# -*- coding: utf-8 -*-
"""Driver for FreeStyle Precision Neo devices.
"""

import collections
import datetime

from glucometerutils import common
from glucometerutils.support import freestyle


# The type is a string because it precedes the parsing of the object.
_TYPE_GLUCOSE_READING = '7'

_NeoReading = collections.namedtuple('_NeoReading', (
    'type',  # 7 = blood glucose
    'id',
    'month', 'day', 'year',  # year is two-digits
    'hour', 'minute',
    'unknown2',
    'value',
    'unknown3', 'unknown4', 'unknown5', 'unknown6', 'unknown7',
    'unknown8', 'unknown9', 'unknown10', 'unknown11', 'unknown12',
))


class Device(freestyle.FreeStyleHidDevice):
    """Glucometer driver for FreeStyle Precision Neo devices."""

    def get_meter_info(self):
        """Return the device information in structured form."""
        return common.MeterInfo(
            'FreeStyle Precision Neo',
            serial_number=self.get_serial_number(),
            version_info=(
                'Software version: ' + self._get_version(),),
            native_unit=self.get_glucose_unit())

    def _get_version(self):
        """Return the software version of the device."""
        return self._send_text_command(b'$swver?').rstrip('\r\n')

    def get_serial_number(self):
        """Returns the serial number of the device."""
        return self._send_text_command(b'$serlnum?').rstrip('\r\n')

    def get_glucose_unit(self):
        """Returns the glucose unit of the device."""
        return common.UNIT_MGDL

    def get_readings(self):
        """Iterate through the reading records in the device."""
        for record in self._get_multirecord(b'$record?'):
            if not record or record[0] != _TYPE_GLUCOSE_READING:
                continue

            # Build a _NeoReading object by parsing each of the entries in the
            # CSV as integers.
            raw_reading = _NeoReading._make([int(v) for v in record])

            timestamp = datetime.datetime(
                raw_reading.year + 2000, raw_reading.month, raw_reading.day,
                raw_reading.hour, raw_reading.minute)

            yield common.Reading(timestamp, raw_reading.value)