common/logger.py

"""
Centralized logging configuration for Medical Transcriber application.

Provides consistent logging across all modules with file and console output.
"""

import logging
import logging.handlers
from pathlib import Path
from datetime import datetime
from typing import Optional

from .constants import LoggingConfig, PROJECT_ROOT, LOGS_DIR


class LoggerSetup:
    """Centralized logger configuration."""
    
    _initialized = False
    
    @classmethod
    def setup(cls, log_file: Optional[str] = None, level: str = LoggingConfig.LOG_LEVEL) -> None:
        """
        Initialize logging configuration for the entire application.
        
        Args:
            log_file: Optional custom log file name. If None, uses auto-generated name.
            level: Logging level (DEBUG, INFO, WARNING, ERROR, CRITICAL)
        """
        if cls._initialized:
            return
        
        # Create logs directory if it doesn't exist
        LOGS_DIR.mkdir(parents=True, exist_ok=True)
        
        # Generate log file path
        if log_file is None:
            timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
            log_file = f"transcription_{timestamp}.log"
        
        log_path = LOGS_DIR / log_file
        
        # Create root logger
        root_logger = logging.getLogger()
        root_logger.setLevel(getattr(logging, level))
        
        # File handler
        file_handler = logging.handlers.RotatingFileHandler(
            log_path,
            maxBytes=10 * 1024 * 1024,  # 10 MB
            backupCount=5,
            encoding='utf-8'
        )
        file_handler.setLevel(getattr(logging, level))
        
        # Console handler
        console_handler = logging.StreamHandler()
        console_handler.setLevel(getattr(logging, level))
        
        # Formatter
        formatter = logging.Formatter(
            LoggingConfig.LOG_FORMAT,
            datefmt=LoggingConfig.LOG_DATE_FORMAT
        )
        
        file_handler.setFormatter(formatter)
        console_handler.setFormatter(formatter)
        
        # Add handlers to root logger
        root_logger.addHandler(file_handler)
        root_logger.addHandler(console_handler)
        
        cls._initialized = True
        
        root_logger.info(f"Logging initialized. Log file: {log_path}")
    
    @classmethod
    def get_logger(cls, name: str) -> logging.Logger:
        """
        Get logger instance for a module.
        
        Args:
            name: Module name (usually __name__)
            
        Returns:
            Configured logger instance
        """
        if not cls._initialized:
            cls.setup()
        
        return logging.getLogger(name)


def configure_logging(
    log_file: Optional[str] = None,
    level: str = LoggingConfig.LOG_LEVEL
) -> None:
    """
    Configure logging for the application.
    
    Args:
        log_file: Optional custom log file name
        level: Logging level
    """
    LoggerSetup.setup(log_file, level)


def get_logger(name: str) -> logging.Logger:
    """
    Get a logger instance.
    
    Args:
        name: Logger name (usually __name__)
        
    Returns:
        Configured logger instance
    """
    return LoggerSetup.get_logger(name)