#  -*- 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>
#
# *****************************************************************************

"""drivers for trinamic PD-1161 motors"""

import time
import os
import struct
from secop.core import BoolType, Command, EnumType, FloatRange, IntRange, \
    HasIodev, Parameter, Property, Drivable, TupleOf, Done
from secop.bytesio import BytesIO
from secop.lib import getGeneralConfig
from secop.errors import CommunicationFailedError, HardwareError

MOTOR_STOP = 3
MOVE = 4
SET_AXIS_PAR = 5
GET_AXIS_PAR = 6
SAVE_AXIS_PAR = 7
LOAD_AXIS_PAR = 8
SET_GLOB_PAR = 9
GET_GLOB_PAR = 10
SAVE_GLOB_PAR = 11
LOAD_GLOB_PAR = 12
SET_IO = 14
GET_IO = 15

MOT_FACT = object()

CONFIG = getGeneralConfig()


class AxisPar(Parameter):
    SET = SET_AXIS_PAR
    GET = GET_AXIS_PAR

    def __init__(self, adr, min=None, max=None, unit=None, scale=1, readonly=False, poll=True):
        if unit:
            datatype = FloatRange(min, max, unit=unit)
        else:
            datatype = IntRange(min, max)
        super().__init__('_', datatype, readonly=readonly, poll=poll)
        self.adr = adr
        self.scale = scale

    def to_raw(self, motor, value):
        return round(value / self.scale)

    def from_raw(self, motor, value):
        return value * self.scale

    def read(self, motor):
        return round(self.from_raw(motor, motor.comm(self.GET, self.adr)), 3)

    def write(self, motor, value):
        rvalue = self.to_raw(motor, value)
        motor.comm(self.SET, self.adr, rvalue)
        reply = motor.comm(self.GET, self.adr)
        if rvalue != reply:
            raise HardwareError('%s: reply does not match: %r != %r' % (self.name, rvalue, reply))
        return round(self.from_raw(motor,reply), 3)

    def __set_name__(self, owner, name):
        super().__set_name__(owner, name)
        setattr(owner, 'read_' + name, lambda self, pobj=self: pobj.read(self))

        if not self.readonly:

            setattr(owner, 'write_' + name, lambda self, value, pobj=self: pobj.write(self, value))


class IoPar(AxisPar):
    SET = SET_IO
    GET = GET_IO

    def __init__(self, adr, bank, datatype=EnumType(CLOSED=0, OPEN=1), scale=1, readonly=False, poll=True):
        Parameter.__init__(self, '_', datatype, readonly=readonly, poll=poll)
        self.adr = adr + 1000 * bank
        self.scale = scale

    def read(self, motor):
        return motor.comm(self.GET, self.adr)

    def write(self, motor, value):
        motor.comm(self.SET, self.adr, int(value))
        return value


class AxisDiffPar(AxisPar):
    @staticmethod
    def to_raw(motor, value):
        return round(value / motor.fact)

    @staticmethod
    def from_raw(motor, value):
        return round(value * motor.fact, 3)


class AxisZeroPar(AxisPar):
    @staticmethod
    def to_raw(motor, value):
        return round(value / motor.fact - motor.zero)

    @staticmethod
    def from_raw(motor, value):
        return round(value * motor.fact + motor.zero, 3)


BAUDRATES = [9600, 0, 19200, 0, 38400, 57600, 0, 115200]


class Motor(HasIodev, Drivable):
    address = Property('module address', IntRange(0, 255), default=1)
    fact = Property('gear factor', FloatRange(unit='deg/step'), default=1.8/256)
    limit_pin_mask = Property('input pin mask for lower/upper limit switch',
                              TupleOf(IntRange(0, 15), IntRange(0, 15)),
                              default=(8, 0))
    value = Parameter('motor position', FloatRange(unit='deg'))
    target = Parameter('_', FloatRange(unit='$'), default=0)
    zero = Parameter('zero point', FloatRange(unit='$'), readonly=False, default=0)
    tolerance = Parameter('positioning tolerance', FloatRange(unit='$'), readonly=False, default=0.9)
    encoder = Parameter('encoder value', FloatRange(unit='$'), needscfg=False)
    steppos = Parameter('motor steps position', FloatRange(unit='$'), needscfg=False)
    at_upper_limit = Parameter('upper limit switch touched', BoolType(), needscfg=False)
    at_lower_limit = Parameter('lower limit switch touched', BoolType(), needscfg=False)
    pull_up = Parameter('activate pull up resistors', BoolType(), needscfg=False)
    baudrate = Parameter('baud rate code', EnumType({'%d' % v: i for i, v in enumerate(BAUDRATES)}),
                         readonly=False, default=0, poll=True)

