Personal RAG MCP Server

"""Reranker strategies for result reranking."""

from abc import ABC, abstractmethod
from typing import List

from ..storage.schema import SearchResult


class Reranker(ABC):
    """Base reranker interface."""

    @abstractmethod
    async def rerank(
        self,
        query: str,
        results: List[SearchResult]
    ) -> List[SearchResult]:
        """Rerank search results."""
        pass


class NoOpReranker(Reranker):
    """No-op reranker - returns results unchanged."""

    async def rerank(
        self,
        query: str,
        results: List[SearchResult]
    ) -> List[SearchResult]:
        """Pass through results without reranking."""
        return results


# Future: CrossEncoderReranker
# class CrossEncoderReranker(Reranker):
#     """Rerank using sentence transformers cross-encoder."""
#     pass