/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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 "mozilla/dom/MediaKeys.h"
#include "GMPService.h"
#include "mozilla/dom/HTMLMediaElement.h"
#include "mozilla/dom/MediaKeysBinding.h"
#include "mozilla/dom/MediaKeyMessageEvent.h"
#include "mozilla/dom/MediaKeyError.h"
#include "mozilla/dom/MediaKeySession.h"
#include "mozilla/dom/DOMException.h"
#include "mozilla/dom/UnionTypes.h"
#include "mozilla/Telemetry.h"
#include "GMPCDMProxy.h"
#include "mozilla/EMEUtils.h"
#include "nsContentUtils.h"
#include "nsIScriptObjectPrincipal.h"
#include "nsContentTypeParser.h"
#ifdef MOZ_FMP4
#include "MP4Decoder.h"
#endif
#ifdef XP_WIN
#include "mozilla/WindowsVersion.h"
#endif
#include "nsContentCID.h"
#include "nsServiceManagerUtils.h"
#include "mozilla/dom/MediaKeySystemAccess.h"
#include "nsPrintfCString.h"

namespace mozilla {

namespace dom {

NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(MediaKeys,
                                      mElement,
                                      mParent,
                                      mKeySessions,
                                      mPromises,
                                      mPendingSessions);
NS_IMPL_CYCLE_COLLECTING_ADDREF(MediaKeys)
NS_IMPL_CYCLE_COLLECTING_RELEASE(MediaKeys)
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(MediaKeys)
  NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
  NS_INTERFACE_MAP_ENTRY(nsISupports)
NS_INTERFACE_MAP_END

MediaKeys::MediaKeys(nsPIDOMWindowInner* aParent,
                     const nsAString& aKeySystem,
                     const nsAString& aCDMVersion,
                     bool aDistinctiveIdentifierRequired,
                     bool aPersistentStateRequired)
  : mParent(aParent)
  , mKeySystem(aKeySystem)
  , mCDMVersion(aCDMVersion)
  , mCreatePromiseId(0)
  , mDistinctiveIdentifierRequired(aDistinctiveIdentifierRequired)
  , mPersistentStateRequired(aPersistentStateRequired)
{
  EME_LOG("MediaKeys[%p] constructed keySystem=%s",
          this, NS_ConvertUTF16toUTF8(mKeySystem).get());
}

MediaKeys::~MediaKeys()
{
  Shutdown();
  EME_LOG("MediaKeys[%p] destroyed", this);
}

void
MediaKeys::Terminated()
{
  EME_LOG("MediaKeys[%p] CDM crashed unexpectedly", this);

  KeySessionHashMap keySessions;
  // Remove entries during iteration will screw it. Make a copy first.
  for (auto iter = mKeySessions.Iter(); !iter.Done(); iter.Next()) {
    RefPtr<MediaKeySession>& session = iter.Data();
    keySessions.Put(session->GetSessionId(), session);
  }
  for (auto iter = keySessions.Iter(); !iter.Done(); iter.Next()) {
    RefPtr<MediaKeySession>& session = iter.Data();
    session->OnClosed();
  }
  keySessions.Clear();
  MOZ_ASSERT(mKeySessions.Count() == 0);

  // Notify the element about that CDM has terminated.
  if (mElement) {
    mElement->DecodeError(NS_ERROR_DOM_MEDIA_CDM_ERR);
  }

  Shutdown();
}

void
MediaKeys::Shutdown()
{
  if (mProxy) {
    mProxy->Shutdown();
    mProxy = nullptr;
  }

