/* -*- 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 "BroadcastChannelService.h"

#include "BroadcastChannelParent.h"

#include "mozilla/dom/File.h"

#include "mozilla/dom/IPCBlobUtils.h"

#include "mozilla/ipc/BackgroundParent.h"

#ifdef XP_WIN

#undef PostMessage

#endif

namespace mozilla {

using namespace ipc;

namespace dom {

namespace {

BroadcastChannelService* sInstance = nullptr;

} // namespace

BroadcastChannelService::BroadcastChannelService()

{

  AssertIsOnBackgroundThread();

  // sInstance is a raw BroadcastChannelService*.

  MOZ_ASSERT(!sInstance);

  sInstance = this;

}

BroadcastChannelService::~BroadcastChannelService()

{

  AssertIsOnBackgroundThread();

  MOZ_ASSERT(sInstance == this);

  MOZ_ASSERT(mAgents.Count() == 0);

  sInstance = nullptr;

}

// static

already_AddRefed<BroadcastChannelService>

BroadcastChannelService::GetOrCreate()

{

  AssertIsOnBackgroundThread();

  RefPtr<BroadcastChannelService> instance = sInstance;

  if (!instance) {

    instance = new BroadcastChannelService();

  }

  return instance.forget();

}

void

BroadcastChannelService::RegisterActor(BroadcastChannelParent* aParent,

                                       const nsAString& aOriginChannelKey)

{

  AssertIsOnBackgroundThread();

  MOZ_ASSERT(aParent);

  nsTArray<BroadcastChannelParent*>* parents =

    mAgents.LookupForAdd(aOriginChannelKey).OrInsert(

      [] () { return new nsTArray<BroadcastChannelParent*>(); });

  MOZ_ASSERT(!parents->Contains(aParent));

  parents->AppendElement(aParent);

}

void

BroadcastChannelService::UnregisterActor(BroadcastChannelParent* aParent,

                                         const nsAString& aOriginChannelKey)

{

  AssertIsOnBackgroundThread();

  MOZ_ASSERT(aParent);

  if (auto entry = mAgents.Lookup(aOriginChannelKey)) {

    entry.Data()->RemoveElement(aParent);

    // remove the entry if the array is now empty

    if (entry.Data()->IsEmpty()) {

      entry.Remove();

    }

  } else {

    MOZ_CRASH("Invalid state");

  }

}

void

BroadcastChannelService::PostMessage(BroadcastChannelParent* aParent,

                                     const ClonedMessageData& aData,

                                     const nsAString& aOriginChannelKey)

{

  AssertIsOnBackgroundThread();

  MOZ_ASSERT(aParent);

  nsTArray<BroadcastChannelParent*>* parents;

  if (!mAgents.Get(aOriginChannelKey, &parents)) {

    MOZ_CRASH("Invalid state");

  }

  // We need to keep the array alive for the life-time of this operation.

  nsTArray<RefPtr<BlobImpl>> blobImpls;

  if (!aData.blobs().IsEmpty()) {

    blobImpls.SetCapacity(aData.blobs().Length());

    for (uint32_t i = 0, len = aData.blobs().Length(); i < len; ++i) {

      RefPtr<BlobImpl> impl = IPCBlobUtils::Deserialize(aData.blobs()[i]);

      MOZ_ASSERT(impl);

      blobImpls.AppendElement(impl);

    }

  }

  // For each parent actor, we notify the message.

  for (uint32_t i = 0; i < parents->Length(); ++i) {

    BroadcastChannelParent* parent = parents->ElementAt(i);

    MOZ_ASSERT(parent);

    if (parent == aParent) {

      continue;

    }

    // We need to have a copy of the data for this parent.

    ClonedMessageData newData(aData);

    MOZ_ASSERT(blobImpls.Length() == newData.blobs().Length());

    if (!blobImpls.IsEmpty()) {

      // Serialize Blob objects for this message.

      for (uint32_t i = 0, len = blobImpls.Length(); i < len; ++i) {

        nsresult rv = IPCBlobUtils::Serialize(blobImpls[i], parent->Manager(),

                                              newData.blobs()[i]);

        if (NS_WARN_IF(NS_FAILED(rv))) {

          return;

        }

      }

    }

    Unused << parent->SendNotify(newData);

  }

}

} // namespace dom

} // namespace mozilla