import re

SENDER_ID_PATTERN = re.compile(r"^[A-Z0-9]{3,11}$")
DLT_ENTITY_PATTERN = re.compile(r"^\d{12,25}$")


def normalize_sender_id(value: str) -> str:
    return value.strip().upper()


def validate_sender_id(value: str) -> str:
    sender_id = normalize_sender_id(value)
    if not SENDER_ID_PATTERN.match(sender_id):
        raise ValueError("Sender ID must be 3–11 uppercase letters or numbers")
    return sender_id


def validate_sender_type(value: str) -> str:
    normalized = value.strip().lower()
    if normalized not in {"promotional", "transactional"}:
        raise ValueError("Type must be promotional or transactional")
    return normalized


def validate_purpose(value: str) -> str:
    purpose = value.strip()
    if len(purpose) < 10:
        raise ValueError("Purpose must be at least 10 characters")
    if len(purpose) > 500:
        raise ValueError("Purpose must be 500 characters or fewer")
    return purpose


def validate_dlt_entity_id(value: str) -> str:
    entity_id = value.strip()
    if not DLT_ENTITY_PATTERN.match(entity_id):
        raise ValueError("DLT Entity ID must be 12–25 digits")
    return entity_id