/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set sw=2 ts=2 et 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/layers/CompositorChild.h"
#include <stddef.h>                     // for size_t
#include "ClientLayerManager.h"         // for ClientLayerManager
#include "base/message_loop.h"          // for MessageLoop
#include "base/process_util.h"          // for OpenProcessHandle
#include "base/task.h"                  // for NewRunnableMethod, etc
#include "base/tracked.h"               // for FROM_HERE
#include "mozilla/layers/LayerTransactionChild.h"
#include "mozilla/layers/PLayerTransactionChild.h"
#include "mozilla/mozalloc.h"           // for operator new, etc
#include "nsDebug.h"                    // for NS_RUNTIMEABORT
#include "nsIObserver.h"                // for nsIObserver
#include "nsISupportsImpl.h"            // for MOZ_COUNT_CTOR, etc
#include "nsTArray.h"                   // for nsTArray, nsTArray_Impl
#include "nsXULAppAPI.h"                // for XRE_GetIOMessageLoop, etc
#include "FrameLayerBuilder.h"
#include "mozilla/dom/TabChild.h"
#include "mozilla/unused.h"
#include "mozilla/DebugOnly.h"
#if defined(XP_WIN)
#include "WinUtils.h"
#endif

using mozilla::layers::LayerTransactionChild;
using mozilla::dom::TabChildBase;
using mozilla::unused;

namespace mozilla {
namespace layers {

/*static*/ CompositorChild* CompositorChild::sCompositor;

Atomic<int32_t> CompositableForwarder::sSerialCounter(0);

CompositorChild::CompositorChild(ClientLayerManager *aLayerManager)
  : mLayerManager(aLayerManager)
{
}

CompositorChild::~CompositorChild()
{
}

void
CompositorChild::Destroy()
{
  mLayerManager->Destroy();
  mLayerManager = nullptr;
  // start from the end of the array because Destroy() can cause the
  // LayerTransactionChild to be removed from the array.
  for (int i = ManagedPLayerTransactionChild().Length() - 1; i >= 0; --i) {
    RefPtr<LayerTransactionChild> layers =
      static_cast<LayerTransactionChild*>(ManagedPLayerTransactionChild()[i]);
    layers->Destroy();
  }
  SendStop();
}

bool
CompositorChild::LookupCompositorFrameMetrics(const FrameMetrics::ViewID aId,
                                              FrameMetrics& aFrame)
{
  SharedFrameMetricsData* data = mFrameMetricsTable.Get(aId);
  if (data) {
    data->CopyFrameMetrics(&aFrame);
    return true;
  }
  return false;
}

/*static*/ PCompositorChild*
CompositorChild::Create(Transport* aTransport, ProcessId aOtherProcess)
{
  // There's only one compositor per child process.
  MOZ_ASSERT(!sCompositor);

  nsRefPtr<CompositorChild> child(new CompositorChild(nullptr));
  ProcessHandle handle;
  if (!base::OpenProcessHandle(aOtherProcess, &handle)) {
    // We can't go on without a compositor.
    NS_RUNTIMEABORT("Couldn't OpenProcessHandle() to parent process.");
    return nullptr;
  }
  if (!child->Open(aTransport, handle, XRE_GetIOMessageLoop(), ipc::ChildSide)) {
    NS_RUNTIMEABORT("Couldn't Open() Compositor channel.");
    return nullptr;
  }

  // We release this ref in ActorDestroy().
  sCompositor = child.forget().take();

  int32_t width;
  int32_t height;
  sCompositor->SendGetTileSize(&width, &height);
  gfxPlatform::GetPlatform()->SetTileSize(width, height);

  // We release this ref in ActorDestroy().
  return sCompositor;
}

/*static*/ CompositorChild*
CompositorChild::Get()
{
  // This is only expected to be used in child processes.
  MOZ_ASSERT(XRE_GetProcessType() != GeckoProcessType_Default);
  return sCompositor;
}

