"""Model for a message from a kafka replication topic."""

import base64
import json


class KafkaMessage:
    """MSK event record.

    Message structure:
    {
        topic: {topic name}
        partition: {partition name}
        offset: {message offset}
        timestamp: {unix timestamp}
        timestampType: {timestamp type}
        key: {base64 encoded message key}
        value: {base64 encoded message value}
    }
    """

    def __init__(self, record):
        """Initialize."""
        self.topic = record.get('topic')
        self.partition = record.get('partition')
        self.offset = record.get('offset')
        self.timestamp = record.get('timestamp')
        self.timestamp_type = record.get('timestampType')
        self._key = record.get('key')
        self._value = record.get('value')

    @property
    def value(self):
        """Return event dict."""
        if not self._value:
            return None
        return json.loads(
            base64.b64decode(
                self._value
            )
        )

    @property
    def key(self):
        """Return parsed key property."""
        json.loads(
            base64.b64decode(
                self._key
            )
        )