/*
 * EMT.hpp, part of Hadrons (https://github.com/aportelli/Hadrons)
 *
 * Copyright (C) 2015 - 2023
 *
 * Author: Antonin Portelli <antonin.portelli@me.com>
 * Author: Simon Bürger <simon.buerger@rwth-aachen.de>
 *
 * Hadrons is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 *
 * Hadrons is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Hadrons.  If not, see <http://www.gnu.org/licenses/>.
 *
 * See the full license in the file "LICENSE" in the top level distribution 
 * directory.
 */

/*  END LEGAL */
#ifndef Hadrons_MScalarSUN_EMT_hpp_
#define Hadrons_MScalarSUN_EMT_hpp_

#include <Hadrons/Global.hpp>
#include <Hadrons/Module.hpp>
#include <Hadrons/ModuleFactory.hpp>
#include <Hadrons/Modules/MScalarSUN/Utils.hpp>
#include <Hadrons/Serialization.hpp>

BEGIN_HADRONS_NAMESPACE

/******************************************************************************
 *                         Energy-momentum tensor                             *
 ******************************************************************************/
BEGIN_MODULE_NAMESPACE(MScalarSUN)

class EMTPar: Serializable
{
public:
    GRID_SERIALIZABLE_CLASS_MEMBERS(EMTPar,
                                    std::string, kinetic,
                                    std::string, phiPow,
                                    std::string, improvement,
                                    double     , m2,
                                    double     , lambda,
                                    double     , g,
                                    double     , xi,
                                    std::string, output);
};

class EMTResult: Serializable
{
public:
    GRID_SERIALIZABLE_CLASS_MEMBERS(EMTResult,
                                    std::vector<std::vector<Complex>>, value,
                                    double,                            m2,
                                    double,                            lambda,
                                    double,                            g,
                                    double,                            xi);
};

template <typename SImpl>
class TEMT: public Module<EMTPar>
{
public:
    typedef typename SImpl::Field        Field;
    typedef typename SImpl::ComplexField ComplexField;
public:
    // constructor
    TEMT(const std::string name);
    // destructor
    virtual ~TEMT(void) {};
    // dependency relation
    virtual std::vector<std::string> getInput(void);
    virtual std::vector<std::string> getOutput(void);
    // setup
    virtual void setup(void);
    // execution
    virtual void execute(void);
};

MODULE_REGISTER_TMP(EMTSU2, TEMT<ScalarNxNAdjImplR<2>>, MScalarSUN);
MODULE_REGISTER_TMP(EMTSU3, TEMT<ScalarNxNAdjImplR<3>>, MScalarSUN);
MODULE_REGISTER_TMP(EMTSU4, TEMT<ScalarNxNAdjImplR<4>>, MScalarSUN);
MODULE_REGISTER_TMP(EMTSU5, TEMT<ScalarNxNAdjImplR<5>>, MScalarSUN);
MODULE_REGISTER_TMP(EMTSU6, TEMT<ScalarNxNAdjImplR<6>>, MScalarSUN);

/******************************************************************************
 *                           TEMT implementation                              *
 ******************************************************************************/
// constructor /////////////////////////////////////////////////////////////////
template <typename SImpl>
TEMT<SImpl>::TEMT(const std::string name)
: Module<EMTPar>(name)
{}

// dependencies/products ///////////////////////////////////////////////////////
template <typename SImpl>
std::vector<std::string> TEMT<SImpl>::getInput(void)
{
    std::vector<std::string> in;
    
    for (unsigned int mu = 0; mu < env().getNd(); ++mu)
    for (unsigned int nu = mu; nu < env().getNd(); ++nu)
    {
        in.push_back(varName(par().kinetic, mu, nu));
        if (!par().improvement.empty())
        {
            in.push_back(varName(par().improvement, mu, nu));
        }
    }
    in.push_back(varName(par().kinetic, "sum"));
    in.push_back(varName(par().phiPow, 2));
    in.push_back(varName(par().phiPow, 4));

    return in;
}

template <typename SImpl>
std::vector<std::string> TEMT<SImpl>::getOutput(void)
{
    std::vector<std::string> out;
    
    for (unsigned int mu = 0; mu < env().getNd(); ++mu)
    for (unsigned int nu = mu; nu < env().getNd(); ++nu)
    {
        out.push_back(varName(getName(), mu, nu));
    }
    out.push_back(getName());

    return out;
}

// setup ///////////////////////////////////////////////////////////////////////
template <typename SImpl>
void TEMT<SImpl>::setup(void)
{
    for (unsigned int mu = 0; mu < env().getNd(); ++mu)
    for (unsigned int nu = mu; nu < env().getNd(); ++nu)
    {
        envCreateLat(ComplexField, varName(getName(), mu, nu));
    }
    envCreate(HadronsSerializable, getName(), 1, 0);
}

// execution ///////////////////////////////////////////////////////////////////
template <typename SImpl>
void TEMT<SImpl>::execute(void)
{
    LOG(Message) << "Computing energy-momentum tensor" << std::endl;
    LOG(Message) << "  kinetic terms: '" << par().kinetic << "'" << std::endl;
    LOG(Message) << "      tr(phi^n): '" << par().phiPow << "'" << std::endl;
    if (!par().improvement.empty())
    {
        LOG(Message) << "    improvement: '" << par().improvement << "'" << std::endl;
    }
    LOG(Message) << "            m^2= " << par().m2 << std::endl;
    LOG(Message) << "         lambda= " << par().lambda << std::endl;
    LOG(Message) << "              g= " << par().g << std::endl;
    if (!par().improvement.empty())
    {
        LOG(Message) << "             xi= " << par().xi << std::endl;
    }

    const unsigned int N = SImpl::Group::Dimension, nd = env().getNd();
    auto               &trphi2 = envGet(ComplexField, varName(par().phiPow, 2));
    auto               &trphi4 = envGet(ComplexField, varName(par().phiPow, 4));
    auto               &sumkin = envGet(ComplexField, varName(par().kinetic, "sum"));
    EMTResult          result;

    if (!par().output.empty())
    {
        result.m2     = par().m2;
        result.g      = par().g;
        result.lambda = par().lambda;
        result.xi     = par().xi;
        result.value.resize(nd, std::vector<Complex>(nd));
    }
    for (unsigned int mu = 0; mu < nd; ++mu)
    for (unsigned int nu = mu; nu < nd; ++nu)
    {
        auto &out   = envGet(ComplexField, varName(getName(), mu, nu));
        auto &trkin = envGet(ComplexField, varName(par().kinetic, mu, nu));
        
        out = 2.*trkin;
        if (!par().improvement.empty())
        {
            auto &imp = envGet(ComplexField, varName(par().improvement, mu, nu));

            out += par().xi*imp;
        }
        if (mu == nu)
        {
            out -= sumkin + par().m2*trphi2 + par().lambda*trphi4;
        }
        out *= N/par().g;
        if (!par().output.empty())
        {
            result.value[mu][nu] = TensorRemove(sum(out));
            result.value[mu][nu] = result.value[nu][mu];
        }
    }

    saveResult(par().output, "emt", result);
    envGet(HadronsSerializable, getName()) = result;
}

END_MODULE_NAMESPACE

END_HADRONS_NAMESPACE

#endif // Hadrons_MScalarSUN_EMT_hpp_