////////////////////////////////////////////////////////////////////////////////
/// @brief Aql, collection
///
/// @file
///
/// DISCLAIMER
///
/// Copyright 2014 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
/// @author Copyright 2014, ArangoDB GmbH, Cologne, Germany
/// @author Copyright 2012-2013, triAGENS GmbH, Cologne, Germany
////////////////////////////////////////////////////////////////////////////////

#include "Collection.h"
#include "Aql/ExecutionEngine.h"
#include "Basics/StringUtils.h"
#include "Cluster/ClusterInfo.h"
#include "Utils/Exception.h"
#include "VocBase/document-collection.h"
#include "VocBase/transaction.h"
#include "VocBase/vocbase.h"

using namespace triagens::aql;
      
// -----------------------------------------------------------------------------
// --SECTION--                                        constructors / destructors
// -----------------------------------------------------------------------------

////////////////////////////////////////////////////////////////////////////////
/// @brief create a collection wrapper
////////////////////////////////////////////////////////////////////////////////

Collection::Collection (std::string const& name,
                        struct TRI_vocbase_s* vocbase,
                        TRI_transaction_type_e accessType) 
  : currentShard(),
    name(name),
    vocbase(vocbase),
    collection(nullptr),
    accessType(accessType) {
          
  TRI_ASSERT(! name.empty());
  TRI_ASSERT(vocbase != nullptr);
}

////////////////////////////////////////////////////////////////////////////////
/// @brief destroy a collection wrapper
////////////////////////////////////////////////////////////////////////////////
      
Collection::~Collection () {
  for (auto idx : indexes) {
    delete idx;
  }
}

// -----------------------------------------------------------------------------
// --SECTION--                                                  public functions
// -----------------------------------------------------------------------------

////////////////////////////////////////////////////////////////////////////////
/// @brief count the LOCAL number of documents in the collection
////////////////////////////////////////////////////////////////////////////////

size_t Collection::count () const {
  if (numDocuments == UNINITIALIZED) {
    if (ExecutionEngine::isCoordinator()) {
      /// TODO: determine the proper number of documents in the coordinator case
      numDocuments = 1000;
    }
    else {
      auto document = documentCollection();
      // cache the result
      numDocuments = static_cast<int64_t>(document->size(document));
    }
  }

  return static_cast<size_t>(numDocuments);
}

////////////////////////////////////////////////////////////////////////////////
/// @brief returns the shard ids of a collection
////////////////////////////////////////////////////////////////////////////////

std::vector<std::string> Collection::shardIds () const {
  auto clusterInfo = triagens::arango::ClusterInfo::instance();
  auto collectionInfo = clusterInfo->getCollection(std::string(vocbase->_name), name);
  if (collectionInfo.get() == nullptr) {
    THROW_ARANGO_EXCEPTION_MESSAGE(TRI_ERROR_INTERNAL, "collection not found");
  }

  std::vector<std::string> ids;
  for (auto const& it : collectionInfo.get()->shardIds()) {
    ids.emplace_back(it.first);
  }
  return ids;
}

////////////////////////////////////////////////////////////////////////////////
/// @brief returns the indexes of the collection
////////////////////////////////////////////////////////////////////////////////

std::vector<Index*> Collection::getIndexes () {
  fillIndexes();

  return indexes;
}

////////////////////////////////////////////////////////////////////////////////
/// @brief return an index by its id
////////////////////////////////////////////////////////////////////////////////
  
Index* Collection::getIndex (TRI_idx_iid_t id) const {
  fillIndexes();

  for (auto idx : indexes) {
    if (idx->id == id) {
      return idx;
    }
  }

  return nullptr;
}

////////////////////////////////////////////////////////////////////////////////
/// @brief return an index by its id
////////////////////////////////////////////////////////////////////////////////
  
Index* Collection::getIndex (std::string const& id) const {
  return getIndex(triagens::basics::StringUtils::uint64(id));
}

// -----------------------------------------------------------------------------
// --SECTION--                                                 private functions
// -----------------------------------------------------------------------------

////////////////////////////////////////////////////////////////////////////////
/// @brief fills the index list for the collection
////////////////////////////////////////////////////////////////////////////////

void Collection::fillIndexes () const {
  if (! indexes.empty()) {
    return;
  }

  if (ExecutionEngine::isCoordinator()) {
    // coordinator case, remote collection
    auto clusterInfo = triagens::arango::ClusterInfo::instance();
    auto collectionInfo = clusterInfo->getCollection(std::string(vocbase->_name), name);
    if (collectionInfo.get() == nullptr || (*collectionInfo).empty()) {
      THROW_ARANGO_EXCEPTION_MESSAGE(TRI_ERROR_INTERNAL, "collection not found");
    }

    TRI_json_t const* json = (*collectionInfo).getIndexes();

    if (TRI_IsListJson(json)) {
      size_t const n = TRI_LengthListJson(json);
      indexes.reserve(n);

      for (size_t i = 0; i < n; ++i) {
        TRI_json_t const* v = TRI_LookupListJson(json, i);
        if (v != nullptr) {
          indexes.emplace_back(new Index(v));
        }
      }
    }
  }
  else {
    // local collection
    TRI_ASSERT(collection != nullptr);
    auto document = documentCollection();
    size_t const n = document->_allIndexes._length;
    indexes.reserve(n);

    for (size_t i = 0; i < n; ++i) {
      indexes.emplace_back(new Index(static_cast<TRI_index_t*>(document->_allIndexes._buffer[i])));
    }
  }
}

// -----------------------------------------------------------------------------
// --SECTION--                                                       END-OF-FILE
// -----------------------------------------------------------------------------

// Local Variables:
// mode: outline-minor
// outline-regexp: "/// @brief\\|/// {@inheritDoc}\\|/// @page\\|// --SECTION--\\|/// @\\}"
// End: