/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  v1806                                 |
|   \\  /    A nd           | Web:      www.OpenFOAM.com                      |
|    \\/     M anipulation  |                                                 |
-------------------------------------------------------------------------------
License
    This file is part of OpenFOAM.

    OpenFOAM 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 3 of the License, or
    (at your option) any later version.

    OpenFOAM 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 OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
\*---------------------------------------------------------------------------*/

#include "fvCFD.H"

// ************************************************************************* //

int main(int argc, char *argv[])
{

    // additional message that will be displayed in the help options
    // i.e. when running "waveFoam -help"
    argList::addNote(
     "this application solves the wave equation over given mesh"
    );

	// Set up the case, parse command line options and create the grid
	#include "setRootCase.H"
	#include "createTime.H"
	#include "createMesh.H"

    // reading amplitude field "h" data and wave speed "C"
	#include "createFields.H"

    // starting time loop
    Info << nl << "Starting time loop..." << endl;

    // wave equation has no steady state solution, i.e. always transient in
    // nature. Hence looping through runTime.

    while(runTime.loop())
    {
        // printing current run time on to screen
        Info << nl << "Time = " << runTime.timeName() << endl;

        Info << "Solving h field" << endl;

        // defining the wave equation in OpenFOAM's format
        fvScalarMatrix hEqn
        (
           fvm::d2dt2(h) // second order temporal discretization of amplitude
           == fvm::laplacian(sqr(C),h) // laplacian operation on amplitude, in implicit way.
        );

        // solving the wave equation for current time step.
        hEqn.solve();

        // saving the current timestep solution and writing it to file when
        // insisted by "writeControl" and "writeInterval" on controlDict
        runTime.write();

        // printing execution time information i.e. how much physical time it
        // took to solve the equation
        Info<< "ExecutionTime = " << runTime.elapsedCpuTime() << " s" << endl;
    }

    Info << nl << "End." << endl;

    return 0;
}


// ************************************************************************* //