/*
 * This file is part of the GROMACS molecular simulation package.
 *
 * Copyright 2013- The GROMACS Authors
 * and the project initiators Erik Lindahl, Berk Hess and David van der Spoel.
 * Consult the AUTHORS/COPYING files and https://www.gromacs.org for details.
 *
 * GROMACS 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 2.1
 * of the License, or (at your option) any later version.
 *
 * GROMACS 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 GROMACS; if not, see
 * https://www.gnu.org/licenses, or write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA.
 *
 * If you want to redistribute modifications to GROMACS, please
 * consider that scientific software is very special. Version
 * control is crucial - bugs must be traceable. We will be happy to
 * consider code for inclusion in the official distribution, but
 * derived work must not be called official GROMACS. Details are found
 * in the README & COPYING files - if they are missing, get the
 * official version at https://www.gromacs.org.
 *
 * To help us fund GROMACS development, we humbly ask that you cite
 * the research papers on the package. Check out https://www.gromacs.org.
 */

/*! \internal \file
 * \brief
 * Tests for the mdrun -rerun functionality
 *
 * \author Mark Abraham <mark.j.abraham@gmail.com>
 * \ingroup module_mdrun_integration_tests
 */
#include "gmxpre.h"

#include "config.h"

#include "gromacs/topology/ifunc.h"
#include "gromacs/utility/strconvert.h"
#include "gromacs/utility/stringutil.h"

#include "testutils/mpitest.h"
#include "testutils/simulationdatabase.h"

#include "moduletest.h"
#include "simulatorcomparison.h"

namespace gmx
{
namespace test
{
namespace
{
/*! \brief Test fixture base for mdrun -rerun
 *
 * This test ensures mdrun can run a simulation, writing a trajectory
 * and matching energies, and reproduce the same energies from a rerun
 * to within a tight tolerance. It says nothing about whether a rerun
 * can reproduce energies from a trajectory generated with older code,
 * since that is not a useful property. Whether mdrun produced correct
 * energies then and now needs different kinds of testing, but if
 * true, this test ensures the rerun has the expected property.
 *
 * The limitations of mdrun and its output means that reproducing the
 * same energies is currently only meaningful for integration without
 * thermostats or barostats, however the present form of the test
 * infrastructure has in-principle support for such, if that is ever
 * needed/useful.
 *
 * We should also not compare pressure, because with constraints the
 * non-search steps need a much larger tolerance, and per Issue #1868
 * we should stop computing pressure in reruns anyway.
 *
 * Similarly, per 1868, in the present implementation the kinetic
 * energy quantities are not generally reproducible, either.
 *
 * The choices for tolerance are arbitrary but sufficient.  Rerun does
 * pair search every frame, so it cannot in general exactly reproduce
 * quantities from a normal run, because the accumulation order
 * differs. (Nor does it reproduce pair-search frames exactly,
 * either). */
class MdrunRerunTest :
    public MdrunTestFixture,
    public ::testing::WithParamInterface<std::tuple<std::string, std::string>>
{
public:
    //! Trajectory components to compare
    static const TrajectoryFrameMatchSettings trajectoryMatchSettings;
};

// Compare box, positions and forces, but not velocities
// (velocities are ignored in reruns)
const TrajectoryFrameMatchSettings MdrunRerunTest::trajectoryMatchSettings = {
    true,
    true,
    true,
    ComparisonConditions::MustCompare,
    ComparisonConditions::NoComparison,
    ComparisonConditions::MustCompare,
    MaxNumFrames::compareAllFrames()
};

void executeRerunTest(TestFileManager*            fileManager,
                      SimulationRunner*           runner,
                      const std::string&          simulationName,
                      int                         numWarningsToTolerate,
                      const MdpFieldValues&       mdpFieldValues,
                      const EnergyTermsToCompare& energyTermsToCompare,
                      const TrajectoryComparison& trajectoryComparison)
{
    // TODO At some point we should also test PME-only ranks.
    int numRanksAvailable = getNumberOfTestMpiRanks();
    if (!isNumberOfPpRanksSupported(simulationName, numRanksAvailable))
    {
        fprintf(stdout,
                "Test system '%s' cannot run with %d ranks.\n"
                "The supported numbers are: %s\n",
                simulationName.c_str(),
                numRanksAvailable,
                reportNumbersOfPpRanksSupported(simulationName).c_str());
        return;
    }

