////////////////////////////////////////////////////////////////////////////////
/// DISCLAIMER
///
/// Copyright 2014-2016 ArangoDB GmbH, Cologne, Germany
/// Copyright 2004-2014 triAGENS GmbH, Cologne, Germany
///
/// Licensed under the Apache License, Version 2.0 (the "License");
/// you may not use this file except in compliance with the License.
/// You may obtain a copy of the License at
///
///     http://www.apache.org/licenses/LICENSE-2.0
///
/// Unless required by applicable law or agreed to in writing, software
/// distributed under the License is distributed on an "AS IS" BASIS,
/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
/// See the License for the specific language governing permissions and
/// limitations under the License.
///
/// Copyright holder is ArangoDB GmbH, Cologne, Germany
///
/// @author Jan Steemann
////////////////////////////////////////////////////////////////////////////////

#ifndef ARANGOD_UTILS_V8_RESOLVER_GUARD_H
#define ARANGOD_UTILS_V8_RESOLVER_GUARD_H 1

#include "Basics/Common.h"

#include "Utils/CollectionNameResolver.h"
#include "Utils/V8TransactionContext.h"
#include "VocBase/vocbase.h"
#include "V8/v8-globals.h"
#include <v8.h>

namespace arangodb {

class V8ResolverGuard {
 public:
  //////////////////////////////////////////////////////////////////////////////
  /// @brief create the guard
  //////////////////////////////////////////////////////////////////////////////

  V8ResolverGuard(TRI_vocbase_t* vocbase)
      : _v8g(static_cast<TRI_v8_global_t*>(
            v8::Isolate::GetCurrent()->GetData(V8DataSlot))),
        _ownResolver(false) {
    if (!static_cast<V8TransactionContext*>(_v8g->_transactionContext)
             ->hasResolver()) {
      static_cast<V8TransactionContext*>(_v8g->_transactionContext)
          ->setResolver(new CollectionNameResolver(vocbase));
      _ownResolver = true;
    }
  }

  //////////////////////////////////////////////////////////////////////////////
  /// @brief destroy the guard
  //////////////////////////////////////////////////////////////////////////////

  ~V8ResolverGuard() {
    if (_ownResolver &&
        static_cast<V8TransactionContext*>(_v8g->_transactionContext)
            ->hasResolver()) {
      static_cast<V8TransactionContext*>(_v8g->_transactionContext)
          ->deleteResolver();
    }
  }

 public:
  //////////////////////////////////////////////////////////////////////////////
  /// @brief return the resolver
  //////////////////////////////////////////////////////////////////////////////

  inline CollectionNameResolver const* getResolver() const {
    TRI_ASSERT(static_cast<V8TransactionContext*>(
                             _v8g->_transactionContext)->hasResolver());
    return static_cast<V8TransactionContext*>(_v8g->_transactionContext)
        ->getResolver();
  }

 private:
  //////////////////////////////////////////////////////////////////////////////
  /// @brief v8 global context
  //////////////////////////////////////////////////////////////////////////////

  TRI_v8_global_t* _v8g;

  //////////////////////////////////////////////////////////////////////////////
  /// @brief whether or not we are responsible for the resolver
  //////////////////////////////////////////////////////////////////////////////

  bool _ownResolver;
};
}

#endif