/*  RetroArch - A frontend for libretro.
 *  Copyright (C) 2013-2014 - Jason Fetters
 *  Copyright (C) 2011-2015 - 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 <IOKit/hid/IOHIDManager.h>
#include <IOKit/hid/IOHIDKeys.h>
#include "apple_input.h"
#include "input_autodetect.h"
#include "input_common.h"
#include "../general.h"

struct pad_connection
{
   int v_id;
   int p_id;
   uint32_t slot;
   IOHIDDeviceRef device_handle;
   uint8_t data[2048];
};

static joypad_connection_t *slots;
static IOHIDManagerRef g_hid_manager;

static void hid_pad_connection_send_control(void *data, uint8_t* data_buf, size_t size)
{
   struct pad_connection* connection = (struct pad_connection*)data;

   if (connection)
      IOHIDDeviceSetReport(connection->device_handle,
            kIOHIDReportTypeOutput, 0x01, data_buf + 1, size - 1);
}

/* NOTE: I pieced this together through trial and error,
 * any corrections are welcome. */

static void hid_device_input_callback(void* context, IOReturn result,
      void* sender, IOHIDValueRef value)
{
   apple_input_data_t *apple = (apple_input_data_t*)driver.input_data;
   struct pad_connection* connection = (struct pad_connection*)context;
   IOHIDElementRef element = IOHIDValueGetElement(value);
   uint32_t type    = IOHIDElementGetType(element);
   uint32_t page    = IOHIDElementGetUsagePage(element);
   uint32_t use     = IOHIDElementGetUsage(element);

   /* Joystick handler.
    * TODO: Can GamePad work the same? */

   if (
         (type == kIOHIDElementTypeInput_Misc) ||
         (type == kIOHIDElementTypeInput_Button) ||
         (type == kIOHIDElementTypeInput_Axis)
      )
   {
      switch (page)
      {
         case kHIDPage_GenericDesktop:
            switch (type)
            {
               case kIOHIDElementTypeInput_Misc:
                  switch (use)
                  {
                     case kHIDUsage_GD_Hatswitch:
                        break;
                     default:
                        {
                           static const uint32_t axis_use_ids[4] = { 48, 49, 50, 53 };
                           int i;

                           for (i = 0; i < 4; i ++)
                           {
                              CFIndex min   = IOHIDElementGetPhysicalMin(element);
                              CFIndex max   = IOHIDElementGetPhysicalMax(element) - min;
                              CFIndex state = IOHIDValueGetIntegerValue(value) - min;
                              float val     = (float)state / (float)max;

                              if (use != axis_use_ids[i])
                                 continue;

                              apple->axes[connection->slot][i] =
                                 ((val * 2.0f) - 1.0f) * 32767.0f;
                           }
                        }
                        break;
                  }
                  break;
            }
            break;
         case kHIDPage_Button:
            switch (type)
            {
               case kIOHIDElementTypeInput_Button:
                  {
                     CFIndex state = IOHIDValueGetIntegerValue(value);
                     unsigned id = use - 1;

                     if (state)
                        BIT32_SET(apple->buttons[connection->slot], id);
                     else
                        BIT32_CLEAR(apple->buttons[connection->slot], id);
                  }
                  break;
            }
            break;
      }
   }
}

static void remove_device(void* context, IOReturn result, void* sender)
{
   apple_input_data_t *apple = (apple_input_data_t*)driver.input_data;
   struct pad_connection* connection = (struct pad_connection*)context;

   if (connection && connection->slot < MAX_USERS)
   {
      char msg[512];
      snprintf(msg, sizeof(msg), "Joypad #%u (%s) disconnected.",
            connection->slot, "N/A");
      msg_queue_push(g_extern.msg_queue, msg, 0, 60);
      RARCH_LOG("[apple_input]: %s\n", msg);

      apple->buttons[connection->slot] = 0;
      memset(apple->axes[connection->slot], 0, sizeof(apple->axes));

      pad_connection_pad_deinit(&slots[connection->slot], connection->slot);
      free(connection);
   }

