// Copyright (c) 2010 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "webkit/glue/plugins/pepper_audio.h"

#include "base/logging.h"
#include "third_party/ppapi/c/ppb_audio.h"
#include "third_party/ppapi/c/ppb_audio_trusted.h"


namespace pepper {

namespace {

// PPB_AudioConfig functions

PP_Resource CreateStereo16bit(PP_Module module_id, uint32_t sample_rate,
                              uint32_t sample_frame_count) {
  PluginModule* module = PluginModule::FromPPModule(module_id);
  if (!module)
    return 0;

  scoped_refptr<AudioConfig> config(new AudioConfig(module, sample_rate,
                                                    sample_frame_count));
  return config->GetReference();
}

uint32_t GetSampleRate(PP_Resource config_id) {
  scoped_refptr<AudioConfig> config = Resource::GetAs<AudioConfig>(config_id);
  return config ? config->sample_rate() : 0;
}

uint32_t GetSampleFrameCount(PP_Resource config_id) {
  scoped_refptr<AudioConfig> config = Resource::GetAs<AudioConfig>(config_id);
  return config ? config->sample_frame_count() : 0;
}

// PPB_Audio functions

PP_Resource Create(PP_Instance instance_id, PP_Resource config_id,
                   PPB_Audio_Callback callback, void* user_data) {
  PluginInstance* instance = PluginInstance::FromPPInstance(instance_id);
  if (!instance)
    return 0;
  // TODO(neb): Require callback to be present for untrusted plugins.
  scoped_refptr<Audio> audio(new Audio(instance->module()));
  if (!audio->Init(instance->delegate(), config_id, callback, user_data))
    return 0;
  return audio->GetReference();
}

PP_Resource GetCurrentConfiguration(PP_Resource audio_id) {
  scoped_refptr<Audio> audio = Resource::GetAs<Audio>(audio_id);
  return audio ? audio->GetCurrentConfiguration() : 0;
}

bool StartPlayback(PP_Resource audio_id) {
  scoped_refptr<Audio> audio = Resource::GetAs<Audio>(audio_id);
  return audio ? audio->StartPlayback() : false;
}

bool StopPlayback(PP_Resource audio_id) {
  scoped_refptr<Audio> audio = Resource::GetAs<Audio>(audio_id);
  return audio ? audio->StopPlayback() : false;
}

// PPB_AudioTrusted functions

PP_Resource GetBuffer(PP_Resource audio_id) {
  // TODO(neb): Implement me!
  return 0;
}

int GetOSDescriptor(PP_Resource audio_id) {
  // TODO(neb): Implement me!
  return -1;
}

const PPB_AudioConfig ppb_audioconfig = {
  &CreateStereo16bit,
  &GetSampleRate,
  &GetSampleFrameCount
};

const PPB_Audio ppb_audio = {
  &Create,
  &GetCurrentConfiguration,
  &StartPlayback,
  &StopPlayback,
};

const PPB_AudioTrusted ppb_audiotrusted = {
  &GetBuffer,
  &GetOSDescriptor
};

}  // namespace

AudioConfig::AudioConfig(PluginModule* module, int32_t sample_rate,
                         int32_t sample_frame_count)
    : Resource(module),
      sample_rate_(sample_rate),
      sample_frame_count_(sample_frame_count) {
}

const PPB_AudioConfig* AudioConfig::GetInterface() {
  return &ppb_audioconfig;
}

AudioConfig* AudioConfig::AsAudioConfig() {
  return this;
}

Audio::Audio(PluginModule* module)
    : Resource(module),
      socket_(NULL),
      shared_memory_(NULL),
      shared_memory_size_(0),
      callback_(NULL),
      user_data_(NULL) {
}

Audio::~Audio() {
  // Calling ShutDown() makes sure StreamCreated cannot be called anymore.
  audio_->ShutDown();
  // Closing the socket causes the thread to exit - wait for it.
  socket_->Close();
  if (audio_thread_.get()) {
    audio_thread_->Join();
    audio_thread_.reset();
  }
  // Shared memory destructor will unmap the memory automatically.
}


const PPB_Audio* Audio::GetInterface() {
  return &ppb_audio;
}

const PPB_AudioTrusted* Audio::GetTrustedInterface() {
  return &ppb_audiotrusted;
}

Audio* Audio::AsAudio() {
  return this;
}

bool Audio::Init(PluginDelegate* plugin_delegate, PP_Resource config_id,
                 PPB_Audio_Callback callback, void* user_data) {
  CHECK(!audio_.get());
  config_ = Resource::GetAs<AudioConfig>(config_id);
  if (!config_)
    return false;
  callback_ = callback;
  user_data_ = user_data;
  // When the stream is created, we'll get called back in StreamCreated().
  audio_.reset(plugin_delegate->CreateAudio(config_->sample_rate(),
                                            config_->sample_frame_count(),
                                            this));
  return audio_.get() != NULL;
}

void Audio::StreamCreated(base::SharedMemoryHandle shared_memory_handle,
                          size_t shared_memory_size,
                          base::SyncSocket::Handle socket_handle) {
  socket_.reset(new base::SyncSocket(socket_handle));
  shared_memory_.reset(new base::SharedMemory(shared_memory_handle, false));
  shared_memory_size_ = shared_memory_size;

  if (callback_) {
    shared_memory_->Map(shared_memory_size_);
    audio_thread_.reset(new base::DelegateSimpleThread(this,
                                                       "plugin_audio_thread"));
    audio_thread_->Start();
  }
}

void Audio::Run() {
  int pending_data;
  void* buffer = shared_memory_->memory();

  while (sizeof(pending_data) ==
      socket_->Receive(&pending_data, sizeof(pending_data)) &&
      pending_data >= 0) {
    callback_(buffer, user_data_);
  }
}

}  // namespace pepper