/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim:set ts=2 sw=2 sts=2 et cindent: */

/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "nsISupportsPrimitives.h"

#include "nsSpeechTask.h"

#include "mozilla/Logging.h"

#include "mozilla/dom/ContentChild.h"

#include "mozilla/dom/Element.h"

#include "mozilla/dom/SpeechSynthesisBinding.h"

#include "SpeechSynthesis.h"

#include "nsContentUtils.h"

#include "nsSynthVoiceRegistry.h"

#include "nsIDocument.h"

#include "nsIDocShell.h"

#undef LOG

mozilla::LogModule*

GetSpeechSynthLog()

{

  static mozilla::LazyLogModule sLog("SpeechSynthesis");

  return sLog;

}

#define LOG(type, msg) MOZ_LOG(GetSpeechSynthLog(), type, msg)

namespace mozilla {

namespace dom {

NS_IMPL_CYCLE_COLLECTION_CLASS(SpeechSynthesis)

NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(SpeechSynthesis, DOMEventTargetHelper)

  NS_IMPL_CYCLE_COLLECTION_UNLINK(mCurrentTask)

  NS_IMPL_CYCLE_COLLECTION_UNLINK(mSpeechQueue)

  tmp->mVoiceCache.Clear();

NS_IMPL_CYCLE_COLLECTION_UNLINK_END

NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(SpeechSynthesis, DOMEventTargetHelper)

  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mCurrentTask)

  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mSpeechQueue)

  for (auto iter = tmp->mVoiceCache.Iter(); !iter.Done(); iter.Next()) {

    SpeechSynthesisVoice* voice = iter.UserData();

    cb.NoteXPCOMChild(voice);

  }

NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END

NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(SpeechSynthesis)

  NS_INTERFACE_MAP_ENTRY(nsIObserver)

  NS_INTERFACE_MAP_ENTRY(nsISupportsWeakReference)

NS_INTERFACE_MAP_END_INHERITING(DOMEventTargetHelper)

NS_IMPL_ADDREF_INHERITED(SpeechSynthesis, DOMEventTargetHelper)

NS_IMPL_RELEASE_INHERITED(SpeechSynthesis, DOMEventTargetHelper)

SpeechSynthesis::SpeechSynthesis(nsPIDOMWindowInner* aParent)

  : DOMEventTargetHelper(aParent)

  , mHoldQueue(false)

  , mInnerID(aParent->WindowID())

{

  MOZ_ASSERT(NS_IsMainThread());

  nsCOMPtr<nsIObserverService> obs = mozilla::services::GetObserverService();

  if (obs) {

    obs->AddObserver(this, "inner-window-destroyed", true);

    obs->AddObserver(this, "synth-voices-changed", true);

  }

}

SpeechSynthesis::~SpeechSynthesis()

{

}

JSObject*

SpeechSynthesis::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)

{

  return SpeechSynthesis_Binding::Wrap(aCx, this, aGivenProto);

}

bool

SpeechSynthesis::Pending() const

{

  switch (mSpeechQueue.Length()) {

  case 0:

    return false;

  case 1:

    return mSpeechQueue.ElementAt(0)->GetState() == SpeechSynthesisUtterance::STATE_PENDING;

  default:

    return true;

  }

}

bool

SpeechSynthesis::Speaking() const

{

  if (!mSpeechQueue.IsEmpty() &&

      mSpeechQueue.ElementAt(0)->GetState() == SpeechSynthesisUtterance::STATE_SPEAKING) {

    return true;

  }

  // Returns global speaking state if global queue is enabled. Or false.

  return nsSynthVoiceRegistry::GetInstance()->IsSpeaking();

}

bool

SpeechSynthesis::Paused() const

{

  return mHoldQueue || (mCurrentTask && mCurrentTask->IsPrePaused()) ||

         (!mSpeechQueue.IsEmpty() && mSpeechQueue.ElementAt(0)->IsPaused());

}

bool

SpeechSynthesis::HasEmptyQueue() const

{

  return mSpeechQueue.Length() == 0;

}

bool SpeechSynthesis::HasVoices() const

{

  uint32_t voiceCount = mVoiceCache.Count();

  if (voiceCount == 0) {

    nsresult rv = nsSynthVoiceRegistry::GetInstance()->GetVoiceCount(&voiceCount);

    if(NS_WARN_IF(NS_FAILED(rv))) {

      return false;

    }

  }

  return voiceCount != 0;

}

void

SpeechSynthesis::Speak(SpeechSynthesisUtterance& aUtterance)

{

  if (!mInnerID) {

    return;

  }

  if (aUtterance.mState != SpeechSynthesisUtterance::STATE_NONE) {

    // XXX: Should probably raise an error

    return;

  }

  mSpeechQueue.AppendElement(&aUtterance);

  aUtterance.mState = SpeechSynthesisUtterance::STATE_PENDING;

  // If we only have one item in the queue, we aren't pre-paused, and

  // we have voices available, speak it.

  if (mSpeechQueue.Length() == 1 && !mCurrentTask && !mHoldQueue && HasVoices()) {

    AdvanceQueue();

  }

}

void

SpeechSynthesis::AdvanceQueue()

{

  LOG(LogLevel::Debug,

      ("SpeechSynthesis::AdvanceQueue length=%zu", mSpeechQueue.Length()));

  if (mSpeechQueue.IsEmpty()) {

    return;