   IOHIDDeviceClose(sender, kIOHIDOptionsTypeSeizeDevice);
}

static void hid_device_report(void* context, IOReturn result, void *sender,
      IOHIDReportType type, uint32_t reportID, uint8_t *report,
      CFIndex reportLength)
{
   struct pad_connection* connection = (struct pad_connection*)context;

   if (!connection)
      return;

   pad_connection_packet(&slots[connection->slot], connection->slot,
         connection->data, reportLength + 1);
}

static void add_device(void* context, IOReturn result,
      void* sender, IOHIDDeviceRef device)
{
   char device_name[PATH_MAX_LENGTH];
   CFStringRef device_name_ref;
   CFNumberRef vendorID, productID;
   struct pad_connection* connection = (struct pad_connection*)
      calloc(1, sizeof(*connection));

   connection->device_handle = device;
   connection->slot          = MAX_USERS;

   IOHIDDeviceOpen(device, kIOHIDOptionsTypeNone);

   /* Move the device's run loop to this thread. */
   IOHIDDeviceScheduleWithRunLoop(device, CFRunLoopGetCurrent(),
         kCFRunLoopCommonModes);
   IOHIDDeviceRegisterRemovalCallback(device, remove_device, connection);

#ifndef IOS
   device_name_ref = IOHIDDeviceGetProperty(device, CFSTR(kIOHIDProductKey));
   CFStringGetCString(device_name_ref, device_name,
         sizeof(device_name), kCFStringEncodingUTF8);
#endif

   vendorID = (CFNumberRef)IOHIDDeviceGetProperty(device, CFSTR(kIOHIDVendorIDKey));
   CFNumberGetValue(vendorID, kCFNumberIntType, &connection->v_id);

   productID = (CFNumberRef)IOHIDDeviceGetProperty(device, CFSTR(kIOHIDProductIDKey));
   CFNumberGetValue(productID, kCFNumberIntType, &connection->p_id);

   connection->slot = pad_connection_pad_init(slots, device_name,
         connection, &hid_pad_connection_send_control);

   if (pad_connection_has_interface(slots, connection->slot))
      IOHIDDeviceRegisterInputReportCallback(device,
            connection->data + 1, sizeof(connection->data) - 1,
            hid_device_report, connection);
   else
      IOHIDDeviceRegisterInputValueCallback(device,
            hid_device_input_callback, connection);

   if (device_name[0] != '\0')
   {
      strlcpy(g_settings.input.device_names[connection->slot],
            device_name, sizeof(g_settings.input.device_names));

      input_config_autoconfigure_joypad(connection->slot,
            device_name, connection->v_id, connection->p_id, apple_hid_joypad.ident);
      RARCH_LOG("Port %d: %s.\n", connection->slot, device_name);
   }
}

static void append_matching_dictionary(CFMutableArrayRef array,
      uint32_t page, uint32_t use)
{
   CFNumberRef usen;
   CFMutableDictionaryRef matcher = CFDictionaryCreateMutable(kCFAllocatorDefault, 0,
         &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks);
   CFNumberRef pagen = CFNumberCreate(kCFAllocatorDefault, kCFNumberIntType, &page);

   CFDictionarySetValue(matcher, CFSTR(kIOHIDDeviceUsagePageKey), pagen);
   CFRelease(pagen);

   usen = CFNumberCreate(kCFAllocatorDefault, kCFNumberIntType, &use);
   CFDictionarySetValue(matcher, CFSTR(kIOHIDDeviceUsageKey), usen);
   CFRelease(usen);

