////////////////////////////////////////////////////////////////////////////////
/// @brief Class for arangodb's graph features. Wrapper around the graph informations
///
/// @file
///
/// DISCLAIMER
///
/// Copyright 2014-2015 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 Michael Hackstein
/// @author Copyright 2014-2015, ArangoDB GmbH, Cologne, Germany
/// @author Copyright 2011-2013, triAGENS GmbH, Cologne, Germany
////////////////////////////////////////////////////////////////////////////////

#include "Basics/JsonHelper.h"
#include "Aql/Graphs.h"
#include "VocBase/Graphs.h"
#include "Utils/transactions.h"
#include "Cluster/ClusterMethods.h"
using namespace triagens::basics;
using namespace triagens::arango;

const std::string graphs = "_graphs";


// -----------------------------------------------------------------------------
// --SECTION--                                                      GraphFactory
// -----------------------------------------------------------------------------

////////////////////////////////////////////////////////////////////////////////
/// @brief Load a graph from the _graphs collection; local and coordinator way
////////////////////////////////////////////////////////////////////////////////

triagens::aql::Graph* triagens::arango::lookupGraphByName (TRI_vocbase_t* vocbase, std::string const& name) {
  triagens::aql::Graph* g = nullptr;

  if (ServerState::instance()->isCoordinator()) {
    triagens::rest::HttpResponse::HttpResponseCode responseCode;
    std::unique_ptr<std::map<std::string, std::string>> headers
        (new std::map<std::string, std::string>());
    std::map<std::string, std::string> resultHeaders;
    std::string resultBody;

    TRI_voc_rid_t rev = 0;

    int error = triagens::arango::getDocumentOnCoordinator(vocbase->_name,
                                                           graphs,
                                                           name,
                                                           rev,
                                                           headers,
                                                           true,
                                                           responseCode,
                                                           resultHeaders,
                                                           resultBody);

    if (error != TRI_ERROR_NO_ERROR) {
      THROW_ARANGO_EXCEPTION_FORMAT(error,
                                    "while fetching _graph['%s'] entry: `%s`",
                                    name.c_str(),
                                    resultBody.c_str());
    }

    auto json = JsonHelper::fromString(resultBody);
    if (json == nullptr) {
      THROW_ARANGO_EXCEPTION_FORMAT(TRI_ERROR_HTTP_CORRUPTED_JSON,
                                    "while fetching _graph['%s'] entry: `%s`",
                                    name.c_str(),
                                    resultBody.c_str());
    }
    g = new triagens::aql::Graph(Json(TRI_UNKNOWN_MEM_ZONE, json));
  }
  else {
    CollectionNameResolver resolver(vocbase);
    auto collName = resolver.getCollectionId(graphs);


    SingleCollectionReadOnlyTransaction trx(new StandaloneTransactionContext(), vocbase, collName);
    int res = trx.begin();
    if (res != TRI_ERROR_NO_ERROR) {
      THROW_ARANGO_EXCEPTION_FORMAT(res,
                                    "while looking up graph '%s' in _graphs",
                                    name.c_str());
    }
    TRI_doc_mptr_copy_t mptr;
    res = trx.read(&mptr, name);
    if (res != TRI_ERROR_NO_ERROR) {
      THROW_ARANGO_EXCEPTION_FORMAT(res,
                                    "while looking up graph '%s' in _graphs",
                                    name.c_str());
    }
    TRI_shaped_json_t document;
    TRI_EXTRACT_SHAPED_JSON_MARKER(document, mptr.getDataPtr());
    auto shaper = trx.trxCollection()->_collection->_collection->getShaper();
    auto j = TRI_JsonShapedJson(shaper, &document);
    if (j == nullptr) {
      THROW_ARANGO_EXCEPTION_FORMAT(TRI_ERROR_ARANGO_SHAPER_FAILED,
                                    "while accessing shape for _graph['%s'] entry",
                                    name.c_str());
    }
    g = new triagens::aql::Graph(Json(TRI_UNKNOWN_MEM_ZONE, j));
    trx.finish(res);
  }
  return g;
}