from __future__ import annotations
from dataclasses import dataclass, field
from typing import Protocol, Any, AsyncIterator, runtime_checkable

from ..events import QueryEvent


@dataclass
class AgentTools:
    """Structured container for agent tool configuration (local mode only)."""
    function_tools: list[Any] = field(default_factory=list)
    mcp_servers: list[Any] = field(default_factory=list)


@runtime_checkable
class Backend(Protocol):
    # Collection management
    def create_collection(self, name: str) -> None: ...
    def get_or_create_collection(self, name: str) -> None: ...
    def list_collections(self) -> list[str]: ...
    def delete_collection(self, name: str) -> None: ...

    # Document management
    def add_document(self, collection: str, file_path: str) -> str: ...
    def get_document(self, collection: str, doc_id: str, include_text: bool = False) -> dict: ...
    def get_document_structure(self, collection: str, doc_id: str) -> list: ...
    def get_page_content(self, collection: str, doc_id: str, pages: str) -> list: ...
    def list_documents(self, collection: str) -> list[dict]: ...
    def delete_document(self, collection: str, doc_id: str) -> None: ...

    # Query
    def query(self, collection: str, question: str, doc_ids: list[str] | None = None) -> str: ...
    async def query_stream(self, collection: str, question: str,
                           doc_ids: list[str] | None = None) -> AsyncIterator[QueryEvent]: ...