    temperature = IoPar(9, 1, IntRange(), readonly=True)
    operating_voltage = IoPar(8, 1, IntRange(), readonly=True)

    enc_tolerance = AxisDiffPar(212, 0, 360., '$')
    maxspeed = AxisPar(4, 0, 2047)
    minspeed = AxisPar(130, 0, 2047)
    maxcurrent = AxisPar(6, 0, 2.8, 'A', 2.8/250)
    standby_current = AxisPar(7, 0, 2.8, 'A', 2.8/250)
    acceleration = AxisPar(5, 0, 2047)
    internal_target = AxisZeroPar(0, unit='$')
    target_reached = AxisPar(8, readonly=True)
    move_status = AxisPar(207, readonly=True)
    error_bits = AxisPar(208, readonly=True)
    free_wheeling = AxisPar(204, 0, 60, 'sec', scale=0.001)

    fast_pollfactor = 0.001
    _targettime = None
    _prevconn = None
    iodevClass = BytesIO
    _commcnt = 0
    _pollcnt = 0
    _lastpoll = 0
    _calcTimeout = True

    def earlyInit(self):
        self.resetValues = dict(self.writeDict)

    def startModule(self, started_callback):
        loaded_pos = None
        try:
            print(self.save_filename())
            with open(self.save_filename()) as f:
                loaded_pos = float(f.read())
        except FileNotFoundError:
            pass
        super().startModule(started_callback)
        encoder = self.read_encoder()
        if loaded_pos is not None:
            diff = loaded_pos - encoder + 180
            if abs(diff % 360 - 180) < self.enc_tolerance:
                diff = round(diff / 180) * 180
                if diff:
                    self.comm(SET_AXIS_PAR, 209, AxisZeroPar.to_raw(self, encoder + diff))
            else:
                msg = 'loaded pos (%g) does not match encoder reading' % loaded_pos
                self.status = self.Status.ERROR, msg
                self.log.error(msg + ' (%g)' % encoder)

    def comm(self, cmd, adr=0, value=0):
        if self._calcTimeout:
            self._calcTimeout = False
            baudrate = getattr(self._iodev._conn.connection, 'baudrate', None)
            if baudrate:
                if baudrate not in BAUDRATES:
                    raise CommunicationFailedError('unsupported baud rate: %d' % baudrate)
                self._iodev.timeout = 0.03 + 200 / baudrate

        self._commcnt = self._commcnt + 1
        bank = adr // 1000
        iadr = adr % 1000
        for itry in range(3):
            byt = struct.pack('>BBBBi', self.address, cmd, iadr, bank, round(value))
            try:
                reply = self._iodev.communicate(byt + bytes([sum(byt) & 0xff]), 9)
            except Exception as e:
                print(repr(e), adr, bank)
                continue
            if sum(reply[:-1]) & 0xff == reply[-1]:
                break
        else:
            raise CommunicationFailedError('checksum error')
        radr, modadr, status, rcmd, result = struct.unpack('>BBBBix', reply)
        if status != 100:
            self.log.warning('bad status from cmd %r %s: %d', cmd, adr, status)
        if radr != 2 or modadr != self.address or cmd != rcmd:
            raise CommunicationFailedError('bad reply %r to command %s %d' % (reply, cmd, adr))
        return result

    def read_value(self):
        now = time.time()
        if now > self._lastpoll + 1:
            print(now - self._lastpoll, self._commcnt, self._pollcnt)
            self._commcnt = 0
            self._pollcnt = 0
            self._lastpoll = now
        self._pollcnt = self._pollcnt + 1

