"""Core enums - pure value types with no dependencies.

These enums are safe to import anywhere without circular import risk.
"""

from enum import StrEnum


class MessageRole(StrEnum):
    """Role of a message in conversation history."""

    SYSTEM = "system"
    USER = "user"
    ASSISTANT = "assistant"
    TOOL = "tool"


class AttachmentType(StrEnum):
    """Type of attachment in a message."""

    IMAGE = "image"
    FILE = "file"
    URL = "url"


__all__ = [
    "AttachmentType",
    "MessageRole",
]
