"""
Logging configuration for the AI chatbot backend.

This module sets up structured logging with appropriate levels
and formats for production use.
"""

import logging
import sys
from typing import Optional
import os


def setup_logging(
    level: Optional[str] = None,
    log_file: Optional[str] = None
) -> None:
    """
    Configure structured logging for the application.

    Args:
        level: Logging level (DEBUG, INFO, WARNING, ERROR, CRITICAL)
        log_file: Optional file path for log output
    """
    # Get log level from environment or parameter
    log_level_str = level or os.getenv("LOG_LEVEL", "INFO")
    log_level = getattr(logging, log_level_str.upper(), logging.INFO)

    # Create formatter
    formatter = logging.Formatter(
        fmt='%(asctime)s - %(name)s - %(levelname)s - %(message)s',
        datefmt='%Y-%m-%d %H:%M:%S'
    )

    # Configure root logger
    root_logger = logging.getLogger()
    root_logger.setLevel(log_level)

    # Remove existing handlers
    root_logger.handlers.clear()

    # Console handler
    console_handler = logging.StreamHandler(sys.stdout)
    console_handler.setLevel(log_level)
    console_handler.setFormatter(formatter)
    root_logger.addHandler(console_handler)

    # File handler (if specified)
    if log_file:
        file_handler = logging.FileHandler(log_file)
        file_handler.setLevel(log_level)
        file_handler.setFormatter(formatter)
        root_logger.addHandler(file_handler)

    # Set specific logger levels
    logging.getLogger("uvicorn").setLevel(logging.INFO)
    logging.getLogger("sqlalchemy.engine").setLevel(logging.WARNING)

    logging.info(f"Logging configured at {log_level_str} level")


# Auto-configure logging on import
setup_logging()