/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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/HTMLFieldSetElement.h"
#include "mozilla/dom/HTMLFieldSetElementBinding.h"
#include "nsContentList.h"
#include "nsEventDispatcher.h"

NS_IMPL_NS_NEW_HTML_ELEMENT(FieldSet)

namespace mozilla {
namespace dom {

HTMLFieldSetElement::HTMLFieldSetElement(already_AddRefed<nsINodeInfo> aNodeInfo)
  : nsGenericHTMLFormElement(aNodeInfo)
  , mElements(nullptr)
  , mFirstLegend(nullptr)
{
  SetIsDOMBinding();

  // <fieldset> is always barred from constraint validation.
  SetBarredFromConstraintValidation(true);

  // We start out enabled
  AddStatesSilently(NS_EVENT_STATE_ENABLED);
}

HTMLFieldSetElement::~HTMLFieldSetElement()
{
  uint32_t length = mDependentElements.Length();
  for (uint32_t i = 0; i < length; ++i) {
    mDependentElements[i]->ForgetFieldSet(this);
  }
}

// nsISupports

NS_IMPL_CYCLE_COLLECTION_INHERITED_2(HTMLFieldSetElement, nsGenericHTMLFormElement,
                                     mValidity, mElements)

NS_IMPL_ADDREF_INHERITED(HTMLFieldSetElement, Element)
NS_IMPL_RELEASE_INHERITED(HTMLFieldSetElement, Element)

// QueryInterface implementation for HTMLFieldSetElement
NS_INTERFACE_TABLE_HEAD_CYCLE_COLLECTION_INHERITED(HTMLFieldSetElement)
  NS_HTML_CONTENT_INTERFACES(nsGenericHTMLFormElement)
  NS_INTERFACE_TABLE_INHERITED2(HTMLFieldSetElement,
                                nsIDOMHTMLFieldSetElement,
                                nsIConstraintValidation)
  NS_INTERFACE_TABLE_TO_MAP_SEGUE
NS_ELEMENT_INTERFACE_MAP_END

NS_IMPL_ELEMENT_CLONE(HTMLFieldSetElement)


NS_IMPL_BOOL_ATTR(HTMLFieldSetElement, Disabled, disabled)
NS_IMPL_STRING_ATTR(HTMLFieldSetElement, Name, name)

// nsIConstraintValidation
NS_IMPL_NSICONSTRAINTVALIDATION(HTMLFieldSetElement)

bool
HTMLFieldSetElement::IsDisabledForEvents(uint32_t aMessage)
{
  return IsElementDisabledForEvents(aMessage, nullptr);
}

// nsIContent
nsresult
HTMLFieldSetElement::PreHandleEvent(nsEventChainPreVisitor& aVisitor)
{
  // Do not process any DOM events if the element is disabled.
  aVisitor.mCanHandle = false;
  if (IsDisabledForEvents(aVisitor.mEvent->message)) {
    return NS_OK;
  }

  return nsGenericHTMLFormElement::PreHandleEvent(aVisitor);
}

nsresult
HTMLFieldSetElement::AfterSetAttr(int32_t aNameSpaceID, nsIAtom* aName,
                                  const nsAttrValue* aValue, bool aNotify)
{
  if (aNameSpaceID == kNameSpaceID_None && aName == nsGkAtoms::disabled &&
      nsINode::GetFirstChild()) {
    if (!mElements) {
      mElements = new nsContentList(this, MatchListedElements, nullptr, nullptr,
                                    true);
    }

    uint32_t length = mElements->Length(true);
    for (uint32_t i=0; i<length; ++i) {
      static_cast<nsGenericHTMLFormElement*>(mElements->Item(i))
        ->FieldSetDisabledChanged(aNotify);
    }
  }

  return nsGenericHTMLFormElement::AfterSetAttr(aNameSpaceID, aName,
                                                aValue, aNotify);
}

// nsIDOMHTMLFieldSetElement

NS_IMETHODIMP
HTMLFieldSetElement::GetForm(nsIDOMHTMLFormElement** aForm)
{
  return nsGenericHTMLFormElement::GetForm(aForm);
}

