/* -*- 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/DocGroup.h"

#include "mozilla/dom/HTMLSlotElement.h"

#include "mozilla/dom/HTMLSlotElementBinding.h"

#include "mozilla/dom/HTMLUnknownElement.h"

#include "mozilla/dom/ShadowRoot.h"

#include "nsGkAtoms.h"

#include "nsDocument.h"

nsGenericHTMLElement*

NS_NewHTMLSlotElement(already_AddRefed<mozilla::dom::NodeInfo>&& aNodeInfo,

                      mozilla::dom::FromParser aFromParser)

{

  RefPtr<mozilla::dom::NodeInfo> nodeInfo(std::move(aNodeInfo));

  if (nsDocument::IsShadowDOMEnabled(nodeInfo->GetDocument())) {

    return new mozilla::dom::HTMLSlotElement(nodeInfo.forget());

  }

  return new mozilla::dom::HTMLUnknownElement(nodeInfo.forget());

}

namespace mozilla {

namespace dom {

HTMLSlotElement::HTMLSlotElement(already_AddRefed<mozilla::dom::NodeInfo>&& aNodeInfo)

  : nsGenericHTMLElement(std::move(aNodeInfo))

{

}

HTMLSlotElement::~HTMLSlotElement() = default;

NS_IMPL_ADDREF_INHERITED(HTMLSlotElement, nsGenericHTMLElement)

NS_IMPL_RELEASE_INHERITED(HTMLSlotElement, nsGenericHTMLElement)

NS_IMPL_CYCLE_COLLECTION_INHERITED(HTMLSlotElement,

                                   nsGenericHTMLElement,

                                   mAssignedNodes)

NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(HTMLSlotElement)

NS_INTERFACE_MAP_END_INHERITING(nsGenericHTMLElement)

NS_IMPL_ELEMENT_CLONE(HTMLSlotElement)

nsresult

HTMLSlotElement::BindToTree(nsIDocument* aDocument,

                            nsIContent* aParent,

                            nsIContent* aBindingParent)

{

  RefPtr<ShadowRoot> oldContainingShadow = GetContainingShadow();

  nsresult rv = nsGenericHTMLElement::BindToTree(aDocument, aParent,

                                                 aBindingParent);

  NS_ENSURE_SUCCESS(rv, rv);

  ShadowRoot* containingShadow = GetContainingShadow();

  if (containingShadow && !oldContainingShadow) {

    containingShadow->AddSlot(this);

  }

  return NS_OK;

}

void

HTMLSlotElement::UnbindFromTree(bool aDeep, bool aNullParent)

{

  RefPtr<ShadowRoot> oldContainingShadow = GetContainingShadow();

  nsGenericHTMLElement::UnbindFromTree(aDeep, aNullParent);

  if (oldContainingShadow && !GetContainingShadow()) {

    oldContainingShadow->RemoveSlot(this);

  }

}

nsresult

HTMLSlotElement::BeforeSetAttr(int32_t aNameSpaceID, nsAtom* aName,

                               const nsAttrValueOrString* aValue,

                               bool aNotify)

{

  if (aNameSpaceID == kNameSpaceID_None && aName == nsGkAtoms::name) {

    if (ShadowRoot* containingShadow = GetContainingShadow()) {

      containingShadow->RemoveSlot(this);

    }

  }

  return nsGenericHTMLElement::BeforeSetAttr(aNameSpaceID, aName, aValue,

                                             aNotify);

}

nsresult

HTMLSlotElement::AfterSetAttr(int32_t aNameSpaceID, nsAtom* aName,

                              const nsAttrValue* aValue,

                              const nsAttrValue* aOldValue,

                              nsIPrincipal* aSubjectPrincipal,

                              bool aNotify)

{

  if (aNameSpaceID == kNameSpaceID_None && aName == nsGkAtoms::name) {

    if (ShadowRoot* containingShadow = GetContainingShadow()) {

      containingShadow->AddSlot(this);

    }

  }

  return nsGenericHTMLElement::AfterSetAttr(aNameSpaceID, aName, aValue,

                                            aOldValue, aSubjectPrincipal,

                                            aNotify);

}

/**

 * Flatten assigned nodes given a slot, as in:

