"""
Amazon SQS connector
====================

"""

import base64
import json

import boto3

from ytownership import config
from ytownership.connectors.loggly import get_current_logger
from ytownership.utils.misc import DotDict


CORRELATION_ID_ATTRIBUTE = 'Correlation-Id'
APPROXIMATE_RECEIVE_COUNT_ATTRIBUTE = 'ApproximateReceiveCount'


class JSONMessageExt():
    """Wrapper for SQS Messages that provides a logger with Correlation-Id
    """

    def __init__(self, message=None):
        """Create new instance of JSONMessageExt
        """
        self._message = message
        self._context = DotDict()

    @property
    def context(self):
        """Stores an additional context for message (e.g. logging adapter)

        Returns:
             DotDict: an object that holds message context
        """

        return self._context

    @property
    def correlation_id(self):
        """Get Correlation-Id extracted from message attributes

        Returns:
            str: correlation Id
        """
        return self._message.message_attributes.get(
            CORRELATION_ID_ATTRIBUTE, {}).get('StringValue')

    @property
    def logger(self):
        """Get logging adapter for current message

        Returns:
              OwsLoggingAdapter: Logging adapter with Correlation-Id,
              extracted from SQS message attributes
        """
        if not self.context.logger:
            self.context.logger = get_current_logger(self.correlation_id)
        return self.context.logger

    @property
    def receive_count(self):
        """Get approximate message receive count

        Returns:
              int: approximate number of times the message has been received
        """

        count = self._message.attributes.get(
            APPROXIMATE_RECEIVE_COUNT_ATTRIBUTE, 0)
        return int(count)

    @property
    def message(self):
        """Get the message object"""
        return self._message

    def get_body(self):
        """Get the message body"""
        return json.loads(base64.b64decode(self._message.body).decode())

    def delete(self):
        """Delete the message from SQS queue"""
        return self._message.delete()

    def change_visibility(self, queue_timeout):
        """Set visibility of message in SQS queue"""
        return self._message.change_visibility(VisibilityTimeout=queue_timeout)


def get_connection():
    """Get connection to Amazon SQS services
    """
    return boto3.resource('sqs', region_name=config.AWS_REGION)


def get_queue(queue_name, sqs_connection=None):
    """Get connection to Amazon SQS services"""

    connection = sqs_connection if sqs_connection else get_connection()
    queue = connection.get_queue_by_name(QueueName=queue_name)
    return queue