bt_factory.h

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/* Copyright (C) 2018 Michele Colledanchise -  All Rights Reserved
 * Copyright (C) 2018-2020 Davide Faconti, Eurecat -  All Rights Reserved
*
*   Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"),
*   to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
*   and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
*   The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
*
*   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
*   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
*   WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/

#ifndef BT_FACTORY_H
#define BT_FACTORY_H

#include <functional>
#include <memory>
#include <unordered_map>
#include <unordered_set>
#include <cstring>
#include <algorithm>
#include <set>

#include "behaviortree_cpp_v3/behavior_tree.h"

namespace BT
{
typedef std::function<std::unique_ptr<TreeNode>(const std::string&,
                                                const NodeConfiguration&)>
    NodeBuilder;

template <typename T>
using has_default_constructor = typename std::is_constructible<T, const std::string&>;

template <typename T>
using has_params_constructor =
    typename std::is_constructible<T, const std::string&, const NodeConfiguration&>;

template <typename T>
inline NodeBuilder
CreateBuilder(typename std::enable_if<has_default_constructor<T>::value &&
                                      has_params_constructor<T>::value>::type* = nullptr)
{
  return [](const std::string& name, const NodeConfiguration& config) {
    // Special case. Use default constructor if parameters are empty
    if (config.input_ports.empty() && config.output_ports.empty() &&
        has_default_constructor<T>::value)
    {
      return std::make_unique<T>(name);
    }
    return std::make_unique<T>(name, config);
  };
}

template <typename T>
inline NodeBuilder
CreateBuilder(typename std::enable_if<!has_default_constructor<T>::value &&
                                      has_params_constructor<T>::value>::type* = nullptr)
{
  return [](const std::string& name, const NodeConfiguration& params) {
    return std::unique_ptr<TreeNode>(new T(name, params));
  };
}

template <typename T>
inline NodeBuilder
CreateBuilder(typename std::enable_if<has_default_constructor<T>::value &&
                                      !has_params_constructor<T>::value>::type* = nullptr)
{
  return [](const std::string& name, const NodeConfiguration&) {
    return std::unique_ptr<TreeNode>(new T(name));
  };
}

template <typename T>
inline TreeNodeManifest CreateManifest(const std::string& ID,
                                       PortsList portlist = getProvidedPorts<T>())
{
  return {getType<T>(), ID, portlist, {}};
}

#ifdef BT_PLUGIN_EXPORT

#if defined(_WIN32)
  #define BTCPP_EXPORT extern "C" __declspec(dllexport)
#else
  // Unix-like OSes
  #define BTCPP_EXPORT extern "C" __attribute__ ((visibility ("default")))
#endif

#else
  #define BTCPP_EXPORT static
#endif
/* Use this macro to automatically register one or more custom Nodes
* into a factory. For instance:
*
*   BT_REGISTER_NODES(factory)
*   {
*     factory.registerNodeType<MoveBaseAction>("MoveBase");
*   }
*
* IMPORTANT: this function MUST be declared in a cpp file, NOT a header file.
* In your cake, you must add the definition [BT_PLUGIN_EXPORT] with:
*
*   target_compile_definitions(my_plugin_target PRIVATE  BT_PLUGIN_EXPORT )

* See examples in sample_nodes directory.
*/

#define BT_REGISTER_NODES(factory)                                                       \
  BTCPP_EXPORT void BT_RegisterNodesFromPlugin(BT::BehaviorTreeFactory& factory)

constexpr const char* PLUGIN_SYMBOL = "BT_RegisterNodesFromPlugin";

class Tree
{
public:
  std::vector<TreeNode::Ptr> nodes;
  std::vector<Blackboard::Ptr> blackboard_stack;
  std::unordered_map<std::string, TreeNodeManifest> manifests;

  Tree()
  {}

  // non-copyable. Only movable
  Tree(const Tree&) = delete;
  Tree& operator=(const Tree&) = delete;

