# THIS FILE IS PART OF THE CYLC WORKFLOW ENGINE.
# Copyright (C) NIWA & British Crown (Met Office) & Contributors.
#
# 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 3 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, see <http://www.gnu.org/licenses/>.
"""Submits job scripts to the Moab workload manager with ``msub``.

.. cylc-scope:: flow.cylc[runtime][<namespace>]

Moab directives can be provided in the flow.cylc file; the syntax is
very similar to PBS:

.. code-block:: cylc
   :caption: global.cylc

   [platforms]
       [[myplatform]]
           job runner = moab

.. code-block:: cylc
   :caption: flow.cylc

   [runtime]
       [[my_task]]
           platform = myplatform
           execution time limit = PT1M
           [[[directives]]]
               -V =
               -q = foo
               -l nodes = 1

These are written to the top of the job script like this:

.. code-block:: bash

   #!/bin/bash
   # DIRECTIVES
   #PBS -V
   #PBS -q foo
   #PBS -l nodes=1
   #PBS -l walltime=60

(Moab understands ``#PBS`` directives).

If :cylc:conf:`execution time limit` is specified, it is used to generate the
``-l walltime`` directive. Do not specify the ``-l walltime`` directive
explicitly if :cylc:conf:`execution time limit` is specified.  Otherwise, the
execution time limit known by the workflow may be out of sync with what is
submitted to the job runner.

.. cylc-scope::

"""

import re

from cylc.flow.id import Tokens


class MoabHandler:

    """Moab job runner job submission and manipulation."""

    DIRECTIVE_PREFIX = "#PBS "
    KILL_CMD_TMPL = "mjobctl -c '%(job_id)s'"
    # N.B. The "qstat JOB_ID" command returns 1 if JOB_ID is no longer in the
    # system, so there is no need to filter its output.
    POLL_CMD = "checkjob"
    REC_ID_FROM_SUBMIT_OUT = re.compile(r"""\A\s*(?P<id>\S+)\s*\Z""")
    SUBMIT_CMD_TMPL = "msub '%(job)s'"
    TIME_LIMIT_DIRECTIVE = "-l walltime"

    def format_directives(self, job_conf):
        """Format the job directives for a job file."""
        job_file_path = job_conf['job_file_path']
        directives = job_conf["directives"].__class__()  # an ordereddict

        tokens = Tokens(job_conf['task_id'], relative=True)
        directives["-N"] = (
            f'{tokens["task"]}.{tokens["cycle"]}.{job_conf["workflow_name"]}'
        )
        directives["-o"] = job_file_path + ".out"
        directives["-e"] = job_file_path + ".err"
        if (job_conf["execution_time_limit"] and
                directives.get(self.TIME_LIMIT_DIRECTIVE) is None):
            directives[self.TIME_LIMIT_DIRECTIVE] = "%d" % job_conf[
                "execution_time_limit"]
        # restartable?
        directives.update(job_conf["directives"])
        lines = []
        for key, value in directives.items():
            if value and " " in key:
                # E.g. -l walltime=3:00:00
                lines.append("%s%s=%s" % (self.DIRECTIVE_PREFIX, key, value))
            elif value:
                # E.g. -q queue_name
                lines.append("%s%s %s" % (self.DIRECTIVE_PREFIX, key, value))
            else:
                # E.g. -V
                lines.append(self.DIRECTIVE_PREFIX + key)
        return lines


JOB_RUNNER_HANDLER = MoabHandler()
