bt_factory.h

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/* Copyright (C) 2018 Michele Colledanchise -  All Rights Reserved
 * Copyright (C) 2018-2019 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/behavior_tree.h"

namespace BT
{

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

constexpr const char* PLUGIN_SYMBOL = "BT_RegisterNodesFromPlugin";

#ifndef BT_PLUGIN_EXPORT

/* 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 must funtion MUST be declared in a cpp file, NOT a header file.
See examples for more information about configuring CMake correctly
*/
#define BT_REGISTER_NODES(factory)                                                                 \
        static void BT_RegisterNodesFromPlugin(BT::BehaviorTreeFactory& factory)

#else

#ifdef __linux__

#define BT_REGISTER_NODES(factory)                                                                 \
    extern "C" void __attribute__((visibility("default")))                                         \
        BT_RegisterNodesFromPlugin(BT::BehaviorTreeFactory& factory)

#elif _WIN32

#define BT_REGISTER_NODES(factory)                                                                 \
                __declspec(dllexport) void BT_RegisterNodesFromPlugin(BT::BehaviorTreeFactory& factory)
#endif

#endif


struct Tree
{
    TreeNode* root_node;
    std::vector<TreeNode::Ptr> nodes;
    std::vector<Blackboard::Ptr> blackboard_stack;
    std::unordered_map<std::string, TreeNodeManifest> manifests;

    Tree() : root_node(nullptr) { }
    ~Tree();

    Blackboard::Ptr rootBlackboard();
};

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 = BehaviorTreeFactory::buildManifest<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);

    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,
                      "[registerBuilder]: accepts only classed derived from either ActionNodeBase, "
                      "DecoratorNode, ControlNode or ConditionNode");

        static_assert(!std::is_abstract<T>::value,
                      "[registerBuilder]: 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,
                      "[registerBuilder]: the registered class must have at least one of these two "
                      "constructors: "
                      "  (const std::string&, const NodeParameters&) or (const std::string&).");

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

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

        registerNodeTypeImpl<T>(ID);
    }

    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());

    template <typename T> static
    TreeNodeManifest buildManifest(const std::string& ID)
    {
        return { getType<T>(), ID, getProvidedPorts<T>() };
    }

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

    // template specialization = SFINAE + black magic

    // clang-format off
    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>
    void registerNodeTypeImpl(const std::string& ID)
    {
        NodeBuilder builder = getBuilder<T>();
        registerBuilder( buildManifest<T>(ID), builder);
    }

    template <typename T> static
    NodeBuilder getBuilder(typename std::enable_if<has_default_constructor<T>::value &&
                                                   has_params_constructor<T>::value >::type* = nullptr)
    {
        return [](const std::string& name, const NodeConfiguration& config)
        {
            //TODO FIXME

            // 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> static
    NodeBuilder getBuilder(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> static
    NodeBuilder getBuilder(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));
        };
    }
    // clang-format on
};

}   // end namespace

#endif   // BT_FACTORY_H