/*---------------------------------------------------------------------------*\
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 * In real Time Highly Advanced Computational Applications for Finite Volumes
 * Copyright (C) 2017 by the ITHACA-FV authors
-------------------------------------------------------------------------------
License
    This file is part of ITHACA-FV
    ITHACA-FV is free software: you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.
    ITHACA-FV 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 Lesser General Public License for more details.
    You should have received a copy of the GNU Lesser General Public License
    along with ITHACA-FV. If not, see <http://www.gnu.org/licenses/>.
Description
    Example of steady NS Reduction Problem solved by the use of the SIMPLE algorithm
SourceFiles
    12simpleSteadyNS.C
\*---------------------------------------------------------------------------*/

#include "SteadyNSSimple.H"
#include "ITHACAstream.H"
#include "ITHACAPOD.H"
#include "ReducedSimpleSteadyNS.H"
#include "forces.H"
#include "IOmanip.H"


class tutorial12 : public SteadyNSSimple
{
    public:
        /// Constructor
        explicit tutorial12(int argc, char* argv[])
            :
            SteadyNSSimple(argc, argv),
            U(_U()),
            p(_p()),
            phi(_phi())
        {}

        /// Velocity field
        volVectorField& U;
        /// Pressure field
        volScalarField& p;
        ///
        surfaceScalarField& phi;

        /// Perform an Offline solve
        void offlineSolve()
        {
            Vector<double> inl(0, 0, 0);
            List<scalar> mu_now(1);

            // if the offline solution is already performed read the fields
            if (offline)
            {
                ITHACAstream::read_fields(Ufield, U, "./ITHACAoutput/Offline/");
                ITHACAstream::read_fields(Pfield, p, "./ITHACAoutput/Offline/");
                mu_samples =
                    ITHACAstream::readMatrix("./ITHACAoutput/Offline/mu_samples_mat.txt");
            }
            else
            {
                Vector<double> Uinl(1, 0, 0);
                label BCind = 0;

                for (label i = 0; i < mu.cols(); i++)
                {
                    mu_now[0] = mu(0, i);
                    change_viscosity(mu(0, i));
                    assignIF(U, Uinl);
                    truthSolve2(mu_now);
                }
            }
        }

};

int main(int argc, char* argv[])
{
    // Construct the tutorial object
    tutorial12 example(argc, argv);
    // Read some parameters from file
    ITHACAparameters* para = ITHACAparameters::getInstance(example._mesh(),
                             example._runTime());
    int NmodesUout = para->ITHACAdict->lookupOrDefault<int>("NmodesUout", 15);
    int NmodesPout = para->ITHACAdict->lookupOrDefault<int>("NmodesPout", 15);
    int NmodesUproj = para->ITHACAdict->lookupOrDefault<int>("NmodesUproj", 10);
    int NmodesPproj = para->ITHACAdict->lookupOrDefault<int>("NmodesPproj", 10);
    // Read the par file where the parameters are stored
    word filename("./par");
    example.mu = ITHACAstream::readMatrix(filename);
    // Set the inlet boundaries patch 0 directions x and y
    example.inletIndex.resize(1, 2);
    example.inletIndex(0, 0) = 0;
    example.inletIndex(0, 1) = 0;
    // Perform the offline solve
    example.offlineSolve();
    ITHACAstream::read_fields(example.liftfield, example.U, "./lift/");
    // Homogenize the snapshots
    example.computeLift(example.Ufield, example.liftfield, example.Uomfield);
    // Perform POD on velocity and pressure and store the first 10 modes
    ITHACAPOD::getModes(example.Uomfield, example.Umodes, example._U().name(),
                        example.podex, 0, 0,
                        NmodesUout);
    ITHACAPOD::getModes(example.Pfield, example.Pmodes, example._p().name(),
                        example.podex, 0, 0,
                        NmodesPout);
    // Create the reduced object
    reducedSimpleSteadyNS reduced(example);
    PtrList<volVectorField> U_rec_list;
    PtrList<volScalarField> P_rec_list;
    // Reads inlet volocities boundary conditions.
    word vel_file(para->ITHACAdict->lookup("online_velocities"));
    Eigen::MatrixXd vel = ITHACAstream::readMatrix(vel_file);

    //Perform the online solutions
    for (label k = 0; k < (example.mu).size(); k++)
    {
        scalar mu_now = example.mu(0, k);
        example.change_viscosity(mu_now);
        reduced.setOnlineVelocity(vel);
        reduced.solveOnline_Simple(mu_now, NmodesUproj, NmodesPproj);
    }

    return 0;
}