#!/usr/bin/env python
# -*- coding: utf-8 -*-

#-------------------------------------------------------------------------------

# This file is part of Code_Saturne, a general-purpose CFD tool.
#
# Copyright (C) 1998-2013 EDF S.A.
#
# This program 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 2 of the License, or (at your option) any later
# version.
#
# This program 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
# this program; if not, write to the Free Software Foundation, Inc., 51 Franklin
# Street, Fifth Floor, Boston, MA 02110-1301, USA.

#-------------------------------------------------------------------------------

try:
    import ConfigParser  # Python2
    configparser = ConfigParser
except Exception:
    import configparser  # Python3

import datetime
import fnmatch
import os
import subprocess
import sys
import platform
import tempfile

python_version = sys.version[:3]

#===============================================================================
# Utility functions
#===============================================================================

def abs_exec_path(path):
    """
    Find an executable in the system path.
    """

    abs_path = None

    if os.path.isabs(path):
        return path

    else:
        try:
            for d in os.getenv('PATH').split():
                f = os.path.join(d, path)
                if os.path.isfile(f):
                    return f
        except Exception:
            pass

    return None

#---------------------------------------------------------------------------

def separate_args(s):
    """
    Separate arguments that may contain whitespace, depending on whether
    whitespace is protected or not by ", ', and \ characters.
    If quotes are found after the beginning of a string, such as in
    --option="string 1", do not remove them.
    """

    l = []
    if s:
        a = ''
        sep = False
        protected = False
        in_quotes = ''
        for i in range(len(s)):
            if protected:
                a += s[i]
                protected = False
            else:
                if s[i] == '\\':
                    protected = True
                elif s[i] == '"' or s[i] == "'":
                    if in_quotes == s[i]:
                        a += s[i]
                        in_quotes = ''
                    elif in_quotes != '':
                            a += s[i]
                    else:
                        a += s[i]
                        in_quotes = s[i]
                elif in_quotes != '':
                    a += s[i]
                elif (s[i] == ' ' or s[i] == '\t'):
                    if a != '':
                        if (a[0] == a[-1:]) and (a[0] == '"' or a[0] == "'"):
                            l.append(a[1:-1])
                        else:
                            l.append(a)
                        a = ''
                else:
                    a += s[i]

        if a != '':
            l.append(a)

    return l

#---------------------------------------------------------------------------

def enquote_arg(s):
    """
    Add quotes around argument if it contains whitespace, leave it
    unchanged otherwise; if the argument already contains unprotected
    quotes, do not add any more (so for example --option="string 1"
    is unchanged).
    """

    if s:
        if (s.find(' ') > -1):
            protect = False
            for i in range(len(s)):
                if s[i] == '\\':
                    protect = not protect
                if not protect and s[i] == '"':
                    return s
            return '"' + s + '"'
        else:
            return s
    else:
        return s

#---------------------------------------------------------------------------

def get_shell_type():
    """
    Get name of current shell if available.
    (Bourne shell variants are handled, C-shell variants are not).
    """

    if sys.platform.startswith('win'):
        return None

    user_shell = os.getenv('SHELL')
    if not user_shell:
        user_shell = '/bin/sh'
    elif user_shell[-3:] == 'csh':
        user_shell = '/bin/sh'

    return user_shell

#-------------------------------------------------------------------------------

def write_shell_shebang(fd):
    """
    Write the shell shebang or '@echo off' for a Windows COMMAND.
    """

    if sys.platform.startswith('win'):
        fd.write('@echo off\n\n')
    else:
        user_shell = get_shell_type()
        fd.write('#!' + user_shell + '\n\n')

#-------------------------------------------------------------------------------

def write_script_comment(fd, comment):
    """
    Write a comment in a script in the correct form.
    (starting with a '#' for Linux shells and 'rem' for Windows COMMAND).
    """

    if sys.platform.startswith('win'):
        fd.write('rem ')
    else:
        fd.write('# ')
    fd.write(comment)

#-------------------------------------------------------------------------------

def write_export_env(fd, var, value):
    """
    Write the correct command so as to export environment variables.
    """

    if sys.platform.startswith('win'):
        export_cmd = 'set ' + var + '=' + value
    else:
        if get_shell_type()[-3:] == 'csh': # handle C-type shells
            export_cmd = 'setenv ' + var + ' ' + value
        else:                              # handle Bourne-type shells
            export_cmd = 'export ' + var + '=' + value
    export_cmd = export_cmd + '\n'
    fd.write(export_cmd)

#-------------------------------------------------------------------------------

def write_prepend_path(fd, var, user_path):
    """
    Write the correct command so as to export PATH-type variables.
    """

    # Caution: Windows PATH must NOT must double-quoted to account for blanks
    # =======  in paths,contrary to UNIX systems
    if sys.platform.startswith('win'):
        export_cmd = 'set ' + var + '=' + user_path + ';%' + var + '%'
    else:
        if get_shell_type()[-3:] == 'csh': # handle C-type shells
            export_cmd = 'setenv ' + var + ' "' + user_path + '":$' + var
        else:                              # handle Bourne-type shells
            export_cmd = 'export ' + var + '="' + user_path + '":$' + var
    export_cmd = export_cmd + '\n'
    fd.write(export_cmd)

#-------------------------------------------------------------------------------

def clean_path(path):
    """
    Remove duplicates from path.
    """

    # Case for a string

    if type(path) == str:

        if not path:
            return ''

        if sys.platform.startswith('win'):
            s = ';'
        else:
            s = ':'

        vals = path.split(s)

        clean_path(vals)

        value = ''
        for v in vals:
            if value:
                value += s + v
            else:
                value = v

        return value

    # Case for a list

    elif type(path) == list:

        i = len(path) - 1
        while i > -1:
            if path.count(i) > 1 or not path[i]:
                path.pop(i)
            i -= 1

    return path

#-------------------------------------------------------------------------------

def get_script_positional_args():
    """
    Write the positional arguments with a newline character.
    """

    if sys.platform.startswith('win'):
        args = '%*'
    else:
        args = '$@'
    return args

