// 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 "chrome/browser/media/media_capture_devices_dispatcher.h"

#include "chrome/browser/prefs/scoped_user_pref_update.h"
#include "chrome/common/pref_names.h"
#include "content/public/browser/browser_thread.h"
#include "content/public/browser/media_devices_monitor.h"
#include "content/public/common/media_stream_request.h"

using content::BrowserThread;
using content::MediaStreamDevices;

MediaCaptureDevicesDispatcher::MediaCaptureDevicesDispatcher()
    : devices_enumerated_(false) {}

MediaCaptureDevicesDispatcher::~MediaCaptureDevicesDispatcher() {}

void MediaCaptureDevicesDispatcher::RegisterUserPrefs(
    PrefServiceSyncable* user_prefs) {
  if (!user_prefs->FindPreference(prefs::kDefaultAudioCaptureDevice)) {
    user_prefs->RegisterStringPref(prefs::kDefaultAudioCaptureDevice,
                                   std::string(),
                                   PrefServiceSyncable::UNSYNCABLE_PREF);
  }
  if (!user_prefs->FindPreference(prefs::kDefaultVideoCaptureDevice)) {
    user_prefs->RegisterStringPref(prefs::kDefaultVideoCaptureDevice,
                                   std::string(),
                                   PrefServiceSyncable::UNSYNCABLE_PREF);
  }
}

void MediaCaptureDevicesDispatcher::AudioCaptureDevicesChanged(
    const MediaStreamDevices& devices) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));

  BrowserThread::PostTask(
      BrowserThread::UI, FROM_HERE,
      base::Bind(&MediaCaptureDevicesDispatcher::UpdateAudioDevicesOnUIThread,
                 this, devices));
}

void MediaCaptureDevicesDispatcher::VideoCaptureDevicesChanged(
    const MediaStreamDevices& devices) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));

  BrowserThread::PostTask(
      BrowserThread::UI, FROM_HERE,
      base::Bind(&MediaCaptureDevicesDispatcher::UpdateVideoDevicesOnUIThread,
                 this, devices));
}

void MediaCaptureDevicesDispatcher::AddObserver(Observer* observer) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  if (!observers_.HasObserver(observer))
    observers_.AddObserver(observer);
}

void MediaCaptureDevicesDispatcher::RemoveObserver(Observer* observer) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  observers_.RemoveObserver(observer);
}

const MediaStreamDevices&
MediaCaptureDevicesDispatcher::GetAudioCaptureDevices() {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  if (!devices_enumerated_) {
    BrowserThread::PostTask(
        BrowserThread::IO, FROM_HERE,
        base::Bind(&content::EnsureMonitorCaptureDevices));
    devices_enumerated_ = true;
  }
  return audio_devices_;
}

const MediaStreamDevices&
MediaCaptureDevicesDispatcher::GetVideoCaptureDevices() {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  if (!devices_enumerated_) {
    BrowserThread::PostTask(
        BrowserThread::IO, FROM_HERE,
        base::Bind(&content::EnsureMonitorCaptureDevices));
    devices_enumerated_ = true;
  }
  return video_devices_;
}

void MediaCaptureDevicesDispatcher::UpdateAudioDevicesOnUIThread(
    const content::MediaStreamDevices& devices) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  devices_enumerated_ = true;
  audio_devices_ = devices;
  FOR_EACH_OBSERVER(Observer, observers_,
                    OnUpdateAudioDevices(audio_devices_));
}

void MediaCaptureDevicesDispatcher::UpdateVideoDevicesOnUIThread(
    const content::MediaStreamDevices& devices){
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  devices_enumerated_ = true;
  video_devices_ = devices;
  FOR_EACH_OBSERVER(Observer, observers_,
                    OnUpdateVideoDevices(video_devices_));
}