/**
 *   Copyright 2011-2015 Quickstep Technologies LLC.
 *   Copyright 2015-2016 Pivotal Software, Inc.
 *
 *   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.
 **/

#ifndef QUICKSTEP_RELATIONAL_OPERATORS_REBUILD_WORKORDER_HPP_
#define QUICKSTEP_RELATIONAL_OPERATORS_REBUILD_WORKORDER_HPP_

#include <cstddef>
#include <cstdlib>
#include <ostream>
#include <utility>

#include "catalog/CatalogTypedefs.hpp"
#include "query_execution/QueryExecutionMessages.pb.h"
#include "query_execution/QueryExecutionTypedefs.hpp"
#include "query_execution/QueryExecutionUtil.hpp"
#include "relational_operators/WorkOrder.hpp"
#include "storage/StorageBlock.hpp"
#include "utility/Macros.hpp"

#include "tmb/message_bus.h"
#include "tmb/tagged_message.h"

#include "glog/logging.h"

namespace quickstep {

/** \addtogroup RelationalOperators
 *  @{
 */

class RebuildWorkOrder : public WorkOrder {
 public:
  /**
   * @brief Constructor used in the single-node version.
   *
   * @param block_ref A MutableBlockReference to the storage block which needs
   *        to be rebuilt.
   * @param input_operator_index The index of the relational operator in the
   *        query plan DAG that produced the output block.
   * @param input_relation_id The ID of the CatalogRelation to which the given
   *        storage block belongs to.
   * @param foreman_client_id The TMB client ID of the Foreman thread.
   * @param agent_client_id The TMB client ID of the agent that sends messages
   *        to Foreman.
   * @param bus A pointer to the TMB.
   **/
  RebuildWorkOrder(MutableBlockReference &&block_ref,
                   const std::size_t input_operator_index,
                   const relation_id input_relation_id,
                   const client_id foreman_client_id,
                   const client_id agent_client_id,
                   tmb::MessageBus *bus)
      : block_ref_(std::move(block_ref)),
        input_operator_index_(input_operator_index),
        input_relation_id_(input_relation_id),
        foreman_client_id_(foreman_client_id),
        agent_client_id_(agent_client_id),
        bus_(bus) {}

  ~RebuildWorkOrder() {}

  void execute() {
    if (!block_ref_->rebuild()) {
      LOG_WARNING("Rebuilding of StorageBlock with ID: "
                  << block_ref_->getID() << " invalidated one or more "
                  "IndexSubBlocks.");
    }

    serialization::DataPipelineMessage proto;
    proto.set_operator_index(input_operator_index_);
    proto.set_block_id(block_ref_->getID());
    proto.set_relation_id(input_relation_id_);

    // NOTE(zuyu): Using the heap memory to serialize proto as a c-like string.
    const std::size_t proto_length = proto.ByteSize();
    char *proto_bytes = static_cast<char*>(std::malloc(proto_length));
    CHECK(proto.SerializeToArray(proto_bytes, proto_length));

    tmb::TaggedMessage tagged_message(static_cast<const void *>(proto_bytes),
                                      proto_length,
                                      kDataPipelineMessage);
    std::free(proto_bytes);

    const tmb::MessageBus::SendStatus send_status =
        QueryExecutionUtil::SendTMBMessage(bus_,
                                           agent_client_id_,
                                           foreman_client_id_,
                                           std::move(tagged_message));
    CHECK(send_status == tmb::MessageBus::SendStatus::kOK)
        << "Message could not be sent from the TMB client ID " << agent_client_id_
        << " to Foreman with TMB client ID " << foreman_client_id_;
  }

 private:
  MutableBlockReference block_ref_;
  const std::size_t input_operator_index_;
  const relation_id input_relation_id_;
  const client_id foreman_client_id_, agent_client_id_;

  tmb::MessageBus *bus_;

  DISALLOW_COPY_AND_ASSIGN(RebuildWorkOrder);
};

/** @} */

}  // namespace quickstep

#endif  // QUICKSTEP_RELATIONAL_OPERATORS_REBUILD_WORKORDER_HPP_