#-------------------------------------------------------------------------------

def get_script_return_code():
    """
    Write the return code with a newline character.
    """

    if sys.platform.startswith('win'):
        ret_code = '%ERROR_LEVEL%'
    else:
        ret_code = '$?'
    return ret_code

#-------------------------------------------------------------------------------

def run_command(cmd, pkg = None, echo = False,
                stdout = sys.stdout, stderr = sys.stderr, env = None):
    """
    Run a command.
    """
    if echo == True:
        if type(cmd) == str:
            stdout.write(str(cmd) + '\n')
        else:
            l = ''
            for s in cmd:
                if (s.find(' ') > -1):
                    l += ' ' + enquote_arg(s)
                else:
                    l += ' ' + s
            stdout.write(l.strip() + '\n')

    # Modify the PATH for relocatable installation: add Code_Saturne "bindir"

    if pkg != None:
        if pkg.config.features['relocatable'] == "yes":
            if sys.platform.startswith("win"):
                sep = ";"
            else:
                sep = ":"
            saved_path = os.environ['PATH']
            os.environ['PATH'] = pkg.get_dir('bindir') + sep + saved_path

    # As a workaround for a bug in which the standard output an error
    # are "lost" (observed in an apparently random manner, with Python 2.4),
    # we only add the stdout and stderr keywords if they are non-default.

    kwargs = {}
    if (stdout != sys.stdout):
        kwargs['stdout'] = stdout
    if (stderr != sys.stderr):
        kwargs['stderr'] = stderr

    if type(cmd) == str:
        p = subprocess.Popen(cmd,
                             shell=True,
                             executable=get_shell_type(),
                             env = env,
                             **kwargs)
    else:
        p = subprocess.Popen(cmd, env = env, **kwargs)

    p.communicate()

    # Reset the PATH to its previous value

    if pkg != None:
        if pkg.config.features['relocatable'] == "yes":
            os.environ['PATH'] = saved_path

    return p.returncode

#-------------------------------------------------------------------------------

def get_command_output(cmd):
    """
    Run a command and return it's standard output.
    """
    p = subprocess.Popen(cmd,
                         shell=True,
                         executable=get_shell_type(),
                         stdout=subprocess.PIPE,
                         stderr=subprocess.PIPE)
    output = p.communicate()
    if p.returncode != 0:
        sys.stderr.write(output[1] + '\n')
        return ''
    else:
        return output[0]

#-------------------------------------------------------------------------------

def get_command_outputs(cmd):
    """
    Run a command and return it's standard and error outputs.
    """
    p = subprocess.Popen(cmd,
                         shell=True,
                         executable=get_shell_type(),
                         stdout=subprocess.PIPE,
                         stderr=subprocess.STDOUT)
    return p.communicate()[0]

#-------------------------------------------------------------------------------

def set_modules(pkg):
    """
    Set environment modules if present.
    """

    if pkg.config.env_modules == "no":
        return

    cmd_prefix = pkg.config.env_modulecmd

    cmds = ['purge']
    for m in pkg.config.env_modules.strip().split():
        cmds.append('load ' + m)
    for cmd in cmds:
        (output, error) = subprocess.Popen([cmd_prefix, 'python'] + cmd.split(),
                                           stdout=subprocess.PIPE).communicate()
        exec(output)

#-------------------------------------------------------------------------------

def source_shell_script(path):
    """
    Source shell script.
    """

    if not os.path.isfile(path):
        sys.stderr.write('Warning:\n'
                         + '   file ' + path + '\n'
                         + 'not present, so cannot be sourced.\n\n')

    if sys.platform.startswith('win'):
        return

    user_shell = os.getenv('SHELL')
    if not user_shell:
        user_shell = '/bin/sh'

    cmd = ['source ' + path + ' && env']

    p = subprocess.Popen(cmd,
                         shell=True,
                         executable=user_shell,
                         stdout=subprocess.PIPE,
                         stderr=subprocess.PIPE)

    output = p.communicate()[0]

    for line in output.splitlines():

        (key, _, value) = line.partition("=")

        # For paths, cleanup (remove multiple values) first
        if key[-4:] == 'PATH':
            value = clean_path(value)

        # Add key, value
        os.environ[key] = value

        # additional handling for Python path
        if key == 'PYTHONPATH':
            vals = value.split(':')
            vals.reverse()
            for v in vals:
                if v:
                    sys.path.insert(0, v)
            sys.path = clean_path(sys.path)

#-------------------------------------------------------------------------------

def source_rcfile(pkg):
    """
    Source user environement if defined by rcfile in preferences file.
    """

    config = configparser.ConfigParser()
    config.read(pkg.get_configfiles())

    if config.has_option('install', 'rcfile'):
        rcfile = config.get('install', 'rcfile')
        if not os.path.isabs(rcfile):
            rcfile = '~/.' + rcfile
        source_shell_script(rcfile)

#-------------------------------------------------------------------------------

class batch_info:

    #---------------------------------------------------------------------------

    def __init__(self):

        """
        Get batch system information.
        """

        self.batch_type = None
        self.submit_dir = None
        self.job_file = None
        self.job_name = None
        self.job_id = None
        self.queue = None

        # Check for specific batch environments

        s = os.getenv('LSB_JOBID') # LSF
        if s != None:
            self.batch_type = 'LSF'
            self.submit_dir = os.getenv('LS_SUBCWDIR')
            self.job_file = os.getenv('LSB_JOBFILENAME')
            self.job_name = os.getenv('LSB_JOBNAME')
            self.job_id = os.getenv('LSB_BATCH_JID')
            self.queue = os.getenv('LSB_QUEUE')

        if self.batch_type == None:
            s = os.getenv('PBS_JOBID') # PBS
            if s != None:
                self.batch_type = 'PBS'
                self.submit_dir = os.getenv('PBS_O_WORKDIR')
                self.job_name = os.getenv('PBS_JOBNAME')
                self.job_id = os.getenv('PBS_JOBID')
                self.queue = os.getenv('PBS_QUEUE')