  RefPtr<MediaKeys> kungFuDeathGrip = this;

  for (auto iter = mPromises.Iter(); !iter.Done(); iter.Next()) {
    RefPtr<dom::DetailedPromise>& promise = iter.Data();
    promise->MaybeReject(NS_ERROR_DOM_INVALID_STATE_ERR,
                         NS_LITERAL_CSTRING("Promise still outstanding at MediaKeys shutdown"));
    Release();
  }
  mPromises.Clear();
}

nsPIDOMWindowInner*
MediaKeys::GetParentObject() const
{
  return mParent;
}

JSObject*
MediaKeys::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
{
  return MediaKeysBinding::Wrap(aCx, this, aGivenProto);
}

void
MediaKeys::GetKeySystem(nsString& aOutKeySystem) const
{
  aOutKeySystem.Assign(mKeySystem);
}

already_AddRefed<DetailedPromise>
MediaKeys::SetServerCertificate(const ArrayBufferViewOrArrayBuffer& aCert, ErrorResult& aRv)
{
  RefPtr<DetailedPromise> promise(MakePromise(aRv,
    NS_LITERAL_CSTRING("MediaKeys.setServerCertificate")));
  if (aRv.Failed()) {
    return nullptr;
  }

  if (!mProxy) {
    NS_WARNING("Tried to use a MediaKeys without a CDM");
    promise->MaybeReject(NS_ERROR_DOM_INVALID_STATE_ERR,
                         NS_LITERAL_CSTRING("Null CDM in MediaKeys.setServerCertificate()"));
    return promise.forget();
  }

  nsTArray<uint8_t> data;
  CopyArrayBufferViewOrArrayBufferData(aCert, data);
  if (data.IsEmpty()) {
    promise->MaybeReject(NS_ERROR_DOM_TYPE_ERR,
      NS_LITERAL_CSTRING("Empty certificate passed to MediaKeys.setServerCertificate()"));
    return promise.forget();
  }

  mProxy->SetServerCertificate(StorePromise(promise), data);
  return promise.forget();
}

already_AddRefed<DetailedPromise>
MediaKeys::MakePromise(ErrorResult& aRv, const nsACString& aName)
{
  nsCOMPtr<nsIGlobalObject> global = do_QueryInterface(GetParentObject());
  if (!global) {
    NS_WARNING("Passed non-global to MediaKeys ctor!");
    aRv.Throw(NS_ERROR_UNEXPECTED);
    return nullptr;
  }
  return DetailedPromise::Create(global, aRv, aName);
}

PromiseId
MediaKeys::StorePromise(DetailedPromise* aPromise)
{
  static uint32_t sEMEPromiseCount = 1;
  MOZ_ASSERT(aPromise);
  uint32_t id = sEMEPromiseCount++;

  EME_LOG("MediaKeys[%p]::StorePromise() id=%d", this, id);

  // Keep MediaKeys alive for the lifetime of its promises. Any still-pending
  // promises are rejected in Shutdown().
  AddRef();

#ifdef DEBUG
  // We should not have already stored this promise!
  for (auto iter = mPromises.ConstIter(); !iter.Done(); iter.Next()) {
    MOZ_ASSERT(iter.Data() != aPromise);
  }
#endif

  mPromises.Put(id, aPromise);
  return id;
}

already_AddRefed<DetailedPromise>
MediaKeys::RetrievePromise(PromiseId aId)
{
  if (!mPromises.Contains(aId)) {
    NS_WARNING(nsPrintfCString("Tried to retrieve a non-existent promise id=%d", aId).get());
    return nullptr;
  }
  RefPtr<DetailedPromise> promise;
  mPromises.Remove(aId, getter_AddRefs(promise));
  Release();
  return promise.forget();
}

void
MediaKeys::RejectPromise(PromiseId aId, nsresult aExceptionCode,
                         const nsCString& aReason)
{
  EME_LOG("MediaKeys[%p]::RejectPromise(%d, 0x%x)", this, aId, aExceptionCode);

  RefPtr<DetailedPromise> promise(RetrievePromise(aId));
  if (!promise) {
    return;
  }
  if (mPendingSessions.Contains(aId)) {
    // This promise could be a createSession or loadSession promise,
    // so we might have a pending session waiting to be resolved into
    // the promise on success. We've been directed to reject to promise,
    // so we can throw away the corresponding session object.
    mPendingSessions.Remove(aId);
  }

