/*  RetroArch - A frontend for libretro.
 *  Copyright (C) 2010-2014 - Hans-Kristian Arntzen
 *  Copyright (C) 2011-2014 - Chris Moeller
 * 
 *  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 "../general.h"
#include "../fifo_buffer.h"
#include <stdlib.h>
#include "../boolean.h"
#include <pthread.h>

#ifdef OSX
#include <CoreAudio/CoreAudio.h>
#else
#include <AudioToolbox/AudioToolbox.h>
#endif

#include <CoreAudio/CoreAudioTypes.h>
#include <AudioUnit/AudioUnit.h>
#include <AudioUnit/AUComponent.h>

typedef struct coreaudio
{
   pthread_mutex_t lock;
   pthread_cond_t cond;

#ifdef OSX_PPC
   ComponentInstance dev;
#else
   AudioComponentInstance dev;
#endif
   bool dev_alive;

   fifo_buffer_t *buffer;
   bool nonblock;
   size_t buffer_size;
} coreaudio_t;

static bool g_interrupted;

static void coreaudio_free(void *data)
{
   coreaudio_t *dev = (coreaudio_t*)data;
   if (!dev)
      return;

   if (dev->dev_alive)
   {
      AudioOutputUnitStop(dev->dev);
#ifdef OSX_PPC
      CloseComponent(dev->dev);
#else
      AudioComponentInstanceDispose(dev->dev);
#endif
   }

   if (dev->buffer)
      fifo_free(dev->buffer);

   pthread_mutex_destroy(&dev->lock);
   pthread_cond_destroy(&dev->cond);

   free(dev);
}

static OSStatus audio_write_cb(void *userdata, AudioUnitRenderActionFlags *action_flags,
      const AudioTimeStamp *time_stamp, UInt32 bus_number,
      UInt32 number_frames, AudioBufferList *io_data)
{
   coreaudio_t *dev = (coreaudio_t*)userdata;
   (void)time_stamp;
   (void)bus_number;
   (void)number_frames;

   if (!io_data)
      return noErr;
   if (io_data->mNumberBuffers != 1)
      return noErr;

   unsigned write_avail = io_data->mBuffers[0].mDataByteSize;
   void *outbuf = io_data->mBuffers[0].mData;

   pthread_mutex_lock(&dev->lock);
   if (fifo_read_avail(dev->buffer) < write_avail)
   {
      *action_flags = kAudioUnitRenderAction_OutputIsSilence;
      memset(outbuf, 0, write_avail); // Seems to be needed.
      pthread_mutex_unlock(&dev->lock);
      pthread_cond_signal(&dev->cond); // Technically possible to deadlock without.
      return noErr;
   }

   fifo_read(dev->buffer, outbuf, write_avail);
   pthread_mutex_unlock(&dev->lock);
   pthread_cond_signal(&dev->cond);
   return noErr;
}

#ifdef OSX
static void choose_output_device(coreaudio_t *dev, const char* device)
{
   AudioObjectPropertyAddress propaddr =
   { 
      kAudioHardwarePropertyDevices, 
      kAudioObjectPropertyScopeGlobal, 
      kAudioObjectPropertyElementMaster 
   };

   UInt32 size = 0;

   if (AudioObjectGetPropertyDataSize(kAudioObjectSystemObject, &propaddr, 0, 0, &size) != noErr)
      return;

   UInt32 deviceCount = size / sizeof(AudioDeviceID);
   AudioDeviceID *devices = malloc(size);

   if (!devices || AudioObjectGetPropertyData(kAudioObjectSystemObject, &propaddr, 0, 0, &size, devices) != noErr)
      goto done;

   propaddr.mScope = kAudioDevicePropertyScopeOutput;
   propaddr.mSelector = kAudioDevicePropertyDeviceName;
   size = 1024;

   for (unsigned i = 0; i < deviceCount; i ++)
   {
      char device_name[1024];
      device_name[0] = 0;

      if (AudioObjectGetPropertyData(devices[i], &propaddr, 0, 0, &size, device_name) == noErr && strcmp(device_name, device) == 0)
      {
         AudioUnitSetProperty(dev->dev, kAudioOutputUnitProperty_CurrentDevice, kAudioUnitScope_Global, 0, &devices[i], sizeof(AudioDeviceID));
         goto done;
      }
   }

