/*  RetroArch - A frontend for libretro.
 *  Copyright (C) 2010-2013 - 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/>.
 */

#ifdef _MSC_VER
#pragma comment(lib, "dinput8")
#endif

#undef DIRECTINPUT_VERSION
#define DIRECTINPUT_VERSION 0x0800
#include <dinput.h>

#include "../general.h"
#include "../boolean.h"
#include "input_common.h"
#include <stdlib.h>
#include <stddef.h>
#include <string.h>

// Context has to be global as joypads also ride on this context.
static LPDIRECTINPUT8 g_ctx;

struct dinput_input
{
   LPDIRECTINPUTDEVICE8 keyboard;
   LPDIRECTINPUTDEVICE8 mouse;
   const rarch_joypad_driver_t *joypad;
   uint8_t state[256];

   int mouse_rel_x;
   int mouse_rel_y;
   int mouse_x;
   int mouse_y;
   bool mouse_l, mouse_r, mouse_m;
};

struct dinput_joypad
{
   LPDIRECTINPUTDEVICE8 joypad;
   DIJOYSTATE2 joy_state;
};

static unsigned g_joypad_cnt;
static struct dinput_joypad g_pads[MAX_PLAYERS];

static void dinput_destroy_context(void)
{
   if (g_ctx)
   {
      IDirectInput8_Release(g_ctx);
      g_ctx = NULL;
   }
}

static bool dinput_init_context(void)
{
   if (g_ctx)
      return true;

   if (driver.display_type != RARCH_DISPLAY_WIN32)
   {
      RARCH_ERR("Cannot open DInput as no Win32 window is present.\n");
      return false;
   }

   CoInitialize(NULL);

   // Who said we shouldn't have same call signature in a COM API? <_<
#ifdef __cplusplus
   if (FAILED(DirectInput8Create(
      GetModuleHandle(NULL), DIRECTINPUT_VERSION, IID_IDirectInput8,
      (void**)&g_ctx, NULL)))
#else
   if (FAILED(DirectInput8Create(
      GetModuleHandle(NULL), DIRECTINPUT_VERSION, &IID_IDirectInput8,
      (void**)&g_ctx, NULL)))
#endif
   {
      RARCH_ERR("Failed to init DirectInput.\n");
      return false;
   }

   return true;
}

static void *dinput_init(void)
{
   if (!dinput_init_context())
      return NULL;

   struct dinput_input *di = (struct dinput_input*)calloc(1, sizeof(*di));
   if (!di)
      return NULL;

#ifdef __cplusplus
   if (FAILED(IDirectInput8_CreateDevice(g_ctx, GUID_SysKeyboard, &di->keyboard, NULL)))
      goto error;
   if (FAILED(IDirectInput8_CreateDevice(g_ctx, GUID_SysMouse, &di->mouse, NULL)))
      goto error;
#else
   if (FAILED(IDirectInput8_CreateDevice(g_ctx, &GUID_SysKeyboard, &di->keyboard, NULL)))
      goto error;
   if (FAILED(IDirectInput8_CreateDevice(g_ctx, &GUID_SysMouse, &di->mouse, NULL)))
      goto error;
#endif

   IDirectInputDevice8_SetDataFormat(di->keyboard, &c_dfDIKeyboard);
   IDirectInputDevice8_SetCooperativeLevel(di->keyboard,
         (HWND)driver.video_window, DISCL_NONEXCLUSIVE | DISCL_FOREGROUND);
   IDirectInputDevice8_Acquire(di->keyboard);

   IDirectInputDevice8_SetDataFormat(di->mouse, &c_dfDIMouse2);
   IDirectInputDevice8_SetCooperativeLevel(di->mouse, (HWND)driver.video_window,
         DISCL_NONEXCLUSIVE | DISCL_FOREGROUND);
   IDirectInputDevice8_Acquire(di->mouse);

   input_init_keyboard_lut(rarch_key_map_dinput);
   di->joypad = input_joypad_init_driver(g_settings.input.joypad_driver);

   return di;

error:
   dinput_destroy_context();
   free(di);
   return NULL;
}

static void dinput_poll(void *data)
{
   struct dinput_input *di = (struct dinput_input*)data;

   memset(di->state, 0, sizeof(di->state));
   if (FAILED(IDirectInputDevice8_GetDeviceState(di->keyboard, sizeof(di->state), di->state)))
   {
      IDirectInputDevice8_Acquire(di->keyboard);
      if (FAILED(IDirectInputDevice8_GetDeviceState(di->keyboard, sizeof(di->state), di->state)))
         memset(di->state, 0, sizeof(di->state));
   }