PLayerTransactionChild*
CompositorChild::AllocPLayerTransactionChild(const nsTArray<LayersBackend>& aBackendHints,
                                             const uint64_t& aId,
                                             TextureFactoryIdentifier*,
                                             bool*)
{
  LayerTransactionChild* c = new LayerTransactionChild();
  c->AddIPDLReference();
  return c;
}

bool
CompositorChild::DeallocPLayerTransactionChild(PLayerTransactionChild* actor)
{
  static_cast<LayerTransactionChild*>(actor)->ReleaseIPDLReference();
  return true;
}

bool
CompositorChild::RecvInvalidateAll()
{
  if (mLayerManager) {
    FrameLayerBuilder::InvalidateAllLayers(mLayerManager);
  }
  return true;
}

#if defined(XP_WIN) || defined(MOZ_WIDGET_GTK)
static void CalculatePluginClip(const nsIntRect& aBounds,
                                const nsTArray<nsIntRect>& aPluginClipRects,
                                const nsIntPoint& aContentOffset,
                                const nsIntRegion& aParentLayerVisibleRegion,
                                nsTArray<nsIntRect>& aResult,
                                nsIntRect& aVisibleBounds,
                                bool& aPluginIsVisible)
{
  aPluginIsVisible = true;
  // aBounds (content origin)
  nsIntRegion contentVisibleRegion(aBounds);
  // aPluginClipRects (plugin widget origin)
  for (uint32_t idx = 0; idx < aPluginClipRects.Length(); idx++) {
    nsIntRect rect = aPluginClipRects[idx];
    // shift to content origin
    rect.MoveBy(aBounds.x, aBounds.y);
    contentVisibleRegion.AndWith(rect);
  }
  // apply layers clip (window origin)
  nsIntRegion region = aParentLayerVisibleRegion;
  region.MoveBy(-aContentOffset.x, -aContentOffset.y);
  contentVisibleRegion.AndWith(region);
  if (contentVisibleRegion.IsEmpty()) {
    aPluginIsVisible = false;
    return;
  }
  // shift to plugin widget origin
  contentVisibleRegion.MoveBy(-aBounds.x, -aBounds.y);
  nsIntRegionRectIterator iter(contentVisibleRegion);
  for (const nsIntRect* rgnRect = iter.Next(); rgnRect; rgnRect = iter.Next()) {
    aResult.AppendElement(*rgnRect);
    aVisibleBounds.UnionRect(aVisibleBounds, *rgnRect);
  }
}
#endif

bool
CompositorChild::RecvUpdatePluginConfigurations(const nsIntPoint& aContentOffset,
                                                const nsIntRegion& aParentLayerVisibleRegion,
                                                nsTArray<PluginWindowData>&& aPlugins)
{
#if !defined(XP_WIN) && !defined(MOZ_WIDGET_GTK)
  NS_NOTREACHED("CompositorChild::RecvUpdatePluginConfigurations calls "
                "unexpected on this platform.");
  return false;
#else
  // Now that we are on the main thread, update plugin widget config.
  // This should happen a little before we paint to the screen assuming
  // the main thread is running freely.
  DebugOnly<nsresult> rv;
  MOZ_ASSERT(NS_IsMainThread());

  // Tracks visible plugins we update, so we can hide any plugins we don't.
  nsTArray<uintptr_t> visiblePluginIds;

  for (uint32_t pluginsIdx = 0; pluginsIdx < aPlugins.Length(); pluginsIdx++) {
    nsIWidget* widget = nsIWidget::LookupRegisteredPluginWindow(aPlugins[pluginsIdx].windowId());
    bool isVisible = aPlugins[pluginsIdx].visible();
    if (widget && !widget->Destroyed()) {
      nsIntRect bounds;
      nsIntRect visibleBounds;
      // If the plugin is visible update it's geometry.
      if (isVisible) {
        // bounds (content origin) - don't pass true to Resize, it triggers a
        // sync paint update to the plugin process on Windows, which happens
        // prior to clipping information being applied.
        bounds = aPlugins[pluginsIdx].bounds();
        rv = widget->Resize(aContentOffset.x + bounds.x,
                            aContentOffset.y + bounds.y,
                            bounds.width, bounds.height, false);
        NS_ASSERTION(NS_SUCCEEDED(rv), "widget call failure");
        nsTArray<nsIntRect> rectsOut;
        CalculatePluginClip(bounds, aPlugins[pluginsIdx].clip(),
                            aContentOffset, aParentLayerVisibleRegion,
                            rectsOut, visibleBounds, isVisible);
        if (isVisible) {
          // content clipping region (widget origin)
          rv = widget->SetWindowClipRegion(rectsOut, false);
          NS_ASSERTION(NS_SUCCEEDED(rv), "widget call failure");
        }
      }

