modules.h

// Copyright 2018 The Darwin Neuroevolution Framework Authors.
//
// 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.

#pragma once

#include "utils.h"

#include <functional>
#include <map>
#include <memory>
#include <string>
using namespace std;

namespace core {

template <class INTERFACE>
class TypeFactory : public core::NonCopyable {
  using Factory = std::function<INTERFACE*()>;

 public:
  template <class IMPL>
  void add(const string& name) {
    auto factory = [] { return new IMPL(); };
    CHECK(implementations_.insert({ name, factory }).second);
  }

  INTERFACE* create(const string& name) const {
    auto it = implementations_.find(name);
    return it != implementations_.end() ? it->second() : nullptr;
  }

  auto begin() const { return implementations_.begin(); }

  auto end() const { return implementations_.end(); }

  bool empty() const { return implementations_.empty(); }

 private:
  map<string, Factory> implementations_;
};

template <class INTERFACE>
class ImplementationsSet : public core::NonCopyable {
 public:
  template <class FACTORY>
  void add(const string& name) {
    CHECK(factories_.insert({ name, make_unique<FACTORY>() }).second);
  }

  INTERFACE* find(const string& name) const {
    auto it = factories_.find(name);
    return it != factories_.end() ? it->second.get() : nullptr;
  }

  auto begin() const { return factories_.begin(); }

  auto end() const { return factories_.end(); }

  bool empty() const { return factories_.empty(); }

 private:
  map<string, unique_ptr<INTERFACE>> factories_;
};

class ModuleFactory : public core::NonCopyable {
 public:
  virtual ~ModuleFactory() = default;
};

}  // namespace core