/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     |
    \\  /    A nd           | www.openfoam.com
     \\/     M anipulation  |
-------------------------------------------------------------------------------
    Copyright (C) 2022 OpenCFD Ltd.
-------------------------------------------------------------------------------
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/>.

Application
    Test-parallel-comm2

Description
    Basic communicator tests

\*---------------------------------------------------------------------------*/

#include "argList.H"
#include "Time.H"
#include "IPstream.H"
#include "OPstream.H"
#include "Pair.H"
#include "Tuple2.H"
#include "IOstreams.H"
#include "PstreamReduceOps.H"

using namespace Foam;

void rankInfo(const label comm)
{
    const int ranki = UPstream::myProcNo(comm);

    Pout<< "comm:" << comm
        << "(parent:" << UPstream::parent(comm) << ')'
        << " rank:" << ranki
        << "(sub:" << UPstream::is_subrank(comm)
        << ") nProcs:" << UPstream::nProcs(comm)
        << " baseProcNo:" << UPstream::baseProcNo(comm, ranki);
}


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

int main(int argc, char *argv[])
{
    argList::noBanner();
    argList::noCheckProcessorDirectories();
    argList::addBoolOption("verbose", "Set debug level");

    // Capture manually. We need values before proper startup
    int nVerbose = 0;
    for (int argi = 1; argi < argc; ++argi)
    {
        if (strcmp(argv[argi], "-verbose") == 0)
        {
            ++nVerbose;
        }
    }

    UPstream::debug = nVerbose;

    #include "setRootCase.H"

    Info<< nl
        << "nProcs = " << UPstream::nProcs()
        << " with " << UPstream::nComms() << " predefined comm(s)" << nl;

    Info<< nl;

    //- Process IDs within a given communicator
    Info<< "procIDs: "
        << flatOutput(UPstream::procID(UPstream::worldComm)) << endl;

    rankInfo(UPstream::worldComm);
    Pout<< endl;

    const int myProci = UPstream::myProcNo(UPstream::worldComm);
    int localRanki = myProci;

    labelList subRanks;
    UPstream::communicator newComm;

    #if 1
    // With first ranks
    subRanks = identity(UPstream::nProcs(UPstream::worldComm) / 2);

    newComm.reset(UPstream::worldComm, subRanks);
    localRanki = UPstream::myProcNo(newComm);

    Pout.prefix() =
    (
        '[' + Foam::name(myProci) + " a:" + Foam::name(localRanki) + "] "
    );

    Info<< "procIDs: "
        << flatOutput(UPstream::procID(newComm)) << endl;

    rankInfo(newComm);
    Pout<< endl;
    #endif

    #if 1
    // With every other rank
    subRanks = identity(UPstream::nProcs(UPstream::worldComm));

    for (label& val : subRanks)
    {
        if (val % 2) val = -1;
    }

    newComm.reset(UPstream::worldComm, subRanks);
    localRanki = UPstream::myProcNo(newComm);

    Pout.prefix() =
    (
        '[' + Foam::name(myProci) + " b:" + Foam::name(localRanki) + "] "
    );

    Info<< "procIDs: "
        << flatOutput(UPstream::procID(newComm)) << endl;

    rankInfo(newComm);
    Pout<< endl;
    #endif

    Info<< "\nEnd\n" << endl;

    return 0;
}


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