        if self.batch_type == None:
            s = os.getenv('LOADL_JOB_NAME') # LoadLeveler
            if s != None:
                self.batch_type = 'LOADL'
                self.job_file = os.getenv('LOADL_STEP_COMMAND')
                self.submit_dir = os.getenv('LOADL_STEP_INITDIR')
                self.job_name = os.getenv('LOADL_JOB_NAME')
                self.job_id = os.getenv('LOADL_STEP_ID')
                self.queue = os.getenv('LOADL_STEP_CLASS')

        if self.batch_type == None:
            s = os.getenv('SGE_TASK_ID') # Sun Grid Engine
            if s != None:
                self.batch_type = 'SGE'
                self.submit_dir = os.getenv('SGE_O_WORKDIR')
                self.job_name = os.getenv('JOB_NAME')
                self.job_id = os.getenv('JOB_ID')
                self.queue = os.getenv('QUEUE')

        if self.batch_type == None:
            s = os.getenv('SLURM_JOBID') # SLURM
            if s != None:
                self.batch_type = 'SLURM'
                self.submit_dir = os.getenv('SLURM_SUBMIT_DIR')
                self.job_name = os.getenv('SLURM_JOB_NAME')
                self.job_id = os.getenv('SLURM_JOBID')
                self.queue = os.getenv('SLURM_PARTITION')

    #---------------------------------------------------------------------------

    def get_remaining_time(self):

        """
        Get remaining time if available from batch system.
        """

        rtime = None

        if self.batch_type == 'PBS':
            cmd = "qstat -r $PBS_JOBID | grep $PBS_JOBID" \
                + " | sed -e's/ \{1,\}/ /g' | cut -d ' ' -f 9"
            rtime = get_command_output(cmd)

        return rtime

#-------------------------------------------------------------------------------

class resource_info(batch_info):

    #---------------------------------------------------------------------------

    def __init__(self, n_procs = None, n_procs_default = None):

        """
        Get execution resources information.
        """

        batch_info.__init__(self)

        self.manager = None
        self.n_procs = None
        self.n_nodes = None

        # If obtained from an environment variable, express
        # the hosts file using a shell variable rather than
        # an absolute name (for use in generated scripts).

        self.hosts_file = None
        self.hosts_list = None

        # Check for resource manager

        # Test for SLURM (Simple Linux Utility for Resource Management).
        # Note that we could also use SLURM_CPUS_PER_TASK to
        # determine Open MP behavior when that is ready.

        s = os.getenv('SLURM_NPROCS')
        if s != None:
            self.manager = 'SLURM'
            self.n_procs = int(s)
            s = os.getenv('SLURM_NNODES')
            if s != None:
                self.n_nodes = int(s)
        else:
            s = os.getenv('SLURM_NNODES')
            if s != None:
                self.manager = 'SLURM'
                self.n_nodes = int(s)
                s = os.getenv('SLURM_TASKS_PER_NODE')
                if s != None:
                    # Syntax may be similar to SLURM_TASKS_PER_NODE=2(x3),1"
                    # indicating three nodes will each execute 2 tasks and
                    # the  fourth node will execute 1 task.
                    self.n_procs = 0
                    for s0 in s.split(','):
                        i = s0.find('(')
                        if i > -1:
                            self.n_procs += int(s0[0:i])*int(s0[i+2:-1])
                        else:
                            self.n_procs += int(s0)
                else:
                    self.n_procs = self.n_nodes

        # Test for Platform LSF.

        if self.manager == None and self.batch_type == 'LSF':
            self.manager = 'LSF'
            self.n_procs = 0
            self.n_nodes = 0
            s = os.getenv('LSB_MCPU_HOSTS')
            if s != None:
                mcpu_list = s.split(' ')
                self.n_nodes = len(mcpu_list)/2
                for i in range(self.n_nodes):
                    self.n_procs += int(mcpu_list[i*2 + 1])
            else:
                s = os.getenv('LSB_HOSTS')
                if s != None:
                    hl = s.split(' ')
                    self.n_procs_from_hosts_list(hl, True)

        # Test for IBM LoadLeveler.

        if self.manager == None and self.batch_type == 'LOADL':
            s = os.getenv('LOADL_TOTAL_TASKS')
            if s == None:
                s = os.getenv('LOADL_BG_SIZE')
            if s != None:
                self.manager = 'LOADL'
                self.n_procs = int(s)
            else:
                s = os.getenv('LOADL_PROCESSOR_LIST')
                if s != None:
                    self.manager = 'LOADL'
                    hl = s.strip().split(' ')
                    self.n_procs_from_hosts_list(hl, True)
            s = os.getenv('LOADL_HOSTFILE')
            if s != None:
                self.manager = 'LOADL'
                self.hosts_file = '$LOADL_HOSTFILE'

        # Test for TORQUE or PBS Pro.

        if self.manager == None and self.batch_type == 'PBS':
            s = os.getenv('PBS_NODEFILE')
            if s != None:
                self.manager = 'PBS'
                self.hosts_file = '$PBS_NODEFILE'

        # Test for Oracle Grid Engine.

        if self.manager == None and self.batch_type == 'SGE':
            s = os.getenv('NSLOTS')
            if s != None:
                self.n_procs = int(s)
            s = os.getenv('NHOSTS')
            if s != None:
                self.n_nodes = int(s)
            s = os.getenv('TMPDIR')
            if s != None:
                s += '/machines'
                if os.path.isfile(s):
                    self.manager = 'SGE'
                    self.hosts_file = '$TMPDIR/machines'
            else:
                s = os.getenv('PE_HOSTFILE')
                if s != None:
                    self.hosts_file = '$PE_HOSTFILE'

        # Check hosts file presence

        if self.hosts_file == '$TMPDIR/machines':
            if not os.path.isfile(os.getenv('TMPDIR') + '/machines'):
                self.hosts_file = None
        elif self.hosts_file != None:
            if self.hosts_file[0] == '$':
                if not os.path.isfile(os.getenv(self.hosts_file[1:])):
                    self.hosts_file = None
            elif not os.path.isfile(self.hosts_file):
                self.hosts_file = None