    // Set file names
    auto simulator1TrajectoryFileName = fileManager->getTemporaryFilePath("sim1.trr");
    auto simulator1EdrFileName        = fileManager->getTemporaryFilePath("sim1.edr");
    auto simulator2TrajectoryFileName = fileManager->getTemporaryFilePath("sim2.trr");
    auto simulator2EdrFileName        = fileManager->getTemporaryFilePath("sim2.edr");

    // Run grompp
    runner->tprFileName_ = fileManager->getTemporaryFilePath("sim.tpr").u8string();
    runner->useTopGroAndNdxFromDatabase(simulationName);
    runner->useStringAsMdpFile(prepareMdpFileContents(mdpFieldValues));
    auto options = std::vector<SimulationOptionTuple>();
    if (numWarningsToTolerate > 0)
    {
        options.emplace_back(SimulationOptionTuple("-maxwarn", std::to_string(numWarningsToTolerate)));
    }
    runGrompp(runner, options);

    // Do first mdrun
    runner->fullPrecisionTrajectoryFileName_ = simulator1TrajectoryFileName.u8string();
    runner->edrFileName_                     = simulator1EdrFileName.u8string();
    runMdrun(runner);

    // Do second mdrun
    runner->fullPrecisionTrajectoryFileName_ = simulator2TrajectoryFileName.u8string();
    runner->edrFileName_                     = simulator2EdrFileName.u8string();
    runMdrun(runner, { SimulationOptionTuple("-rerun", simulator1TrajectoryFileName.u8string()) });

    // Compare simulation results
    compareEnergies(simulator1EdrFileName.u8string(), simulator2EdrFileName.u8string(), energyTermsToCompare);
    compareTrajectories(simulator1TrajectoryFileName.u8string(),
                        simulator2TrajectoryFileName.u8string(),
                        trajectoryComparison);
}

TEST_P(MdrunRerunTest, WithinTolerances)
{
    auto params         = GetParam();
    auto simulationName = std::get<0>(params);
    auto integrator     = std::get<1>(params);
    SCOPED_TRACE(
            formatString("Comparing normal and rerun of simulation '%s' "
                         "with integrator '%s'",
                         simulationName.c_str(),
                         integrator.c_str()));

    auto mdpFieldValues =
            prepareMdpFieldValues(simulationName.c_str(), integrator.c_str(), "no", "no");

    // bd is much less reproducible in a rerun than the other integrators
    const int            toleranceScaleFactor = (integrator == "bd") ? 2 : 1;
    EnergyTermsToCompare energyTermsToCompare{ {
            { interaction_function[F_EPOT].longname,
              relativeToleranceAsPrecisionDependentUlp(
                      10.0, 24 * toleranceScaleFactor, 40 * toleranceScaleFactor) },
    } };

    // Specify how trajectory frame matching must work
    TrajectoryComparison trajectoryComparison{ trajectoryMatchSettings,
                                               TrajectoryComparison::s_defaultTrajectoryTolerances };

    int numWarningsToTolerate = 0;
    executeRerunTest(&fileManager_,
                     &runner_,
                     simulationName,
                     numWarningsToTolerate,
                     mdpFieldValues,
                     energyTermsToCompare,
                     trajectoryComparison);
}

