# *****************************************************************************
# 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>
#   Anik Stark <anik.stark@psi.ch>
# *****************************************************************************

from frappy.core import StringIO, HasIO, Drivable, Parameter, Property, FloatRange, BoolType, \
    EnumType, BUSY, IDLE, WARN
from frappy.errors import CommunicationFailedError


class IO(StringIO):
    end_of_line = '\n'
    identification = [('*IDN?', 'FUG.*')]    # returns the fabrication number
    default_settings = {'baudrate': 230000}


class Voltage(HasIO, Drivable):

    ioClass = IO    # define IO class for automatic creation of the IO module

    value = Parameter('voltage reading', FloatRange(unit='V', fmtstr='%.2f'))
    target = Parameter('voltage target value', FloatRange(0, 6500, unit='V', fmtstr='%.2f'), readonly=False)
    setpoint = Parameter('effective voltage setpoint', FloatRange(unit='V', fmtstr='%.2f'))
    on = Parameter('turn voltage on/off', BoolType(), readonly=False)
    current = Parameter('current reading', FloatRange(unit='A', fmtstr='%.8f'))
    overcurrent_protection = Parameter('flag to turn voltage off in current control', BoolType(), readonly=False, default=False)
    current_limit = Parameter('current limit', FloatRange(unit='A', fmtstr='%.8f'), readonly=False, value=1e-6)
    ramp = Parameter('ramp voltage value', FloatRange(unit='V/s', fmtstr='%.2f'), readonly=False)
    ramp_mode = Parameter('ramp mode', EnumType(off=0, on=1, rampup_only=2), readonly=False)
    tolerance = Property('tolerance for target vs. readback voltage', FloatRange(0, 5, unit='V'), default=1)
    offset = Parameter('expected offset correction for target', FloatRange(-3, 0, unit='V'), default=-2.8, readonly=False)
    _busy = False
    _idle_status = IDLE, ''
    _count = 0
    _setpoint = 0

    def request(self, name):
        reply, txtvalue = self.communicate(f'>{name} ?').split(':')
        if reply != name:
            raise CommunicationFailedError(f'bad reply: {reply}')
        return float(txtvalue)  # from scientific notation to float

    def set(self, name, value):
        reply = self.communicate(f'>{name} {value:g}')
        if reply != 'E0':
            raise CommunicationFailedError(f'bad reply: {reply}')
        return self.request(name)

    def read_on(self):
        return self.request('BON')

    def write_on(self, value):
        return self.set('BON', value)

    def read_value(self):
        return self.request('M0')

    def write_target(self, target):
        self._count = 0
        self.target = target
        self._setpoint = max(0, target + self.offset)
        self.setFastPoll(True, 0.25)
        if self.target > 0:
            self._idle_status = IDLE, ''
            if not self.read_on():
                self.write_on(1)
                self._off = False
        else:
            self._idle_status = IDLE, 'off'
        self._busy = True
        self.set('S0', self._setpoint)
        self.read_status()

    def read_setpoint(self):
        return self.request('S0A')

    def read_current(self):
        return self.request('M1')

    def write_overcurrent_protection(self, value):
        self._idle_status = IDLE, ''
        self.read_status()

    def read_current_limit(self):
        return self.request('S1')

    def write_current_limit(self, value):
        self._idle_status = IDLE, ''
        self.read_status()
        return self.set('S1', value)

    def read_ramp(self):
        return self.request('S0R')

    def write_ramp(self, value):
        return self.set('S0R', value)

    def read_ramp_mode(self):
        return self.request('S0B')

    def write_ramp_mode(self, value):
        return self.set('S0B', value.value)

    def read_status(self):
        name, status = self.communicate('>KS?').split(':')
        if name != 'KS':
            raise CommunicationFailedError(f'bad reply: {name}')
        setpoint = self.read_setpoint()
        if setpoint == 0 and self.value + self.offset < self.tolerance:     # turn device off if ramp at 0
            self.write_on(0)
            self._idle_status = IDLE, 'off'
        if status[0] == '1':  # current control mode
            if self.overcurrent_protection:
                self.write_on(0)
                self._busy = False
                self.setFastPoll(False)
                self._idle_status = WARN, 'overcurrent: device turned off'
                return self._idle_status
            if self._busy:
                self._count += 1
                if self._count > 80:
                    self.setFastPoll(False)
                    self._busy = False
            return WARN, 'current limited'
        if not self._busy:
            return self._idle_status
        if abs(setpoint - self._setpoint) > 0.1:
            return BUSY, 'ramping'
        target = max(self.target, -self.offset) if self.on else 0
        if abs(target - self.value) < self.tolerance:
            self.setFastPoll(False)
            self._busy = False
            return self._idle_status
        return BUSY, ''

    def stop(self):
        """stop ramping"""
        if self.isBusy():
            self.write_target(self.read_setpoint())