/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     | Website:  https://openfoam.org
    \\  /    A nd           | Copyright (C) 2016-2026 OpenFOAM Foundation
     \\/     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 "fieldExpression.H"
#include "dictionary.H"

// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //

namespace Foam
{
namespace functionObjects
{
    defineTypeNameAndDebug(fieldExpression, 0);
}
}


const Foam::word Foam::functionObjects::fieldExpression::noFieldName_;


const Foam::word Foam::functionObjects::fieldExpression::noDefaultFieldName_;


// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //

Foam::functionObjects::fieldExpression::fieldExpression
(
    const word& name,
    const Time& runTime,
    const dictionary& dict,
    const word& functionName,
    const word& defaultFieldName
)
:
    fvMeshFunctionObject(name, runTime, dict),
    fieldName_
    (
        &defaultFieldName == &noFieldName_ ? word::null
      : &defaultFieldName == &noDefaultFieldName_ ? dict.lookup<word>("field")
      : dict.lookupOrDefault("field", defaultFieldName)
    ),
    resultName_
    (
        dict.found("result") ? dict.lookup<word>("result")
      : &defaultFieldName == &noFieldName_ ? functionName
      : fieldName_ == defaultFieldName ? functionName
      : word(functionName, '(' + fieldName_, ')')
    )
{
    read(dict);
}


// * * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * //

Foam::functionObjects::fieldExpression::~fieldExpression()
{}


// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //

Foam::wordList Foam::functionObjects::fieldExpression::fields() const
{
    return fieldName_ == word::null ? wordList() : wordList(fieldName_);
}


bool Foam::functionObjects::fieldExpression::execute()
{
    if (!calc())
    {
        Warning
            << "    functionObjects::" << type() << " " << name()
            << " failed to execute." << endl;

        // Clear the result field from the objectRegistry if present
        clear();

        return false;
    }
    else
    {
        return true;
    }
}


bool Foam::functionObjects::fieldExpression::write()
{
    return writeObject(resultName_);
}


bool Foam::functionObjects::fieldExpression::clear()
{
    return clearObject(resultName_);
}


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