/* 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/ChildSHistory.h"
#include "mozilla/dom/ChildSHistoryBinding.h"
#include "mozilla/dom/ContentFrameMessageManager.h"
#include "nsComponentManagerUtils.h"
#include "nsSHistory.h"
#include "nsDocShell.h"
#include "nsXULAppAPI.h"

namespace mozilla {
namespace dom {

ChildSHistory::ChildSHistory(nsDocShell* aDocShell)
    : mDocShell(aDocShell), mHistory(new nsSHistory(aDocShell)) {}

ChildSHistory::~ChildSHistory() {}

int32_t ChildSHistory::Count() { return mHistory->GetCount(); }

int32_t ChildSHistory::Index() {
  int32_t index;
  mHistory->GetIndex(&index);
  return index;
}

void ChildSHistory::Reload(uint32_t aReloadFlags, ErrorResult& aRv) {
  aRv = mHistory->Reload(aReloadFlags);
}

bool ChildSHistory::CanGo(int32_t aOffset) {
  CheckedInt<int32_t> index = Index();
  index += aOffset;
  if (!index.isValid()) {
    return false;
  }
  return index.value() < Count() && index.value() >= 0;
}

void ChildSHistory::Go(int32_t aOffset, ErrorResult& aRv) {
  CheckedInt<int32_t> index = Index();
  index += aOffset;
  if (!index.isValid()) {
    aRv.Throw(NS_ERROR_FAILURE);
    return;
  }
  aRv = mHistory->GotoIndex(index.value());
}

void ChildSHistory::EvictLocalContentViewers() {
  mHistory->EvictAllContentViewers();
}

nsISHistory* ChildSHistory::LegacySHistory() { return mHistory; }

ParentSHistory* ChildSHistory::GetParentIfSameProcess() {
  if (XRE_IsContentProcess()) {
    return nullptr;
  }

  MOZ_CRASH("Unimplemented!");
}

NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(ChildSHistory)
  NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
  NS_INTERFACE_MAP_ENTRY(nsISupports)
NS_INTERFACE_MAP_END

NS_IMPL_CYCLE_COLLECTING_ADDREF(ChildSHistory)
NS_IMPL_CYCLE_COLLECTING_RELEASE(ChildSHistory)

NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(ChildSHistory, mDocShell, mHistory)

JSObject* ChildSHistory::WrapObject(JSContext* cx,
                                    JS::Handle<JSObject*> aGivenProto) {
  return ChildSHistory_Binding::Wrap(cx, this, aGivenProto);
}

nsISupports* ChildSHistory::GetParentObject() const {
  // We want to get the BrowserChildMessageManager, which is the
  // messageManager on mDocShell.
  RefPtr<ContentFrameMessageManager> mm;
  if (mDocShell) {
    mm = mDocShell->GetMessageManager();
  }
  // else we must be unlinked... can that happen here?
  return ToSupports(mm);
}

}  // namespace dom
}  // namespace mozilla