# src/utils/logger.py
import logging
import sys
from typing import Optional

def setup_logger(
    name: str = "chatbot", 
    log_level: str = "INFO",
    log_file: Optional[str] = None
) -> logging.Logger:
    """
    Set up a comprehensive logger for the application
    
    Args:
        name (str): Name of the logger
        log_level (str): Logging level (DEBUG, INFO, WARNING, ERROR, CRITICAL)
        log_file (Optional[str]): Path to log file (optional)
    
    Returns:
        logging.Logger: Configured logger instance
    """
    # Create logger
    logger = logging.getLogger(name)
    logger.setLevel(getattr(logging, log_level.upper()))
    
    # Create formatters
    console_formatter = logging.Formatter(
        '%(asctime)s - %(name)s - %(levelname)s - %(message)s'
    )
    file_formatter = logging.Formatter(
        '%(asctime)s - %(name)s - %(levelname)s - %(filename)s:%(lineno)d - %(message)s'
    )
    
    # Console Handler
    console_handler = logging.StreamHandler(sys.stdout)
    console_handler.setFormatter(console_formatter)
    logger.addHandler(console_handler)
    
    # File Handler (if log_file is provided)
    if log_file:
        file_handler = logging.FileHandler(log_file)
        file_handler.setFormatter(file_formatter)
        logger.addHandler(file_handler)
    
    return logger

# Global logger instance
logger = setup_logger()

class AppException(Exception):
    """
    Custom base exception for the application
    """
    def __init__(self, message: str, error_code: Optional[str] = None):
        """
        Initialize custom exception
        
        Args:
            message (str): Error message
            error_code (Optional[str]): Optional error code
        """
        self.message = message
        self.error_code = error_code
        super().__init__(self.message)
        
        # Log the exception
        logger.error(f"AppException: {message}")

class ConfigurationError(AppException):
    """Exception raised for configuration-related errors"""
    pass

class LLMProviderError(AppException):
    """Exception raised for LLM provider-related errors"""
    pass

class EmbeddingError(AppException):
    """Exception raised for embedding-related errors"""
    pass

class VectorStoreError(AppException):
    """Exception raised for vector store-related errors"""
    pass