  Tree(Tree&& other)
  {
    (*this) = std::move(other);
  }

  Tree& operator=(Tree&& other)
  {
    nodes = std::move(other.nodes);
    blackboard_stack = std::move(other.blackboard_stack);
    manifests = std::move(other.manifests);
    wake_up_ = other.wake_up_;
    return *this;
  }

  void initialize()
  {
    wake_up_ = std::make_shared<WakeUpSignal>();
    for (auto& node : nodes)
    {
      node->setWakeUpInstance(wake_up_);
    }
  }

  void haltTree()
  {
    if (!rootNode())
    {
      return;
    }
    // the halt should propagate to all the node if the nodes
    // have been implemented correctly
    rootNode()->halt();
    rootNode()->setStatus(NodeStatus::IDLE);

    //but, just in case.... this should be no-op
    auto visitor = [](BT::TreeNode* node) {
      node->halt();
      node->setStatus(BT::NodeStatus::IDLE);
    };
    BT::applyRecursiveVisitor(rootNode(), visitor);
  }

  TreeNode* rootNode() const
  {
    return nodes.empty() ? nullptr : nodes.front().get();
  }

  NodeStatus tickRootWhileRunning(std::chrono::milliseconds sleep_time = std::chrono::milliseconds(10))
  {
    NodeStatus status = tickRoot();

    while (status == NodeStatus::RUNNING)
    {
      this->sleep(sleep_time);
      status = tickRoot();
    }
    return status;
  }

  NodeStatus tickRoot()
  {
    if (!wake_up_)
    {
      initialize();
    }

    if (!rootNode())
    {
      throw RuntimeError("Empty Tree");
    }
    NodeStatus ret = rootNode()->executeTick();
    if (ret == NodeStatus::SUCCESS || ret == NodeStatus::FAILURE)
    {
      rootNode()->setStatus(BT::NodeStatus::IDLE);
    }
    return ret;
  }

  void sleep(std::chrono::system_clock::duration timeout);

  ~Tree();

  Blackboard::Ptr rootBlackboard();

private:
  std::shared_ptr<WakeUpSignal> wake_up_;
};

class Parser;

class BehaviorTreeFactory
{
public:
  BehaviorTreeFactory();

  bool unregisterBuilder(const std::string& ID);

  void registerBuilder(const TreeNodeManifest& manifest, const NodeBuilder& builder);

  template <typename T>
  void registerBuilder(const std::string& ID, const NodeBuilder& builder)
  {
    auto manifest = CreateManifest<T>(ID);
    registerBuilder(manifest, builder);
  }

  void registerSimpleAction(const std::string& ID,
                            const SimpleActionNode::TickFunctor& tick_functor,
                            PortsList ports = {});
  void registerSimpleCondition(const std::string& ID,
                               const SimpleConditionNode::TickFunctor& tick_functor,
                               PortsList ports = {});
  void registerSimpleDecorator(const std::string& ID,
                               const SimpleDecoratorNode::TickFunctor& tick_functor,
                               PortsList ports = {});

  void registerFromPlugin(const std::string& file_path);

  void registerFromROSPlugins();

  void registerBehaviorTreeFromFile(const std::string& filename);

  void registerBehaviorTreeFromText(const std::string& xml_text);

  std::vector<std::string> registeredBehaviorTrees() const;

  void clearRegisteredBehaviorTrees();

  std::unique_ptr<TreeNode> instantiateTreeNode(const std::string& name,
                                                const std::string& ID,
                                                const NodeConfiguration& config) const;

  template <typename T>
  void registerNodeType(const std::string& ID)
  {
    static_assert(std::is_base_of<ActionNodeBase, T>::value ||
                      std::is_base_of<ControlNode, T>::value ||
                      std::is_base_of<DecoratorNode, T>::value ||
                      std::is_base_of<ConditionNode, T>::value,
                  "[registerNode]: accepts only classed derived from either "
                  "ActionNodeBase, "
                  "DecoratorNode, ControlNode or ConditionNode");

    static_assert(!std::is_abstract<T>::value, "[registerNode]: Some methods are pure "
                                               "virtual. "
                                               "Did you override the methods tick() and "
                                               "halt()?");

    constexpr bool default_constructable =
        std::is_constructible<T, const std::string&>::value;
    constexpr bool param_constructable =
        std::is_constructible<T, const std::string&, const NodeConfiguration&>::value;
    constexpr bool has_static_ports_list = has_static_method_providedPorts<T>::value;