  MOZ_ASSERT(NS_FAILED(aExceptionCode));
  promise->MaybeReject(aExceptionCode, aReason);

  if (mCreatePromiseId == aId) {
    // Note: This will probably destroy the MediaKeys object!
    Release();
  }
}

void
MediaKeys::OnSessionIdReady(MediaKeySession* aSession)
{
  if (!aSession) {
    NS_WARNING("Invalid MediaKeySession passed to OnSessionIdReady()");
    return;
  }
  if (mKeySessions.Contains(aSession->GetSessionId())) {
    NS_WARNING("MediaKeySession's made ready multiple times!");
    return;
  }
  if (mPendingSessions.Contains(aSession->Token())) {
    NS_WARNING("MediaKeySession made ready when it wasn't waiting to be ready!");
    return;
  }
  if (aSession->GetSessionId().IsEmpty()) {
    NS_WARNING("MediaKeySession with invalid sessionId passed to OnSessionIdReady()");
    return;
  }
  mKeySessions.Put(aSession->GetSessionId(), aSession);
}

void
MediaKeys::ResolvePromise(PromiseId aId)
{
  EME_LOG("MediaKeys[%p]::ResolvePromise(%d)", this, aId);

  RefPtr<DetailedPromise> promise(RetrievePromise(aId));
  if (!promise) {
    return;
  }
  if (mPendingSessions.Contains(aId)) {
    // We should only resolve LoadSession calls via this path,
    // not CreateSession() promises.
    RefPtr<MediaKeySession> session;
    if (!mPendingSessions.Get(aId, getter_AddRefs(session)) ||
        !session ||
        session->GetSessionId().IsEmpty()) {
      NS_WARNING("Received activation for non-existent session!");
      promise->MaybeReject(NS_ERROR_DOM_INVALID_ACCESS_ERR,
                           NS_LITERAL_CSTRING("CDM LoadSession() returned a different session ID than requested"));
      mPendingSessions.Remove(aId);
      return;
    }
    mPendingSessions.Remove(aId);
    mKeySessions.Put(session->GetSessionId(), session);
    promise->MaybeResolve(session);
  } else {
    promise->MaybeResolveWithUndefined();
  }
  MOZ_ASSERT(!mPromises.Contains(aId));
}

class MediaKeysGMPCrashHelper : public GMPCrashHelper
{
public:
  explicit MediaKeysGMPCrashHelper(MediaKeys* aMediaKeys)
    : mMediaKeys(aMediaKeys)
  {
    MOZ_ASSERT(NS_IsMainThread()); // WeakPtr isn't thread safe.
  }
  already_AddRefed<nsPIDOMWindowInner>
  GetPluginCrashedEventTarget() override
  {
    MOZ_ASSERT(NS_IsMainThread()); // WeakPtr isn't thread safe.
    EME_LOG("MediaKeysGMPCrashHelper::GetPluginCrashedEventTarget()");
    return (mMediaKeys && mMediaKeys->GetParentObject()) ?
      do_AddRef(mMediaKeys->GetParentObject()) : nullptr;
  }
private:
  WeakPtr<MediaKeys> mMediaKeys;
};

already_AddRefed<DetailedPromise>
MediaKeys::Init(ErrorResult& aRv)
{
  RefPtr<DetailedPromise> promise(MakePromise(aRv,
    NS_LITERAL_CSTRING("MediaKeys::Init()")));
  if (aRv.Failed()) {
    return nullptr;
  }

  mProxy = new GMPCDMProxy(this,
                           mKeySystem,
                           new MediaKeysGMPCrashHelper(this),
                           mDistinctiveIdentifierRequired,
                           mPersistentStateRequired);

  // Determine principal (at creation time) of the MediaKeys object.
  nsCOMPtr<nsIScriptObjectPrincipal> sop = do_QueryInterface(GetParentObject());
  if (!sop) {
    promise->MaybeReject(NS_ERROR_DOM_INVALID_STATE_ERR,
                         NS_LITERAL_CSTRING("Couldn't get script principal in MediaKeys::Init"));
    return promise.forget();
  }
  mPrincipal = sop->GetPrincipal();