   DIMOUSESTATE2 mouse_state;
   memset(&mouse_state, 0, sizeof(mouse_state));
   if (FAILED(IDirectInputDevice8_GetDeviceState(di->mouse, sizeof(mouse_state), &mouse_state)))
   {
      IDirectInputDevice8_Acquire(di->mouse);
      if (FAILED(IDirectInputDevice8_GetDeviceState(di->mouse, sizeof(mouse_state), &mouse_state)))
         memset(&mouse_state, 0, sizeof(mouse_state));
   }

   di->mouse_rel_x = mouse_state.lX;
   di->mouse_rel_y = mouse_state.lY;
   di->mouse_l = mouse_state.rgbButtons[0];
   di->mouse_r = mouse_state.rgbButtons[1];
   di->mouse_m = mouse_state.rgbButtons[2];

   // No simple way to get absolute coordinates for RETRO_DEVICE_POINTER. Just use Win32 APIs.
   POINT point = {0};
   GetCursorPos(&point);
   ScreenToClient((HWND)driver.video_window, &point);
   di->mouse_x = point.x;
   di->mouse_y = point.y;

   input_joypad_poll(di->joypad);
}

static bool dinput_keyboard_pressed(struct dinput_input *di, unsigned key)
{
   if (key >= RETROK_LAST)
      return false;

   unsigned sym = input_translate_rk_to_keysym((enum retro_key)key);
   return di->state[sym] & 0x80;
}

static bool dinput_is_pressed(struct dinput_input *di, const struct retro_keybind *binds,
      unsigned port, unsigned id)
{
   if (id >= RARCH_BIND_LIST_END)
      return false;

   const struct retro_keybind *bind = &binds[id];
   return dinput_keyboard_pressed(di, bind->key) || input_joypad_pressed(di->joypad, port, binds, id);
}

static bool dinput_key_pressed(void *data, int key)
{
   return dinput_is_pressed((struct dinput_input*)data, g_settings.input.binds[0], 0, key);
}

static int16_t dinput_lightgun_state(struct dinput_input *di, unsigned id)
{
   switch (id)
   {
      case RETRO_DEVICE_ID_LIGHTGUN_X:
         return di->mouse_rel_x;
      case RETRO_DEVICE_ID_LIGHTGUN_Y:
         return di->mouse_rel_y;
      case RETRO_DEVICE_ID_LIGHTGUN_TRIGGER:
         return di->mouse_l;
      case RETRO_DEVICE_ID_LIGHTGUN_CURSOR:
         return di->mouse_m;
      case RETRO_DEVICE_ID_LIGHTGUN_TURBO:
         return di->mouse_r;
      case RETRO_DEVICE_ID_LIGHTGUN_START:
         return di->mouse_m && di->mouse_r; 
      case RETRO_DEVICE_ID_LIGHTGUN_PAUSE:
         return di->mouse_m && di->mouse_l; 
      default:
         return 0;
   }
}

static int16_t dinput_mouse_state(struct dinput_input *di, unsigned id)
{
   switch (id)
   {
      case RETRO_DEVICE_ID_MOUSE_X:
         return di->mouse_rel_x;
      case RETRO_DEVICE_ID_MOUSE_Y:
         return di->mouse_rel_y;
      case RETRO_DEVICE_ID_MOUSE_LEFT:
         return di->mouse_l;
      case RETRO_DEVICE_ID_MOUSE_RIGHT:
         return di->mouse_r;
      default:
         return 0;
   }
}

static int16_t dinput_pointer_state(struct dinput_input *di, 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(di->mouse_x, di->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 di->mouse_l;
      default:
         return 0;
   }
}

static int16_t dinput_input_state(void *data,
      const struct retro_keybind **binds, unsigned port,
      unsigned device, unsigned index, unsigned id)
{
   struct dinput_input *di = (struct dinput_input*)data;
   switch (device)
   {
      case RETRO_DEVICE_JOYPAD:
         return dinput_is_pressed(di, binds[port], port, id);

      case RETRO_DEVICE_KEYBOARD:
         return dinput_keyboard_pressed(di, id);

      case RETRO_DEVICE_ANALOG:
         return input_joypad_analog(di->joypad, port, index, id, g_settings.input.binds[port]);

