/*  RetroArch - A frontend for libretro.
 *  Copyright (C) 2010-2014 - Hans-Kristian Arntzen
 *  Copyright (C) 2011-2017 - Daniel De Matteis
 *  Copyright (C) 2014-2017 - 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 <compat/strl.h>

#include "SDL.h"

#include "../input_driver.h"

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

typedef struct _sdl_joypad
{
   SDL_Joystick *joypad;
#ifdef HAVE_SDL2
   SDL_GameController *controller;
   SDL_Haptic *haptic;
   int rumble_effect; /* -1 = not initialized, -2 = error/unsupported */
#endif
   unsigned num_axes;
   unsigned num_buttons;
   unsigned num_hats;
#ifdef HAVE_SDL2
   unsigned num_balls;
#endif
} sdl_joypad_t;

/* TODO/FIXME - static globals */
static sdl_joypad_t sdl_pads[MAX_USERS];
#ifdef HAVE_SDL2
static bool g_has_haptic                = false;
#endif

static const char *sdl_joypad_name(unsigned pad)
{
   if (pad >= MAX_USERS)
      return NULL;

#ifdef HAVE_SDL2
   if (sdl_pads[pad].controller)
      return SDL_GameControllerNameForIndex(pad);
   return SDL_JoystickNameForIndex(pad);
#else
   return SDL_JoystickName(pad);
#endif
}

static uint8_t sdl_pad_get_button(sdl_joypad_t *pad, unsigned button)
{
#ifdef HAVE_SDL2
   /* TODO: see if a LUT like xinput_joypad.c's button_index_to_bitmap_code is needed. */
   if (pad->controller)
      return SDL_GameControllerGetButton(pad->controller, (SDL_GameControllerButton)button);
#endif
   return SDL_JoystickGetButton(pad->joypad, button);
}

static uint8_t sdl_pad_get_hat(sdl_joypad_t *pad, unsigned hat)
{
#ifdef HAVE_SDL2
   if (pad->controller)
      return sdl_pad_get_button(pad, hat);
#endif
   return SDL_JoystickGetHat(pad->joypad, hat);
}

static int16_t sdl_pad_get_axis(sdl_joypad_t *pad, unsigned axis)
{
#ifdef HAVE_SDL2
   /* TODO: see if a rarch <-> sdl translation is needed. */
   if (pad->controller)
      return SDL_GameControllerGetAxis(pad->controller, (SDL_GameControllerAxis)axis);
#endif
   return SDL_JoystickGetAxis(pad->joypad, axis);
}

static void sdl_pad_connect(unsigned id)
{
   sdl_joypad_t *pad          = (sdl_joypad_t*)&sdl_pads[id];
   bool success               = false;
   int32_t product            = 0;
   int32_t vendor             = 0;

#ifdef HAVE_SDL2
   SDL_JoystickGUID guid;
   uint16_t *guid_ptr         = NULL;

   if (SDL_IsGameController(id))
   {
      pad->controller = SDL_GameControllerOpen(id);
      pad->joypad     = SDL_GameControllerGetJoystick(pad->controller);

      success = pad->joypad != NULL && pad->controller != NULL;
   }
   else
#endif
   {
      pad->joypad = SDL_JoystickOpen(id);
      success = pad->joypad != NULL;
   }

   if (!success)
   {
      RARCH_ERR("[SDL]: Couldn't open joystick #%u: %s.\n", id, SDL_GetError());

      if (pad->joypad)
         SDL_JoystickClose(pad->joypad);

      pad->joypad = NULL;

      return;
   }

#ifdef HAVE_SDL2
   guid       = SDL_JoystickGetGUID(pad->joypad);
   guid_ptr   = (uint16_t*)guid.data;
#ifdef __linux
   vendor     = guid_ptr[2];
   product    = guid_ptr[4];
#elif _WIN32
   vendor     = guid_ptr[0];
   product    = guid_ptr[1];
#endif
#endif

   input_autoconfigure_connect(
         sdl_joypad_name(id),
         NULL,
         sdl_joypad.ident,
         id,
         vendor,
         product);

