"""Decorators for error handling and common patterns."""
from functools import wraps
from typing import Callable, TypeVar, ParamSpec
import logging
from .constants import MSG_QUERY_FAILED, MSG_NO_DATA
logger = logging.getLogger(__name__)
P = ParamSpec('P')
R = TypeVar('R')
def handle_api_errors(data_type: str = "", use_code_param: bool = False):
"""
Decorator to handle common API errors and logging.
Args:
data_type: Type of data being queried (e.g., "券商資料")
use_code_param: If True, expects the function to have a 'code' parameter
and includes it in error messages
Usage:
@handle_api_errors(data_type="券商資料")
def get_broker_info() -> str:
...
@handle_api_errors(use_code_param=True)
def get_stock_info(code: str) -> str:
...
"""
def decorator(func: Callable[P, R]) -> Callable[P, R]:
@wraps(func)
def wrapper(*args: P.args, **kwargs: P.kwargs) -> R:
try:
return func(*args, **kwargs)
except Exception as e:
# Extract code parameter if it exists
code = None
if use_code_param:
# Try to get 'code' from kwargs or first positional arg
code = kwargs.get('code')
if code is None and len(args) > 0:
code = args[0]
# Log the error with context
error_context = f" for code {code}" if code else ""
logger.error(f"Error in {func.__name__}{error_context}: {e}", exc_info=True)
# Return formatted error message
return MSG_QUERY_FAILED.format(error=str(e))
return wrapper
return decorator
def handle_empty_response(data_type: str):
"""
Decorator to handle empty API responses.
This should be used in conjunction with handle_api_errors.
Args:
data_type: Type of data for the error message (e.g., "券商資料")
Usage:
@handle_empty_response(data_type="券商資料")
@handle_api_errors()
def get_broker_info() -> str:
data = fetch_data()
if not data:
return None # Will be caught by decorator
return format_data(data)
"""
def decorator(func: Callable[P, R]) -> Callable[P, R]:
@wraps(func)
def wrapper(*args: P.args, **kwargs: P.kwargs) -> R:
result = func(*args, **kwargs)
if result is None or result == "":
return MSG_NO_DATA.format(data_type=data_type)
return result
return wrapper
return decorator
