"""Parallel workflow execution via OAR http://oar.imag.fr
"""

import os
import stat
from time import sleep
import subprocess
import json

from .base import (SGELikeBatchManagerBase, logger, iflogger, logging)

from nipype.interfaces.base import CommandLine


class OARPlugin(SGELikeBatchManagerBase):
    """Execute using OAR

    The plugin_args input to run can be used to control the OAR execution.
    Currently supported options are:

    - template : template to use for batch job submission
    - oarsub_args : arguments to be prepended to the job execution
                    script in the oarsub call
    - max_jobname_len: maximum length of the job name.  Default 15.

    """

    # Addtional class variables
    _max_jobname_len = 15
    _oarsub_args = ''

    def __init__(self, **kwargs):
        template = """
# oarsub -J
        """
        self._retry_timeout = 2
        self._max_tries = 2
        self._max_jobname_length = 15
        if 'plugin_args' in kwargs and kwargs['plugin_args']:
            if 'oarsub_args' in kwargs['plugin_args']:
                self._oarsub_args = kwargs['plugin_args']['oarsub_args']
            if 'retry_timeout' in kwargs['plugin_args']:
                self._retry_timeout = kwargs['plugin_args']['retry_timeout']
            if 'max_tries' in kwargs['plugin_args']:
                self._max_tries = kwargs['plugin_args']['max_tries']
            if 'max_jobname_len' in kwargs['plugin_args']:
                self._max_jobname_len = \
                    kwargs['plugin_args']['max_jobname_len']
        super(OARPlugin, self).__init__(template, **kwargs)

    def _is_pending(self, taskid):
        #  subprocess.Popen requires taskid to be a string
        proc = subprocess.Popen(
            ['oarstat', '-J', '-s',
             '-j', taskid],
            stdout=subprocess.PIPE,
            stderr=subprocess.PIPE
        )
        o, e = proc.communicate()
        parsed_result = json.loads(o)[taskid].lower()
        is_pending = (
            ('error' not in parsed_result) and
            ('terminated' not in parsed_result)
        )
        return is_pending

    def _submit_batchtask(self, scriptfile, node):
        cmd = CommandLine('oarsub', environ=dict(os.environ),
                          terminal_output='allatonce')
        path = os.path.dirname(scriptfile)
        oarsubargs = ''
        if self._oarsub_args:
            oarsubargs = self._oarsub_args
        if 'oarsub_args' in node.plugin_args:
            if (
               'overwrite' in node.plugin_args and
               node.plugin_args['overwrite']
               ):
                oarsubargs = node.plugin_args['oarsub_args']
            else:
                oarsubargs += (" " + node.plugin_args['oarsub_args'])

        if node._hierarchy:
            jobname = '.'.join((dict(os.environ)['LOGNAME'],
                                node._hierarchy,
                                node._id))
        else:
            jobname = '.'.join((dict(os.environ)['LOGNAME'],
                                node._id))
        jobnameitems = jobname.split('.')
        jobnameitems.reverse()
        jobname = '.'.join(jobnameitems)
        jobname = jobname[0:self._max_jobname_len]

        if '-O' not in oarsubargs:
            oarsubargs = '%s -O %s' % (
                oarsubargs,
                os.path.join(path, jobname + '.stdout')
            )
        if '-E' not in oarsubargs:
            oarsubargs = '%s -E %s' % (
                oarsubargs,
                os.path.join(path, jobname + '.stderr')
            )
        if '-J' not in oarsubargs:
            oarsubargs = '%s -J' % (oarsubargs)

        os.chmod(scriptfile, stat.S_IEXEC | stat.S_IREAD | stat.S_IWRITE)
        cmd.inputs.args = '%s -n %s -S %s' % (
           oarsubargs,
           jobname,
           scriptfile
        )

        oldlevel = iflogger.level
        iflogger.setLevel(logging.getLevelName('CRITICAL'))
        tries = 0
        while True:
            try:
                result = cmd.run()
            except Exception as e:
                if tries < self._max_tries:
                    tries += 1
                    sleep(self._retry_timeout)
                    # sleep 2 seconds and try again.
                else:
                    iflogger.setLevel(oldlevel)
                    raise RuntimeError('\n'.join((('Could not submit OAR task'
                                                   ' for node %s') % node._id,
                                                  str(e))))
            else:
                break
        iflogger.setLevel(oldlevel)
        # retrieve OAR taskid

        o = ''
        add = False
        for line in result.runtime.stdout.splitlines():
            if line.strip().startswith('{'):
                add = True
            if add:
                o += line + '\n'
            if line.strip().startswith('}'):
                break
        taskid = json.loads(o)['job_id']
        self._pending[taskid] = node.output_dir()
        logger.debug('submitted OAR task: %s for node %s' % (taskid, node._id))
        return taskid