 * https://dom.spec.whatwg.org/#find-flattened-slotables

 */

static void

FlattenAssignedNodes(HTMLSlotElement* aSlot, nsTArray<RefPtr<nsINode>>& aNodes)

{

  if (!aSlot->GetContainingShadow()) {

    return;

  }

  const nsTArray<RefPtr<nsINode>>& assignedNodes = aSlot->AssignedNodes();

  // If assignedNodes is empty, use children of slot as fallback content.

  if (assignedNodes.IsEmpty()) {

    for (nsIContent* child = aSlot->GetFirstChild();

         child;

         child = child->GetNextSibling()) {

      if (!child->IsSlotable()) {

        continue;

      }

      if (auto* slot = HTMLSlotElement::FromNode(child)) {

        FlattenAssignedNodes(slot, aNodes);

      } else {

        aNodes.AppendElement(child);

      }

    }

    return;

  }

  for (const RefPtr<nsINode>& assignedNode : assignedNodes) {

    if (auto* slot = HTMLSlotElement::FromNode(assignedNode)) {

      FlattenAssignedNodes(slot, aNodes);

    } else {

      aNodes.AppendElement(assignedNode);

    }

  }

}

void

HTMLSlotElement::AssignedNodes(const AssignedNodesOptions& aOptions,

                               nsTArray<RefPtr<nsINode>>& aNodes)

{

  if (aOptions.mFlatten) {

    return FlattenAssignedNodes(this, aNodes);

  }

  aNodes = mAssignedNodes;

}

const nsTArray<RefPtr<nsINode>>&

HTMLSlotElement::AssignedNodes() const

{

  return mAssignedNodes;

}

void

HTMLSlotElement::InsertAssignedNode(uint32_t aIndex, nsINode* aNode)

{

  MOZ_ASSERT(!aNode->AsContent()->GetAssignedSlot(), "Losing track of a slot");

  mAssignedNodes.InsertElementAt(aIndex, aNode);

  aNode->AsContent()->SetAssignedSlot(this);

}

void

HTMLSlotElement::AppendAssignedNode(nsINode* aNode)

{

  MOZ_ASSERT(!aNode->AsContent()->GetAssignedSlot(), "Losing track of a slot");

  mAssignedNodes.AppendElement(aNode);

  aNode->AsContent()->SetAssignedSlot(this);

}

void

HTMLSlotElement::RemoveAssignedNode(nsINode* aNode)

{

  // This one runs from unlinking, so we can't guarantee that the slot pointer

  // hasn't been cleared.

  MOZ_ASSERT(!aNode->AsContent()->GetAssignedSlot() ||

             aNode->AsContent()->GetAssignedSlot() == this, "How exactly?");

  mAssignedNodes.RemoveElement(aNode);

  aNode->AsContent()->SetAssignedSlot(nullptr);

}

void

HTMLSlotElement::ClearAssignedNodes()

{

  for (RefPtr<nsINode>& node : mAssignedNodes) {

    MOZ_ASSERT(!node->AsContent()->GetAssignedSlot() ||

               node->AsContent()->GetAssignedSlot() == this, "How exactly?");

    node->AsContent()->SetAssignedSlot(nullptr);

  }

  mAssignedNodes.Clear();

}

void

HTMLSlotElement::EnqueueSlotChangeEvent()

{

  if (mInSignalSlotList) {

    return;

  }

  // FIXME(bug 1459704): Need to figure out how to deal with microtasks posted

  // during shutdown.

  if (gXPCOMThreadsShutDown) {

    return;

  }

  DocGroup* docGroup = OwnerDoc()->GetDocGroup();

  if (!docGroup) {

    return;

  }

  mInSignalSlotList = true;

  docGroup->SignalSlotChange(*this);

}

void

HTMLSlotElement::FireSlotChangeEvent()

{

  nsContentUtils::DispatchTrustedEvent(OwnerDoc(),

                                       static_cast<nsIContent*>(this),

                                       NS_LITERAL_STRING("slotchange"),

                                       CanBubble::eYes,

                                       Cancelable::eNo);

}

JSObject*

HTMLSlotElement::WrapNode(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)

{

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

}

} // namespace dom

} // namespace mozilla