"""
Utility functions shared across the EAMCO Authorize service.
"""
import re

def sanitize_input(text, max_len, allow_spaces=False, is_zip=False):
    """
    Sanitize input string by removing invalid characters.
    
    Args:
        text: Input text/number/value
        max_len: Maximum length of the output string
        allow_spaces: If True, allows spaces in the output
        is_zip: If True, allows hyphens (for ZIP+4)
        
    Returns:
        Sanitized string truncated to max_len
    """
    if not text:
        return ""
    
    if is_zip:
        pattern = r'[^a-zA-Z0-9-]'
    else:
        pattern = r'[^a-zA-Z0-9]' if not allow_spaces else r'[^a-zA-Z0-9\s]'
        
    sanitized = re.sub(pattern, '', str(text))
    return sanitized.strip()[:max_len]