done:
   free(devices);
}
#endif

#ifdef IOS
static void coreaudio_interrupt_listener(void *data, UInt32 interrupt_state)
{
   (void)data;
   g_interrupted = (interrupt_state == kAudioSessionBeginInterruption);
}
#endif

static void *coreaudio_init(const char *device, unsigned rate, unsigned latency)
{
   (void)device;

   coreaudio_t *dev = (coreaudio_t*)calloc(1, sizeof(*dev));
   if (!dev)
      return NULL;

   pthread_mutex_init(&dev->lock, NULL);
   pthread_cond_init(&dev->cond, NULL);

#ifdef IOS
   static bool session_initialized = false;
   if (!session_initialized)
   {
      session_initialized = true;
      AudioSessionInitialize(0, 0, coreaudio_interrupt_listener, 0);
      AudioSessionSetActive(true);
   }
#endif

   // Create AudioComponent
#ifdef OSX_PPC
   ComponentDescription desc = {0};
#else
   AudioComponentDescription desc = {0};
#endif
   desc.componentType = kAudioUnitType_Output;
#ifdef IOS
   desc.componentSubType = kAudioUnitSubType_RemoteIO;
#else
   desc.componentSubType = kAudioUnitSubType_HALOutput;
#endif
   desc.componentManufacturer = kAudioUnitManufacturer_Apple;

#ifdef OSX_PPC
   Component comp = FindNextComponent(NULL, &desc);
#else
   AudioComponent comp = AudioComponentFindNext(NULL, &desc);
#endif
   if (comp == NULL)
      goto error;
   
#ifdef OSX_PPC
   if (OpenAComponent(comp, &dev->dev) != noErr)
#else
   if (AudioComponentInstanceNew(comp, &dev->dev) != noErr)
#endif
      goto error;

#ifdef OSX
   if (device)
      choose_output_device(dev, device);
#endif

   dev->dev_alive = true;

   // Set audio format
   AudioStreamBasicDescription stream_desc = {0};
   AudioStreamBasicDescription real_desc;
   
   stream_desc.mSampleRate = rate;
   stream_desc.mBitsPerChannel = sizeof(float) * CHAR_BIT;
   stream_desc.mChannelsPerFrame = 2;
   stream_desc.mBytesPerPacket = 2 * sizeof(float);
   stream_desc.mBytesPerFrame = 2 * sizeof(float);
   stream_desc.mFramesPerPacket = 1;
   stream_desc.mFormatID = kAudioFormatLinearPCM;
   stream_desc.mFormatFlags = kAudioFormatFlagIsFloat | kAudioFormatFlagIsPacked | (is_little_endian() ? 0 : kAudioFormatFlagIsBigEndian);
   
   if (AudioUnitSetProperty(dev->dev, kAudioUnitProperty_StreamFormat,
         kAudioUnitScope_Input, 0, &stream_desc, sizeof(stream_desc)) != noErr)
      goto error;
   
   // Check returned audio format
   UInt32 i_size = sizeof(real_desc);;
   if (AudioUnitGetProperty(dev->dev, kAudioUnitProperty_StreamFormat, kAudioUnitScope_Input, 0, &real_desc, &i_size) != noErr)
      goto error;

   if (real_desc.mChannelsPerFrame != stream_desc.mChannelsPerFrame)
      goto error;
   if (real_desc.mBitsPerChannel != stream_desc.mBitsPerChannel)
      goto error;
   if (real_desc.mFormatFlags != stream_desc.mFormatFlags)
      goto error;
   if (real_desc.mFormatID != stream_desc.mFormatID)
      goto error;

   RARCH_LOG("[CoreAudio]: Using output sample rate of %.1f Hz\n", (float)real_desc.mSampleRate);
   g_settings.audio.out_rate = real_desc.mSampleRate;


