/*  RetroArch - A frontend for libretro.
 *  Copyright (C) 2013-2014 - Jason Fetters
 *  Copyright (C) 2011-2017 - Daniel De Matteis
 *
 *  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 <string.h>
#include <stdlib.h>

#include <boolean.h>
#include "joypad_connection.h"
#include "../input_defines.h"

struct hidpad_ps2adapter_data
{
   struct pad_connection* connection;
   uint8_t data[64];
   uint32_t slot;
   uint64_t buttons;
};

static void* hidpad_ps2adapter_init(void *data, uint32_t slot, send_control_t ptr)
{
   struct pad_connection* connection = (struct pad_connection*)data;
   struct hidpad_ps2adapter_data* device    = (struct hidpad_ps2adapter_data*)
      calloc(1, sizeof(struct hidpad_ps2adapter_data));

   if (!device)
      return NULL;

   if (!connection)
   {
      free(device);
      return NULL;
   }

   device->connection   = connection;
   device->slot         = slot;

   return device;
}

static void hidpad_ps2adapter_deinit(void *data)
{
   struct hidpad_ps2adapter_data *device = (struct hidpad_ps2adapter_data*)data;

   if (device)
      free(device);
}

static uint64_t hidpad_ps2adapter_get_buttons(void *data)
{
   struct hidpad_ps2adapter_data *device = (struct hidpad_ps2adapter_data*)data;
   if (!device)
      return 0;
   return device->buttons;
}

static int16_t hidpad_ps2adapter_get_axis(void *data, unsigned axis)
{
   int val                               = 0;
   struct hidpad_ps2adapter_data *device = (struct hidpad_ps2adapter_data*)data;

   if (!device || axis >= 2)
      return 0;
   
   switch (axis)
   {
      case 0:
         val = device->data[4];
         break;
      case 1:
         val = device->data[5];
         break;
      case 2:
         val = device->data[3];
         break;
      case 3:
         val = device->data[2];
         break;
   }
   
   val = (val << 8) - 0x8000;

   return (abs(val) > 0x1000) ? val : 0;
}

#define PS2_H_GET(a) (a & 0x0F) /*HAT MASK = 0x0F */
#define PS2_H_LEFT(a) (a == 0x05) || (a == 0x06) || (a == 0x07)
#define PS2_H_RIGHT(a) (a == 0x01) || (a == 0x02) || (a == 0x03)
#define PS2_H_UP(a) (a == 0x07) || (a == 0x00) || (a == 0x01)
#define PS2_H_DOWN(a) (a == 0x03) || (a == 0x04) || (a == 0x05)

static void hidpad_ps2adapter_packet_handler(void *data, uint8_t *packet, uint16_t size)
{
   uint32_t i, pressed_keys;
   int16_t hat_value;
   static const uint32_t button_mapping[17] =
   {
      RETRO_DEVICE_ID_JOYPAD_L2,
      RETRO_DEVICE_ID_JOYPAD_R2,
      RETRO_DEVICE_ID_JOYPAD_L,
      RETRO_DEVICE_ID_JOYPAD_R,
      RETRO_DEVICE_ID_JOYPAD_SELECT,
      RETRO_DEVICE_ID_JOYPAD_START,
      RETRO_DEVICE_ID_JOYPAD_L3,
      RETRO_DEVICE_ID_JOYPAD_R3,
      NO_BTN,
      NO_BTN,
      NO_BTN,
      NO_BTN,
      RETRO_DEVICE_ID_JOYPAD_X,
      RETRO_DEVICE_ID_JOYPAD_A,
      RETRO_DEVICE_ID_JOYPAD_B,
      RETRO_DEVICE_ID_JOYPAD_Y,
   };
   struct hidpad_ps2adapter_data *device = (struct hidpad_ps2adapter_data*)data;

   if (!device)
      return;

   /* Check if the data corresponds to the first controller, exit otherwise */
   if (packet[1] != 1)
      return;
   
   memcpy(device->data, packet, size);

   device->buttons = 0;

   pressed_keys  = device->data[7] | (device->data[6] << 8);

   for (i = 0; i < 16; i ++)
      if (button_mapping[i] != NO_BTN)
         device->buttons |= (pressed_keys & (1 << i)) ? (UINT64_C(1) << button_mapping[i]) : 0;
         
   /* Now process the hat values as if they were pad buttons */
   hat_value = PS2_H_GET(device->data[6]);
   device->buttons |= PS2_H_LEFT(hat_value) ? (UINT64_C(1) << RETRO_DEVICE_ID_JOYPAD_LEFT) : 0;
   device->buttons |= PS2_H_RIGHT(hat_value) ? (UINT64_C(1) << RETRO_DEVICE_ID_JOYPAD_RIGHT) : 0;
   device->buttons |= PS2_H_UP(hat_value) ? (UINT64_C(1) << RETRO_DEVICE_ID_JOYPAD_UP) : 0;
   device->buttons |= PS2_H_DOWN(hat_value) ? (UINT64_C(1) << RETRO_DEVICE_ID_JOYPAD_DOWN) : 0;
}

static void hidpad_ps2adapter_set_rumble(void *data,
      enum retro_rumble_effect effect, uint16_t strength)
{
	(void)data;
	(void)effect;
   (void)strength;
}

const char * hidpad_ps2adapter_get_name(void *data)
{
	(void)data;
	/* For now we return a single static name */
	return "PS2/PSX Controller Adapter";
}

pad_connection_interface_t pad_connection_ps2adapter = {
   hidpad_ps2adapter_init,
   hidpad_ps2adapter_deinit,
   hidpad_ps2adapter_packet_handler,
   hidpad_ps2adapter_set_rumble,
   hidpad_ps2adapter_get_buttons,
   hidpad_ps2adapter_get_axis,
   hidpad_ps2adapter_get_name,
};
