"""
Input validation utilities for SneakyScanner web application.

Provides validation functions for API inputs and data integrity.
"""

from typing import Optional


def validate_scan_status(status: str) -> tuple[bool, Optional[str]]:
    """
    Validate scan status value.

    Args:
        status: Status string to validate

    Returns:
        Tuple of (is_valid, error_message)

    Examples:
        >>> validate_scan_status('running')
        (True, None)
        >>> validate_scan_status('invalid')
        (False, 'Invalid status: invalid. Must be one of: running, completed, failed')
    """
    valid_statuses = ['running', 'completed', 'failed']

    if status not in valid_statuses:
        return False, f'Invalid status: {status}. Must be one of: {", ".join(valid_statuses)}'

    return True, None