   CFArrayAppendValue(array, matcher);
   CFRelease(matcher);
}

static bool apple_joypad_init(void)
{
   CFMutableArrayRef matcher;

   if (!(g_hid_manager = IOHIDManagerCreate(
         kCFAllocatorDefault, kIOHIDOptionsTypeNone)))
      return false;

   matcher = CFArrayCreateMutable(kCFAllocatorDefault, 0,
         &kCFTypeArrayCallBacks);

   append_matching_dictionary(matcher, kHIDPage_GenericDesktop,
         kHIDUsage_GD_Joystick);
   append_matching_dictionary(matcher, kHIDPage_GenericDesktop,
         kHIDUsage_GD_GamePad);

   IOHIDManagerSetDeviceMatchingMultiple(g_hid_manager, matcher);
   CFRelease(matcher);

   IOHIDManagerRegisterDeviceMatchingCallback(g_hid_manager,
         add_device, 0);
   IOHIDManagerScheduleWithRunLoop(g_hid_manager, CFRunLoopGetMain(),
         kCFRunLoopCommonModes);

   IOHIDManagerOpen(g_hid_manager, kIOHIDOptionsTypeNone);
    
   slots = (joypad_connection_t*)pad_connection_init(MAX_USERS);

   return true;
}

static bool apple_joypad_query_pad(unsigned pad)
{
   return pad < MAX_USERS;
}

static void apple_joypad_hid_destroy(void)
{
   if (!g_hid_manager)
      return;

   IOHIDManagerClose(g_hid_manager, kIOHIDOptionsTypeNone);
   IOHIDManagerUnscheduleFromRunLoop(g_hid_manager,
         CFRunLoopGetCurrent(), kCFRunLoopCommonModes);

   CFRelease(g_hid_manager);

   g_hid_manager = NULL;
}

static void apple_joypad_destroy(void)
{
   pad_connection_destroy(slots);
   apple_joypad_hid_destroy();
}

static bool apple_joypad_button(unsigned port, uint16_t joykey)
{
   apple_input_data_t *apple = (apple_input_data_t*)driver.input_data;
   uint32_t buttons = pad_connection_get_buttons(&slots[port], port);

   if (!apple || joykey == NO_BTN)
      return false;

   /* Check hat. */
   if (GET_HAT_DIR(joykey))
      return false;

   /* Check the button. */
   if ((port < MAX_USERS) && (joykey < 32))
       return ((apple->buttons[port] & (1 << joykey)) != 0) ||
              ((buttons & (1 << joykey)) != 0);
    return false;
}

static int16_t apple_joypad_axis(unsigned port, uint32_t joyaxis)
{
   apple_input_data_t *apple = (apple_input_data_t*)driver.input_data;
   int16_t val = 0;

   if (!apple || joyaxis == AXIS_NONE)
      return 0;

   if (AXIS_NEG_GET(joyaxis) < 4)
   {
      val = apple->axes[port][AXIS_NEG_GET(joyaxis)];
      val += pad_connection_get_axis(&slots[port], port, AXIS_NEG_GET(joyaxis));
      val = (val < 0) ? val : 0;
   }
   else if(AXIS_POS_GET(joyaxis) < 4)
   {
      val = apple->axes[port][AXIS_POS_GET(joyaxis)];
      val += pad_connection_get_axis(&slots[port], port, AXIS_POS_GET(joyaxis));
      val = (val > 0) ? val : 0;
   }

   return val;
}

static void apple_joypad_poll(void)
{
}

static bool apple_joypad_rumble(unsigned pad,
      enum retro_rumble_effect effect, uint16_t strength)
{
   return pad_connection_rumble(&slots[pad], pad, effect, strength);
}

static const char *apple_joypad_name(unsigned pad)
{
   /* TODO/FIXME - implement properly */
   if (pad >= MAX_USERS)
      return NULL;

   return NULL;
}

rarch_joypad_driver_t apple_hid_joypad = {
   apple_joypad_init,
   apple_joypad_query_pad,
   apple_joypad_destroy,
   apple_joypad_button,
   apple_joypad_axis,
   apple_joypad_poll,
   apple_joypad_rumble,
   apple_joypad_name,
   "apple_hid"
};