCH_ANALOG_RIGHT_X_MINUS;
         *id_plus  = RARCH_ANALOG_RIGHT_X_PLUS;
         break;

      case (RETRO_DEVICE_INDEX_ANALOG_RIGHT << 1) | RETRO_DEVICE_ID_ANALOG_Y:
         *id_minus = RARCH_ANALOG_RIGHT_Y_MINUS;
         *id_plus  = RARCH_ANALOG_RIGHT_Y_PLUS;
         break;
   }
}

static int16_t sdl_analog_device_state(sdl_input_t *sdl, const struct retro_keybind **binds_,
      unsigned port_num, unsigned index, unsigned id)
{
   const struct retro_keybind *binds = binds_[port_num];
   if (id >= RARCH_BIND_LIST_END)
      return 0;

   unsigned id_minus = 0;
   unsigned id_plus  = 0;
   conv_analog_id_to_bind_id(index, id, &id_minus, &id_plus);

   const struct retro_keybind *bind_minus = &binds[id_minus];
   const struct retro_keybind *bind_plus  = &binds[id_plus];
   if (!bind_minus->valid || !bind_plus->valid)
      return 0;

   // A user might have bound minus axis to positive axis in SDL.
#ifdef HAVE_DINPUT
   int16_t pressed_minus = abs(sdl_dinput_axis(sdl->di, port_num, bind_minus));
   int16_t pressed_plus  = abs(sdl_dinput_axis(sdl->di, port_num, bind_plus));
#else
   int16_t pressed_minus = abs(sdl_axis_analog(sdl, port_num, bind_minus->joyaxis));
   int16_t pressed_plus  = abs(sdl_axis_analog(sdl, port_num, bind_plus->joyaxis));
#endif

   int16_t res = pressed_plus - pressed_minus;

   // TODO: Does it make sense to use axis thresholding here?
   if (res != 0)
      return res;

   int16_t digital_left  = sdl_is_pressed(sdl, port_num, bind_minus) ? -0x7fff : 0;
   int16_t digital_right = sdl_is_pressed(sdl, port_num, bind_plus)  ?  0x7fff : 0;
   return digital_right + digital_left;
}

static int16_t sdl_keyboard_device_state(sdl_input_t *sdl, unsigned id)
{
   return sdl->use_keyboard && 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_X:
         return sdl->mouse_x;
      case RETRO_DEVICE_ID_MOUSE_Y:
         return sdl->mouse_y;
      default:
         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; 
      default:
         return 0;
   }
}

static int16_t sdl_input_state(void *data_, const struct retro_keybind **binds, unsigned port, unsigned device, unsigned index, unsigned id)
{
   sdl_input_t *data = (sdl_input_t*)data_;
   switch (device)
   {
      case RETRO_DEVICE_JOYPAD:
         return sdl_joypad_device_state(data, binds, port, id);
      case RETRO_DEVICE_ANALOG:
         return sdl_analog_device_state(data, binds, port, index, id);
      case RETRO_DEVICE_MOUSE:
         return sdl_mouse_device_state(data, id);
      case RETRO_DEVICE_KEYBOARD:
         return sdl_keyboard_device_state(data, id);
      case RETRO_DEVICE_LIGHTGUN:
         return sdl_lightgun_device_state(data, id);

      default:
         return 0;
   }
}

static void sdl_input_free(void *data)
{
   if (data)
   {
      // Flush out all pending events.
      SDL_Event event;
      while (SDL_PollEvent(&event));

      sdl_input_t *sdl = (sdl_input_t*)data;

#ifdef HAVE_DINPUT
      sdl_dinput_free(sdl->di);
#else
      for (int i = 0; i < MAX_PLAYERS; i++)
      {
         if (sdl->joysticks[i])
            SDL_JoystickClose(sdl->joysticks[i]);
      }
      SDL_QuitSubSystem(SDL_INIT_JOYSTICK);
#endif

      free(data);
   }
}

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

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

#ifdef HAVE_DINPUT
   sdl_dinput_poll(sdl->di);
#else
   SDL_JoystickUpdate();
#endif

   sdl_poll_mouse(sdl);
}

const input_driver_t input_sdl = {
   sdl_input_init,
   sdl_input_poll,
   sdl_input_state,
   sdl_bind_button_pressed,
   sdl_input_free,
   "sdl"
};