/* -*- 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 "DocumentOrShadowRoot.h"
#include "mozilla/EventStateManager.h"
#include "mozilla/dom/HTMLInputElement.h"
#include "mozilla/dom/ShadowRoot.h"
#include "mozilla/dom/StyleSheetList.h"
#include "nsDocument.h"
#include "nsFocusManager.h"
#include "nsIRadioVisitor.h"
#include "nsIFormControl.h"
#include "nsLayoutUtils.h"
#include "nsSVGUtils.h"
#include "nsWindowSizes.h"

namespace mozilla {
namespace dom {

DocumentOrShadowRoot::DocumentOrShadowRoot(
    mozilla::dom::ShadowRoot& aShadowRoot)
    : mAsNode(aShadowRoot), mKind(Kind::ShadowRoot) {}

DocumentOrShadowRoot::DocumentOrShadowRoot(nsIDocument& aDoc)
    : mAsNode(aDoc), mKind(Kind::Document) {}

void DocumentOrShadowRoot::AddSizeOfOwnedSheetArrayExcludingThis(
    nsWindowSizes& aSizes, const nsTArray<RefPtr<StyleSheet>>& aSheets) const {
  size_t n = 0;
  n += aSheets.ShallowSizeOfExcludingThis(aSizes.mState.mMallocSizeOf);
  for (StyleSheet* sheet : aSheets) {
    if (!sheet->GetAssociatedDocumentOrShadowRoot()) {
      // Avoid over-reporting shared sheets.
      continue;
    }
    n += sheet->SizeOfIncludingThis(aSizes.mState.mMallocSizeOf);
  }

  if (mKind == Kind::ShadowRoot) {
    aSizes.mLayoutShadowDomStyleSheetsSize += n;
  } else {
    aSizes.mLayoutStyleSheetsSize += n;
  }
}

void DocumentOrShadowRoot::AddSizeOfExcludingThis(nsWindowSizes& aSizes) const {
  AddSizeOfOwnedSheetArrayExcludingThis(aSizes, mStyleSheets);
  aSizes.mDOMOtherSize +=
      mIdentifierMap.SizeOfExcludingThis(aSizes.mState.mMallocSizeOf);
}

DocumentOrShadowRoot::~DocumentOrShadowRoot() {
  for (StyleSheet* sheet : mStyleSheets) {
    sheet->ClearAssociatedDocumentOrShadowRoot();
  }
}

StyleSheetList& DocumentOrShadowRoot::EnsureDOMStyleSheets() {
  if (!mDOMStyleSheets) {
    mDOMStyleSheets = new StyleSheetList(*this);
  }
  return *mDOMStyleSheets;
}

void DocumentOrShadowRoot::InsertSheetAt(size_t aIndex, StyleSheet& aSheet) {
  aSheet.SetAssociatedDocumentOrShadowRoot(
      this, StyleSheet::OwnedByDocumentOrShadowRoot);
  mStyleSheets.InsertElementAt(aIndex, &aSheet);
}

already_AddRefed<StyleSheet> DocumentOrShadowRoot::RemoveSheet(
    StyleSheet& aSheet) {
  auto index = mStyleSheets.IndexOf(&aSheet);
  if (index == mStyleSheets.NoIndex) {
    return nullptr;
  }
  RefPtr<StyleSheet> sheet = std::move(mStyleSheets[index]);
  mStyleSheets.RemoveElementAt(index);
  sheet->ClearAssociatedDocumentOrShadowRoot();
  return sheet.forget();
}

Element* DocumentOrShadowRoot::GetElementById(const nsAString& aElementId) {
  if (MOZ_UNLIKELY(aElementId.IsEmpty())) {
    nsContentUtils::ReportEmptyGetElementByIdArg(AsNode().OwnerDoc());
    return nullptr;
  }

  if (nsIdentifierMapEntry* entry = mIdentifierMap.GetEntry(aElementId)) {
    if (Element* el = entry->GetIdElement()) {
      return el;
    }
  }

  return nullptr;
}

already_AddRefed<nsContentList> DocumentOrShadowRoot::GetElementsByTagNameNS(
    const nsAString& aNamespaceURI, const nsAString& aLocalName) {
  ErrorResult rv;
  RefPtr<nsContentList> list =
      GetElementsByTagNameNS(aNamespaceURI, aLocalName, rv);
  if (rv.Failed()) {
    return nullptr;
  }
  return list.forget();
}

