#!/usr/bin/env python
# *****************************************************************************
# 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>
# *****************************************************************************
"""older generation (classic) oxford instruments"""

import time
import re
from frappy.core import Parameter, Property, EnumType, FloatRange, IntRange, BoolType, \
    StringIO, HasIO, Readable, Writable, Drivable, IDLE, WARN, ERROR
from frappy.lib import formatStatusBits
from frappy.lib.enum import Enum
from frappy.errors import BadValueError, HardwareError, CommunicationFailedError
from frappy_psi.magfield import Magfield, Status
from frappy.states import Retry


def bit(x, pos):
    return bool(x & (1 << pos))


class Base(HasIO):

    def query(self, cmd, scale=None):
        reply = self.communicate(cmd)
        if reply[0] != cmd[0]:
            raise CommunicationFailedError(f'bad reply: {reply} to command {cmd}')
        try:
            return float(reply[1:]) * scale
        except Exception:
            pass

    def change(self, cmd, value, scale=None):
        try:
            self.communicate('C3')
            reply = self.communicate(f'{cmd}{round(value / scale)}')
            if reply[0] != cmd[0]:
                raise CommunicationFailedError(f'bad reply: {reply}')
        finally:
            self.communicate('C0')

    def command(self, *cmds):
        try:
            self.communicate('C3')
            for cmd in cmds:
                self.communicate(cmd)
        finally:
            self.communicate('C0')


class IPS_IO(StringIO):
    """oxford instruments power supply IPS120-10"""
    end_of_line = '\r'
    identification = [('V', r'IPS120-10.*')]    # instrument type and software version
    default_settings = {'baudrate': 9600}


Action = Enum(hold=0, run_to_set=1, run_to_zero=2, clamped=4)
status_map = {'0': (IDLE, ''),
              '1': (ERROR, 'quenched'),
              '2': (ERROR, 'overheated'),
              '4': (WARN, 'warming up'),
              '8': (ERROR, '')
              }
limit_map = {'0': (IDLE, ''),
             '1': (WARN, 'on positive voltage limit'),
             '2': (WARN, 'on negative voltage limit'),
             '4': (ERROR, 'outside negative current limit'),
             '8': (ERROR, 'outside positive current limit')
             }


class Field(Base, Magfield):
    """ read commands:
        R1  measured power supply voltage (V)
        R7  demand field (output field) (T)
        R8  setpoint (target field) (T)
        R9  sweep field rate (T/min)
        R18 persistent field (T)
        X   Status
        
        control commands:
        A   set activity
        T   set field sweep rate
        H   set switch heater
        J   set target field """

    ioClass = IPS_IO

    action = Parameter('action', EnumType(Action), readonly=False)
    setpoint = Parameter('field setpoint', FloatRange(unit='T'), default=0)
    voltage = Parameter('leads voltage', FloatRange(unit='V'), default=0)
    persistent_field = Parameter(
        'persistent field at last switch off', FloatRange(unit='T'), readonly=False)
    wait_switch_on = Parameter(default=15)
    wait_switch_off = Parameter(default=15)
    wait_stable_field = Parameter(default=10)
    forced_persistent_field = Parameter(
        'manual indication that persistent field is bad', BoolType(), readonly=False, default=False)
    switch_heater = Parameter('turn switch heater on/off', EnumType(off=0, on=1, forced=2), default=0)

