#  -*- coding: utf-8 -*-
# *****************************************************************************
#
# 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>
#
# *****************************************************************************

"""modules to access parameters"""

from frappy.core import Drivable, IDLE, Attached, StringType, Property, \
    Parameter, FloatRange
from frappy.errors import ConfigError
from frappy_psi.convergence import HasConvergence
from frappy_psi.mixins import HasRamp


class Driv(Drivable):
    value = Parameter(datatype=FloatRange(unit='$'))
    target = Parameter(datatype=FloatRange(unit='$'))
    read = Attached(description='<module>.<parameter> for read')
    write = Attached(description='<module>.<parameter> for read')
    unit = Property('main unit', StringType())

    def setProperty(self, key, value):
        if key in ('read', 'write'):
            value, param = value.split('.')
            setattr(self, f'{key}_param', param)
        super().setProperty(key, value)

    def checkProperties(self):
        self.applyMainUnit(self.unit)
        if self.read == self.name or self.write == self.name:
            raise ConfigError('illegal recursive read/write module')
        super().checkProperties()

    #def registerUpdates(self):
    #    self.read.valueCallbacks[self.read_param].append(self.update_value)
    #    self.write.valueCallbacks[self.write_param].append(self.update_target)
    #
    #def startModule(self, start_events):
    #    start_events.queue(self.registerUpdates)
    #    super().startModule(start_events)

    def read_value(self):
        return getattr(self.read, f'{self.read_param}')

    def read_target(self):
        return getattr(self.write, f'{self.write_param}')

    def read_status(self):
        return IDLE, ''

    def write_target(self, target):
        return getattr(self.write, f'write_{self.write_param}')(target)


class Converging(HasConvergence, Driv):
    """drivable with convergence"""
    pollinterval = 1

    def checkProperties(self):
        self.parameters['tolerance'].setProperty('unit', self.unit)
        super().checkProperties()

    #def update_value(self, value):
    #    print('UV', value)
    #    self.value = value

    #def error_update_value(self, err):
    #    raise err

    #def update_target(self, value):
    #    self.target = value

    #def error_update_target(self, err):
    #    raise err

    def write_target(self, target):
        self.convergence_start()
        return super().write_target(target)


class RampDriv(HasRamp, Driv):
    pass