// TODO The time for OpenCL kernel compilation means these tests time
// out. Once that compilation is cached for the whole process, these
// tests can run in such configurations.
#if !GMX_GPU_OPENCL
INSTANTIATE_TEST_SUITE_P(
        NormalMdrunIsReproduced,
        MdrunRerunTest,
        ::testing::Combine(::testing::Values("argon12", "tip3p5", "alanine_vsite_vacuo"),
                           ::testing::Values("md", "md-vv", "bd", "sd")));
#else
INSTANTIATE_TEST_SUITE_P(
        DISABLED_NormalMdrunIsReproduced,
        MdrunRerunTest,
        ::testing::Combine(::testing::Values("argon12", "tip3p5", "alanine_vsite_vacuo"),
                           ::testing::Values("md", "md-vv", "bd", "sd")));
#endif

class MdrunRerunFreeEnergyTest :
    public MdrunTestFixture,
    public ::testing::WithParamInterface<std::tuple<std::string, std::string, int>>
{
};

TEST_P(MdrunRerunFreeEnergyTest, WithinTolerances)
{
    auto params          = GetParam();
    auto simulationName  = std::get<0>(params);
    auto integrator      = std::get<1>(params);
    auto initLambdaState = std::get<2>(params);
    SCOPED_TRACE(
            formatString("Comparing normal and rerun of simulation '%s' "
                         "with integrator '%s' for initial lambda state %d",
                         simulationName.c_str(),
                         integrator.c_str(),
                         initLambdaState));

    auto mdpFieldValues =
            prepareMdpFieldValues(simulationName.c_str(), integrator.c_str(), "no", "no");
    mdpFieldValues["init-lambda-state"] = toString(initLambdaState);

    EnergyTermsToCompare energyTermsToCompare{
        { { interaction_function[F_EPOT].longname, relativeToleranceAsPrecisionDependentUlp(10.0, 24, 32) },
          { interaction_function[F_DVDL_COUL].longname, relativeToleranceAsPrecisionDependentUlp(1.0, 8, 8) },
          { interaction_function[F_DVDL_VDW].longname, relativeToleranceAsPrecisionDependentUlp(1.0, 8, 8) },
          { interaction_function[F_DVDL_BONDED].longname,
            relativeToleranceAsPrecisionDependentUlp(1.0, 8, 8) },
          { interaction_function[F_DVDL_RESTRAINT].longname,
            relativeToleranceAsPrecisionDependentUlp(1.0, 8, 8) } }
    };

    // Specify how trajectory frame matching must work
    TrajectoryComparison trajectoryComparison{ MdrunRerunTest::trajectoryMatchSettings,
                                               TrajectoryComparison::s_defaultTrajectoryTolerances };

    // The md integrator triggers a warning for nearly decoupled
    // states, which we need to suppress. TODO sometimes?
    int numWarningsToTolerate = (integrator == "md") ? 1 : 0;
    executeRerunTest(&fileManager_,
                     &runner_,
                     simulationName,
                     numWarningsToTolerate,
                     mdpFieldValues,
                     energyTermsToCompare,
                     trajectoryComparison);
}

// TODO The time for OpenCL kernel compilation means these tests time
// out. Once that compilation is cached for the whole process, these
// tests can run in such configurations.
#if !GMX_GPU_OPENCL
INSTANTIATE_TEST_SUITE_P(MdrunIsReproduced,
                         MdrunRerunFreeEnergyTest,
                         ::testing::Combine(::testing::Values("nonanol_vacuo"),
                                            ::testing::Values("md", "md-vv", "sd"),
                                            ::testing::Range(0, 11)));
#else
INSTANTIATE_TEST_SUITE_P(DISABLED_MdrunIsReproduced,
                         MdrunRerunFreeEnergyTest,
                         ::testing::Combine(::testing::Values("nonanol_vacuo"),
                                            ::testing::Values("md", "md-vv", "sd"),
                                            ::testing::Range(0, 11)));
#endif

} // namespace
} // namespace test
} // namespace gmx
