LazyCutCallback.h

//
// Created by henri on 11/04/23.
//
 
#ifndef CCG_WITH_NESTED_CG_LAZYCUTCALLBACK_H
#define CCG_WITH_NESTED_CG_LAZYCUTCALLBACK_H
 
#include "CutSeparation.h"
#include "idol/mixed-integer/optimizers/callbacks/CallbackFactory.h"
 
namespace idol {
    class LazyCutCallback;
}
 
class idol::LazyCutCallback : public CallbackFactory {
    std::unique_ptr<Model> m_model;
    std::unique_ptr<OptimizerFactory> m_optimizer_factory;
    GenerationPattern<Ctr> m_cut;
    CtrType m_type;
 
    LazyCutCallback(const LazyCutCallback& t_src)
        : m_model(t_src.m_model->clone()),
          m_cut(t_src.m_cut),
          m_type(t_src.m_type),
          m_optimizer_factory(t_src.m_optimizer_factory ? t_src.m_optimizer_factory->clone() : nullptr) {}
public:
    LazyCutCallback(const Model& t_model, GenerationPattern<Ctr> t_cut, CtrType t_type = LessOrEqual) : m_model(t_model.clone()), m_cut(std::move(t_cut)), m_type(t_type) {}
 
    class Strategy : public impl::CutSeparation {
    protected:
        void hook_add_cut(const TempCtr &t_cut) override {
                add_lazy_cut(t_cut);
        }
 
        [[nodiscard]] std::string name() const override {
            return "lazy-cut-callback";
        }
 
    public:
        explicit Strategy(Model* t_separation_problem, GenerationPattern<Ctr> t_cut, CtrType t_type)
                : impl::CutSeparation(IncumbentSolution, t_separation_problem, std::move(t_cut), t_type) {}
 
    };
 
    Callback *operator()() override {
 
        if (!m_optimizer_factory) {
            throw Exception("No optimizer has been given.");
        }
 
        auto* model = m_model->clone();
        model->use(*m_optimizer_factory);
 
        auto* result = new Strategy(model, m_cut, m_type);
 
        return result;
    }
 
    [[nodiscard]] CallbackFactory *clone() const override {
        return new LazyCutCallback(*this);
    }
 
    LazyCutCallback& with_separation_optimizer(const OptimizerFactory& t_optimizer_factory) {
 
        if (m_optimizer_factory) {
            throw Exception("An optimizer has already been given.");
        }
 
        m_optimizer_factory.reset(t_optimizer_factory.clone());
 
        return *this;
    }
 
};
 
#endif //CCG_WITH_NESTED_CG_LAZYCUTCALLBACK_H