#ifdef HAVE_SDL2
   if (pad->controller)
   {
      /* SDL_GameController internally supports all axis/button IDs, even if
       * the controller's mapping does not have a binding for it.
       *
       * So, we can claim to support all axes/buttons, and when we try to poll
       * an unbound ID, SDL simply returns the correct unpressed value.
       *
       * Note that, in addition to 0 trackballs, we also have 0 hats. This is
       * because the d-pad is in the button list, as the last 4 enum entries.
       *
       * -flibit
       */
      pad->num_axes    = SDL_CONTROLLER_AXIS_MAX;
      pad->num_buttons = SDL_CONTROLLER_BUTTON_MAX;
      pad->num_hats    = 0;
      pad->num_balls   = 0;

      /* SDL Device supports Game Controller API. */
   }
   else
   {
      pad->num_axes    = SDL_JoystickNumAxes(pad->joypad);
      pad->num_buttons = SDL_JoystickNumButtons(pad->joypad);
      pad->num_hats    = SDL_JoystickNumHats(pad->joypad);
      pad->num_balls   = SDL_JoystickNumBalls(pad->joypad);
   }

   pad->haptic    = NULL;
   
   if (g_has_haptic)
   {
      pad->haptic = SDL_HapticOpenFromJoystick(pad->joypad);

      if (!pad->haptic)
         RARCH_WARN("[SDL]: Couldn't open haptic device of the joypad #%u: %s\n",
               id, SDL_GetError());
   }

   pad->rumble_effect = -1;

   if (pad->haptic)
   {
      SDL_HapticEffect efx;
      efx.type = SDL_HAPTIC_LEFTRIGHT;
      efx.leftright.type = SDL_HAPTIC_LEFTRIGHT;
      efx.leftright.large_magnitude = efx.leftright.small_magnitude = 0x4000;
      efx.leftright.length = 5000;

      if (SDL_HapticEffectSupported(pad->haptic, &efx) == SDL_FALSE)
      {
         pad->rumble_effect = -2;
         RARCH_WARN("[SDL]: Device #%u does not support rumble.\n", id);
      }
   }
#else
   pad->num_axes    = SDL_JoystickNumAxes(pad->joypad);
   pad->num_buttons = SDL_JoystickNumButtons(pad->joypad);
   pad->num_hats    = SDL_JoystickNumHats(pad->joypad);
#endif
}

static void sdl_pad_disconnect(unsigned id)
{
#ifdef HAVE_SDL2
   if (sdl_pads[id].haptic)
      SDL_HapticClose(sdl_pads[id].haptic);

   if (sdl_pads[id].controller)
   {
      SDL_GameControllerClose(sdl_pads[id].controller);
      input_autoconfigure_disconnect(id, sdl_joypad.ident);
   }
   else
#endif
   if (sdl_pads[id].joypad)
   {
      SDL_JoystickClose(sdl_pads[id].joypad);
      input_autoconfigure_disconnect(id, sdl_joypad.ident);
   }

   memset(&sdl_pads[id], 0, sizeof(sdl_pads[id]));
}

static void sdl_joypad_destroy(void)
{
   unsigned i;
   for (i = 0; i < MAX_USERS; i++)
      sdl_pad_disconnect(i);

   memset(sdl_pads, 0, sizeof(sdl_pads));
}

static void *sdl_joypad_init(void *data)
{
   unsigned i, num_sticks;
#ifdef HAVE_SDL2
   uint32_t subsystem           = SDL_INIT_GAMECONTROLLER;
#else
   uint32_t subsystem           = SDL_INIT_JOYSTICK;
#endif
   uint32_t sdl_subsystem_flags = SDL_WasInit(0);

   /* Initialise joystick/controller subsystem, if required */
   if (sdl_subsystem_flags == 0)
   {
      if (SDL_Init(subsystem) < 0)
         return NULL;
   }
   else if ((sdl_subsystem_flags & subsystem) == 0)
   {
      if (SDL_InitSubSystem(subsystem) < 0)
         return NULL;
   }