        # Determine number of processors from hosts file or list

        if self.n_procs == None:
            if self.hosts_file != None:
                self.n_procs_from_hosts_file(self.hosts_file)
            elif self.hosts_list != None:
                self.n_procs_from_hosts_list(self.hosts_list)

        # Check and possibly set number of processes

        if n_procs != None:
            if self.n_procs != None:
                if self.n_procs != n_procs:
                    sys.stderr.write('Warning:\n'
                                     +'   Will use ' + str(self.n_procs)
                                     + ' processes while resource manager ('
                                     + self.manager + ')\n   allows for '
                                     + str(n_procs) + '.\n\n')
            self.n_procs = n_procs

        if self.n_procs == None:
            self.n_procs = n_procs_default

    #---------------------------------------------------------------------------

    def n_procs_per_node(self):

        """
        Determine number of processors per node.
        """

        ppn = 1
        if self.n_procs != None and  self.n_nodes != None:
            ppn = self.n_procs / self.n_nodes

        return ppn

    #---------------------------------------------------------------------------

    def n_procs_from_hosts_file(self, hosts_file):

        """
        Compute number of hosts from a hostsfile.
        """

        self.n_procs = 0
        if hosts_file == '$TMPDIR/machines':
           path = os.getenv('TMPDIR') + '/machines'
        elif hosts_file[0] == '$':
           path = os.getenv(hosts_file[1:])
        else:
           path = hosts_file
        f = open(path, 'r')
        for line in f:
            self.n_procs += 1
        f.close()

    #---------------------------------------------------------------------------

    def n_procs_from_hosts_list(self, hosts_list, is_copy=False):

        """
        Determine number of processors and nodes from hosts list.
        """

        self.n_procs = len(hosts_list)
        self.n_nodes = 1

        # If the hosts list is not already a copy, build one so
        # that sorting will not alter the original list.

        if is_copy == False:
            hl = []
            for s in hosts_list:
                hl.append(s)
        else:
            hl = hosts_list

        hl.sort()

        for i in range(self.n_procs - 1):
            if hl[i] != hl[i+1]:
                self.n_nodes += 1

    #---------------------------------------------------------------------------

    def get_hosts_list(self):

        """
        Get execution resources information.
        """

        hosts_list = None

        # Hosts list may already have been defined by constructor

        if self.hosts_list != None:
            hosts_list = self.hosts_list

        # Check for resource manager and eventual hostsfile

        elif self.manager == 'SLURM':
            s = os.getenv('SLURM_TASKS_PER_NODE')
            hosts_count = None
            if s != None:
                # Syntax may be similar to SLURM_TASKS_PER_NODE=2(x3),1"
                # indicating three nodes will each execute 2 tasks and
                # the  fourth node will execute 1 task.
                hosts_count = []
                for s0 in s.split(','):
                    i = s0.find('(')
                    if i > -1:
                        for j in range(int(s0[i+2:-1])):
                            hosts_count.append(int(s0[0:i]))
                    else:
                        hosts_count.append(int(s0))
            s = os.getenv('SLURM_NODELIST')
            if s != None:
                hosts_list = []
                l = 0
                # List uses a compact representation
                for s0 in s.split(','):
                    i = s0.find('[')
                    if i > -1:
                        basename = s0[0:i]
                        for s1 in s0[i+1:-1].split(','):
                            s2 = s1.split('-')
                            if len(s2) > 1:
                                fmt_s = basename + '%0' + str(len(s2[0])) + 'd'
                                for j in range(int(s2[0]), int(s2[1])+1):
                                    host_name = fmt_s % j
                                    if hosts_count:
                                        for k in range(hosts_count[l]):
                                            hosts_list.append(host_name)
                                        l += 1
                                    else:
                                        hosts_list.append(host_name)
                            else:
                                if hosts_count:
                                    for k in range(hosts_count[l]):
                                        hosts_list.append(s2[0])
                                    l += 1
                                else:
                                    hosts_list.append(s2[0])
                    else:
                        if hosts_count:
                            for k in range(hosts_count[l]):
                                hosts_list.append(s0)
                            l += 1
                        else:
                            hosts_list.append(s0)
            else:
                hosts_list = get_command_output('srun hostname -s').split()
                hosts_list.sort()

        elif self.manager == 'LSF':
            s = os.getenv('LSB_MCPU_HOSTS')
            if s != None:
                mcpu_list = s.split(' ')
                hosts_list = []
                for i in range(len(mcpu_list)/2):
                    host = mcpu_list[i*2]
                    count = int(mcpu_list[i*2 + 1])
                    for j in range(count):
                        hosts_list.append(host)
            else:
                s = os.getenv('LSB_HOSTS')
                if s != None:
                    hosts_list = s.split(' ')

        elif self.manager == 'LOADL':
            hosts_list = []
            s = os.getenv('LOADL_PROCESSOR_LIST')
            if s != None:
                hosts_list = s.split(' ')

        return hosts_list

    #---------------------------------------------------------------------------

    def get_hosts_file(self, wdir = None):
        """
        Returns the name of the hostsfile associated with the
        resource manager. A hostsfile is built from a hosts
        list if necessary.
        """

        hosts_file = self.hosts_file

        if self.hosts_file == None:

            hosts_list = self.get_hosts_list()

            if hosts_list != None:
                if wdir != None:
                    hosts_file = os.path.join(wdir, 'hostsfile')
                else:
                    hosts_file = 'hostsfile'
                f = open(hosts_file, 'w')
                # If number of procs not specified, determine it by list
                if self.n_procs == None or self.n_procs < 1:
                    n_procs = 0
                    for host in hosts_list:
                        f.write(host + '\n')
                        n_procs += 1
                # If the number of procs is known, use only beginning of list
                # if it contains more entries than the required number, or
                # loop through list as many time as necessary to reach
                # prescribed proc count
                else:
                    proc_count = 0
                    while proc_count < self.n_procs:
                        for host in hosts_list:
                            if proc_count < self.n_procs:
                                f.write(host + '\n')
                                proc_count += 1
                f.close()

            self.hosts_file = hosts_file

        return hosts_file

#-------------------------------------------------------------------------------
# MPI environments and associated commands
#-------------------------------------------------------------------------------