  }

  RefPtr<SpeechSynthesisUtterance> utterance = mSpeechQueue.ElementAt(0);

  nsAutoString docLang;

  nsCOMPtr<nsPIDOMWindowInner> window = GetOwner();

  nsIDocument* doc = window ? window->GetExtantDoc() : nullptr;

  if (doc) {

    Element* elm = doc->GetHtmlElement();

    if (elm) {

      elm->GetLang(docLang);

    }

  }

  mCurrentTask =

    nsSynthVoiceRegistry::GetInstance()->SpeakUtterance(*utterance, docLang);

  if (mCurrentTask) {

    mCurrentTask->SetSpeechSynthesis(this);

  }

}

void

SpeechSynthesis::Cancel()

{

  if (!mSpeechQueue.IsEmpty() &&

      mSpeechQueue.ElementAt(0)->GetState() == SpeechSynthesisUtterance::STATE_SPEAKING) {

    // Remove all queued utterances except for current one, we will remove it

    // in OnEnd

    mSpeechQueue.RemoveElementsAt(1, mSpeechQueue.Length() - 1);

  } else {

    mSpeechQueue.Clear();

  }

  if (mCurrentTask) {

    mCurrentTask->Cancel();

  }

}

void

SpeechSynthesis::Pause()

{

  if (Paused()) {

    return;

  }

  if (mCurrentTask && !mSpeechQueue.IsEmpty() &&

      mSpeechQueue.ElementAt(0)->GetState() == SpeechSynthesisUtterance::STATE_SPEAKING) {

    mCurrentTask->Pause();

  } else {

    mHoldQueue = true;

  }

}

void

SpeechSynthesis::Resume()

{

  if (!Paused()) {

    return;

  }

  mHoldQueue = false;

  if (mCurrentTask) {

    mCurrentTask->Resume();

  } else {

    AdvanceQueue();

  }

}

void

SpeechSynthesis::OnEnd(const nsSpeechTask* aTask)

{

  MOZ_ASSERT(mCurrentTask == aTask);

  if (!mSpeechQueue.IsEmpty()) {

    mSpeechQueue.RemoveElementAt(0);

  }

  mCurrentTask = nullptr;

  AdvanceQueue();

}

void

SpeechSynthesis::GetVoices(nsTArray< RefPtr<SpeechSynthesisVoice> >& aResult)

{

  aResult.Clear();

  uint32_t voiceCount = 0;

  nsCOMPtr<nsPIDOMWindowInner> window = GetOwner();

  nsCOMPtr<nsIDocShell> docShell = window ? window->GetDocShell() : nullptr;

  if (nsContentUtils::ShouldResistFingerprinting(docShell)) {

    return;

  }

  nsresult rv = nsSynthVoiceRegistry::GetInstance()->GetVoiceCount(&voiceCount);

  if(NS_WARN_IF(NS_FAILED(rv))) {

    return;

  }

  nsISupports* voiceParent = NS_ISUPPORTS_CAST(nsIObserver*, this);

  for (uint32_t i = 0; i < voiceCount; i++) {

    nsAutoString uri;

    rv = nsSynthVoiceRegistry::GetInstance()->GetVoice(i, uri);

    if (NS_FAILED(rv)) {

      NS_WARNING("Failed to retrieve voice from registry");

      continue;

    }

    SpeechSynthesisVoice* voice = mVoiceCache.GetWeak(uri);

    if (!voice) {

      voice = new SpeechSynthesisVoice(voiceParent, uri);

    }

    aResult.AppendElement(voice);

  }

  mVoiceCache.Clear();

  for (uint32_t i = 0; i < aResult.Length(); i++) {

    SpeechSynthesisVoice* voice = aResult[i];

    mVoiceCache.Put(voice->mUri, voice);

  }

}

// For testing purposes, allows us to cancel the current task that is

// misbehaving, and flush the queue.

void

SpeechSynthesis::ForceEnd()

{

  if (mCurrentTask) {

    mCurrentTask->ForceEnd();

  }

}

NS_IMETHODIMP

SpeechSynthesis::Observe(nsISupports* aSubject, const char* aTopic,

                         const char16_t* aData)

{

  MOZ_ASSERT(NS_IsMainThread());

  if (strcmp(aTopic, "inner-window-destroyed") == 0) {

    nsCOMPtr<nsISupportsPRUint64> wrapper = do_QueryInterface(aSubject);

    NS_ENSURE_TRUE(wrapper, NS_ERROR_FAILURE);

    uint64_t innerID;

    nsresult rv = wrapper->GetData(&innerID);

    NS_ENSURE_SUCCESS(rv, rv);

    if (innerID == mInnerID) {

      mInnerID = 0;

      Cancel();

      nsCOMPtr<nsIObserverService> obs = mozilla::services::GetObserverService();

      if (obs) {

        obs->RemoveObserver(this, "inner-window-destroyed");

      }

    }

  } else if (strcmp(aTopic, "synth-voices-changed") == 0) {

    LOG(LogLevel::Debug, ("SpeechSynthesis::onvoiceschanged"));

    nsCOMPtr<nsPIDOMWindowInner> window = GetOwner();

    nsCOMPtr<nsIDocShell> docShell = window ? window->GetDocShell() : nullptr;

    if (!nsContentUtils::ShouldResistFingerprinting(docShell)) {

      DispatchTrustedEvent(NS_LITERAL_STRING("voiceschanged"));

      // If we have a pending item, and voices become available, speak it.

      if (!mCurrentTask && !mHoldQueue && HasVoices()) {

        AdvanceQueue();

      }

    }

  }

  return NS_OK;

}

} // namespace dom

} // namespace mozilla