      // visible state - updated after clipping, prior to invalidating
      rv = widget->Show(isVisible);
      NS_ASSERTION(NS_SUCCEEDED(rv), "widget call failure");

      // Handle invalidation, this can be costly, avoid if it is not needed.
      if (isVisible) {
        // invalidate region (widget origin)
        nsIntRect bounds = aPlugins[pluginsIdx].bounds();
        nsIntRect rect(0, 0, bounds.width, bounds.height);
#if defined(XP_WIN)
        // Work around for flash's crummy sandbox. See bug 762948. This call
        // digs down into the window hirearchy, invalidating regions on
        // windows owned by other processes.
        mozilla::widget::WinUtils::InvalidatePluginAsWorkaround(widget, visibleBounds);
#else
        rv = widget->Invalidate(visibleBounds);
        NS_ASSERTION(NS_SUCCEEDED(rv), "widget call failure");
#endif
        visiblePluginIds.AppendElement(aPlugins[pluginsIdx].windowId());
      }
    }
  }
  // Any plugins we didn't update need to be hidden, as they are
  // not associated with visible content.
  nsIWidget::UpdateRegisteredPluginWindowVisibility(visiblePluginIds);
  return true;
#endif // !defined(XP_WIN) && !defined(MOZ_WIDGET_GTK)
}

bool
CompositorChild::RecvDidComposite(const uint64_t& aId, const uint64_t& aTransactionId)
{
  if (mLayerManager) {
    MOZ_ASSERT(aId == 0);
    mLayerManager->DidComposite(aTransactionId);
  } else if (aId != 0) {
    dom::TabChild *child = dom::TabChild::GetFrom(aId);
    if (child) {
      child->DidComposite(aTransactionId);
    }
  }
  return true;
}

bool
CompositorChild::RecvOverfill(const uint32_t &aOverfill)
{
  for (size_t i = 0; i < mOverfillObservers.Length(); i++) {
    mOverfillObservers[i]->RunOverfillCallback(aOverfill);
  }
  mOverfillObservers.Clear();
  return true;
}

void
CompositorChild::AddOverfillObserver(ClientLayerManager* aLayerManager)
{
  MOZ_ASSERT(aLayerManager);
  mOverfillObservers.AppendElement(aLayerManager);
}

void
CompositorChild::ActorDestroy(ActorDestroyReason aWhy)
{
  MOZ_ASSERT(sCompositor == this);

#ifdef MOZ_B2G
  // Due to poor lifetime management of gralloc (and possibly shmems) we will
  // crash at some point in the future when we get destroyed due to abnormal
  // shutdown. Its better just to crash here. On desktop though, we have a chance
  // of recovering.
  if (aWhy == AbnormalShutdown) {
    NS_RUNTIMEABORT("ActorDestroy by IPC channel failure at CompositorChild");
  }
#endif
  if (sCompositor) {
    sCompositor->Release();
    sCompositor = nullptr;
  }
  // We don't want to release the ref to sCompositor here, during
  // cleanup, because that will cause it to be deleted while it's
  // still being used.  So defer the deletion to after it's not in
  // use.
  MessageLoop::current()->PostTask(
    FROM_HERE,
    NewRunnableMethod(this, &CompositorChild::Release));
}

bool
CompositorChild::RecvSharedCompositorFrameMetrics(
    const mozilla::ipc::SharedMemoryBasic::Handle& metrics,
    const CrossProcessMutexHandle& handle,
    const uint32_t& aAPZCId)
{
  SharedFrameMetricsData* data = new SharedFrameMetricsData(metrics, handle, aAPZCId);
  mFrameMetricsTable.Put(data->GetViewID(), data);
  return true;
}

bool
CompositorChild::RecvReleaseSharedCompositorFrameMetrics(
    const ViewID& aId,
    const uint32_t& aAPZCId)
{
  SharedFrameMetricsData* data = mFrameMetricsTable.Get(aId);
  // The SharedFrameMetricsData may have been removed previously if
  // a SharedFrameMetricsData with the same ViewID but later APZCId had
  // been store and over wrote it.
  if (data && (data->GetAPZCId() == aAPZCId)) {
    mFrameMetricsTable.Remove(aId);
  }
  return true;
}