already_AddRefed<nsContentList> DocumentOrShadowRoot::GetElementsByTagNameNS(
    const nsAString& aNamespaceURI, const nsAString& aLocalName,
    mozilla::ErrorResult& aResult) {
  int32_t nameSpaceId = kNameSpaceID_Wildcard;

  if (!aNamespaceURI.EqualsLiteral("*")) {
    aResult = nsContentUtils::NameSpaceManager()->RegisterNameSpace(
        aNamespaceURI, nameSpaceId);
    if (aResult.Failed()) {
      return nullptr;
    }
  }

  NS_ASSERTION(nameSpaceId != kNameSpaceID_Unknown, "Unexpected namespace ID!");
  return NS_GetContentList(&AsNode(), nameSpaceId, aLocalName);
}

already_AddRefed<nsContentList> DocumentOrShadowRoot::GetElementsByClassName(
    const nsAString& aClasses) {
  return nsContentUtils::GetElementsByClassName(&AsNode(), aClasses);
}

nsIContent* DocumentOrShadowRoot::Retarget(nsIContent* aContent) const {
  for (nsIContent* cur = aContent; cur; cur = cur->GetContainingShadowHost()) {
    if (cur->SubtreeRoot() == &AsNode()) {
      return cur;
    }
  }
  return nullptr;
}

Element* DocumentOrShadowRoot::GetRetargetedFocusedElement() {
  if (nsCOMPtr<nsPIDOMWindowOuter> window = AsNode().OwnerDoc()->GetWindow()) {
    nsCOMPtr<nsPIDOMWindowOuter> focusedWindow;
    nsIContent* focusedContent = nsFocusManager::GetFocusedDescendant(
        window, nsFocusManager::eOnlyCurrentWindow,
        getter_AddRefs(focusedWindow));
    // be safe and make sure the element is from this document
    if (focusedContent && focusedContent->OwnerDoc() == AsNode().OwnerDoc()) {
      if (focusedContent->ChromeOnlyAccess()) {
        focusedContent = focusedContent->FindFirstNonChromeOnlyAccessContent();
      }

      if (focusedContent) {
        if (nsIContent* retarget = Retarget(focusedContent)) {
          return retarget->AsElement();
        }
      }
    }
  }

  return nullptr;
}

Element* DocumentOrShadowRoot::GetPointerLockElement() {
  nsCOMPtr<Element> pointerLockedElement =
      do_QueryReferent(EventStateManager::sPointerLockedElement);
  if (!pointerLockedElement) {
    return nullptr;
  }

  nsIContent* retargetedPointerLockedElement = Retarget(pointerLockedElement);
  return retargetedPointerLockedElement &&
                 retargetedPointerLockedElement->IsElement()
             ? retargetedPointerLockedElement->AsElement()
             : nullptr;
}

Element* DocumentOrShadowRoot::GetFullscreenElement() {
  if (!AsNode().IsInComposedDoc()) {
    return nullptr;
  }

  Element* element = AsNode().OwnerDoc()->FullscreenStackTop();
  NS_ASSERTION(!element || element->State().HasState(NS_EVENT_STATE_FULLSCREEN),
               "Fullscreen element should have fullscreen styles applied");

  nsIContent* retargeted = Retarget(element);
  if (retargeted && retargeted->IsElement()) {
    return retargeted->AsElement();
  }

  return nullptr;
}

namespace {

enum class FromPointRequestKind {
  Element,
  Elements,
};

enum class FlushLayout {
  No,
  Yes,
};

using FrameForPointOption = nsLayoutUtils::FrameForPointOption;

static void ElementsFromPointHelper(
    DocumentOrShadowRoot& aRoot, float aX, float aY,
    EnumSet<FrameForPointOption> aOptions, FlushLayout aShouldFlushLayout,
    FromPointRequestKind aRequestKind,
    nsTArray<RefPtr<mozilla::dom::Element>>& aElements) {
  // As per the spec, we return null if either coord is negative
  if (!aOptions.contains(FrameForPointOption::IgnoreRootScrollFrame) &&
      (aX < 0 || aY < 0)) {
    return;
  }

  nscoord x = nsPresContext::CSSPixelsToAppUnits(aX);
  nscoord y = nsPresContext::CSSPixelsToAppUnits(aY);
  nsPoint pt(x, y);

  nsCOMPtr<nsIDocument> doc = aRoot.AsNode().OwnerDoc();