      case RETRO_DEVICE_MOUSE:
         return dinput_mouse_state(di, id);

      case RETRO_DEVICE_POINTER:
      case RARCH_DEVICE_POINTER_SCREEN:
         return dinput_pointer_state(di, index, id, device == RARCH_DEVICE_POINTER_SCREEN);

      case RETRO_DEVICE_LIGHTGUN:
         return dinput_lightgun_state(di, id);

      default:
         return 0;
   }
}

static void dinput_free(void *data)
{
   struct dinput_input *di = (struct dinput_input*)data;
   LPDIRECTINPUT8 hold_ctx = g_ctx;

   if (di)
   {
      g_ctx = NULL; // Prevent a joypad driver to kill our context prematurely.
      di->joypad->destroy();
      g_ctx = hold_ctx;

      if (di->keyboard)
         IDirectInputDevice8_Release(di->keyboard);

      if (di->mouse)
         IDirectInputDevice8_Release(di->mouse);

      free(di);
   }

   dinput_destroy_context();
}

static void dinput_grab_mouse(void *data, bool state)
{
   struct dinput_input *di = (struct dinput_input*)data;
   IDirectInputDevice8_Unacquire(di->mouse);
   IDirectInputDevice8_SetCooperativeLevel(di->mouse,
      (HWND)driver.video_window,
      state ?
      (DISCL_EXCLUSIVE | DISCL_FOREGROUND) :
      (DISCL_NONEXCLUSIVE | DISCL_FOREGROUND));
   IDirectInputDevice8_Acquire(di->mouse);
}

const input_driver_t input_dinput = {
   dinput_init,
   dinput_poll,
   dinput_input_state,
   dinput_key_pressed,
   dinput_free,
   NULL,
   "dinput",

   dinput_grab_mouse,
};

static void dinput_joypad_destroy(void)
{
   for (unsigned i = 0; i < MAX_PLAYERS; i++)
   {
      if (g_pads[i].joypad)
      {
         IDirectInputDevice8_Unacquire(g_pads[i].joypad);
         IDirectInputDevice8_Release(g_pads[i].joypad);
      }
   }

   g_joypad_cnt = 0;
   memset(g_pads, 0, sizeof(g_pads));

   // Can be blocked by global Dinput context.
   dinput_destroy_context();
}

static BOOL CALLBACK enum_axes_cb(const DIDEVICEOBJECTINSTANCE *inst, void *p)
{
   LPDIRECTINPUTDEVICE8 joypad = (LPDIRECTINPUTDEVICE8)p;

   DIPROPRANGE range;
   memset(&range, 0, sizeof(range));
   range.diph.dwSize = sizeof(DIPROPRANGE);
   range.diph.dwHeaderSize = sizeof(DIPROPHEADER);
   range.diph.dwHow = DIPH_BYID;
   range.diph.dwObj = inst->dwType;
   range.lMin = -0x7fff;
   range.lMax = 0x7fff;
   IDirectInputDevice8_SetProperty(joypad, DIPROP_RANGE, &range.diph);

   return DIENUM_CONTINUE;
}

static BOOL CALLBACK enum_joypad_cb(const DIDEVICEINSTANCE *inst, void *p)
{
   (void)p;
   if (g_joypad_cnt == MAX_PLAYERS)
      return DIENUM_STOP;

   LPDIRECTINPUTDEVICE8 *pad = &g_pads[g_joypad_cnt].joypad;

#ifdef __cplusplus
   if (FAILED(IDirectInput8_CreateDevice(g_ctx, inst->guidInstance, pad, NULL)))
#else
   if (FAILED(IDirectInput8_CreateDevice(g_ctx, &inst->guidInstance, pad, NULL)))
#endif
      return DIENUM_CONTINUE;

   IDirectInputDevice8_SetDataFormat(*pad, &c_dfDIJoystick2);
   IDirectInputDevice8_SetCooperativeLevel(*pad, (HWND)driver.video_window,
         DISCL_NONEXCLUSIVE | DISCL_BACKGROUND);

   IDirectInputDevice8_EnumObjects(*pad, enum_axes_cb, 
         *pad, DIDFT_ABSAXIS);

   g_joypad_cnt++;

   return DIENUM_CONTINUE; 
}

static bool dinput_joypad_init(void)
{
   if (!dinput_init_context())
      return false;