CompositorChild::SharedFrameMetricsData::SharedFrameMetricsData(
    const ipc::SharedMemoryBasic::Handle& metrics,
    const CrossProcessMutexHandle& handle,
    const uint32_t& aAPZCId) :
    mMutex(nullptr),
    mAPZCId(aAPZCId)
{
  mBuffer = new ipc::SharedMemoryBasic(metrics);
  mBuffer->Map(sizeof(FrameMetrics));
  mMutex = new CrossProcessMutex(handle);
  MOZ_COUNT_CTOR(SharedFrameMetricsData);
}

CompositorChild::SharedFrameMetricsData::~SharedFrameMetricsData()
{
  // When the hash table deletes the class, delete
  // the shared memory and mutex.
  delete mMutex;
  mBuffer = nullptr;
  MOZ_COUNT_DTOR(SharedFrameMetricsData);
}

void
CompositorChild::SharedFrameMetricsData::CopyFrameMetrics(FrameMetrics* aFrame)
{
  FrameMetrics* frame = static_cast<FrameMetrics*>(mBuffer->memory());
  MOZ_ASSERT(frame);
  mMutex->Lock();
  *aFrame = *frame;
  mMutex->Unlock();
}

FrameMetrics::ViewID
CompositorChild::SharedFrameMetricsData::GetViewID()
{
  FrameMetrics* frame = static_cast<FrameMetrics*>(mBuffer->memory());
  MOZ_ASSERT(frame);
  // Not locking to read of mScrollId since it should not change after being
  // initially set.
  return frame->GetScrollId();
}

uint32_t
CompositorChild::SharedFrameMetricsData::GetAPZCId()
{
  return mAPZCId;
}


bool
CompositorChild::RecvRemotePaintIsReady()
{
  // Used on the content thread, this bounces the message to the
  // TabParent (via the TabChild) if the notification was previously requested.
  // XPCOM gives a soup of compiler errors when trying to do_QueryReference
  // so I'm using static_cast<>
  MOZ_LAYERS_LOG(("[RemoteGfx] CompositorChild received RemotePaintIsReady"));
  nsRefPtr<nsISupports> iTabChildBase(do_QueryReferent(mWeakTabChild));
  if (!iTabChildBase) {
    MOZ_LAYERS_LOG(("[RemoteGfx] Note: TabChild was released before RemotePaintIsReady. "
        "MozAfterRemotePaint will not be sent to listener."));
    return true;
  }
  TabChildBase* tabChildBase = static_cast<TabChildBase*>(iTabChildBase.get());
  TabChild* tabChild = static_cast<TabChild*>(tabChildBase);
  MOZ_ASSERT(tabChild);
  unused << tabChild->SendRemotePaintIsReady();
  mWeakTabChild = nullptr;
  return true;
}


void
CompositorChild::RequestNotifyAfterRemotePaint(TabChild* aTabChild)
{
  MOZ_ASSERT(aTabChild, "NULL TabChild not allowed in CompositorChild::RequestNotifyAfterRemotePaint");
  mWeakTabChild = do_GetWeakReference( static_cast<dom::TabChildBase*>(aTabChild) );
  unused << SendRequestNotifyAfterRemotePaint();
}

void
CompositorChild::CancelNotifyAfterRemotePaint(TabChild* aTabChild)
{
  nsRefPtr<nsISupports> iTabChildBase(do_QueryReferent(mWeakTabChild));
  if (!iTabChildBase) {
    return;
  }
  TabChildBase* tabChildBase = static_cast<TabChildBase*>(iTabChildBase.get());
  TabChild* tabChild = static_cast<TabChild*>(tabChildBase);
  if (tabChild == aTabChild) {
    mWeakTabChild = nullptr;
  }
}

} // namespace layers
} // namespace mozilla