MPI_MPMD_none       = 0
MPI_MPMD_mpiexec    = (1<<0) # mpiexec colon-separated syntax
MPI_MPMD_configfile = (1<<1) # mpiexec -configfile syntax
MPI_MPMD_script     = (1<<2)

class mpi_environment:

    def __init__(self, pkg, resource_info=None, wdir = None):
        """
        Returns MPI environment info.
        """

        # Note that self.mpiexec_n will usually be ' -n ' if present;
        # blanks are used to separate from the surrounding arguments,
        # but in the case of srun, which uses a -n<n_procs> instead
        # of -n <n_procs> syntax, setting it to ' -n' will be enough.

        self.type = pkg.config.libs['mpi'].variant
        self.bindir = pkg.config.libs['mpi'].bindir

        self.gen_hostsfile = None
        self.del_hostsfile = None
        self.mpiboot = None
        self.mpihalt = None
        self.mpiexec = None
        self.mpiexec_opts = None
        self.mpiexec_n = None
        self.mpiexec_n_per_node = None
        self.mpiexec_separator = None
        self.mpiexec_exe = None
        self.mpiexec_args = None
        self.mpmd = MPI_MPMD_none

        self.info_cmds = None

        # Initialize based on known MPI types, or default.

        init_method = self.__init_other__

        if len(self.type) > 0:
            mpi_env_by_type = {'MPICH':self.__init_mpich2_3__,
                               'MPICH2':self.__init_mpich2_3__,
                               'Intel_MPI':self.__init_mpich2_3__,
                               'MSMPI':self.__init_msmpi__,
                               'OpenMPI':self.__init_openmpi__,
                               'BullxMPI':self.__init_openmpi__,
                               'LAM_MPI':self.__init_lam__,
                               'BGP_MPI':self.__init_bgp__,
                               'BGQ_MPI':self.__init_bgq__,
                               'HP_MPI':self.__init_hp_mpi__,
                               'MPICH1':self.__init_mpich1__,
                               'MPIBULL2':self.__init_mpibull2__}
            if self.type in mpi_env_by_type:
                init_method = mpi_env_by_type[self.type]

        p = os.getenv('PATH').split(':')
        if len(self.bindir) > 0:
            p.insert(0, self.bindir)

        init_method(p, resource_info, wdir)

    #---------------------------------------------------------------------------

    def __get_mpich2_3_default_pm__(self, mpiexec_path):

        """
        Try to determine the program manager for MPICH2 or MPICH-3.
        """

        # Only smpd is supported on Windows, so that one is easy.

        if sys.platform.startswith('win'):
            return 'smpd'

        # Check if we have a suffix which is self-explanatory

        i = mpiexec_path.rfind('.')

        if i > -1:
            suffix = mpiexec_path[i+1:]
            if suffix in ['hydra', 'smpd', 'mpd', 'gforker', 'remshell']:
                return suffix

        # Use mpichversion/mpich2version preferentially

        infoname = os.path.join(os.path.split(mpiexec_path)[0],
                                'mpichversion')
        if not os.path.isfile(infoname):
            infoname = os.path.join(os.path.split(mpiexec_path)[0],
                                    'mpich2version')

        if os.path.isfile(infoname):

            # If program managers were specified at configure time,
            # the first is the default

            info = get_command_outputs(infoname + ' -configure')
            i = info.find('-with-pm=')
            if i > -1:
                s = info[i + 8:]
                for pm in ['hydra', 'smpd', 'mpd', 'gforker', 'remshell']:
                    if s[0:len(pm)] == pm_c:
                        return pm

            # Otherwise, we know the default changed with MPICH2 1.3,
            # from MPD to Hydra.

            info = get_command_outputs(infoname + ' -version')
            v = info.rstrip().split('\t')[1].split('.')
            if int(v[0]) == 1 and int(v[1]) < 3:
                return 'mpd'
            else:
                return 'hydra'

        # If MPICH2 / MPICH-3 info is not available, try
        # to determine this in another way

        if os.path.islink(mpiexec_path):
            if os.path.basename(os.path.realpath(mpiexec_path)) == 'mpiexec.py':
                return 'mpd'
        info = get_command_outputs(mpiexec_path + ' -help')
        if info.find('Hydra') > -1:
            return 'hydra'
        elif info.find(' smpd ') > -1:
            return 'smpd'
        elif info.find('-usize') > -1:
            return 'gforker' # might also be remshell

        sys.stderr.write('Warning:\n'
                         + '   Unable to determine MPICH program manager:'
                         + ' assume "Hydra".\n\n')

        return 'hydra'

    #---------------------------------------------------------------------------

    def __init_mpich2_3__(self, p, resource_info=None, wdir = None):

        """
        Initialize for MPICH-3 environment.

        MPICH2 and MPICH-3 allow for 4 different process managers, all or some
        of which may be built depending on installation options:

        - HYDRA is the default on Unix-type systems. It natively uses
          existing daemons on the system such as ssh, SLURM, PBS, etc.

        - MPD was the traditional process manager, until it was deprecated
          in MPICH2-1.3. It consists of a ring of daemons. A hostsfile may
          be defined to start this ring (a machinefile may still be used for
          mpiexec for finer control, though we do not use it here).
          We try to test if such a ring is already running, and
          start and stop it if this is not the case.

        - spmd may be used both on Windows and Linux. It consists
          of independent daemons, so if a hostsfile is used, it
          must be passed to mpiexec (we do not attempt to start
          or stop the daemons here if this manager is used).

        - gforker is a simple manager that creates all processes on
          a single machine (the equivalent seem possible with HYDRA
          using "mpiexec -bootstrap fork")

        - remsh is a very simple version of mpiexec which makes use of
          the ssh command to start processes on a collection of
          machines. It ignores the command line options which control
          the environment variables given to MPI programs.
          A hostsfile by name of machines should contain the list
          of machines on which to run, one machine name per line
          (machines may be listed multiple times if necessary).
        """

        # Determine base executable paths

        # Using mpd,  mpirun is a wrapper to mpdboot + mpiexec + mpiallexec,
        # so it does not require running mpdboot and mpdallexit separately.

