"""Long running process that processes messages in SQS."""
from availability import config
from availability.connectors import loggly
from availability.connectors.sqs import JSONMessageExt
from availability.constants import models
from availability.logic import polling
from availability.models import task

logger = loggly.get_current_logger()


def process_messages(queue):
    """Infinite loop that constantly checks for new messages.

    Args:
        queue (boto3.sqs.Queue): Instance of Amazon SQS.
    """
    for message_number in range(config.SQS_NUM_MESSAGES_TO_PROCESS):
        message = queue.receive_messages(
            WaitTimeSeconds=config.SQS_WAIT_TIME_SECONDS,
            VisibilityTimeout=config.SQS_MESSAGE_VISIBILITY_TIMEOUT_SECONDS)
        if not message:
            continue

        single_message = JSONMessageExt(message[0])
        message_dict = single_message.get_body()
        logger.info('Message received: {}'.format(message_dict))
        single_message.delete()
        process_single_message(message_dict)


def process_single_message(message):
    """Process message from SQS by invoking all required functions.

    Args:
        message (dict): Dict with attributes required to update product status.
    """
    task.change_status(
        message['product_in_store_id'], models.TASK_STATUS_PROCESSING)
    logger.info('Task status set to processing')
    try:
        polling.update_product_status(**message)
    except Exception:
        logger.exception('Exception while updating product status')
        task_change_result = task.change_status(
            message['product_in_store_id'], models.TASK_STATUS_FAILED)
        logger.info('Task status set to failed')
    else:
        task_change_result = task.change_status(
            message['product_in_store_id'], models.TASK_STATUS_OK)
        logger.info('Task status set to ok')
    assert task_change_result, task_change_result.errors