"""Logging adapter for owsclient with automatic extra kwargs injection."""
from __future__ import annotations

import logging
from typing import Any, MutableMapping

# Global dictionary to store default extra kwargs for all loggers
_DEFAULT_EXTRA_KWARGS: dict[str, Any] = {
    "library": {
        "name": "python-owsclient",
        "language": "python",
    }
}


class OwsClientLoggerAdapter(logging.LoggerAdapter[logging.Logger]):
    """Logger adapter that automatically merges extra kwargs.

    This adapter combines:
    1. Global default extras (set via set_default_extra_kwargs)
    2. Instance-level extras (passed when creating the adapter)
    3. Per-call extras (passed to individual log calls)

    Later extras override earlier ones in case of conflicts.
    """

    def process(
        self, msg: str, kwargs: MutableMapping[str, Any]
    ) -> tuple[str, MutableMapping[str, Any]]:
        """Process the logging call, merging all extra kwargs.

        Args:
        ----
            msg: The log message
            kwargs: Keyword arguments for the log call

        Returns:
        -------
            Tuple of (message, updated kwargs)

        """
        # Start with global defaults
        merged_extra = _DEFAULT_EXTRA_KWARGS.copy()

        # Merge instance-level extras
        if self.extra:
            merged_extra.update(self.extra)

        # Merge per-call extras
        if "extra" in kwargs:
            merged_extra.update(kwargs["extra"])

        # Update kwargs with merged extras
        kwargs["extra"] = merged_extra

        return msg, kwargs


def get_logger(
    name: str, extra: dict[str, Any] | None = None
) -> OwsClientLoggerAdapter:
    """Get a logger adapter with automatic extra kwargs injection.

    Args:
    ----
        name: Logger name (typically __name__)
        extra: Optional instance-level extra kwargs to include in all logs

    Returns:
    -------
        OwsClientLoggerAdapter instance

    Example:
    -------
        >>> logger = get_logger(__name__)
        >>> logger.info("Something happened")  # Will include default extras
        >>>
        >>> logger = get_logger(__name__, extra={"component": "auth"})
        >>> logger.info("Auth event")  # Will include defaults + component

    """
    base_logger = logging.getLogger(name)
    return OwsClientLoggerAdapter(base_logger, extra or {})