   // Set channel layout (fails on iOS)
#ifndef IOS
   AudioChannelLayout layout = {0};

   layout.mChannelLayoutTag = kAudioChannelLayoutTag_Stereo;
   if (AudioUnitSetProperty(dev->dev, kAudioUnitProperty_AudioChannelLayout,
         kAudioUnitScope_Input, 0, &layout, sizeof(layout)) != noErr)
      goto error;
#endif

   // Set callbacks and finish up
   AURenderCallbackStruct cb = {0};
   cb.inputProc = audio_write_cb;
   cb.inputProcRefCon = dev;

   if (AudioUnitSetProperty(dev->dev, kAudioUnitProperty_SetRenderCallback,
         kAudioUnitScope_Input, 0, &cb, sizeof(cb)) != noErr)
      goto error;

   if (AudioUnitInitialize(dev->dev) != noErr)
      goto error;

   size_t fifo_size;

   fifo_size = (latency * g_settings.audio.out_rate) / 1000;
   fifo_size *= 2 * sizeof(float);
   dev->buffer_size = fifo_size;

   dev->buffer = fifo_new(fifo_size);
   if (!dev->buffer)
      goto error;

   RARCH_LOG("[CoreAudio]: Using buffer size of %u bytes: (latency = %u ms)\n", (unsigned)fifo_size, latency);

   if (AudioOutputUnitStart(dev->dev) != noErr)
      goto error;

   return dev;

error:
   RARCH_ERR("[CoreAudio]: Failed to initialize driver ...\n");
   coreaudio_free(dev);
   return NULL;
}

static ssize_t coreaudio_write(void *data, const void *buf_, size_t size)
{
   coreaudio_t *dev = (coreaudio_t*)data;

   const uint8_t *buf = (const uint8_t*)buf_;
   size_t written = 0;

#ifdef IOS
   struct timeval time;
   gettimeofday(&time, 0);
   
   struct timespec timeout;
   memset(&timeout, 0, sizeof(timeout));
   timeout.tv_sec = time.tv_sec + 3;
   timeout.tv_nsec = time.tv_usec * 1000;
#endif

   while (!g_interrupted && size > 0)
   {
      pthread_mutex_lock(&dev->lock);

      size_t write_avail = fifo_write_avail(dev->buffer);
      if (write_avail > size)
         write_avail = size;

      fifo_write(dev->buffer, buf, write_avail);
      buf += write_avail;
      written += write_avail;
      size -= write_avail;

      if (dev->nonblock)
      {
         pthread_mutex_unlock(&dev->lock);
         break;
      }

#ifdef IOS
      if (write_avail == 0 && pthread_cond_timedwait(&dev->cond, &dev->lock, &timeout) == ETIMEDOUT)
         g_interrupted = true;
#else
      if (write_avail == 0)
         pthread_cond_wait(&dev->cond, &dev->lock);
#endif
      pthread_mutex_unlock(&dev->lock);
   }

   return written;
}

static bool coreaudio_stop(void *data)
{
   coreaudio_t *dev = (coreaudio_t*)data;
   return AudioOutputUnitStop(dev->dev) == noErr;
}

static void coreaudio_set_nonblock_state(void *data, bool state)
{
   coreaudio_t *dev = (coreaudio_t*)data;
   dev->nonblock = state;
}

static bool coreaudio_start(void *data)
{
   coreaudio_t *dev = (coreaudio_t*)data;
   return AudioOutputUnitStart(dev->dev) == noErr;
}

static bool coreaudio_use_float(void *data)
{
   (void)data;
   return true;
}

static size_t coreaudio_write_avail(void *data)
{
   coreaudio_t *dev = (coreaudio_t*)data;
   pthread_mutex_lock(&dev->lock);
   size_t avail = fifo_write_avail(dev->buffer);
   pthread_mutex_unlock(&dev->lock);
   return avail;
}

static size_t coreaudio_buffer_size(void *data)
{
   coreaudio_t *dev = (coreaudio_t*)data;
   return dev->buffer_size;
}

const audio_driver_t audio_coreaudio = {
   coreaudio_init,
   coreaudio_write,
   coreaudio_stop,
   coreaudio_start,
   coreaudio_set_nonblock_state,
   coreaudio_free,
   coreaudio_use_float,
   "coreaudio",
   coreaudio_write_avail,
   coreaudio_buffer_size,
};