NS_IMETHODIMP
HTMLFieldSetElement::GetType(nsAString& aType)
{
  aType.AssignLiteral("fieldset");
  return NS_OK;
}

/* static */
bool
HTMLFieldSetElement::MatchListedElements(nsIContent* aContent, int32_t aNamespaceID,
                                         nsIAtom* aAtom, void* aData)
{
  nsCOMPtr<nsIFormControl> formControl = do_QueryInterface(aContent);
  return formControl && formControl->GetType() != NS_FORM_LABEL;
}

NS_IMETHODIMP
HTMLFieldSetElement::GetElements(nsIDOMHTMLCollection** aElements)
{
  NS_ADDREF(*aElements = Elements());
  return NS_OK;
}

nsIHTMLCollection*
HTMLFieldSetElement::Elements()
{
  if (!mElements) {
    mElements = new nsContentList(this, MatchListedElements, nullptr, nullptr,
                                  true);
  }

  return mElements;
}

// nsIFormControl

nsresult
HTMLFieldSetElement::Reset()
{
  return NS_OK;
}

NS_IMETHODIMP
HTMLFieldSetElement::SubmitNamesValues(nsFormSubmission* aFormSubmission)
{
  return NS_OK;
}

nsresult
HTMLFieldSetElement::InsertChildAt(nsIContent* aChild, uint32_t aIndex,
                                   bool aNotify)
{
  bool firstLegendHasChanged = false;

  if (aChild->IsHTML(nsGkAtoms::legend)) {
    if (!mFirstLegend) {
      mFirstLegend = aChild;
      // We do not want to notify the first time mFirstElement is set.
    } else {
      // If mFirstLegend is before aIndex, we do not change it.
      // Otherwise, mFirstLegend is now aChild.
      if (int32_t(aIndex) <= IndexOf(mFirstLegend)) {
        mFirstLegend = aChild;
        firstLegendHasChanged = true;
      }
    }
  }

  nsresult rv = nsGenericHTMLFormElement::InsertChildAt(aChild, aIndex, aNotify);
  NS_ENSURE_SUCCESS(rv, rv);

  if (firstLegendHasChanged) {
    NotifyElementsForFirstLegendChange(aNotify);
  }

  return rv;
}

void
HTMLFieldSetElement::RemoveChildAt(uint32_t aIndex, bool aNotify)
{
  bool firstLegendHasChanged = false;

  if (mFirstLegend && (GetChildAt(aIndex) == mFirstLegend)) {
    // If we are removing the first legend we have to found another one.
    nsIContent* child = mFirstLegend->GetNextSibling();
    mFirstLegend = nullptr;
    firstLegendHasChanged = true;

    for (; child; child = child->GetNextSibling()) {
      if (child->IsHTML(nsGkAtoms::legend)) {
        mFirstLegend = child;
        break;
      }
    }
  }

  nsGenericHTMLFormElement::RemoveChildAt(aIndex, aNotify);

  if (firstLegendHasChanged) {
    NotifyElementsForFirstLegendChange(aNotify);
  }
}

void
HTMLFieldSetElement::NotifyElementsForFirstLegendChange(bool aNotify)
{
  /**
   * NOTE: this could be optimized if only call when the fieldset is currently
   * disabled.
   * This should also make sure that mElements is set when we happen to be here.
   * However, this method shouldn't be called very often in normal use cases.
   */
  if (!mElements) {
    mElements = new nsContentList(this, MatchListedElements, nullptr, nullptr,
                                  true);
  }

  uint32_t length = mElements->Length(true);
  for (uint32_t i = 0; i < length; ++i) {
    static_cast<nsGenericHTMLFormElement*>(mElements->Item(i))
      ->FieldSetFirstLegendChanged(aNotify);
  }
}

JSObject*
HTMLFieldSetElement::WrapNode(JSContext* aCx, JS::Handle<JSObject*> aScope)
{
  return HTMLFieldSetElementBinding::Wrap(aCx, aScope, this);
}

} // namespace dom
} // namespace mozilla
