from dataclasses import dataclass
from datetime import datetime
from uuid import UUID

HISTORY_FILE_NAME = 'history.md'


@dataclass(frozen=True, slots=True)
class ChatAttachmentName:
    value: str

    def __post_init__(self) -> None:
        if not self.value or self.value in {'.', '..'}:
            raise ValueError('invalid attachment name')
        if '/' in self.value or '\\' in self.value:
            raise ValueError('invalid attachment name')
        if self.value == HISTORY_FILE_NAME:
            raise ValueError('reserved attachment name')


@dataclass(frozen=True, slots=True)
class Chat:
    chat_id: UUID
    workspace_id: UUID
    created_at: datetime


@dataclass(frozen=True, slots=True)
class ChatFile:
    file_id: UUID
    chat_id: UUID
    name: ChatAttachmentName
    content_type: str | None
    size_bytes: int
    created_at: datetime