"""
Loggly handlers
===============
"""

import uuid

from owslogger.logger import DSNHandler

from masters_registry import config


class CeleryDSNHandler(DSNHandler):
    """Custom DSN Handler for processing celery-specific logging
    """

    def emit(self, record):
        """Emit a record.

        Update the LogRecord with correlation-id to match Orchards format
        and send it to Loggly

        Args:
            record (LogRecord): the record to log.
        """
        # Try to extract correlation ID from task args first
        try:
            correlation_id = record.args[0].correlation_id
        except:  # noqa: E722
            correlation_id = str(uuid.uuid1())

        record.__dict__.update(
            correlation_id=correlation_id)
        return DSNHandler.emit(self, record)

    def get_full_message(self, record):
        """Get the full message for a record.

        Format the record message

        Args:
            record (LogRecord): the record to log.
        Return:
            mixed: the string or an object (dictionary).
        """
        message = DSNHandler.get_full_message(self, record)
        if not record.exc_info:
            message = self.format(record)
        return message


def initialize_celery_logging(logger, format=None, formatter=None):
    """Signal handler for hooking up Loggly with Celery workers

    Args:
        logger (Logger): Logger instance
        format (str): format string
        formatter (Formatter): optional formatter callable

    Returns:
        Logger
    """
    logger.setLevel(config.CELERY_LOGGER_LEVEL)
    if not config.LOGGER_DSN:
        return
    dsn_handler = CeleryDSNHandler(
        config.LOGGER_DSN, config.ENVIRONMENT, config.SERVICE_NAME,
        config.SERVICE_VERSION)
    if formatter:
        dsn_handler.setFormatter(formatter(format))
    logger.addHandler(dsn_handler)
    return logger