"""
Dependency factories for FastAPI dependency injection.
Provides cached singleton instances of EmbeddingService and VectorStore.
"""

from functools import lru_cache

from app.services.embedding_service import EmbeddingService
from app.services.qdrant_vector_store import QdrantVectorStore
from app.services.retrieval_service import RetrievalService
from app.services.vector_store import VectorStore
from app.services.vector_store_contract import VectorStoreContract
from app.utils.config import config_manager

config = config_manager.get_config()


@lru_cache
def get_embedding_service() -> EmbeddingService:
    model_name = config.embedding_model
    return EmbeddingService(
        model_name=model_name,
        api_key=config.gemini_embedding_api_key,
    )


@lru_cache
def get_vector_store() -> VectorStoreContract:
    if config.vector_store_backend == "qdrant":
        return QdrantVectorStore(
            url=config.qdrant_url,
            collection_name=config.qdrant_collection_name,
            vector_size=config.qdrant_vector_size,
            timeout=config.qdrant_timeout,
        )

    if config.vector_store_backend == "chroma":
        persist_path = config.chroma_persist_path
        return VectorStore(persist_path=persist_path)

    raise ValueError(f"Unsupported VECTOR_STORE_BACKEND: {config.vector_store_backend}")


@lru_cache
def get_retrieval_service() -> RetrievalService:
    return RetrievalService(
        embedding_service=get_embedding_service(), vector_store=get_vector_store()
    )