path: root/glucometerutils/drivers/otultraeasy.py

# -*- coding: utf-8 -*-
#
# SPDX-License-Identifier: MIT
"""Driver for LifeScan OneTouch Ultra Easy devices.

Also supports OneTouch Ultra Mini devices (different name, same device).

Supported features:
    - get readings;
    - use the glucose unit preset on the device by default;
    - get and set date and time;
    - get serial number and software version;
    - memory reset (caution!)

Expected device path: /dev/ttyUSB0 or similar serial port device.
"""

import binascii
import datetime
import logging

import construct

from glucometerutils import common
from glucometerutils.support import (
    construct_extras,
    driver_base,
    lifescan,
    lifescan_binary_protocol,
    serial,
)

_PACKET = lifescan_binary_protocol.LifeScanPacket(True)

_INVALID_RECORD = 501

_COMMAND_SUCCESS = construct.Const(b"\x05\x06")

_VERSION_REQUEST = construct.Const(b"\x05\x0d\x02")

_VERSION_RESPONSE = construct.Struct(
    _COMMAND_SUCCESS,
    "version" / construct.PascalString(construct.Byte, encoding="ascii"),
)

_SERIAL_NUMBER_REQUEST = construct.Const(
    b"\x05\x0B\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00"
)

_SERIAL_NUMBER_RESPONSE = construct.Struct(
    _COMMAND_SUCCESS, "serial_number" / construct.GreedyString(encoding="ascii"),
)

_DATETIME_REQUEST = construct.Struct(
    construct.Const(b"\x05\x20"),  # 0x20 is the datetime
    "request_type" / construct.Enum(construct.Byte, write=0x01, read=0x02),
    "timestamp"
    / construct.Default(
        construct_extras.Timestamp(construct.Int32ul),  # type: ignore
        datetime.datetime(1970, 1, 1, 0, 0),
    ),
)

_DATETIME_RESPONSE = construct.Struct(
    _COMMAND_SUCCESS,
    "timestamp" / construct_extras.Timestamp(construct.Int32ul),  # type: ignore
)

_GLUCOSE_UNIT_REQUEST = construct.Const(b"\x05\x09\x02\x09\x00\x00\x00\x00")


_GLUCOSE_UNIT_RESPONSE = construct.Struct(
    _COMMAND_SUCCESS,
    "unit" / lifescan_binary_protocol.GLUCOSE_UNIT,
    construct.Padding(3),
)

_MEMORY_ERASE_REQUEST = construct.Const(b"\x05\x1A")

_READING_COUNT_RESPONSE = construct.Struct(
    construct.Const(b"\x0f"), "count" / construct.Int16ul,
)

_READ_RECORD_REQUEST = construct.Struct(
    construct.Const(b"\x05\x1f"), "record_id" / construct.Int16ul,
)

_READING_RESPONSE = construct.Struct(
    _COMMAND_SUCCESS,
    "timestamp" / construct_extras.Timestamp(construct.Int32ul),  # type: ignore
    "value" / construct.Int32ul,
)


def _make_packet(message, sequence_number, expect_receive, acknowledge, disconnect):
    return _PACKET.build(
        {
            "data": {
                "value": {
                    "message": message,
                    "link_control": {
                        "sequence_number": sequence_number,
                        "expect_receive": expect_receive,
                        "acknowledge": acknowledge,
                        "disconnect": disconnect,
                    },
                }
            }
        }
    )


class Device(serial.SerialDevice, driver_base.GlucometerDriver):
    BAUDRATE = 9600
    DEFAULT_CABLE_ID = "067b:2303"  # Generic PL2303 cable.
    TIMEOUT = 0.5

    def __init__(self, device):
        super(Device, self).__init__(device)

        self.sent_counter_ = False
        self.expect_receive_ = False
        self.buffered_reader_ = construct.Rebuffered(_PACKET, tailcutoff=1024)

    def connect(self):
        try:
            self._send_packet(b"", disconnect=True)
            self._read_ack()
        except construct.ConstructError as e:
            raise lifescan.MalformedCommand(str(e))

    def disconnect(self):
        self.connect()

    def _send_packet(self, message, acknowledge=False, disconnect=False):
        pkt = _make_packet(
            message, self.sent_counter_, self.expect_receive_, acknowledge, disconnect
        )
        logging.debug("sending packet: %s", binascii.hexlify(pkt))

        self.serial_.write(pkt)
        self.serial_.flush()

    def _read_packet(self):
        raw_pkt = self.buffered_reader_.parse_stream(self.serial_).data
        logging.debug("received packet: %r", raw_pkt)

        # discard the checksum and copy
        pkt = raw_pkt.value

        if not pkt.link_control.disconnect and (
            pkt.link_control.sequence_number != self.expect_receive_
        ):
            raise lifescan.MalformedCommand(
                "at position 2[0b] expected %02x, received %02x"
                % (self.expect_receive_, pkt.link_connect.sequence_count)
            )

        return pkt

    def _send_ack(self):
        self._send_packet(b"", acknowledge=True, disconnect=False)

    def _read_ack(self):
        pkt = self._read_packet()
        assert pkt.link_control.acknowledge

    def _send_request(self, request_format, request_obj, response_format):
        try:
            request = request_format.build(request_obj)
            self._send_packet(request, acknowledge=False, disconnect=False)

            self.sent_counter_ = not self.sent_counter_
            self._read_ack()

            response_pkt = self._read_packet()
            assert not response_pkt.link_control.acknowledge

            self.expect_receive_ = not self.expect_receive_
            self._send_ack()

            return response_format.parse(response_pkt.message)
        except construct.ConstructError as e:
            raise lifescan.MalformedCommand(str(e))

    def get_meter_info(self):
        return common.MeterInfo(
            "OneTouch Ultra Easy glucometer",
            serial_number=self.get_serial_number(),
            version_info=("Software version: " + self.get_version(),),
            native_unit=self.get_glucose_unit(),
        )

    def get_version(self):
        response = self._send_request(_VERSION_REQUEST, None, _VERSION_RESPONSE)

        return response.version

    def get_serial_number(self):
        response = self._send_request(
            _SERIAL_NUMBER_REQUEST, None, _SERIAL_NUMBER_RESPONSE
        )

        return response.serial_number

    def get_datetime(self):
        response = self._send_request(
            _DATETIME_REQUEST, {"request_type": "read"}, _DATETIME_RESPONSE
        )

        return response.timestamp

    def _set_device_datetime(self, date):
        response = self._send_request(
            _DATETIME_REQUEST,
            {"request_type": "write", "timestamp": date,},
            _DATETIME_RESPONSE,
        )
        return response.timestamp

    def zero_log(self):
        self._send_request(_MEMORY_ERASE_REQUEST, None, _COMMAND_SUCCESS)

    def get_glucose_unit(self):
        response = self._send_request(
            _GLUCOSE_UNIT_REQUEST, None, _GLUCOSE_UNIT_RESPONSE
        )

        return response.unit

    def _get_reading_count(self):
        response = self._send_request(
            _READ_RECORD_REQUEST,
            {"record_id": _INVALID_RECORD},
            _READING_COUNT_RESPONSE,
        )
        return response.count

    def _get_reading(self, record_id):
        response = self._send_request(
            _READ_RECORD_REQUEST, {"record_id": record_id}, _READING_RESPONSE
        )

        return common.GlucoseReading(response.timestamp, float(response.value))

    def get_readings(self):
        record_count = self._get_reading_count()
        for record_id in range(record_count):
            yield self._get_reading(record_id)