#if HAVE_SDL2
   g_has_haptic = false;

   /* Initialise haptic subsystem, if required */
   if ((sdl_subsystem_flags & SDL_INIT_HAPTIC) == 0)
   {
      if (SDL_InitSubSystem(SDL_INIT_HAPTIC) < 0)
         RARCH_WARN("[SDL]: Failed to initialize haptic device support: %s\n",
               SDL_GetError());
      else
         g_has_haptic = true;
   }
   else
      g_has_haptic = true;
#endif

   memset(sdl_pads, 0, sizeof(sdl_pads));

   num_sticks = SDL_NumJoysticks();
   if (num_sticks > MAX_USERS)
      num_sticks = MAX_USERS;

   for (i = 0; i < num_sticks; i++)
      sdl_pad_connect(i);

#ifndef HAVE_SDL2
   /* quit if no joypad is detected. */
   num_sticks = 0;
   for (i = 0; i < MAX_USERS; i++)
      if (sdl_pads[i].joypad)
         num_sticks++;

   if (num_sticks == 0)
      goto error;
#endif

   return (void*)-1;

#ifndef HAVE_SDL2
error:
   sdl_joypad_destroy();

   return NULL;
#endif
}

static int16_t sdl_joypad_button_state(
      sdl_joypad_t *pad,
      unsigned port, uint16_t joykey)
{
   unsigned hat_dir = GET_HAT_DIR(joykey);
   /* Check hat. */
   if (hat_dir)
   {
      uint8_t  dir;
      uint16_t hat  = GET_HAT(joykey);

      if (hat >= pad->num_hats)
         return 0;

      dir = sdl_pad_get_hat(pad, hat);

      switch (hat_dir)
      {
         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:
            break;
      }
      /* hat requested and no hat button down */
   }
   else if (joykey < pad->num_buttons)
      return sdl_pad_get_button(pad, joykey);
   return 0;
}

static int16_t sdl_joypad_button(unsigned port, uint16_t joykey)
{
   sdl_joypad_t *pad                    = (sdl_joypad_t*)&sdl_pads[port];
   if (!pad || !pad->joypad)
      return 0;
   if (port >= DEFAULT_MAX_PADS)
      return 0;
   return sdl_joypad_button_state(pad, port, joykey);
}

static int16_t sdl_joypad_axis_state(
      sdl_joypad_t *pad,
      unsigned port, uint32_t joyaxis)
{
   if (AXIS_NEG_GET(joyaxis) < pad->num_axes)
   {
      int16_t val    = sdl_pad_get_axis(pad, AXIS_NEG_GET(joyaxis));
      /* -0x8000 can cause trouble if we later abs() it. */
      if (val < -0x7fff) 
         return -0x7fff;
      else if (val < 0)
         return val;
   }
   else if (AXIS_POS_GET(joyaxis) < pad->num_axes)
   {
      int16_t val    = sdl_pad_get_axis(pad, AXIS_POS_GET(joyaxis));
      if (val > 0)
         return val;
   }

   return 0;
}

static int16_t sdl_joypad_axis(unsigned port, uint32_t joyaxis)
{
   sdl_joypad_t *pad = (sdl_joypad_t*)&sdl_pads[port];
   if (!pad || !pad->joypad)
      return false;
   return sdl_joypad_axis_state(pad, port, joyaxis);
}

static int16_t sdl_joypad_state(
      rarch_joypad_info_t *joypad_info,
      const struct retro_keybind *binds,
      unsigned port)
{
   unsigned i;
   int16_t ret                          = 0;
   uint16_t port_idx                    = joypad_info->joy_idx;
   sdl_joypad_t *pad                    = (sdl_joypad_t*)&sdl_pads[port_idx];

   if (!pad || !pad->joypad)
      return 0;
   if (port_idx >= DEFAULT_MAX_PADS)
      return 0;