  // Determine principal of the "top-level" window; the principal of the
  // page that will display in the URL bar.
  nsCOMPtr<nsPIDOMWindowInner> window = GetParentObject();
  if (!window) {
    promise->MaybeReject(NS_ERROR_DOM_INVALID_STATE_ERR,
                         NS_LITERAL_CSTRING("Couldn't get top-level window in MediaKeys::Init"));
    return promise.forget();
  }
  nsCOMPtr<nsPIDOMWindowOuter> top = window->GetOuterWindow()->GetTop();
  if (!top || !top->GetExtantDoc()) {
    promise->MaybeReject(NS_ERROR_DOM_INVALID_STATE_ERR,
                         NS_LITERAL_CSTRING("Couldn't get document in MediaKeys::Init"));
    return promise.forget();
  }

  mTopLevelPrincipal = top->GetExtantDoc()->NodePrincipal();

  if (!mPrincipal || !mTopLevelPrincipal) {
    NS_WARNING("Failed to get principals when creating MediaKeys");
    promise->MaybeReject(NS_ERROR_DOM_INVALID_STATE_ERR,
                         NS_LITERAL_CSTRING("Couldn't get principal(s) in MediaKeys::Init"));
    return promise.forget();
  }

  nsAutoCString origin;
  nsresult rv = mPrincipal->GetOrigin(origin);
  if (NS_FAILED(rv)) {
    promise->MaybeReject(NS_ERROR_DOM_INVALID_STATE_ERR,
                         NS_LITERAL_CSTRING("Couldn't get principal origin string in MediaKeys::Init"));
    return promise.forget();
  }
  nsAutoCString topLevelOrigin;
  rv = mTopLevelPrincipal->GetOrigin(topLevelOrigin);
  if (NS_FAILED(rv)) {
    promise->MaybeReject(NS_ERROR_DOM_INVALID_STATE_ERR,
                         NS_LITERAL_CSTRING("Couldn't get top-level principal origin string in MediaKeys::Init"));
    return promise.forget();
  }

  nsIDocument* doc = window->GetExtantDoc();
  const bool inPrivateBrowsing = nsContentUtils::IsInPrivateBrowsing(doc);

  EME_LOG("MediaKeys[%p]::Create() (%s, %s), %s",
          this,
          origin.get(),
          topLevelOrigin.get(),
          (inPrivateBrowsing ? "PrivateBrowsing" : "NonPrivateBrowsing"));

  // The CDMProxy's initialization is asynchronous. The MediaKeys is
  // refcounted, and its instance is returned to JS by promise once
  // it's been initialized. No external refs exist to the MediaKeys while
  // we're waiting for the promise to be resolved, so we must hold a
  // reference to the new MediaKeys object until it's been created,
  // or its creation has failed. Store the id of the promise returned
  // here, and hold a self-reference until that promise is resolved or
  // rejected.
  MOZ_ASSERT(!mCreatePromiseId, "Should only be created once!");
  mCreatePromiseId = StorePromise(promise);
  AddRef();
  mProxy->Init(mCreatePromiseId,
               NS_ConvertUTF8toUTF16(origin),
               NS_ConvertUTF8toUTF16(topLevelOrigin),
               KeySystemToGMPName(mKeySystem),
               inPrivateBrowsing);

  return promise.forget();
}

enum CDMCreatedType {
  eClearKey = 0,
  ePrimetime = 1,
  eWidevine = 2,
  eUnknown = 3
};

