"""Sets up global logging configuration for the application."""

import logging
import os

logger = logging.getLogger(__name__)


def configure_logging():
    """
    Called at startup of a FastAPI application instance to setup logging. Depending on the environment, it will log to stdout or to Loki.
    """

    is_debug = os.getenv('DEBUG', "false") == "true"
    is_kubernetes = os.getenv('KUBERNETES_SERVICE_HOST') is not None


    if is_kubernetes:
        # in that case we want to log to stdout and also to loki
        from loki_logger_handler.loki_logger_handler import LokiLoggerHandler
        loki_url = os.getenv('LOKI_URL')
        if loki_url is None:
            raise ValueError("LOKI_URL environment variable is not set")

        loki_handler = LokiLoggerHandler(
            url = loki_url,
            labels = {'app': 'anyway', 'environment': 'staging' if is_debug else 'production'}
        )

        logger.info(f"Logging to Loki at {loki_url} with {loki_handler.labels} and {is_debug=}")
        logging_handlers = [loki_handler, logging.StreamHandler()]
        logging_level = logging.DEBUG if is_debug else logging.INFO
        # silence the chatty logs loki generates itself
        logging.getLogger('urllib3.connectionpool').setLevel(logging.WARNING)
        # no need for time since it's added by loki or can be shown in kube logs
        logging_format = '%(name)s - %(levelname)s - %(message)s'

    else:
        # if we are in a debug (local) session, set verbose and rich logging
        from rich.logging import RichHandler
        logging_handlers = [RichHandler()]
        logging_level = logging.DEBUG if is_debug else logging.INFO
        logging_format = '%(asctime)s - %(name)s - %(levelname)s - %(message)s'



    logging.basicConfig(
        level = logging_level,
        format = logging_format,
        handlers = logging_handlers
    )

    # also overwrite the uvicorn loggers
    logging.getLogger('uvicorn').handlers = logging_handlers
    logging.getLogger('uvicorn.access').handlers = logging_handlers
    logging.getLogger('uvicorn.error').handlers = logging_handlers