ExactDiagonalizer.h

/* Copyright 2016 Kristofer Björnson
 *
 * 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.
 */


#ifndef COM_DAFER45_TBTK_SOLVER_EXACT_DIAGONALIZATION
#define COM_DAFER45_TBTK_SOLVER_EXACT_DIAGONALIZATION

#include "TBTK/Solver/Diagonalizer.h"
#include "TBTK/FockStateRuleSet.h"
#include "TBTK/FockStateRule/WrapperRule.h"
#include "TBTK/InteractionAmplitudeSet.h"
#include "TBTK/Model.h"
#include "TBTK/ManyParticleContext.h"
#include "TBTK/Solver/Solver.h"

#include <initializer_list>

namespace TBTK{
namespace Solver{

class ExactDiagonalizer : public Solver{
public:
    ExactDiagonalizer(
//      Model *model
    );

    virtual ~ExactDiagonalizer();

    unsigned int addSubspace(std::initializer_list<const FockStateRule::WrapperRule> rules);

    unsigned int addSubspace(std::vector<FockStateRule::WrapperRule> rules);

    unsigned int addSubspace(const FockStateRuleSet &rules);

    void run(unsigned int subspace);

    const CArray<double>& getEigenValues(unsigned int subspace);

    const double getEigenValue(unsigned int subspace, int state);

    const std::complex<double> getAmplitude(
        unsigned int subspace,
        int state,
        const Index &index
    );

//  Model* getModel();
private:
//  Model *model;

    class SubspaceContext{
    public:
        SubspaceContext(
            std::initializer_list<const FockStateRule::WrapperRule> rules
        );

        SubspaceContext(
            std::vector<FockStateRule::WrapperRule> rules
        );

        SubspaceContext(
            const FockStateRuleSet &rules
        );

        ~SubspaceContext();

//      std::vector<FockStateRule::WrapperRule> rules;
        FockStateRuleSet fockStateRuleSet;

//      Model *manyParticleModel;
        std::shared_ptr<Model> manyParticleModel;

//      Diagonalizer *dSolver;
        std::shared_ptr<Diagonalizer> dSolver;
    private:
    };

    std::vector<SubspaceContext> subspaceContexts;

    void setupManyParticleModel(unsigned int subspace);

    template<typename BIT_REGISTER>
    void setupManyParticleModel(unsigned int subspace);
};

inline const CArray<double>& ExactDiagonalizer::getEigenValues(
    unsigned int subspace
){
    return subspaceContexts.at(subspace).dSolver->getEigenValues();
}

inline const double ExactDiagonalizer::getEigenValue(
    unsigned int subspace,
    int state
){
    return subspaceContexts.at(subspace).dSolver->getEigenValue(state);
}

inline const std::complex<double> ExactDiagonalizer::getAmplitude(
    unsigned int subspace,
    int state,
    const Index &index
){
    return subspaceContexts.at(subspace).dSolver->getAmplitude(
        state,
        index
    );
}

/*inline Model* ExactDiagonalizer::getModel(){
    return model;
}*/

};  //End of namespace Solver
};  //End of namespace TBTK

#endif