# *****************************************************************************
# 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>
# *****************************************************************************

"""interlocks for furnace"""

from frappy.core import Module, Writable, Attached, Parameter, FloatRange, Readable,\
     BoolType, ERROR, IDLE
from frappy.errors import ImpossibleError
from frappy.mixins import HasControlledBy
from frappy_psi.picontrol import PImixin
from frappy_psi.convergence import HasConvergence
from frappy_psi.ionopimax import CurrentInput, LogVoltageInput
import frappy_psi.tdkpower as tdkpower
import frappy_psi.bkpower as bkpower


class Interlocks(Writable):
    value = Parameter('interlock o.k.', BoolType(), default=True)
    target = Parameter('set to true to confirm', BoolType(), readonly=False)
    input = Attached(Readable, 'the input module', mandatory=False)  # TODO: remove
    vacuum = Attached(Readable, 'the vacuum pressure', mandatory=False)
    wall_T = Attached(Readable, 'the wall temperature', mandatory=False)
    htr_T = Attached(Readable, 'the heater temperature', mandatory=False)
    main_T = Attached(Readable, 'the main temperature')
    extra_T = Attached(Readable, 'the extra temperature')
    control = Attached(Module, 'the control module')
    htr = Attached(Module, 'the heater module', mandatory=False)
    relais = Attached(Writable, 'the interlock relais', mandatory=False)
    flowswitch = Attached(Readable, 'the flow switch', mandatory=False)
    wall_limit = Parameter('maximum wall temperature', FloatRange(0, unit='degC'),
                           default = 50, readonly = False)
    vacuum_limit = Parameter('maximum vacuum pressure', FloatRange(0, unit='mbar'),
                             default = 0.1, readonly = False)
    htr_T_limit = Parameter('maximum htr temperature', FloatRange(0, unit='degC'),
                            default = 530, readonly = False)
    main_T_limit = Parameter('maximum main temperature', FloatRange(0, unit='degC'),
                             default = 530, readonly = False)
    extra_T_limit = Parameter('maximum extra temperature', FloatRange(0, unit='degC'),
                             default = 530, readonly = False)

    _off_reason = None  # reason triggering interlock
    _conditions = ''  # summary of reasons why locked now

    def initModule(self):
        super().initModule()
        self._sensor_checks = [
            (self.wall_T, 'wall_limit'),
            (self.main_T, 'main_T_limit'),
            (self.extra_T, 'extra_T_limit'),
            (self.htr_T, 'htr_T_limit'),
            (self.vacuum, 'vacuum_limit'),
        ]

    def write_target(self, value):
        if value:
            self.read_status()
            if self._conditions:
                raise ImpossibleError('not ready to start')
            self._off_reason = None
            self.value = True
        elif self.value:
            self.switch_off()
            self._off_reason = 'switched off'
            self.value = False
        self.read_status()

    def switch_off(self):
        if self.value:
            self._off_reason = self._conditions
            self.value = False
        if self.control.control_active:
            self.log.error('switch control off %r', self.control.status)
            self.control.write_control_active(False)
            self.control.status = ERROR, self._conditions
        if self.htr and self.htr.target:
            self.htr.write_target(0)
        if self.relais and (self.relais.value or self.relais.target):
            self.relais.write_target(False)

    def read_status(self):
        conditions = []
        if self.flowswitch and self.flowswitch.value == 0:
            conditions.append('no cooling water')
        for sensor, limitname in self._sensor_checks:
            if sensor is None:
                continue
            if sensor.value > getattr(self, limitname):
                conditions.append(f'above {sensor.name} limit')
            if sensor.status[0] >= ERROR:
                conditions.append(f'error at {sensor.name}: {sensor.status[1]}')
                break
        self._conditions = ', '.join(conditions)
        if conditions and (self.control.control_active or self.htr.target):
            self.switch_off()
        if self.value:
            return IDLE, '; '.join(conditions)
        return ERROR, self._off_reason


class PI(HasConvergence, PImixin):
    input_module = Attached(Readable, 'the input module')
    relais = Attached(Writable, 'the interlock relais', mandatory=False)

    def read_value(self):
        return self.input.value

    def write_target(self, value):
        super().write_target(value)
        if self.relais:
            self.relais.write_target(1)


class TdkOutput(HasControlledBy, tdkpower.Output):
    pass


class BkOutput(HasControlledBy, bkpower.Output):
    pass


class PRtransmitter(CurrentInput):
    rawrange = (0.004, 0.02)
    extendedrange = (0.0036, 0.021)


class PKRgauge(LogVoltageInput):
    rawrange = (1.82, 8.6)
    valuerange = (5e-9, 1000)
    extendedrange = (0.5, 9.5)
    value = Parameter(unit='mbar')