"""Utility functions."""

from typing import List, TypeVar, Callable
import json

T = TypeVar('T')


def validate_input(data: dict, required_fields: List[str]) -> bool:
    """Validate that all required fields are present."""
    for field in required_fields:
        if field not in data:
            return False
    return True


def parse_json_safe(json_string: str, default: T = None) -> T:
    """Safely parse JSON string."""
    try:
        return json.loads(json_string)
    except (json.JSONDecodeError, TypeError):
        return default


def retry_operation(func: Callable, max_retries: int = 3, delay: float = 1.0):
    """Retry an operation with exponential backoff."""
    import time

    for attempt in range(max_retries):
        try:
            return func()
        except Exception as e:
            if attempt == max_retries - 1:
                raise e

            time.sleep(delay * (2 ** attempt))

    return None


class Logger:
    """Simple logger utility."""

    def __init__(self, name: str):
        self.name = name

    def info(self, message: str) -> None:
        """Log info message."""
        print(f"[INFO] [{self.name}] {message}")

    def error(self, message: str) -> None:
        """Log error message."""
        print(f"[ERROR] [{self.name}] {message}")

    def debug(self, message: str) -> None:
        """Log debug message."""
        print(f"[DEBUG] [{self.name}] {message}")