    _field_mismatch = None
    __persistent_field = None  # internal value of persistent field
    _status = '00'

    def initModule(self):
        super().initModule()
        try:
            self.write_action(Action.hold)
        except Exception as e:
            self.log.error('can not set to hold %r', e)

    def doPoll(self):
        super().doPoll()
        self.read_current()

    def initialReads(self):
        # on restart, assume switch is changed long time ago, if not, the mercury
        # will complain and this will be handled in start_ramp_to_field
        self.switch_on_time = 0
        self.switch_off_time = 0
        super().initialReads()

    def read_value(self):
        if self.switch_heater:
            self.__persistent_field = self.query('R7')
            self.forced_persistent_field = False
            self._field_mismatch = False
            return self.__persistent_field
        pf = self.query('R18')
        if self.__persistent_field is None:
            self.__persistent_field = pf
            self._field_mismatch = False
        else:
            self._field_mismatch = abs(self.__persistent_field - pf) > self.tolerance * 10
        self.persistent_field = self.__persistent_field
        return self.__persistent_field

    def read_ramp(self):
        return self.query('R9')

    def write_ramp(self, value):
        self.change('T', value)
        return self.read_ramp()

    def write_action(self, value):
        self.change('A', int(value))
        self.read_status()

    def read_voltage(self):
        return self.query('R1')

    def read_setpoint(self):
        return self.query('R8')

    def read_current(self):
        return self.query('R7')

    def write_persistent_field(self, value):
        if self.forced_persistent_field or abs(self.__persistent_field - value) <= self.tolerance * 10:
            self._field_mismatch = False
            self.__persistent_field = value
            return value
        raise BadValueError('changing persistent field needs forced_persistent_field=True')

    def write_target(self, target):
        if self._field_mismatch:
            self.forced_persistent_field = True
            raise BadValueError('persistent field does not match - set persistent field to guessed value first')
        return super().write_target(target)

    def read_switch_heater(self):
        self.read_status()
        return self.switch_heater

    def read_status(self):
        status = self.communicate('X')
        match = re.match(r'X(\d\d)A(\d)C\dH(\d)M\d\dP\d\d', status)
        if match is None:
            raise CommunicationFailedError(f'unexpected status: {status}')
        self._status = match.group(1)
        self.action = int(match.group(2))
        self.switch_heater = match.group(3) == '1'
        if self._status[0] != '0':
            self._state_machine.stop()
            return status_map.get(self._status[0], (ERROR, f'bad status: {self._status}'))
        if self._status[1] != '0':
            return limit_map.get(self._status[1], (ERROR, f'bad status: {self._status}'))  # need to stop sm too?
        return super().read_status()

    def write_switch_heater(self, value):
        if value == self.read_switch_heater():
            self.log.info('switch heater already %r', value)
            # we do not want to restart the timer
            return value
        self.log.debug('switch time fixed for 10 sec')
        self.change('H', int(value))
        #return result
        return int(value)

    def set_and_go(self, value):
        self.change('J', value)
        self.setpoint = self.read_current()
        assert self.write_action(Action.hold) == Action.hold
        assert self.write_action(Action.run_to_set) == Action.run_to_set

    def ramp_to_target(self, sm):
        try:
            return super().ramp_to_target(sm)
        except HardwareError:
            sm.try_cnt -= 1
            if sm.try_cnt < 0:
                raise
            self.set_and_go(sm.target)
            return Retry

    def final_status(self, *args, **kwds):
        self.write_action(Action.hold)
        return super().final_status(*args, **kwds)

    def on_restart(self, sm):
        self.write_action(Action.hold)
        return super().on_restart(sm)

    def start_ramp_to_field(self, sm):
        if abs(self.current - self.__persistent_field) <= self.tolerance:
            self.log.info('leads %g are already at %g', self.current, self.__persistent_field)
            return self.ramp_to_field
        try:
            self.set_and_go(self.__persistent_field)
        except (HardwareError, AssertionError) as e:
            if self.switch_heater:
                self.log.warn('switch is already on!')
                return self.ramp_to_field
            self.log.warn('wait first for switch off current=%g pf=%g %r', self.current, self.__persistent_field, e)
            sm.after_wait = self.ramp_to_field
            return self.wait_for_switch
        return self.ramp_to_field

