/* -------------------------------------------------------------------------- *
 *                                   OpenMM                                   *
 * -------------------------------------------------------------------------- *
 * This is part of the OpenMM molecular simulation toolkit.                   *
 * See https://openmm.org/development.                                        *
 *                                                                            *
 * Portions copyright (c) 2008-2012 Stanford University and the Authors.      *
 * Authors: Peter Eastman                                                     *
 * Contributors:                                                              *
 *                                                                            *
 * Permission is hereby granted, free of charge, to any person obtaining a    *
 * copy of this software and associated documentation files (the "Software"), *
 * to deal in the Software without restriction, including without limitation  *
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 * and/or sell copies of the Software, and to permit persons to whom the      *
 * Software is furnished to do so, subject to the following conditions:       *
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 * The above copyright notice and this permission notice shall be included in *
 * all copies or substantial portions of the Software.                        *
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 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,   *
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#include "openmm/OpenMMException.h"
#include "openmm/internal/ContextImpl.h"
#include "openmm/internal/CustomExternalForceImpl.h"
#include "openmm/kernels.h"
#include <sstream>

using namespace OpenMM;
using std::map;
using std::pair;
using std::vector;
using std::set;
using std::string;
using std::stringstream;

CustomExternalForceImpl::CustomExternalForceImpl(const CustomExternalForce& owner) : owner(owner) {
    forceGroup = owner.getForceGroup();
}

CustomExternalForceImpl::~CustomExternalForceImpl() {
}

void CustomExternalForceImpl::initialize(ContextImpl& context) {
    kernel = context.getPlatform().createKernel(CalcCustomExternalForceKernel::Name(), context);

    // Check for errors in the specification of bonds.

    const System& system = context.getSystem();
    vector<double> parameters;
    int numParameters = owner.getNumPerParticleParameters();
    for (int i = 0; i < owner.getNumParticles(); i++) {
        int particle;
        owner.getParticleParameters(i, particle, parameters);
        if (particle < 0 || particle >= system.getNumParticles()) {
            stringstream msg;
            msg << "CustomExternalForce: Illegal particle index: ";
            msg << particle;
            throw OpenMMException(msg.str());
        }
        if (parameters.size() != numParameters) {
            stringstream msg;
            msg << "CustomExternalForce: Wrong number of parameters for particle ";
            msg << i;
            throw OpenMMException(msg.str());
        }
    }
    kernel.getAs<CalcCustomExternalForceKernel>().initialize(context.getSystem(), owner);
}

double CustomExternalForceImpl::calcForcesAndEnergy(ContextImpl& context, bool includeForces, bool includeEnergy, int groups) {
    if ((groups&(1<<forceGroup)) != 0)
        return kernel.getAs<CalcCustomExternalForceKernel>().execute(context, includeForces, includeEnergy);
    return 0.0;
}

vector<string> CustomExternalForceImpl::getKernelNames() {
    return {CalcCustomExternalForceKernel::Name()};
}

map<string, double> CustomExternalForceImpl::getDefaultParameters() {
    map<string, double> parameters;
    for (int i = 0; i < owner.getNumGlobalParameters(); i++)
        parameters[owner.getGlobalParameterName(i)] = owner.getGlobalParameterDefaultValue(i);
    return parameters;
}

void CustomExternalForceImpl::updateParametersInContext(ContextImpl& context, int firstParticle, int lastParticle) {
    kernel.getAs<CalcCustomExternalForceKernel>().copyParametersToContext(context, owner, firstParticle, lastParticle);
    context.systemChanged();
}
