# Copyright 2013-2020 Lawrence Livermore National Security, LLC and other
# Spack Project Developers. See the top-level COPYRIGHT file for details.
#
# SPDX-License-Identifier: (Apache-2.0 OR MIT)

from spack import *


class Nekbone(Package):
    """NEK5000 emulation software called NEKbone. Nekbone captures the basic
       structure and user interface of the extensive Nek5000 software.
       Nek5000 is a high order, incompressible Navier-Stokes solver based on
       the spectral element method."""

    homepage = "https://github.com/Nek5000/Nekbone"
    git      = "https://github.com/Nek5000/Nekbone.git"

    tags = ['proxy-app', 'ecp-proxy-app']

    version('develop', branch='master')
    version('17.0',
            'ae361cc61368a924398a28a296f675b7f0c4a9516788a7f8fa3c09d787cdf69b',
            url='https://github.com/Nek5000/Nekbone/archive/v17.0.tar.gz',
            extension='.tar.gz')

    # Variants
    variant('mpi', default=True, description='Build with MPI')

    # dependencies
    depends_on('mpi', when='+mpi')

    @run_before('install')
    def fortran_check(self):
        if not self.compiler.fc:
            msg = 'Nekbone can not be built without a Fortran compiler.'
            raise RuntimeError(msg)

    def install(self, spec, prefix):
        mkdir(prefix.bin)

        fc = self.compiler.fc
        cc = self.compiler.cc
        if '+mpi' in spec:
            fc = spec['mpi'].mpif77
            cc = spec['mpi'].mpicc

        # Install Nekbone in prefix.bin
        install_tree(self.stage.source_path, prefix.bin.Nekbone)

        # Install scripts in prefix.bin
        nekpmpi = 'test/example1/nekpmpi'
        makenek = 'test/example1/makenek'

        install(makenek, prefix.bin)
        install(nekpmpi, prefix.bin)

        error = Executable(fc)('empty.f', output=str, error=str,
                               fail_on_error=False)

        fflags = ''
        if 'gfortran' in error or 'GNU' in error or 'gfortran' in fc:
            # Use '-std=legacy' to suppress an error that used to be a
            # warning in previous versions of gfortran.
            fflags = ' -std=legacy'

        with working_dir(prefix.bin):
            filter_file(r'^SOURCE_ROOT\s*=.*', 'SOURCE_ROOT=\"' +
                        prefix.bin.Nekbone + '/src\"', 'makenek')
            filter_file(r'^CC\s*=.*', 'CC=\"' + cc + '\"', 'makenek')
            filter_file(r'^F77\s*=.*', 'F77=\"' + fc + fflags + '\"',
                        'makenek')

            if '+mpi' not in spec:
                filter_file(r'^#IFMPI=\"false\"', 'IFMPI=\"false\"', 'makenek')