# *****************************************************************************
# 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.,
# 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
# Module authors:
#   Markus Zolliker <markus.zolliker@psi.ch>
# *****************************************************************************

import threading
from pathlib import Path
from frappy.core import Drivable, Property, Parameter, Command, StringType, \
    IDLE, BUSY, WARN, ERROR
from frappy.errors import IsBusyError
from frappy.client.interactive import run_script, ClientEnvironment
from frappy.lib import formatExtendedTraceback


class ScriptThread(threading.Thread):
    exc = None

    def __init__(self, completer, *args):
        super().__init__()
        self.completer = completer
        self.args = args
        self.clenv = ClientEnvironment()
        self.clenv.init()

    def run(self):
        try:
            run_script(*self.args, clenv=self.clenv)
        except BaseException as e:
            # print(formatExtendedTraceback())
            print(e)
            self.exc = e
        finally:
            self.completer()

    def stop(self):
        self.clenv.trigger.shutdown()


class Scripts(Drivable):
    scriptdir = Property('directory of scripts used as commands', StringType())
    secnodes = Parameter('remote nodes, space separated', StringType(), readonly=False, default='')
    target = Parameter('script to start', StringType(), readonly=False, default='')
    value = Parameter(datatype=StringType(), default='')
    _status = IDLE, ''
    _thread = None
    _script = ''

    def __new__(cls, modname, logger, cfgdict, dispatcher):
        scriptdir = cfgdict['scriptdir']['value']
        scripts = Path(scriptdir).expanduser().glob('*.py')
        attrs = {}
        for script in scripts:
            name = script.stem
            print(name, script)

            def cmdwrapper(self, target=name):
                self.write_target(target)

            attrs[name] = Command(description=f'script {name}')(cmdwrapper)
        return super().__new__(type(f'Script_{modname}', (cls,), attrs))

    def _start_script(self, script):
        if self.isBusy():
            raise IsBusyError('can not start a script while running')
        self._script = script
        self._thread = ScriptThread(self.read_status, str(script), *self.secnodes.split())
        self._thread.start()

    def read_status(self):
        if self._thread is None:
            return IDLE, ''
        if self._thread.is_alive():
            if self._stopping:
                return BUSY, f'stopping {self.target}'
            self.value = f'{self.target} running'
            return BUSY, self.value
        if self._stopping:
            self.value = f'{self.target} stopped'
            return WARN, self.value
        if self._thread.exc is None:
            self.value = f'{self.target} finished'
            return IDLE, self.value
        return ERROR, f'raised in {self.target}: {self._thread.exc!r}'

    def write_target(self, script):
        """start script given as target"""
        self._start_script(Path(self.scriptdir).expanduser() / f'{script}.py')
        self._stopping = False
        self.value = f'{script} started'
        self.status = BUSY, self.value
        self.setFastPoll(True)

    @Command()
    def stop(self):
        """interrupt script

        a script can only be stopped during setting a parameter,
        when starting a command or when waiting
        """
        if self._thread:
            self._stopping = True
            self._thread.stop()
            self.read_status()

    @Command()
    def reset(self):
        """clear error status"""
        self._thread = None
        self._stopping = False
        self.read_status()