    def start_ramp_to_target(self, sm):
        sm.try_cnt = 5
        try:
            self.set_and_go(sm.target)
        except (HardwareError, AssertionError) as e:
            self.log.warn('switch not yet ready %r', e)
            self.status = Status.PREPARING, 'wait for switch on'
            sm.after_wait = self.ramp_to_target
            return self.wait_for_switch
        return self.ramp_to_target

    def ramp_to_field(self, sm):
        try:
            return super().ramp_to_field(sm)
        except HardwareError:
            sm.try_cnt -= 1
            if sm.try_cnt < 0:
                raise
            self.set_and_go(self.__persistent_field)
            return Retry

    def wait_for_switch(self, sm):
        if not sm.delta(10):
            return Retry
        try:
            self.log.warn('try again')
            # try again
            self.set_and_go(self.__persistent_field)
        except (HardwareError, AssertionError):
            return Retry
        return sm.after_wait

    def wait_for_switch_on(self, sm):
        self.read_switch_heater()  # trigger switch_on/off_time
        if self.switch_heater == self.switch_heater.off:
            if sm.init:  # avoid too many states chained
                return Retry
            self.log.warning('switch turned off manually?')
            return self.start_switch_on
        return super().wait_for_switch_on(sm)

    def wait_for_switch_off(self, sm):
        self.read_switch_heater()
        if self.switch_heater == self.switch_heater.on:
            if sm.init:  # avoid too many states chained
                return Retry
            self.log.warning('switch turned on manually?')
            return self.start_switch_off
        return super().wait_for_switch_off(sm)

    def start_ramp_to_zero(self, sm):
        pf = self.query('R18')
        if abs(pf - self.value) > self.tolerance * 10:
            self.log.warning('persistent field %g does not match %g after switch off', pf, self.value)
        try:
            assert self.write_action(Action.hold) == Action.hold
            assert self.write_action(Action.run_to_zero) == Action.run_to_zero
        except (HardwareError, AssertionError) as e:
            self.log.warn('switch not yet ready %r', e)
            self.status = Status.PREPARING, 'wait for switch off'
            sm.after_wait = self.ramp_to_zero
            return self.wait_for_switch
        return self.ramp_to_zero

    def ramp_to_zero(self, sm):
        try:
            return super().ramp_to_zero(sm)
        except HardwareError:
            sm.try_cnt -= 1
            if sm.try_cnt < 0:
                raise
            assert self.write_action(Action.hold) == Action.hold
            assert self.write_action(Action.run_to_zero) == Action.run_to_zero
            return Retry

    def write_trainmode(self, value):
        self.change('M', '5' if value == 'off' else '1')


class ILM_IO(StringIO):
    """oxford instruments level meter ILM200"""
    end_of_line = '\r'
    identification = [('V', r'ILM200.*')]    # instrument type and software version
    default_settings = {'baudrate': 9600}
    timeout = 5


class Level(Base, Readable):

    """ X code:         XcccSuuvvwwRzz
            c:          position corresponds to channel 1, 2, 3
                        possible values in each position are 0, 1, 2, 3, 9
            vv, uu, ww: channel status for channel 1, 2, 3 respectively, 2 bits each
            zz:         relay status """

    ioClass = ILM_IO

    value = Parameter('level', datatype=FloatRange(unit='%'))
    CHANNEL = None
    X_PATTERN = re.compile(r'X(\d)(\d)(\d)S([0-9A-F]{2})([0-9A-F]{2})([0-9A-F]{2})R\d\d$')
    MEDIUM = None
    _statusbits = None

    def read_value(self):
        return self.query(f'R{self.CHANNEL}', 0.1)

    def write_fast(self, fast):
        self.command(f'T{self.CHANNEL}' if fast else f'S{self.CHANNEL}')

