"""
Structured logging configuration for the Delphi Database FastAPI app.

This module configures structlog to output JSON logs and integrates
context variables so request-specific fields (e.g., request_id) are
included automatically in log records.
"""

from __future__ import annotations

import logging
from typing import Any, Dict

import structlog


def _add_required_defaults(_: Any, __: str, event_dict: Dict[str, Any]) -> Dict[str, Any]:
    """
    Ensure all required fields exist on every log entry so downstream
    consumers receive a consistent schema.
    """
    # Required fields per project requirements
    event_dict.setdefault("request_id", None)
    event_dict.setdefault("http.method", None)
    event_dict.setdefault("http.path", None)
    event_dict.setdefault("status_code", None)
    event_dict.setdefault("user.id", None)
    event_dict.setdefault("duration_ms", None)
    return event_dict


def setup_logging(log_level: int = logging.INFO) -> None:
    """
    Configure structlog for JSON logging with contextvars support.

    Args:
        log_level: Minimum log level for application logs.
    """
    # Configure stdlib logging basic config for third-party libs (uvicorn, etc.)
    logging.basicConfig(level=log_level)

    structlog.configure(
        processors=[
            structlog.contextvars.merge_contextvars,
            structlog.stdlib.add_log_level,
            _add_required_defaults,
            structlog.processors.TimeStamper(fmt="iso", key="timestamp"),
            structlog.processors.dict_tracebacks,
            structlog.processors.JSONRenderer(),
        ],
        context_class=dict,
        logger_factory=structlog.stdlib.LoggerFactory(),
        wrapper_class=structlog.make_filtering_bound_logger(log_level),
        cache_logger_on_first_use=True,
    )