from dataclasses import dataclass
from datetime import datetime
from typing import Optional, Dict


@dataclass(frozen=True)
class MailIntakeMessage:
    """
    Canonical internal representation of a single email message.

    This model is provider-agnostic and safe to persist.
    No Gmail-specific fields should appear here.
    """

    message_id: str
    thread_id: str
    timestamp: datetime

    from_email: str
    from_name: Optional[str]

    subject: str
    body_text: str
    snippet: str

    raw_headers: Dict[str, str]