"""Hybrid retriever — 向量检索 + 元数据证据包。"""

from sqlalchemy.ext.asyncio import AsyncSession

from app.core.logging import get_logger
from app.features.memory.evidence import retrieve_evidence_bundle_async
from app.features.memory.repo import search_chunks_vector
from app.ports.embedding import EmbeddingProvider

logger = get_logger(__name__)


class HybridRetriever:
    """向量 chunk 检索 + facts/summaries/stories。"""

    def __init__(
        self,
        db: AsyncSession,
        *,
        embedding_provider: EmbeddingProvider | None = None,
    ):
        self._db = db
        self._embedding = embedding_provider

    async def retrieve(self, user_id: str, query: str, *, top_k: int = 10) -> dict:
        """
        Return evidence bundle:
        {relevant_chunks, relevant_summaries, relevant_facts, relevant_stories}
        """
        if not query.strip():
            return await retrieve_evidence_bundle_async(
                self._db,
                user_id,
                query,
                top_k=top_k,
                merged_chunk_dicts=[],
            )

        q = query.strip()
        merged_chunk_dicts: list[dict] = []
        if self._embedding:
            q_emb = await self._embedding.embed_text(q)
            if q_emb:
                vector_rows = await search_chunks_vector(
                    self._db, user_id, q_emb, limit=top_k
                )
                merged_chunk_dicts = [
                    {
                        "id": c["id"],
                        "content": c["content"],
                        "chunk_index": c.get("chunk_index", 0),
                    }
                    for c in vector_rows
                ]
            else:
                logger.warning(
                    "HybridRetriever empty_query_embedding user_id={}", user_id
                )
        else:
            logger.warning("HybridRetriever no_embedding_provider user_id={}", user_id)

        return await retrieve_evidence_bundle_async(
            self._db,
            user_id,
            query,
            top_k=top_k,
            merged_chunk_dicts=merged_chunk_dicts,
        )