        # Executables suffixes 'mpich' or 'mpich2' may occur in case
        # of Linux distribution packaging, while 'hydra', 'mpd', 'smpd',
        # 'gforker', and 'remshell' are defined by the standard MPICH
        # install and determine the associated launcher.

        launcher_names = ['mpiexec.mpich', 'mpiexec.mpich2', 'mpiexec',
                          'mpiexec.hydra', 'mpiexec.mpd', 'mpiexec.smpd',
                          'mpiexec.gforker', 'mpiexec.remshell',
                          'mpirun.mpich2', 'mpirun.mpich2', 'mpirun']

        pm = ''
        for d in p:
            for name in launcher_names:
                absname = os.path.join(d, name)
                if os.path.isfile(absname):
                    pm = self.__get_mpich2_3_default_pm__(absname)
                    # Set launcher name
                    if d == self.bindir:
                        self.mpiexec = absname
                    else:
                        self.mpiexec = name
                    break
            if self.mpiexec != None:
                break

        if (self.mpiexec == None):
            basename = 'mpiexec'
            self.mpiexec = 'mpiexec'
        else:
            basename = os.path.basename(self.mpiexec)

        # Determine if SMPD should be handled

        if pm == 'smpd':

            smpdpath = 'smpd'
            if os.path.isfile(os.path.join(d, 'smpd')):
                if d == self.bindir:
                    smpdpath = os.path.join(d, 'smpd')
            if sys.platform.startswith('win'):
                self.mpiboot = smpdpath + ' -start'
                self.mpihalt = smpdpath + ' -stop'
            else:
                self.mpiboot = smpdpath + ' -s'
                self.mpihalt = smpdpath + ' -shutdown'

        # Determine if MPD should be handled
        # (if we are using a root MPD, no need for setup)

        if pm == 'mpd' and basename[:6] != 'mpirun':

            mpd_setup = True
            s = os.getenv('MPD_USE_ROOT_MPD')
            if s != None and int(s) != 0:
                mpd_setup = False

            # If a setup seems necessary, check paths
            if mpd_setup:
                if os.path.isfile(os.path.join(d, 'mpdboot')):
                    if d == self.bindir:
                        self.mpiboot = os.path.join(d, 'mpdboot')
                        self.mpihalt = os.path.join(d, 'mpdallexit')
                        mpdtrace = os.path.join(d, 'mpdtrace')
                        mpdlistjobs = os.path.join(d, 'mpdlistjobs')
                    else:
                        self.mpiboot = 'mpdboot'
                        self.mpihalt = 'mpdallexit'
                        mpdtrace = 'mpdtrace'
                        mpdlistjobs = 'mpdlistjobs'

        # Determine processor count and MPMD handling

        launcher_base = os.path.basename(self.mpiexec)

        if launcher_base[:7] == 'mpiexec':
            self.mpmd = MPI_MPMD_mpiexec | MPI_MPMD_configfile | MPI_MPMD_script
            self.mpiexec_n = ' -n '
        elif launcher_base[:6] == 'mpirun':
            self.mpiexec_n = ' -np '
            self.mpmd = MPI_MPMD_script

        # Other options to add

        # Resource manager info

        rm = None
        if resource_info != None:
            rm = resource_info.manager

        if pm == 'hydra':
            # Nothing to do for resource managers directly handled by Hydra
            if rm not in ['PBS', 'LOADL', 'LSF', 'SGE', 'SLURM']:
                hostsfile = resource_info.get_hosts_file(wdir)
                if hostsfile != None:
                    self.mpiexec += ' -f ' + hostsfile

            if (resource_info != None):
                ppn = resource_info.n_procs_per_node()
                if ppn != 1:
                    self.mpiexec_n_per_node = ' -ppn ' + str(ppn)

        elif pm == 'smpd':
            hostsfile = resource_info.get_hosts_file(wdir)
            if hostsfile != None:
                self.mpiboot += ' --file=' + hostsfile
        elif pm == 'mpd':
            # For SLURM, srun can be used when linking with SLURM's
            # implementation of the PMI library, but this is not always the
            # case: as MPD is obsolete, users who want to use it with SLURM
            # should define this with post-install settings (code_saturne.cfg).
            if rm == 'PBS':
                # Convert PBS to MPD format (based on MPICH2 documentation)
                # before MPI boot.
                if self.mpiboot != None:
                    self.gen_hostsfile = 'sort $PBS_NODEFILE | uniq -C ' \
                        + '| awk \'{ printf("%s:%s", $2, $1); }\' > ./mpd.nodes'
                    self.del_hostsfile = 'rm -f ./mpd.nodes'
                    self.mpiboot += ' --file=./mpd.nodes'
            else:
                hostsfile = resource_info.get_hosts_file(wdir)
                if hostsfile != None:
                    self.mpiboot += ' --file=' + hostsfile

        elif pm == 'gforker':
            hosts = False
            hostslist = resource_info.get_hosts_list()
            if hostslist != None:
                hosts = True
            else:
                hostsfile = resource_info.get_hosts_file(wdir)
                if hostsfile != None:
                    hosts = True
            if hosts == True:
                sys.stderr.write('Warning:\n'
                                 + '   Hosts list will be ignored by'
                                 + ' MPICH gforker program manager.\n\n')

        # Finalize mpiboot and mpihalt commands.
        # With MPD, we use 'mpdtrace' to determine if a ring is already running,
        # and mpdlistjobs to determine if other jobs are still running.
        # This means that a hostsfile will be ignored if an MPD ring
        # is already running, but will avoid killing other running jobs.

        if self.mpiboot != None and pm == 'mpd':
            self.mpiboot = \
                mpdtrace + ' > /dev/null 2>&1\n' \
                + 'if test $? != 0 ; then ' + self.mpiboot + ' ; fi'
            self.mpihalt = \
                'listjobs=`' + mpdlistjobs + ' | wc -l`\n' \
                + 'if test $listjobs = 0 ; then ' + self.mpihalt + ' ; fi'

        # Info commands

        if self.type == 'MPICH':
            self.info_cmds = ['mpichversion']
        if self.type == 'MPICH2':
            self.info_cmds = ['mpich2version']

