text: /*
   * Software License Agreement (BSD License)
   *
   *  Copyright (c) 2018, Locus Robotics
   *  All rights reserved.
   *
   *  Redistribution and use in source and binary forms, with or without
   *  modification, are permitted provided that the following conditions
   *  are met:
   *
   *   * Redistributions of source code must retain the above copyright
   *     notice, this list of conditions and the following disclaimer.
   *   * Redistributions in binary form must reproduce the above
   *     copyright notice, this list of conditions and the following
   *     disclaimer in the documentation and/or other materials provided
   *     with the distribution.
   *   * Neither the name of the copyright holder nor the names of its
   *     contributors may be used to endorse or promote products derived
   *     from this software without specific prior written permission.
   *
   *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   *  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
   *  FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
   *  COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
   *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
   *  BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   *  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
   *  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   *  LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
   *  ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   *  POSSIBILITY OF SUCH DAMAGE.
   */
  #include <fuse_core/graph.h>
  
  #include <fuse_core/transaction.h>
  #include <fuse_core/uuid.h>
  
  #include <boost/iterator/transform_iterator.hpp>
  
  #include <functional>
  
  
  namespace fuse_core
  {
  
  std::ostream& operator <<(std::ostream& stream, const Graph& graph)
  {
    graph.print(stream);
    return stream;
  }
  
  Graph::const_variable_range Graph::getConnectedVariables(const UUID& constraint_uuid) const
  {
    std::function<const fuse_core::Variable&(const UUID& variable_uuid)> uuid_to_variable_ref =
      [this](const UUID& variable_uuid) -> const Variable&
      {
        return this->getVariable(variable_uuid);
      };
  
    const auto& constraint = getConstraint(constraint_uuid);
    const auto& variable_uuids = constraint.variables();
  
    return const_variable_range(
      boost::make_transform_iterator(variable_uuids.cbegin(), uuid_to_variable_ref),
      boost::make_transform_iterator(variable_uuids.cend(), uuid_to_variable_ref));
  }
  
  void Graph::update(const Transaction& transaction)
  {
    // Update the graph with a new transaction. In order to keep the graph consistent, variables are added first,
    // followed by the constraints which might use the newly added variables. Then constraints are removed so that
    // the variable usage is updated. Finally, variables are removed.
  
    // Insert the new variables into the graph
    for (const auto& variable : transaction.addedVariables())
    {
      addVariable(variable.clone());
    }
    // Insert the new constraints into the graph
    for (const auto& constraint : transaction.addedConstraints())
    {
      addConstraint(constraint.clone());
    }
    // Delete constraints from the graph
    for (const auto& constraint_uuid : transaction.removedConstraints())
    {
      removeConstraint(constraint_uuid);
    }
    // Delete variables from the graph
    for (const auto& variable_uuid : transaction.removedVariables())
    {
      removeVariable(variable_uuid);
    }
  }
  
  }  // namespace fuse_core
  