/* -*- 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 "ChangeAttributeTransaction.h"

#include "mozilla/dom/Element.h"        // for Element

#include "nsAString.h"
#include "nsError.h"                    // for NS_ERROR_NOT_INITIALIZED, etc.

namespace mozilla {

using namespace dom;

// static
already_AddRefed<ChangeAttributeTransaction>
ChangeAttributeTransaction::Create(Element& aElement,
                                   nsAtom& aAttribute,
                                   const nsAString& aValue)
{
  RefPtr<ChangeAttributeTransaction> transaction =
    new ChangeAttributeTransaction(aElement, aAttribute, &aValue);
  return transaction.forget();
}

// static
already_AddRefed<ChangeAttributeTransaction>
ChangeAttributeTransaction::CreateToRemove(Element& aElement,
                                           nsAtom& aAttribute)
{
  RefPtr<ChangeAttributeTransaction> transaction =
    new ChangeAttributeTransaction(aElement, aAttribute, nullptr);
  return transaction.forget();
}

ChangeAttributeTransaction::ChangeAttributeTransaction(Element& aElement,
                                                       nsAtom& aAttribute,
                                                       const nsAString* aValue)
  : EditTransactionBase()
  , mElement(&aElement)
  , mAttribute(&aAttribute)
  , mValue(aValue ? *aValue : EmptyString())
  , mRemoveAttribute(!aValue)
  , mAttributeWasSet(false)
{
}

ChangeAttributeTransaction::~ChangeAttributeTransaction()
{
}

NS_IMPL_CYCLE_COLLECTION_INHERITED(ChangeAttributeTransaction,
                                   EditTransactionBase,
                                   mElement)

NS_IMPL_ADDREF_INHERITED(ChangeAttributeTransaction, EditTransactionBase)
NS_IMPL_RELEASE_INHERITED(ChangeAttributeTransaction, EditTransactionBase)
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(ChangeAttributeTransaction)
NS_INTERFACE_MAP_END_INHERITING(EditTransactionBase)

NS_IMETHODIMP
ChangeAttributeTransaction::DoTransaction()
{
  // Need to get the current value of the attribute and save it, and set
  // mAttributeWasSet
  mAttributeWasSet = mElement->GetAttr(kNameSpaceID_None, mAttribute,
                                       mUndoValue);

  // XXX: hack until attribute-was-set code is implemented
  if (!mUndoValue.IsEmpty()) {
    mAttributeWasSet = true;
  }
  // XXX: end hack

  // Now set the attribute to the new value
  if (mRemoveAttribute) {
    return mElement->UnsetAttr(kNameSpaceID_None, mAttribute, true);
  }

  return mElement->SetAttr(kNameSpaceID_None, mAttribute, mValue, true);
}

NS_IMETHODIMP
ChangeAttributeTransaction::UndoTransaction()
{
  if (mAttributeWasSet) {
    return mElement->SetAttr(kNameSpaceID_None, mAttribute, mUndoValue, true);
  }
  return mElement->UnsetAttr(kNameSpaceID_None, mAttribute, true);
}

NS_IMETHODIMP
ChangeAttributeTransaction::RedoTransaction()
{
  if (mRemoveAttribute) {
    return mElement->UnsetAttr(kNameSpaceID_None, mAttribute, true);
  }

  return mElement->SetAttr(kNameSpaceID_None, mAttribute, mValue, true);
}

} // namespace mozilla