// Copyright (c) 2012 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 "content/browser/renderer_host/media/audio_input_device_manager.h"

#include "base/bind.h"
#include "base/memory/scoped_ptr.h"
#include "content/browser/renderer_host/media/audio_input_device_manager_event_handler.h"
#include "content/public/browser/browser_thread.h"
#include "media/audio/audio_manager_base.h"

using content::BrowserThread;

namespace media_stream {

const int AudioInputDeviceManager::kFakeOpenSessionId = 1;
const int AudioInputDeviceManager::kInvalidSessionId = 0;
const char AudioInputDeviceManager::kInvalidDeviceId[] = "";

// Starting id for the first capture session.
const int kFirstSessionId = AudioInputDeviceManager::kFakeOpenSessionId + 1;

AudioInputDeviceManager::AudioInputDeviceManager(
    media::AudioManager* audio_manager)
    : listener_(NULL),
      next_capture_session_id_(kFirstSessionId),
      audio_manager_(audio_manager) {
}

AudioInputDeviceManager::~AudioInputDeviceManager() {
}

void AudioInputDeviceManager::Register(MediaStreamProviderListener* listener) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  DCHECK(!listener_);
  listener_ = listener;
}

void AudioInputDeviceManager::Unregister() {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  DCHECK(listener_);
  listener_ = NULL;
}

void AudioInputDeviceManager::EnumerateDevices() {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  DCHECK(listener_);

  media::AudioDeviceNames device_names;
  audio_manager_->GetAudioInputDeviceNames(&device_names);

  StreamDeviceInfoArray* devices = new StreamDeviceInfoArray;
  for (media::AudioDeviceNames::iterator it = device_names.begin();
       it != device_names.end();
       ++it) {
         devices->push_back(StreamDeviceInfo(
            content::MEDIA_STREAM_DEVICE_TYPE_AUDIO_CAPTURE, it->device_name,
            it->unique_id, false));
  }

  // Returns the device list through the listener by posting a task on
  // IO thread since MediaStreamManager handles the callback asynchronously.
  BrowserThread::PostTask(
      BrowserThread::IO,
      FROM_HERE,
      base::Bind(&AudioInputDeviceManager::DevicesEnumeratedOnIOThread,
                 this,
                 devices));
}

int AudioInputDeviceManager::Open(const StreamDeviceInfo& device) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));

  // Generates a new id for this device.
  int session_id = next_capture_session_id_++;
  DCHECK(devices_.find(session_id) == devices_.end());

  media::AudioDeviceName audio_input_device_name;
  audio_input_device_name.device_name = device.name;
  audio_input_device_name.unique_id = device.device_id;

  // Adds the session_id and device to the list.
  devices_[session_id] = audio_input_device_name;

  // Returns the |session_id| through the listener by posting a task on
  // IO thread since MediaStreamManager handles the callback asynchronously.
  BrowserThread::PostTask(BrowserThread::IO,
                          FROM_HERE,
                          base::Bind(&AudioInputDeviceManager::OpenedOnIOThread,
                                     this,
                                     session_id));

  return session_id;
}

void AudioInputDeviceManager::Close(int session_id) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  DCHECK(listener_);

  if (devices_.find(session_id) != devices_.end())
    devices_.erase(session_id);

  // Checks if the device has been stopped, if not, send stop signal.
  EventHandlerMap::iterator it = event_handlers_.find(session_id);
  if (it != event_handlers_.end()) {
    it->second->OnDeviceStopped(session_id);
    event_handlers_.erase(session_id);
  }

  // Posts a callback through the listener on IO thread since
  // MediaStreamManager handles the callback asynchronously.
  BrowserThread::PostTask(BrowserThread::IO,
                          FROM_HERE,
                          base::Bind(&AudioInputDeviceManager::ClosedOnIOThread,
                                     this,
                                     session_id));
}

void AudioInputDeviceManager::Start(
    int session_id, AudioInputDeviceManagerEventHandler* event_handler) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  DCHECK(event_handler);

  // Solution for not using MediaStreamManager. This is needed when Start() is
  // called without using Open(), we post default device for test purpose.
  // And we do not store the info for the kFakeOpenSessionId but return
  // the callback immediately.
  if (session_id == kFakeOpenSessionId) {
    event_handler->OnDeviceStarted(session_id,
                                   media::AudioManagerBase::kDefaultDeviceId);
    return;
  }

  // Checks if the device has been opened or not.
  std::string device_id = (devices_.find(session_id) == devices_.end()) ?
      kInvalidDeviceId : devices_[session_id].unique_id;

  // Adds the event handler to the session if the session has not been started,
  // otherwise post a |kInvalidDeviceId| to indicate that Start() fails.
  if (event_handlers_.find(session_id) == event_handlers_.end())
    event_handlers_.insert(std::make_pair(session_id, event_handler));
  else
    device_id = kInvalidDeviceId;

  // Posts a callback through the AudioInputRendererHost to notify the renderer
  // that the device has started.
  event_handler->OnDeviceStarted(session_id, device_id);
}

void AudioInputDeviceManager::Stop(int session_id) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));

  // Erases the event handler referenced by the session_id.
  event_handlers_.erase(session_id);
}

void AudioInputDeviceManager::DevicesEnumeratedOnIOThread(
    StreamDeviceInfoArray* devices) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  // Ensures that |devices| gets deleted on exit.
  scoped_ptr<StreamDeviceInfoArray> devices_array(devices);
  if (listener_) {
    listener_->DevicesEnumerated(
        content::MEDIA_STREAM_DEVICE_TYPE_AUDIO_CAPTURE,
        *devices_array);
  }
}

void AudioInputDeviceManager::OpenedOnIOThread(int session_id) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  if (listener_)
    listener_->Opened(content::MEDIA_STREAM_DEVICE_TYPE_AUDIO_CAPTURE,
                      session_id);
}

void AudioInputDeviceManager::ClosedOnIOThread(int session_id) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  if (listener_)
    listener_->Closed(content::MEDIA_STREAM_DEVICE_TYPE_AUDIO_CAPTURE,
                      session_id);
}

}  // namespace media_stream