   RARCH_LOG("Enumerating DInput joypads ...\n");
   IDirectInput8_EnumDevices(g_ctx, DI8DEVCLASS_GAMECTRL,
         enum_joypad_cb, NULL, DIEDFL_ATTACHEDONLY);
   RARCH_LOG("Done enumerating DInput joypads ...\n");
   return true;
}

static bool dinput_joypad_button(unsigned port_num, uint16_t joykey)
{
   if (joykey == NO_BTN)
      return false;

   const struct dinput_joypad *pad = &g_pads[port_num];
   if (!pad->joypad)
      return false;

   // Check hat.
   if (GET_HAT_DIR(joykey))
   {
      unsigned hat = GET_HAT(joykey);
      
      unsigned elems = sizeof(pad->joy_state.rgdwPOV) / sizeof(pad->joy_state.rgdwPOV[0]);
      if (hat >= elems)
         return false;

      unsigned pov = pad->joy_state.rgdwPOV[hat];

      // Magic numbers I'm not sure where originate from.
      if (pov < 36000)
      {
         switch (GET_HAT_DIR(joykey))
         {
            case HAT_UP_MASK:
               return (pov >= 31500) || (pov <= 4500);
            case HAT_RIGHT_MASK:
               return (pov >= 4500) && (pov <= 13500);
            case HAT_DOWN_MASK:
               return (pov >= 13500) && (pov <= 22500);
            case HAT_LEFT_MASK:
               return (pov >= 22500) && (pov <= 31500);
         }
      }

      return false;
   }
   else
   {
      unsigned elems = sizeof(pad->joy_state.rgbButtons) / sizeof(pad->joy_state.rgbButtons[0]);

      if (joykey < elems)
         return pad->joy_state.rgbButtons[joykey];
   }

   return false;
}

static int16_t dinput_joypad_axis(unsigned port_num, uint32_t joyaxis)
{
   if (joyaxis == AXIS_NONE)
      return 0;

   const struct dinput_joypad *pad = &g_pads[port_num];
   if (!pad->joypad)
      return 0;

   int val = 0;

   int axis    = -1;
   bool is_neg = false;
   bool is_pos = false;

   if (AXIS_NEG_GET(joyaxis) <= 5)
   {
      axis = AXIS_NEG_GET(joyaxis);
      is_neg = true;
   }
   else if (AXIS_POS_GET(joyaxis) <= 5)
   {
      axis = AXIS_POS_GET(joyaxis);
      is_pos = true;
   }

   switch (axis)
   {
      case 0: val = pad->joy_state.lX; break;
      case 1: val = pad->joy_state.lY; break;
      case 2: val = pad->joy_state.lZ; break;
      case 3: val = pad->joy_state.lRx; break;
      case 4: val = pad->joy_state.lRy; break;
      case 5: val = pad->joy_state.lRz; break;
   }

   if (is_neg && val > 0)
      val = 0;
   else if (is_pos && val < 0)
      val = 0;

   return val;
}

static void dinput_joypad_poll(void)
{
   for (unsigned i = 0; i < MAX_PLAYERS; i++)
   {
      struct dinput_joypad *pad = &g_pads[i];

      if (pad->joypad)
      {
         memset(&pad->joy_state, 0, sizeof(pad->joy_state));

         if (FAILED(IDirectInputDevice8_Poll(pad->joypad)))
         {
            if (FAILED(IDirectInputDevice8_Acquire(pad->joypad)))
            {
               memset(&pad->joy_state, 0, sizeof(DIJOYSTATE2));
               continue;
            }

            // If this fails, something *really* bad must have happened.
            if (FAILED(IDirectInputDevice8_Poll(pad->joypad)))
            {
               memset(&pad->joy_state, 0, sizeof(DIJOYSTATE2));
               continue;
            }
         }

         IDirectInputDevice8_GetDeviceState(pad->joypad,
               sizeof(DIJOYSTATE2), &pad->joy_state);
      }
   }
}

static bool dinput_joypad_query_pad(unsigned pad)
{
   return pad < MAX_PLAYERS && g_pads[pad].joypad;
}

static const char *dinput_joypad_name(unsigned pad)
{
   (void)pad;
   // FIXME
   return NULL;
}

const rarch_joypad_driver_t dinput_joypad = {
   dinput_joypad_init,
   dinput_joypad_query_pad,
   dinput_joypad_destroy,
   dinput_joypad_button,
   dinput_joypad_axis,
   dinput_joypad_poll,
   dinput_joypad_name,
   "dinput",
};