  // Make sure the layout information we get is up-to-date, and
  // ensure we get a root frame (for everything but XUL)
  if (aShouldFlushLayout == FlushLayout::Yes) {
    doc->FlushPendingNotifications(FlushType::Layout);
  }

  nsIPresShell* ps = doc->GetShell();
  if (!ps) {
    return;
  }

  nsIFrame* rootFrame = ps->GetRootFrame();
  // XUL docs, unlike HTML, have no frame tree until everything's done loading
  if (!rootFrame) {
    return;  // return null to premature XUL callers as a reminder to wait
  }

  nsTArray<nsIFrame*> outFrames;

  aOptions += FrameForPointOption::IgnorePaintSuppression;
  aOptions += FrameForPointOption::IgnoreCrossDoc;

  // Emulate what GetFrameAtPoint does, since we want all the frames under our
  // point.
  nsLayoutUtils::GetFramesForArea(rootFrame, nsRect(pt, nsSize(1, 1)),
                                  outFrames, aOptions);

  // Dunno when this would ever happen, as we should at least have a root frame
  // under us?
  if (outFrames.IsEmpty()) {
    return;
  }

  // Used to filter out repeated elements in sequence.
  nsIContent* lastAdded = nullptr;

  for (uint32_t i = 0; i < outFrames.Length(); i++) {
    nsIContent* node = doc->GetContentInThisDocument(outFrames[i]);

    if (!node || !node->IsElement()) {
      // If this helper is called via ElementsFromPoint, we need to make sure
      // our frame is an element. Otherwise return whatever the top frame is
      // even if it isn't the top-painted element.
      // SVG 'text' element's SVGTextFrame doesn't respond to hit-testing, so
      // if 'node' is a child of such an element then we need to manually defer
      // to the parent here.
      if (aRequestKind != FromPointRequestKind::Element &&
          !nsSVGUtils::IsInSVGTextSubtree(outFrames[i])) {
        continue;
      }

      node = node->GetParent();
      if (ShadowRoot* shadow = ShadowRoot::FromNodeOrNull(node)) {
        node = shadow->Host();
      }
    }

    // XXXsmaug There is plenty of unspec'ed behavior here
    //         https://github.com/w3c/webcomponents/issues/735
    //         https://github.com/w3c/webcomponents/issues/736
    node = aRoot.Retarget(node);

    if (node && node != lastAdded) {
      aElements.AppendElement(node->AsElement());
      lastAdded = node;
      // If this helper is called via ElementFromPoint, just return the first
      // element we find.
      if (aRequestKind == FromPointRequestKind::Element) {
        return;
      }
    }
  }
}

}  // namespace

Element* DocumentOrShadowRoot::ElementFromPoint(float aX, float aY) {
  return ElementFromPointHelper(aX, aY, false, true);
}

void DocumentOrShadowRoot::ElementsFromPoint(
    float aX, float aY, nsTArray<RefPtr<Element>>& aElements) {
  ElementsFromPointHelper(*this, aX, aY, {}, FlushLayout::Yes,
                          FromPointRequestKind::Elements, aElements);
}

Element* DocumentOrShadowRoot::ElementFromPointHelper(
    float aX, float aY, bool aIgnoreRootScrollFrame, bool aFlushLayout) {
  AutoTArray<RefPtr<Element>, 1> elementArray;

  EnumSet<FrameForPointOption> options;
  if (aIgnoreRootScrollFrame) {
    options += FrameForPointOption::IgnoreRootScrollFrame;
  }

  auto flush = aFlushLayout ? FlushLayout::Yes : FlushLayout::No;