    #---------------------------------------------------------------------------

    def __init_mpich1__(self, p, resource_info=None, wdir = None):

        """
        Initialize for MPICH1 environment.
        """

        # Determine base executable paths

        launcher_names = ['mpirun.mpich',
                          'mpirun.mpich-mpd',
                          'mpirun.mpich-shmem',
                          'mpirun']

        for d in p:
            for name in launcher_names:
                absname = os.path.join(d, name)
                if os.path.isfile(absname):
                    if d == self.bindir:
                        self.mpiexec = absname
                    else:
                        self.mpiexec = name
                    break
            if self.mpiexec != None:
                break

        # Determine processor count and MPMD handling

        self.mpiexec_n = ' -np '
        self.mpmd = MPI_MPMD_script

        # MPD daemons must be launched using the ch_p4mpd device,
        # but may not be automated as easily as with MPICH2's mpdboot,
        # so it is not handled here, and must be managed explicitely
        # by the user or environment.

        # Other options to add

        # Resource manager info

        if resource_info != None:
            hostsfile = resource_info.get_hosts_file(wdir)
            if hostsfile != None:
                self.mpiexec += ' -machinefile ' + hostsfile

        # Info commands

        self.info_cmds = ['mpichversion']

    #---------------------------------------------------------------------------

    def __init_openmpi__(self, p, resource_info=None, wdir = None):
        """
        Initialize for OpenMPI environment.
        """

        # Determine base executable paths

        launcher_names = ['mpiexec.openmpi', 'mpirun.openmpi',
                          'mpiexec', 'mpirun']
        info_name = ''

        for d in p:
            for name in launcher_names:
                absname = os.path.join(d, name)
                if os.path.isfile(absname):
                    if d == self.bindir:
                        self.mpiexec = absname
                    else:
                        self.mpiexec = name
                    info_name = os.path.join(d, 'ompi_info')
                    break
            if self.mpiexec != None:
                break

        # Determine processor count and MPMD handling

        launcher_base = os.path.basename(self.mpiexec)

        self.mpiexec_n = ' -n '
        if (resource_info != None):
            ppn = resource_info.n_procs_per_node()
            if ppn != 1:
                self.mpiexec_n_per_node = ' --npernode ' + str(ppn)
        if launcher_base[:7] == 'mpiexec':
            self.mpmd = MPI_MPMD_mpiexec | MPI_MPMD_script
        elif launcher_base[:7] == 'mpirun':
            self.mpmd = MPI_MPMD_script

        # Other options to add

        # Detect if resource manager is known by this Open MPI build

        if resource_info != None:
            known_manager = False
            if os.path.isfile(info_name):
                rc_mca_by_type = {'SLURM':' slurm ',
                                  'LSF':' lsf ',
                                  'LOADL':' loadleveler ',
                                  'PBS':' tm ',
                                  'SGE':' gridengine '}
                if resource_info.manager in rc_mca_by_type:
                    info = get_command_output(info_name)
                    if info.find(rc_mca_by_type[resource_info.manager]) > -1:
                        known_manager = True
            if known_manager == False:
                hostsfile = resource_info.get_hosts_file(wdir)
                if hostsfile != None:
                    self.mpiexec += ' --machinefile ' + hostsfile

        # Info commands

        self.info_cmds = ['ompi_info -a']

    #---------------------------------------------------------------------------

    def __init_lam__(self, p, resource_info=None, wdir = None):
        """
        Initialize for LAM/MPI environment.
        We choose to use the mpiexec command, which wraps lamboot,
        mpirun, and lamhalt, and provides for a basically standard
        mpiexec syntax.
        """

        # Determine base executable paths

        launcher_names = ['mpiexec.lam', 'mpiexec']

        for d in p:
            for name in launcher_names:
                absname = os.path.join(d, name)
                if os.path.isfile(absname):
                    if d == self.bindir:
                        self.mpiexec = absname
                    else:
                        self.mpiexec = name
                    break
            if self.mpiexec != None:
                break

        # Determine processor count and MPMD handling

        launcher_base = os.path.basename(self.mpiexec)

        self.mpiexec_n = ' -n '
        self.mpmd = MPI_MPMD_mpiexec | MPI_MPMD_script

        # Resource manager info

        hostsfile = None
        if resource_info != None:
            hostsfile = resource_info.get_hosts_file(wdir)

        if hostsfile != None:
            self.mpiexec += ' --machinefile ' + hostsfile
        else:
            self.mpiexec += ' --boot'

        # Info commands

        self.info_cmds = ['laminfo -all']

    #---------------------------------------------------------------------------

    def __init_bgp__(self, p, resource_info=None, wdir = None):

        """
        Initialize for Blue Gene/P environment.
        """

        # Set base executable path

        self.mpiexec = 'mpiexec'

        # Determine processor count and MPMD handling

        self.mpiexec_n = None
        self.mpmd = MPI_MPMD_configfile

        # Other options to add

        # Info commands

    #---------------------------------------------------------------------------

    def __init_bgq__(self, p, resource_info=None, wdir = None):

        """
        Initialize for Blue Gene/Q environment.
        """

        # Set base executable path

        self.mpiexec = 'runjob'

        # Determine processor count and MPMD handling

        self.mpiexec_n = ' --np '
        self.mpmd = MPI_MPMD_configfile

        rm = None
        ppn = 1
        if resource_info != None:
            rm = resource_info.manager
            ppn = resource_info.n_procs_per_node()
        if rm == 'SLURM':
            self.mpiexec = 'srun'
            self.mpiexec_n = ' --ntasks='
            if ppn != 1:
                self.mpiexec_n_per_node = ' --ntasks-per-node=' + str(ppn)
        else:
            if ppn != 1:
                self.mpiexec_n_per_node = ' --ranks-per-node ' + str(ppn)
            self.mpiexec_separator = ':'

        # Other options to add

        # self.mpiexec_exe = '--exe'
        # self.mpiexec_args = '--args'
        # self.mpiexec_envs = '--envs OMP_NUM_THREADS=' + str(omp_num_threads)

        # Info commands

    #---------------------------------------------------------------------------

    def __init_hp_mpi__(self, p, resource_info=None, wdir = None):
        """
        Initialize for HP MPI environment.

