/*************************************************************************************
 
 Grid physics library, www.github.com/paboyle/Grid
 
 Source file: Hadrons/Modules/MDistil/Noises.hpp
 
 Copyright (C) 2019
 
 Author: Felix Erben <ferben@ed.ac.uk>
 Author: Michael Marshall <Michael.Marshall@ed.ac.uk>
 
 This program 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.
 
 This program 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 this program; if not, write to the Free Software Foundation, Inc.,
 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
 See the full license in the file "LICENSE" in the top level distribution directory
 *************************************************************************************/
/*  END LEGAL */

#ifndef Hadrons_MDistil_Noises_hpp_
#define Hadrons_MDistil_Noises_hpp_

#include <Hadrons/Modules/MDistil/Distil.hpp>

BEGIN_HADRONS_NAMESPACE
BEGIN_MODULE_NAMESPACE(MDistil)

/******************************************************************************
 *                         Noises                                 *
 ******************************************************************************/

class NoisesPar: Serializable
{
public:
    GRID_SERIALIZABLE_CLASS_MEMBERS(NoisesPar,
                                    std::string, DistilParams,
                                    std::string, NoiseFileName)
};

template <typename FImpl>
class TNoises: public Module<NoisesPar>
{
public:
    // constructor
    TNoises(const std::string name);
    // destructor
    virtual ~TNoises(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(Noises, TNoises<FIMPL>, MDistil);

/******************************************************************************
 *                 TNoises implementation                             *
 ******************************************************************************/
// constructor /////////////////////////////////////////////////////////////////
template <typename FImpl>
TNoises<FImpl>::TNoises(const std::string name) : Module<NoisesPar>(name) {}

// dependencies/products ///////////////////////////////////////////////////////
template <typename FImpl>
std::vector<std::string> TNoises<FImpl>::getInput(void)
{
    return {par().DistilParams};
}

template <typename FImpl>
std::vector<std::string> TNoises<FImpl>::getOutput(void)
{
    return {getName()};
}

// setup ///////////////////////////////////////////////////////////////////////

template <typename FImpl>
void TNoises<FImpl>::setup(void)
{
    const DistilParameters &dp{envGet(DistilParameters, par().DistilParams)};
    const int Nt{env().getDim(Tdir)};
    std::cout << dp.nnoise << dp.nvec << Nt << Ns << std::endl; 
    envCreate(NoiseTensor, getName(), 1, dp.nnoise, Nt, dp.nvec, Ns);
}

// execution ///////////////////////////////////////////////////////////////////
template <typename FImpl>
void TNoises<FImpl>::execute(void)
{
    const DistilParameters &dp{envGet(DistilParameters, par().DistilParams)};
    const int Nt{env().getDim(Tdir)};
    const bool full_tdil{ dp.TI == Nt };
    const bool exact_distillation{ full_tdil && dp.LI == dp.nvec };
    
    // We use our own seeds so we can specify different noises per quark
    Real rn;
    auto &noise = envGet(NoiseTensor, getName());
    for (int inoise = 0; inoise < dp.nnoise; inoise++) 
    {
        for (int t = 0; t < Nt; t++) 
	{
            for (int ivec = 0; ivec < dp.nvec; ivec++) 
	    {
                for (int is = 0; is < Ns; is++) 
		{
                    if (exact_distillation)
		    {
                        noise.tensor(inoise, t, ivec, is) = 1.;
		    }
    		    else
		    {
                        random(rngSerial(),rn);
                        // We could use a greater number of complex roots of unity
                        // ... but this seems to work well
                        noise.tensor(inoise, t, ivec, is) = (rn > 0.5) ? -1 : 1;
                    }
                }
            }
        }
    }
    if (env().getGrid()->IsBoss())
    {
        std::string sName {par().NoiseFileName};
        sName.append(".");
        sName.append(std::to_string(vm().getTrajectory()));
        noise.write(sName.c_str());
    }
}

END_MODULE_NAMESPACE
END_HADRONS_NAMESPACE
#endif