##
# Copyright 2012-2020 Ghent University
#
# This file is part of EasyBuild,
# originally created by the HPC team of Ghent University (http://ugent.be/hpc/en),
# with support of Ghent University (http://ugent.be/hpc),
# the Flemish Supercomputer Centre (VSC) (https://www.vscentrum.be),
# Flemish Research Foundation (FWO) (http://www.fwo.be/en)
# and the Department of Economy, Science and Innovation (EWI) (http://www.ewi-vlaanderen.be/en).
#
# https://github.com/easybuilders/easybuild
#
# EasyBuild 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 v2.
#
# EasyBuild 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 EasyBuild.  If not, see <http://www.gnu.org/licenses/>.
##
"""
Support for OpenMPI as toolchain MPI library.

:author: Stijn De Weirdt (Ghent University)
:author: Kenneth Hoste (Ghent University)
"""
import os
import shutil
import tempfile
from distutils.version import LooseVersion

import easybuild.tools.environment as env
from easybuild.tools.build_log import print_warning
from easybuild.tools.config import build_option
from easybuild.tools.toolchain.constants import COMPILER_VARIABLES, MPI_COMPILER_VARIABLES
from easybuild.tools.toolchain.mpi import Mpi
from easybuild.tools.toolchain.variables import CommandFlagList


TC_CONSTANT_OPENMPI = "OpenMPI"
TC_CONSTANT_MPI_TYPE_OPENMPI = "MPI_TYPE_OPENMPI"


class OpenMPI(Mpi):
    """OpenMPI MPI class"""
    MPI_MODULE_NAME = ['OpenMPI']
    MPI_FAMILY = TC_CONSTANT_OPENMPI
    MPI_TYPE = TC_CONSTANT_MPI_TYPE_OPENMPI

    MPI_LIBRARY_NAME = 'mpi'

    # version-dependent, so defined at runtime
    MPI_COMPILER_MPIF77 = None
    MPI_COMPILER_MPIF90 = None
    MPI_COMPILER_MPIFC = None

    # OpenMPI reads from CC etc env variables
    MPI_SHARED_OPTION_MAP = dict([('_opt_%s' % var, '') for var, _ in MPI_COMPILER_VARIABLES])

    MPI_LINK_INFO_OPTION = '-showme:link'

    def __init__(self, *args, **kwargs):
        """Toolchain constructor"""
        super(OpenMPI, self).__init__(*args, **kwargs)

        self.orig_tmpdir = None

    def prepare(self, *args, **kwargs):
        """
        Prepare for using OpenMPI library in toolchain environment
        """
        super(OpenMPI, self).prepare(*args, **kwargs)

        # OpenMPI 2.x trips if path specified in $TMPDIR is too long
        # see https://www.open-mpi.org/faq/?category=osx#startup-errors-with-open-mpi-2.0.x
        self.orig_tmpdir = os.environ.get('TMPDIR')
        ompi_ver = self.get_software_version(self.MPI_MODULE_NAME)[0]
        if LooseVersion(ompi_ver) >= LooseVersion('2.0') and LooseVersion(ompi_ver) < LooseVersion('3.0'):
            if len(self.orig_tmpdir) > 40:
                tmpdir = tempfile.mkdtemp(prefix='/tmp/')
                env.setvar('TMPDIR', tmpdir)
                warn_msg = "Long $TMPDIR path may cause problems with OpenMPI 2.x, using shorter path: %s" % tmpdir
                self.log.warning(warn_msg)
                print_warning(warn_msg, silent=build_option('silent'))

    def _set_mpi_compiler_variables(self):
        """Define MPI wrapper commands (depends on OpenMPI version) and add OMPI_* variables to set."""
        ompi_ver = self.get_software_version(self.MPI_MODULE_NAME)[0]
        # version-dependent, see http://www.open-mpi.org/faq/?category=mpi-apps#override-wrappers-after-v1.0
        if LooseVersion(ompi_ver) >= LooseVersion('1.7'):
            self.MPI_COMPILER_MPIF77 = 'mpifort'
            self.MPI_COMPILER_MPIF90 = 'mpifort'
            self.MPI_COMPILER_MPIFC = 'mpifort'
        else:
            self.MPI_COMPILER_MPIF77 = 'mpif77'
            self.MPI_COMPILER_MPIF90 = 'mpif90'
            self.MPI_COMPILER_MPIFC = 'mpif90'

        # this needs to be done first, otherwise e.g., CC is set to MPICC if the usempi toolchain option is enabled
        for var, _ in COMPILER_VARIABLES:
            self.variables.nappend('OMPI_%s' % var, str(self.variables[var].get_first()), var_class=CommandFlagList)

        super(OpenMPI, self)._set_mpi_compiler_variables()

    def cleanup(self, *args, **kwargs):
        """Clean up after using OpenMPI in toolchain."""
        super(OpenMPI, self).cleanup(*args, **kwargs)

        tmpdir = os.environ.get('TMPDIR')
        if tmpdir != self.orig_tmpdir:
            try:
                shutil.rmtree(tmpdir)
            except OSError as err:
                print_warning("Failed to clean up temporary directory %s: %s", tmpdir, err)
            env.setvar('TMPDIR', self.orig_tmpdir)
            self.log.info("$TMPDIR restored to %s", self.orig_tmpdir)