        The last version of HP MPI is version 2.3, released early 2009.
        HP MPI was then acquired by Platform MPI (formerly Scali MPI),
        which merged Scali MPI and HP MPI in Platform MPI 8.0.
        Platform MPI still seems to use the mpirun launcher syntax.
        """

        # Determine base executable paths

        self.mpiexec = 'mpirun'

        for d in p:
            if not os.path.isabs(self.mpiexec):
                absname = os.path.join(d, self.mpiexec)
                if os.path.isfile(absname):
                    if d == self.bindir:
                        self.mpiexec = absname
                    break

        # Determine processor count and MPMD handling

        self.mpmd = MPI_MPMD_script
        self.mpiexec_n = '-np'

        # Determine options to add

        # If resource manager is used, add options

        if resource_info != None:
            if resource_info.manager == 'SLURM':
                self.mpiexec += ' -srun'
                self.mpiexec_n = None
            elif resource_info.manager == 'LSF':
                self.mpiexec += ' -lsb_hosts'

        # Info commands

    #---------------------------------------------------------------------------

    def __init_msmpi__(self, p, resource_info=None, wdir = None):

        """
        Initialize for MS-MPI environment.

        Microsoft MPI is based on standard MPICH2 distribution.

        It allows only for the smpd process manager that consists
        of independent daemons, so if a hostsfile is used, it must
        be passed to mpiexec.
        """

        # On Windows, mpiexec.exe will be found through the PATH variable
        # so, unset the MPI 'bindir' variable

        self.bindir = ''

        # Determine MS-MPI configuration

        self.mpiexec = 'mpiexec.exe'
        self.mpmd = MPI_MPMD_mpiexec | MPI_MPMD_configfile
        self.mpiexec_n = ' -n '

        # Other options to add

        # Resource manager info

        # Info commands

    #---------------------------------------------------------------------------

    def __init_mpibull2__(self, p, resource_info=None, wdir = None):
        """
        Initialize for MPIBULL2 environment.
        """

        self.__init_mpich2__(p, resource_info)

        # On a Bull Novascale machine using MPIBULL2 (based on MPICH2),
        # mpdboot and mpdallexit commands and related mpiexec may be found,
        # but the SLURM srun launcher or mpibull2-launch meta-launcher
        # (which can integrate directly to several resource managers
        # using prun, srun, orterun, or mprun) should be simpler to use.

        # The SLURM configuration is slightly different from that of MPICH2.

        if resource_info != None:
            if resource_info.manager == 'SLURM':
                self.mpiexec = 'srun'
                self.mpmd = MPI_MPMD_script
                self.mpiexec_n = None
                self.mpiboot = None
                self.mpihalt = None
            elif resource_info.manager != None:
                err_str = 'Resource manager type ' + resource_info.manager \
                    + ' options not handled yet for MPIBULL2.'
                raise ValueError(err_str)

        # Info commands

        self.info_cmds = ['mpibull2-version']

    #---------------------------------------------------------------------------

    def __init_other__(self, p, resource_info=None, wdir = None):
        """
        Initialize MPI environment info for environments not handled
        in one the the previous cases.
        """

        # If possible, select launcher based on resource manager or
        # specific systems (would be better done in derived classes,
        # but these are cases on systems we have used in the past
        # but do not currently have access to).

        if platform.uname()[0] == 'OSF1':
            if abs_exec_path('prun') != None:
                self.mpiexec = 'prun'
                self.mpiexec_n = ' -n '

        elif platform.uname()[0] == 'AIX':
            if abs_exec_path('poe') != None:
                self.mpiexec = 'poe'
                self.mpiexec_n = None

        self.mpmd = MPI_MPMD_script

    #---------------------------------------------------------------------------

    def info(self):
        """
        Outputs MPI environment information in known cases.
        """
        output = ''

        if self.info_cmds != None:
            for cmd in self.info_cmds:
                output += get_command_output(cmd) + '\n'

        return output

    #---------------------------------------------------------------------------

    def unset_mpmd_mode(self, mpi_mpmd_mode):
        """
        Unset mask allowing a given mpmd mode.
        """

        if self.mpmd & mpi_mpmd_mode:
            self.mpmd = self.mpmd ^ mpi_mpmd_mode

#-------------------------------------------------------------------------------
# Execution environment (including MPI, OpenMP, ...)
#-------------------------------------------------------------------------------

class exec_environment:

    #---------------------------------------------------------------------------

    def __init__(self, pkg, wdir=None, n_procs=None, n_procs_default = None):
        """
        Returns Execution environment.
        """

        if sys.platform.startswith('win'):
            self.user = os.getenv('USERNAME')
        else:
            self.user = os.getenv('USER')

        self.wdir = wdir
        if self.wdir == None:
            self.wdir = os.getcwd()

        self.resources = resource_info(n_procs, n_procs_default)

        self.mpi_env = None

        # Associate default launcher and associated options based on
        # known MPI types, use default otherwise

        self.mpi_env = mpi_environment(pkg, self.resources, wdir)

        # Modify options based on system-wide or user configuration

        config = configparser.ConfigParser()
        config.read(pkg.get_configfiles())

        if config.has_section('mpi'):
            for option in config.items('mpi'):
               k = option[0]
               v = option[1]
               if not v:
                   v = None
               elif v[0] in ['"', "'"]:
                   v = v[1:-1]
               if k == 'mpmd':
                   self.mpi_env.mpmd_mode = eval(v)
               else:
                   self.mpi_env.__dict__[k] = v

#-------------------------------------------------------------------------------

if __name__ == '__main__':

    import cs_package
    pkg = cs_package.package()
    e = exec_environment(pkg)

    import pprint
    pprint.pprint(e.__dict__)
    pprint.pprint(e.resources.__dict__)
    pprint.pprint(e.mpi_env.__dict__)
    print(e.mpi_env.info())

#-------------------------------------------------------------------------------
# End
#-------------------------------------------------------------------------------