    def get_status(self):
        reply = self.communicate('X')
        match = self.X_PATTERN.match(reply)
        if match:
            statuslist = match.groups()
            if statuslist[self.CHANNEL] == '9':
                return ERROR, f'error on {self.MEDIUM} level channel (not connected?)'
            if (statuslist[self.CHANNEL] == '1') != (self.MEDIUM == 'N2'):
                # '1': channel is used for N2
                return ERROR, f'{self.MEDIUM} level channel not configured properly'
            self._statusbits = int(statuslist[self.CHANNEL + 3], 16)
            return None
        return ERROR, f'bad status message {reply}'


class HeLevel(Level):

    fast = Parameter('switching fast/slow', datatype=BoolType(), readonly=False)
    CHANNEL = 1
    MEDIUM = 'He'

    def read_status(self):
        status = self.get_status()
        if status is not None:
            return status
        return IDLE, formatStatusBits(self._statusbits, ['meas', 'fast', 'slow'])


class N2Level(Level):

    ioClass = ILM_IO

    value = Parameter('N2 level', FloatRange(unit='%'))
    CHANNEL = 2
    MEDIUM = 'N2'

    def read_status(self):
        status = self.get_status()
        if status is not None:
            return status
        return IDLE, ''


VALVE_MAP = {'01': 'V9',
             '02': 'V8',
             '03': 'V7',
             '04': 'V11A',
             '05': 'V13A',
             '06': 'V13B',
             '07': 'V11B',
             '08': 'V12B',
             '09': 'He4 rotary pump',
             '10': 'V1',
             '11': 'V5',
             '12': 'V4',
             '13': 'V3',
             '14': 'V14',
             '15': 'V10',
             '16': 'V2',
             '17': 'V2A He4',
             '18': 'V1A He4',
             '19': 'V5A He4',
             '20': 'V4A He4',
             '21': 'V3A He4',
             '22': 'roots pump',
             '23': 'unlabeled pump',
             '24': 'He3 rotary pump',
             }


class IGH_IO(StringIO):
    """oxford instruments dilution gas handling Kelvinox IGH"""
    end_of_line = '\r'
    identification =  [('V', r'IGH.*')]
    default_settings = {'baudrate': 9600}

    X_PATTERN = re.compile(r'X(\d)A\dC\dP([0-9A-F]{2})([0-9A-F]{2})([0-9A-F]{2})([0-9A-F]{2})S[0-9A-F]O\dE\d$')
    statusbits = 0
    ini_valves = 0

    def doPoll(self):
        reply = self.communicate('X')
        match = self.X_PATTERN.match(reply)
        if match:
            statuslist = match.groups()
        # REVISE THE METHOD FROM HERE ON
        # CHECK JUPYTER NOTEBOOK
                # a hex digit indicating if motorized valves are still initializing
            self.ini_valves = int(statuslist[0], 16)


class Valve(Base, Writable):

    ioClass = IGH_IO

    target = Parameter('open or close valve', EnumType(open=1, close=0))
    addr = Property('valve number', IntRange(1,24))

    def write_target(self, val):
        # open: 2N, close: 2N + 1
        self.change('P', (2 * self.addr + 1 - int(val)), 1)

    def read_status(self):
        # CHECK
        status = self.io.statusbits & (1 << self.addr)
        if status is not None:
            return status
        return IDLE, ''


class PulsedValve(Valve):

    delay = Parameter('time valve is open', FloatRange(unit='s'))
    _start = 0

    def write_target(self, val):
        if val:
            self._start = time.time()
            self.setFastPoll(True, 0.01)
        else:
            self.setFastPoll(False)
        self.change('P', (2 * self.addr + 1 - int(val)), 1)

    def doPoll(self):
        super().doPoll()
        if self._start:
            if time.time() > self._start + self.delay:
                self.write_target(False)    # turn valve off
                #self.setFastPoll(False)
                self._start = 0


class MotorValve(Base, Drivable):
    pass


class Pressure(Base, Readable):
    pass


class Heater(Base, Writable):
    pass


class N2Sensor():
    # ask Markus
    pass

class Pump(Base, Writable):
    pass