backend/retry.py

"""
Retry wrapper - executes a callable with exponential backoff and
optional classification-based repair callback.
"""
from __future__ import annotations

import time
import logging
from typing import Callable, Optional, Any

from .classifier import classify

logger = logging.getLogger("retry")


def retry_call(
    fn: Callable[[], Any],
    max_attempts: int = 3,
    base_delay: float = 1.5,
    on_error: Optional[Callable[[Exception, int], None]] = None,
    repair_cb: Optional[Callable[[str], None]] = None,
) -> Any:
    last_exc: Optional[Exception] = None
    for attempt in range(1, max_attempts + 1):
        try:
            return fn()
        except Exception as e:
            last_exc = e
            logger.warning("retry attempt %s failed: %s", attempt, e)
            if on_error:
                try:
                    on_error(e, attempt)
                except Exception:
                    pass
            if repair_cb:
                try:
                    err_class = classify(str(e))
                    if err_class:
                        repair_cb(err_class.category)
                except Exception:
                    pass
            if attempt < max_attempts:
                time.sleep(base_delay * (2 ** (attempt - 1)))
    assert last_exc is not None
    raise last_exc