        init = self.comm(GET_GLOB_PAR, 2255)  # bank 2 adr 255
        if not init or self._prevconn != self._iodev._conn:
            # reset to initial parameters when either motor lost power or connection has changed
            self.log.info('reset initial values')
            for pname, value in self.resetValues.items():
                getattr(self, 'write_' + pname)(value)
            self.comm(SET_GLOB_PAR, 2255, 1)
            self._prevconn = self._iodev._conn
        rawenc = self.comm(GET_AXIS_PAR, 209)
        rawpos = self.comm(GET_AXIS_PAR, 1)
        self.encoder = AxisZeroPar.from_raw(self, rawenc)
        self.save_pos()
        self.steppos = AxisZeroPar.from_raw(self, rawpos)
        if abs(rawenc - rawpos) > 128:
            return self.encoder
        return self.steppos

    def save_filename(self):
        savedir = os.path.join(CONFIG['logdir'], 'persistent')
        os.makedirs(savedir, exist_ok=True)
        return os.path.join(savedir, '%s.%s' % (type(self).__name__, self.name))

    def save_pos(self):
        with open(self.save_filename(), 'w') as f:
            f.write('%g' % self.value)

    def read_status(self):
        if not self._targettime:
            return self.status
        self.get_limits()
        if self.at_lower_limit or self.at_upper_limit:
            self.stop()
            return self.Status.ERROR, 'at limit'
        target_reached = self.read_target_reached()
        if target_reached or self.read_move_status():
            self._targettime = None
            if abs(self.target - self.value) < self.tolerance:
                return self.Status.IDLE, ''
            self.log.warning('out of tolerance (%d)', self.move_status)
            return self.Status.WARN, 'out of tolerance (%d)' % self.move_status
        if time.time() > self._targettime:
            self.log.warning('move timeout')
            return self.Status.WARN, 'move timeout'
        return self.Status.BUSY, 'moving'

    def write_target(self, target):
        rawenc = self.comm(GET_AXIS_PAR, 209)
        rawpos = self.comm(GET_AXIS_PAR, 1)
        if abs(rawenc - rawpos) > 128:
            # adjust missing steps
            missing_steps = round((rawenc - rawpos) / 256.0)
            self.log.warning('correct %s missing steps', missing_steps)
            rawpos += missing_steps * 256
            self.comm(SET_AXIS_PAR, 1, rawpos)
        rawtarget = round((target - self.zero) / self.fact)
        delay = (abs(rawtarget - rawpos) / 30.5 / self.maxspeed
                 + self.maxspeed / self.acceleration / 15.25 + 0.5)
        self._targettime = time.time() + delay
        self.log.info('move to %.1f', target)
        self.comm(MOVE, 0, rawtarget)
        print('write_target')
        self.target_reached = 0
        self.status = self.Status.BUSY, 'changed target'
        return target

    def get_limits(self):
        self.input_bits = self.comm(GET_IO, 255)
        bits = (~ self.input_bits) & 0xf
        self.at_lower_limit = bool(bits & self.limit_pin_mask[0])
        self.at_upper_limit = bool(bits & self.limit_pin_mask[1])

    def read_at_upper_limit(self):
        self.get_limits()
        return Done

    def read_at_lower_limit(self):
        self.get_limits()
        return Done

    def write_pull_up(self, value):
        self.comm(SET_IO, 0, int(value))
        return value

    def write_baudrate(self, value):
        self.comm(SET_GLOB_PAR, 65, int(value))

    def read_baudrate(self):
        reply = self.comm(GET_GLOB_PAR, 65)
        print('BAUD', reply)
        return reply

    @Command(FloatRange())
    def set_zero(self, value):
        self.zero += value - self.read_value()

    @Command
    def stop(self):
        self.comm(MOTOR_STOP)
        self.status = self.Status.IDLE, 'stopped'
        self._targettime = None

    @Command(FloatRange())
    def step(self, value):
        self.comm(MOVE, 1, value / self.fact)

    @Command(IntRange(), result=IntRange())
    def get_axis_par(self, adr):
        return self.comm(GET_AXIS_PAR, adr)

    @Command(IntRange())
    def set_axis_par(self, adr, value):
        return self.comm(SET_AXIS_PAR, adr, value)