    static_assert(default_constructable || param_constructable, "[registerNode]: the "
                                                                "registered class must "
                                                                "have at "
                                                                "least one of these two "
                                                                "constructors: "
                                                                "  (const std::string&, "
                                                                "const "
                                                                "NodeConfiguration&) or "
                                                                "(const "
                                                                "std::string&).\n"
                                                                "Check also if the "
                                                                "constructor "
                                                                "is public!");

    static_assert(!(param_constructable && !has_static_ports_list), "[registerNode]: you "
                                                                    "MUST "
                                                                    "implement the "
                                                                    "static "
                                                                    "method: "
                                                                    "  PortsList "
                                                                    "providedPorts();\n");

    static_assert(!(has_static_ports_list && !param_constructable), "[registerNode]: "
                                                                    "since you "
                                                                    "have a static "
                                                                    "method "
                                                                    "providedPorts(), "
                                                                    "you MUST add a "
                                                                    "constructor sign "
                                                                    "signature (const "
                                                                    "std::string&, const "
                                                                    "NodeParameters&)\n");

    registerBuilder(CreateManifest<T>(ID), CreateBuilder<T>());
  }

  template <typename T>
  void registerNodeType(const std::string& ID, PortsList ports)
  {
    static_assert(std::is_base_of<ActionNodeBase, T>::value ||
                      std::is_base_of<ControlNode, T>::value ||
                      std::is_base_of<DecoratorNode, T>::value ||
                      std::is_base_of<ConditionNode, T>::value,
                  "[registerNode]: accepts only classed derived from either "
                  "ActionNodeBase, "
                  "DecoratorNode, ControlNode or ConditionNode");

    static_assert(!std::is_abstract<T>::value, "[registerNode]: Some methods are pure "
                                               "virtual. "
                                               "Did you override the methods tick() and "
                                               "halt()?");

    constexpr bool default_constructable =
        std::is_constructible<T, const std::string&>::value;
    constexpr bool param_constructable =
        std::is_constructible<T, const std::string&, const NodeConfiguration&>::value;
    constexpr bool has_static_ports_list = has_static_method_providedPorts<T>::value;

    static_assert(default_constructable || param_constructable, "[registerNode]: the "
                                                                "registered class must "
                                                                "have at "
                                                                "least one of these two "
                                                                "constructors: (const "
                                                                "std::string&, const "
                                                                "NodeConfiguration&) or "
                                                                "(const "
                                                                "std::string&).");

    static_assert(!has_static_ports_list, "[registerNode]: ports are passed to this node "
                                          "explicitly. The static method"
                                          "providedPorts() should be removed to avoid "
                                          "ambiguities\n");

    static_assert(param_constructable, "[registerNode]: since this node has ports, "
                                       "you MUST add a constructor sign signature (const "
                                       "std::string&, const "
                                       "NodeParameters&)\n");

    registerBuilder(CreateManifest<T>(ID, ports), CreateBuilder<T>());
  }

  const std::unordered_map<std::string, NodeBuilder>& builders() const;

  const std::unordered_map<std::string, TreeNodeManifest>& manifests() const;

  const std::set<std::string>& builtinNodes() const;

  Tree createTreeFromText(const std::string& text,
                          Blackboard::Ptr blackboard = Blackboard::create());

  Tree createTreeFromFile(const std::string& file_path,
                          Blackboard::Ptr blackboard = Blackboard::create());

  Tree createTree(const std::string& tree_name,
                  Blackboard::Ptr blackboard = Blackboard::create());

  void addDescriptionToManifest(const std::string& node_id,
                                const std::string& description);

private:
  std::unordered_map<std::string, NodeBuilder> builders_;
  std::unordered_map<std::string, TreeNodeManifest> manifests_;
  std::set<std::string> builtin_IDs_;
  std::unordered_map<std::string, Any> behavior_tree_definitions_;

  std::shared_ptr<BT::Parser> parser_;
  // clang-format on
};

}   // namespace BT

#endif   // BT_FACTORY_H