static CDMCreatedType
ToCDMCreatedTelemetryEnum(const nsString& aKeySystem)
{
  if (!CompareUTF8toUTF16(kEMEKeySystemWidevine, aKeySystem)) {
    return CDMCreatedType::eWidevine;
  } else if (!CompareUTF8toUTF16(kEMEKeySystemClearkey, aKeySystem)) {
    return CDMCreatedType::eClearKey;
  } else if (!CompareUTF8toUTF16(kEMEKeySystemPrimetime, aKeySystem)) {
    return CDMCreatedType::ePrimetime;
  }
  return CDMCreatedType::eUnknown;
}

void
MediaKeys::OnCDMCreated(PromiseId aId, const nsACString& aNodeId, const uint32_t aPluginId)
{
  RefPtr<DetailedPromise> promise(RetrievePromise(aId));
  if (!promise) {
    return;
  }
  mNodeId = aNodeId;
  RefPtr<MediaKeys> keys(this);
  EME_LOG("MediaKeys[%p]::OnCDMCreated() resolve promise id=%d", this, aId);
  promise->MaybeResolve(keys);
  if (mCreatePromiseId == aId) {
    Release();
  }

  MediaKeySystemAccess::NotifyObservers(mParent,
                                        mKeySystem,
                                        MediaKeySystemStatus::Cdm_created);

  Telemetry::Accumulate(Telemetry::VIDEO_CDM_CREATED, ToCDMCreatedTelemetryEnum(mKeySystem));
}

already_AddRefed<MediaKeySession>
MediaKeys::CreateSession(JSContext* aCx,
                         MediaKeySessionType aSessionType,
                         ErrorResult& aRv)
{
  if (!mProxy) {
    NS_WARNING("Tried to use a MediaKeys which lost its CDM");
    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
    return nullptr;
  }

  EME_LOG("MediaKeys[%p] Creating session", this);

  RefPtr<MediaKeySession> session = new MediaKeySession(aCx,
                                                          GetParentObject(),
                                                          this,
                                                          mKeySystem,
                                                          mCDMVersion,
                                                          aSessionType,
                                                          aRv);

  if (aRv.Failed()) {
    return nullptr;
  }

  // Add session to the set of sessions awaiting their sessionId being ready.
  mPendingSessions.Put(session->Token(), session);

  return session.forget();
}

void
MediaKeys::OnSessionLoaded(PromiseId aId, bool aSuccess)
{
  RefPtr<DetailedPromise> promise(RetrievePromise(aId));
  if (!promise) {
    return;
  }
  EME_LOG("MediaKeys[%p]::OnSessionLoaded() resolve promise id=%d", this, aId);

  promise->MaybeResolve(aSuccess);
}

void
MediaKeys::OnSessionClosed(MediaKeySession* aSession)
{
  nsAutoString id;
  aSession->GetSessionId(id);
  mKeySessions.Remove(id);
}

already_AddRefed<MediaKeySession>
MediaKeys::GetSession(const nsAString& aSessionId)
{
  RefPtr<MediaKeySession> session;
  mKeySessions.Get(aSessionId, getter_AddRefs(session));
  return session.forget();
}

already_AddRefed<MediaKeySession>
MediaKeys::GetPendingSession(uint32_t aToken)
{
  RefPtr<MediaKeySession> session;
  mPendingSessions.Get(aToken, getter_AddRefs(session));
  mPendingSessions.Remove(aToken);
  return session.forget();
}

const nsCString&
MediaKeys::GetNodeId() const
{
  MOZ_ASSERT(NS_IsMainThread());
  return mNodeId;
}

bool
MediaKeys::IsBoundToMediaElement() const
{
  MOZ_ASSERT(NS_IsMainThread());
  return mElement != nullptr;
}

nsresult
MediaKeys::Bind(HTMLMediaElement* aElement)
{
  MOZ_ASSERT(NS_IsMainThread());
  if (IsBoundToMediaElement()) {
    return NS_ERROR_FAILURE;
  }

  mElement = aElement;

  return NS_OK;
}

void
MediaKeys::Unbind()
{
  MOZ_ASSERT(NS_IsMainThread());
  mElement = nullptr;
}

} // namespace dom
} // namespace mozilla