   for (i = 0; i < RARCH_FIRST_CUSTOM_BIND; i++)
   {
      /* Auto-binds are per joypad, not per user. */
      const uint64_t joykey  = (binds[i].joykey != NO_BTN)
         ? binds[i].joykey  : joypad_info->auto_binds[i].joykey;
      const uint32_t joyaxis = (binds[i].joyaxis != AXIS_NONE)
         ? binds[i].joyaxis : joypad_info->auto_binds[i].joyaxis;
      if (
               (uint16_t)joykey != NO_BTN 
            && sdl_joypad_button_state(pad, port_idx, (uint16_t)joykey)
         )
         ret |= ( 1 << i);
      else if (joyaxis != AXIS_NONE &&
            ((float)abs(sdl_joypad_axis_state(pad, port_idx, joyaxis)) 
             / 0x8000) > joypad_info->axis_threshold)
         ret |= (1 << i);
   }

   return ret;
}

static void sdl_joypad_poll(void)
{
#ifdef HAVE_SDL2
   SDL_Event event;

   SDL_PumpEvents();

   while (SDL_PeepEvents(&event, 1,
            SDL_GETEVENT, SDL_JOYDEVICEADDED, SDL_JOYDEVICEREMOVED) > 0)
   {
      switch (event.type)
      {
         case SDL_JOYDEVICEADDED:
            sdl_pad_connect(event.jdevice.which);
            break;
         case SDL_JOYDEVICEREMOVED:
            sdl_pad_disconnect(event.jdevice.which);
            break;
      }
   }

   SDL_FlushEvents(SDL_JOYAXISMOTION, SDL_CONTROLLERDEVICEREMAPPED);
#else
   SDL_JoystickUpdate();
#endif
}

#ifdef HAVE_SDL2
static bool sdl_joypad_set_rumble(unsigned pad, enum retro_rumble_effect effect, uint16_t strength)
{
   SDL_HapticEffect efx;
   sdl_joypad_t *joypad = (sdl_joypad_t*)&sdl_pads[pad];

   memset(&efx, 0, sizeof(efx));

   if (!joypad->joypad || !joypad->haptic)
      return false;

   efx.type             = SDL_HAPTIC_LEFTRIGHT;
   efx.leftright.type   = SDL_HAPTIC_LEFTRIGHT;
   efx.leftright.length = 5000;

   switch (effect)
   {
      case RETRO_RUMBLE_STRONG:
         efx.leftright.large_magnitude = strength;
         break;
      case RETRO_RUMBLE_WEAK:
         efx.leftright.small_magnitude = strength;
         break;
      default:
         return false;
   }

   if (joypad->rumble_effect == -1)
   {
      joypad->rumble_effect = SDL_HapticNewEffect(sdl_pads[pad].haptic, &efx);
      if (joypad->rumble_effect < 0)
      {
         RARCH_WARN("[SDL]: Failed to create rumble effect for joypad %u: %s\n",
                    pad, SDL_GetError());
         joypad->rumble_effect = -2;
         return false;
      }
   }
   else if (joypad->rumble_effect >= 0)
      SDL_HapticUpdateEffect(joypad->haptic, joypad->rumble_effect, &efx);

   if (joypad->rumble_effect < 0)
      return false;

   if (SDL_HapticRunEffect(joypad->haptic, joypad->rumble_effect, 1) < 0)
   {
      RARCH_WARN("[SDL]: Failed to set rumble effect on joypad %u: %s\n",
                          pad, SDL_GetError());
      return false;
   }

   return true;
}
#endif

static bool sdl_joypad_query_pad(unsigned pad)
{
   return pad < MAX_USERS && sdl_pads[pad].joypad;
}

input_device_driver_t sdl_joypad = {
   sdl_joypad_init,
   sdl_joypad_query_pad,
   sdl_joypad_destroy,
   sdl_joypad_button,
   sdl_joypad_state,
   NULL,
   sdl_joypad_axis,
   sdl_joypad_poll,
#ifdef HAVE_SDL2
   sdl_joypad_set_rumble,
#else
   NULL,
#endif
   sdl_joypad_name,
#ifdef HAVE_SDL2
   "sdl2",
#else
   "sdl"
#endif
};
