###########################################################################
#
# Copyright (c) 2019-2021 Diality Inc. - All Rights Reserved.
#
# THIS CODE MAY NOT BE COPIED OR REPRODUCED IN ANY FORM, IN PART OR IN
# WHOLE, WITHOUT THE EXPLICIT PERMISSION OF THE COPYRIGHT OWNER.
#
# @file    dialysate_flow_sensor.py
#
# @author  (last)      Sean Nash
# @date    (last)      11-Nov-2021
# @author  (original)  Hung Nguyen
# @date    (original)  28-Oct-2021
#
############################################################################
import struct
from logging import Logger

from .constants import RESET, NO_RESET
from ..common.msg_defs import MsgIds, MsgFieldPositions
from ..protocols.CAN import DenaliMessage, DenaliChannels
from ..utils.base import AbstractSubSystem, publish
from ..utils.checks import check_broadcast_interval_override_ms
from ..utils.conversions import integer_to_bytearray, float_to_bytearray


class DialysateFlowSensor(AbstractSubSystem):
    """
    Dialysate Generation (DG) interface for dialysate flow sensor related commands.
    """

    def __init__(self, can_interface, logger: Logger):
        """
        Initialize CAN interface and logger
        @param can_interface: Denali CAN Messenger object
        @param: logger: (Logger) object
        """

        super().__init__()

        self.can_interface = can_interface
        self.logger = logger
        # The flow rate of the sensor mL/min
        self.flow_rate = 0.0

        if self.can_interface is not None:
            channel_id = DenaliChannels.dg_sync_broadcast_ch_id
            msg_id = MsgIds.MSG_ID_DG_DIALYSATE_FLOW_METER_DATA.value
            self.can_interface.register_receiving_publication_function(channel_id, msg_id,
                                                                       self._handler_flow_sensor_sync)

    def get_flow_rate(self):
        """
        Gets a flow value from the sensor

        @param: flow sensor: (int) sensor index
        @return: The dialysate flow rate mL/min of a flow sensor
        """
        return self.flow_rate

    @publish(['flow_rate'])
    def _handler_flow_sensor_sync(self, message):
        """
        Handles published flow sensor message.

        @param message:  published flow sensor message
        @return: none
        """
        flow = struct.unpack('f', bytearray(
            message['message'][MsgFieldPositions.START_POS_FIELD_1:MsgFieldPositions.END_POS_FIELD_1]))

        self.flow_rate = flow[0]

    def cmd_flow_sensor_value_override(self, rate: float, reset: int = NO_RESET) -> int:
        """
        Constructs and sends the flow sensor value override command
        Constraints:
            Must be logged into DG.

        @param rate: (float) the sensor flow rate to be set
        @param reset: (int) 1 to reset a previous override, 0 to override
        @return 1 if successful, zero otherwise
        """
        ml_per_liter: float = 1000.0
        reset_value = integer_to_bytearray(reset)
        vlu = float_to_bytearray(rate / ml_per_liter)    # DG expects the rate in mL/min
        payload = reset_value + vlu

        message = DenaliMessage.build_message(channel_id=DenaliChannels.dialin_to_dg_ch_id,
                                              message_id=MsgIds.MSG_ID_DIALYSATE_MEASURED_FLOW_OVERRIDE.value,
                                              payload=payload)
        self.logger.debug("Overriding dialysate flow sensor broadcast value override")

        # Send message
        received_message = self.can_interface.send(message)

        # If there is content...
        if received_message is not None:
            # response payload is OK or not OK
            return received_message['message'][DenaliMessage.PAYLOAD_START_INDEX]
        else:
            self.logger.debug("Dialysate flow sensor value override Timeout!!!")
            return False

    def cmd_flow_sensor_data_broadcast_interval_override(self, ms: int, reset: int = NO_RESET) -> int:
        """
        Constructs and sends the flow sensor data publish interval command.
        Constraints:
            Must be logged into DG.
            Given interval must be non-zero and a multiple of the DG priority task interval (50 ms).

        @param ms: (int) interval (in ms) to override with
        @param reset: (int) 1 to reset a previous override, 0 to override
        @return: 1 if successful, zero otherwise
        """
        if not check_broadcast_interval_override_ms(ms):
            return False

        rst = integer_to_bytearray(reset)
        mis = integer_to_bytearray(ms)
        payload = rst + mis

        msg_id = MsgIds.MSG_ID_DIALYSATE_FLOW_SEND_INTERVAL_OVERRIDE.value
        message = DenaliMessage.build_message(channel_id=DenaliChannels.dialin_to_dg_ch_id, message_id=msg_id,
                                              payload=payload)

        self.logger.debug("Overriding dialysate flow sensor broadcast interval")

        # Send message
        received_message = self.can_interface.send(message)

        # If there is content...
        if received_message is not None:
            # self.logger.debug(received_message)
            if reset == RESET:
                str_res = "reset back to normal"
            else:
                str_res = str(mis)
            self.logger.debug(
                "Dialysate flow sensor data broadcast interval overridden to " + str_res + " ms: " +
                str(received_message['message'][DenaliMessage.PAYLOAD_START_INDEX]))
            # response payload is OK or not OK
            return received_message['message'][DenaliMessage.PAYLOAD_START_INDEX]
        else:
            self.logger.debug("Timeout!!!!")
            return False