from uuid import UUID

from domain.chat import ChatAttachmentName, ChatFile
from usecase.interface import ChatFileRepository


class InMemoryChatFileRepository(ChatFileRepository):
    def __init__(self) -> None:
        self._by_id: dict[UUID, ChatFile] = {}
        self._by_chat_and_name: dict[tuple[UUID, str], UUID] = {}

    def get(self, file_id: UUID) -> ChatFile | None:
        return self._by_id.get(file_id)

    def get_by_chat_id_and_name(
        self,
        chat_id: UUID,
        name: ChatAttachmentName,
    ) -> ChatFile | None:
        fid = self._by_chat_and_name.get((chat_id, name.value))
        if fid is None:
            return None
        return self._by_id.get(fid)

    def list_by_chat_id(self, chat_id: UUID) -> list[ChatFile]:
        return sorted(
            (f for f in self._by_id.values() if f.chat_id == chat_id),
            key=lambda f: (f.created_at, f.file_id),
        )

    def save(self, chat_file: ChatFile) -> None:
        key = (chat_file.chat_id, chat_file.name.value)
        existing_at_key = self._by_chat_and_name.get(key)
        if existing_at_key is not None and existing_at_key != chat_file.file_id:
            self._by_id.pop(existing_at_key, None)

        previous = self._by_id.get(chat_file.file_id)
        if previous is not None:
            prev_key = (previous.chat_id, previous.name.value)
            if self._by_chat_and_name.get(prev_key) == previous.file_id:
                del self._by_chat_and_name[prev_key]

        self._by_id[chat_file.file_id] = chat_file
        self._by_chat_and_name[key] = chat_file.file_id

    def delete(self, file_id: UUID) -> None:
        chat_file = self._by_id.pop(file_id, None)
        if chat_file is None:
            return
        key = (chat_file.chat_id, chat_file.name.value)
        if self._by_chat_and_name.get(key) == file_id:
            del self._by_chat_and_name[key]

    def delete_by_chat_id(self, chat_id: UUID) -> None:
        file_ids = [f.file_id for f in self._by_id.values() if f.chat_id == chat_id]
        for fid in file_ids:
            self.delete(fid)