"""SQS utility functions."""
import json

import boto3
import botocore
from lambdacommon.common_config import logger

import config

sqs_config = botocore.config.Config(
    retries={
        'max_attempts': 5,
        'mode': 'standard',
    }
)

sqs_client = boto3.client(
    'sqs', config=sqs_config, region_name=config.AWS_REGION)


def delete_message(receipt_handle):
    """
    Delete an SQS message.

    Args:
        receipt_handle (str): Receipt handle of message to delete
    Returns:
        int: HTTP status code from delete method call
    """
    try:
        queue = sqs_client.get_queue_url(QueueName=config.SQS_QUEUE_NAME)
        response = sqs_client.delete_message(
            QueueUrl=queue['QueueUrl'],
            ReceiptHandle=receipt_handle,
        )
    except botocore.exceptions.ClientError as error:
        logger.exception('Error deleting SQS message: {}'.format(
            error.response['Error']['Message']))
        raise error

    return response['ResponseMetadata']['HTTPStatusCode']


def get_queue_message_count():
    """
    Get number of messages in SQS queue.

    Returns:
        int: number of messages in queue
    """
    try:
        queue = sqs_client.get_queue_url(QueueName=config.SQS_QUEUE_NAME)
        queue_attributes = sqs_client.get_queue_attributes(
            QueueUrl=queue['QueueUrl'],
            AttributeNames=['ApproximateNumberOfMessages']
        )
        message_count = int(
            queue_attributes['Attributes']['ApproximateNumberOfMessages'])
    except botocore.exceptions.ClientError as error:
        logger.exception('Error getting SQS attributes: {}'.format(
            error.response['Error']['Message']))
        raise error

    return message_count


def receive_message():
    """
    Receive SQS message with details about break-glass sessions.

    Returns:
        str: SQS message receipt handle
        dict: SQS message body
    """
    try:
        queue = sqs_client.get_queue_url(QueueName=config.SQS_QUEUE_NAME)
        response = sqs_client.receive_message(
            QueueUrl=queue['QueueUrl'],
            WaitTimeSeconds=config.SQS_WAIT_TIME_SECONDS,
            VisibilityTimeout=config.SQS_MESSAGE_VISIBILITY_TIMEOUT,
            MaxNumberOfMessages=1,
        )
        if 'Messages' in response:
            message = response['Messages'][0]
            receipt_handle = message['ReceiptHandle']
            message_body = json.loads(message['Body'])
        else:
            logger.warning('No messages receieved from queue: this is '
                           'unexpected and suggests multiple consumers')
            return {}, {}
    except botocore.exceptions.ClientError as error:
        logger.exception('Error getting SQS messages: {}'.format(
            error.response['Error']['Message']))
        raise error

    return receipt_handle, message_body