  ElementsFromPointHelper(*this, aX, aY, options, flush,
                          FromPointRequestKind::Element, elementArray);

  return elementArray.SafeElementAt(0);
}

Element* DocumentOrShadowRoot::AddIDTargetObserver(nsAtom* aID,
                                                   IDTargetObserver aObserver,
                                                   void* aData,
                                                   bool aForImage) {
  nsDependentAtomString id(aID);

  if (!CheckGetElementByIdArg(id)) {
    return nullptr;
  }

  nsIdentifierMapEntry* entry = mIdentifierMap.PutEntry(aID);
  NS_ENSURE_TRUE(entry, nullptr);

  entry->AddContentChangeCallback(aObserver, aData, aForImage);
  return aForImage ? entry->GetImageIdElement() : entry->GetIdElement();
}

void DocumentOrShadowRoot::RemoveIDTargetObserver(nsAtom* aID,
                                                  IDTargetObserver aObserver,
                                                  void* aData, bool aForImage) {
  nsDependentAtomString id(aID);

  if (!CheckGetElementByIdArg(id)) {
    return;
  }

  nsIdentifierMapEntry* entry = mIdentifierMap.GetEntry(aID);
  if (!entry) {
    return;
  }

  entry->RemoveContentChangeCallback(aObserver, aData, aForImage);
}

Element* DocumentOrShadowRoot::LookupImageElement(const nsAString& aId) {
  if (aId.IsEmpty()) {
    return nullptr;
  }

  nsIdentifierMapEntry* entry = mIdentifierMap.GetEntry(aId);
  return entry ? entry->GetImageIdElement() : nullptr;
}

void DocumentOrShadowRoot::ReportEmptyGetElementByIdArg() {
  nsContentUtils::ReportEmptyGetElementByIdArg(AsNode().OwnerDoc());
}

/**
 * A struct that holds all the information about a radio group.
 */
struct nsRadioGroupStruct {
  nsRadioGroupStruct()
      : mRequiredRadioCount(0), mGroupSuffersFromValueMissing(false) {}

  /**
   * A strong pointer to the currently selected radio button.
   */
  RefPtr<HTMLInputElement> mSelectedRadioButton;
  nsCOMArray<nsIFormControl> mRadioButtons;
  uint32_t mRequiredRadioCount;
  bool mGroupSuffersFromValueMissing;
};

nsresult DocumentOrShadowRoot::WalkRadioGroup(const nsAString& aName,
                                              nsIRadioVisitor* aVisitor,
                                              bool aFlushContent) {
  nsRadioGroupStruct* radioGroup = GetOrCreateRadioGroup(aName);

  for (int i = 0; i < radioGroup->mRadioButtons.Count(); i++) {
    if (!aVisitor->Visit(radioGroup->mRadioButtons[i])) {
      return NS_OK;
    }
  }

  return NS_OK;
}

void DocumentOrShadowRoot::SetCurrentRadioButton(const nsAString& aName,
                                                 HTMLInputElement* aRadio) {
  nsRadioGroupStruct* radioGroup = GetOrCreateRadioGroup(aName);
  radioGroup->mSelectedRadioButton = aRadio;
}

HTMLInputElement* DocumentOrShadowRoot::GetCurrentRadioButton(
    const nsAString& aName) {
  return GetOrCreateRadioGroup(aName)->mSelectedRadioButton;
}

nsresult DocumentOrShadowRoot::GetNextRadioButton(
    const nsAString& aName, const bool aPrevious,
    HTMLInputElement* aFocusedRadio, HTMLInputElement** aRadioOut) {
  // XXX Can we combine the HTML radio button method impls of
  //     nsDocument and nsHTMLFormControl?
  // XXX Why is HTML radio button stuff in nsDocument, as
  //     opposed to nsHTMLDocument?
  *aRadioOut = nullptr;

  nsRadioGroupStruct* radioGroup = GetOrCreateRadioGroup(aName);

  // Return the radio button relative to the focused radio button.
  // If no radio is focused, get the radio relative to the selected one.
  RefPtr<HTMLInputElement> currentRadio;
  if (aFocusedRadio) {
    currentRadio = aFocusedRadio;
  } else {
    currentRadio = radioGroup->mSelectedRadioButton;
    if (!currentRadio) {
      return NS_ERROR_FAILURE;
    }
  }
  int32_t index = radioGroup->mRadioButtons.IndexOf(currentRadio);
  if (index < 0) {
    return NS_ERROR_FAILURE;
  }

