# *****************************************************************************
#
# 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:
#   Andrea Plank <andrea.plank@psi.ch>
#   Markus Zolliker <markus.zolliker@psi.ch>
#
# *****************************************************************************
import sys
import time
from ast import literal_eval
from threading import RLock
import snap7
from frappy.core import Readable, Parameter, FloatRange, HasIO, StringIO, Property, StringType,IDLE, BUSY, WARN, ERROR,Writable,  Drivable, BoolType, IntRange, Communicator
from frappy.errors import CommunicationFailedError


class IO(Communicator):
    tcap_client = Property('tcap_client', IntRange())
    tsap_server = Property('tcap_server', IntRange())
    ip_address = Property('numeric ip address', StringType())
    _plc = None
    _last_try = 0

    def initModule(self):
        self._lock = RLock()
        super().initModule()

    def _init(self):
        if not self._plc:
            if time.time() < self._last_try + 10:
                raise CommunicationFailedError('logo PLC not reachable')
            self._plc = snap7.logo.Logo()
            prev_stderr = sys.stdout
            sys.stderr = open('/dev/null', 'w')  # suppress output of snap7
            try:
                self._plc.connect(self.ip_address, self.tcap_client, self.tsap_server)
                if self._plc.get_connected():
                    return
            except Exception:
                pass
            finally:
                sys.stderr = prev_stderr
            self._plc = None
            self._last_try = time.time()
            raise CommunicationFailedError('logo PLC not reachable')

    def communicate(self, cmd):
        with self._lock:
            self._init()
            cmd = cmd.split(maxsplit=1)
            if len(cmd) == 2:
                self._plc.write(cmd[0], literal_eval(cmd[1]))
            try:
                return self._plc.read(cmd[0])
            except Exception as e:
                if self._plc:
                    self.log.exception('error in plc read')
                self._plc = None
                raise


class Snap7Mixin(HasIO):
    ioclass = IO

    def get_vm_value(self, vm_address):
        return self.io.communicate(vm_address)


    def set_vm_value(self, vm_address, value):
        return self.io.communicate(f'{vm_address} {value}')


class Pressure(Snap7Mixin, Readable):
    vm_address = Property('VM address', datatype= StringType())
    value = Parameter('pressure', datatype = FloatRange(unit = 'mbar'))

    pollinterval = 0.5

    def read_value(self):
        return self.get_vm_value(self.vm_address)

    def read_status(self):
        return IDLE, ''


class Valve(Snap7Mixin, Drivable):
    vm_address_input = Property('VM address input', datatype= StringType())
    vm_address_output = Property('VM address output', datatype= StringType())

    target = Parameter('Valve target', datatype = BoolType())
    value = Parameter('Value state', datatype = BoolType())


    def read_value(self):
        return self.get_vm_value(self.vm_address_input)

    def write_target(self, target):
        return self.set_vm_value(self.vm_address_output, target)

    def read_status(self):
        return IDLE, ''


class FluidMachines(Snap7Mixin, Drivable):
    vm_address_output = Property('VM address output', datatype= StringType())

    target = Parameter('Valve target', datatype = BoolType())
    value = Parameter('Value state', datatype = BoolType())

    def read_value(self):
        return self.get_vm_value(self.vm_address_output)

    def write_target(self, target):
        return self.set_vm_value(self.vm_address_output, target)

    def read_status(self):
        return IDLE, ''


class TempSensor(Snap7Mixin, Readable):
    vm_address = Property('VM address', datatype= StringType())
    value = Parameter('resistance', datatype = FloatRange(unit = 'Ohm'))

    def read_value(self):
        return self.get_vm_value(self.vm_address)

    def read_status(self):
        return IDLE, ''


class HeaterParam(Snap7Mixin, Writable):
    vm_address = Property('VM address output', datatype= StringType())

    target = Parameter('Heater target', datatype = FloatRange(unit='%'))
    value = Parameter('Heater Param', datatype = FloatRange(unit='%'))

    def read_value(self):
        return self.get_vm_value(self.vm_address) * 0.1

    def write_target(self, target):
        return self.set_vm_value(self.vm_address, round(target * 10)) * 0.1

    def read_status(self):
        return IDLE, ''