  int32_t numRadios = radioGroup->mRadioButtons.Count();
  RefPtr<HTMLInputElement> radio;
  do {
    if (aPrevious) {
      if (--index < 0) {
        index = numRadios - 1;
      }
    } else if (++index >= numRadios) {
      index = 0;
    }
    NS_ASSERTION(
        static_cast<nsGenericHTMLFormElement*>(radioGroup->mRadioButtons[index])
            ->IsHTMLElement(nsGkAtoms::input),
        "mRadioButtons holding a non-radio button");
    radio = static_cast<HTMLInputElement*>(radioGroup->mRadioButtons[index]);
  } while (radio->Disabled() && radio != currentRadio);

  radio.forget(aRadioOut);
  return NS_OK;
}

void DocumentOrShadowRoot::AddToRadioGroup(const nsAString& aName,
                                           HTMLInputElement* aRadio) {
  nsRadioGroupStruct* radioGroup = GetOrCreateRadioGroup(aName);
  radioGroup->mRadioButtons.AppendObject(aRadio);

  if (aRadio->IsRequired()) {
    radioGroup->mRequiredRadioCount++;
  }
}

void DocumentOrShadowRoot::RemoveFromRadioGroup(const nsAString& aName,
                                                HTMLInputElement* aRadio) {
  nsRadioGroupStruct* radioGroup = GetOrCreateRadioGroup(aName);
  radioGroup->mRadioButtons.RemoveObject(aRadio);

  if (aRadio->IsRequired()) {
    NS_ASSERTION(radioGroup->mRequiredRadioCount != 0,
                 "mRequiredRadioCount about to wrap below 0!");
    radioGroup->mRequiredRadioCount--;
  }
}

uint32_t DocumentOrShadowRoot::GetRequiredRadioCount(
    const nsAString& aName) const {
  nsRadioGroupStruct* radioGroup = GetRadioGroup(aName);
  return radioGroup ? radioGroup->mRequiredRadioCount : 0;
}

void DocumentOrShadowRoot::RadioRequiredWillChange(const nsAString& aName,
                                                   bool aRequiredAdded) {
  nsRadioGroupStruct* radioGroup = GetOrCreateRadioGroup(aName);

  if (aRequiredAdded) {
    radioGroup->mRequiredRadioCount++;
  } else {
    NS_ASSERTION(radioGroup->mRequiredRadioCount != 0,
                 "mRequiredRadioCount about to wrap below 0!");
    radioGroup->mRequiredRadioCount--;
  }
}

bool DocumentOrShadowRoot::GetValueMissingState(const nsAString& aName) const {
  nsRadioGroupStruct* radioGroup = GetRadioGroup(aName);
  return radioGroup && radioGroup->mGroupSuffersFromValueMissing;
}

void DocumentOrShadowRoot::SetValueMissingState(const nsAString& aName,
                                                bool aValue) {
  nsRadioGroupStruct* radioGroup = GetOrCreateRadioGroup(aName);
  radioGroup->mGroupSuffersFromValueMissing = aValue;
}

nsRadioGroupStruct* DocumentOrShadowRoot::GetRadioGroup(
    const nsAString& aName) const {
  nsRadioGroupStruct* radioGroup = nullptr;
  mRadioGroups.Get(aName, &radioGroup);
  return radioGroup;
}

nsRadioGroupStruct* DocumentOrShadowRoot::GetOrCreateRadioGroup(
    const nsAString& aName) {
  return mRadioGroups.LookupForAdd(aName).OrInsert(
      []() { return new nsRadioGroupStruct(); });
}

void DocumentOrShadowRoot::Traverse(DocumentOrShadowRoot* tmp,
                                    nsCycleCollectionTraversalCallback& cb) {
  for (auto iter = tmp->mRadioGroups.Iter(); !iter.Done(); iter.Next()) {
    nsRadioGroupStruct* radioGroup = iter.UserData();
    NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(
        cb, "mRadioGroups entry->mSelectedRadioButton");
    cb.NoteXPCOMChild(ToSupports(radioGroup->mSelectedRadioButton));

    uint32_t i, count = radioGroup->mRadioButtons.Count();
    for (i = 0; i < count; ++i) {
      NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(
          cb, "mRadioGroups entry->mRadioButtons[i]");
      cb.NoteXPCOMChild(radioGroup->mRadioButtons[i]);
    }
  }
}

void DocumentOrShadowRoot::Unlink(DocumentOrShadowRoot* tmp) {
  tmp->mRadioGroups.Clear();
}

}  // namespace dom
}  // namespace mozilla