"""Share backend wiring for bootstrap."""

from __future__ import annotations

from functools import lru_cache

from app.application.agent import AgentConversationService, AgentSessionService
from app.application.documents import DocumentCommandService, DocumentQueryService
from app.application.knowledge import KnowledgeRetrievalService
from app.config.settings import settings
from app.infrastructure.embedding.openai_compatible_embedding_provider import OpenAICompatibleEmbeddingProvider
from app.infrastructure.llm.openai_compatible_answer_generator import OpenAICompatibleAnswerGenerator
from app.infrastructure.parser.aliyun_document_parser import AliyunDocumentParser
from app.infrastructure.parser.local_chunk_builder import LocalRegulationChunkBuilder
from app.infrastructure.parser.local_document_parser import LocalDocumentParser
from app.infrastructure.parser.vector_chunk_builder import AliyunVectorChunkBuilder
from app.infrastructure.session.in_memory_conversation_store import InMemoryConversationStore
from app.infrastructure.storage.json_document_repository import JsonDocumentRepository
from app.infrastructure.storage.minio_binary_store import MinioDocumentBinaryStore
from app.infrastructure.storage.postgres_document_repository import PostgresDocumentRepository
from app.infrastructure.storage.postgres_parse_artifact_store import PostgresParseArtifactStore
from app.infrastructure.vectorstore.bm25_retriever import BM25Retriever
from app.infrastructure.vectorstore.dense_retriever import DenseRetriever
from app.infrastructure.vectorstore.milvus_vector_index import MilvusVectorIndex
from app.infrastructure.vectorstore.cross_encoder_reranker import OpenAICompatibleReranker
from app.infrastructure.perception.mock_event_store import MockEventStore
from app.application.perception.services import PerceptionService
# Keep shared wiring centralized so dependency construction remains consistent.



@lru_cache
def get_document_repository():
    """Return document repository (json or postgres, controlled by settings)."""
    if settings.document_repository_backend == "postgres":
        return PostgresDocumentRepository()
    return JsonDocumentRepository(settings.document_metadata_path)


@lru_cache
def get_parse_artifact_store():
    """Return parse artifact store, or None when postgres backend is not enabled."""
    if settings.document_repository_backend == "postgres":
        return PostgresParseArtifactStore()
    return None


@lru_cache
def get_binary_store() -> MinioDocumentBinaryStore:
    """Return binary store."""
    return MinioDocumentBinaryStore()


@lru_cache
def get_parser():
    """Return parser."""
    if settings.parser_backend == "aliyun":
        return AliyunDocumentParser()
    return LocalDocumentParser()


@lru_cache
def get_chunk_builder():
    """Return chunk builder."""
    if settings.chunk_backend == "aliyun":
        return AliyunVectorChunkBuilder()
    return LocalRegulationChunkBuilder(
        chunk_size=settings.chunk_size,
        chunk_overlap=settings.chunk_overlap,
    )


@lru_cache
def get_embedding_provider() -> OpenAICompatibleEmbeddingProvider:
    """Return embedding provider."""
    return OpenAICompatibleEmbeddingProvider()


@lru_cache
def get_vector_index() -> MilvusVectorIndex:
    """Return vector index."""
    return MilvusVectorIndex()


@lru_cache
def get_reranker():
    """Return reranker if enabled, else None."""
    if settings.reranker_enabled and settings.reranker_base_url:
        return OpenAICompatibleReranker()
    return None


@lru_cache
def get_bm25_retriever() -> BM25Retriever | None:
    """Return BM25 retriever if rank_bm25 + jieba are installed, else None."""
    retriever = BM25Retriever(vector_index=get_vector_index())
    return retriever if retriever.available else None


@lru_cache
def get_retrieval_service() -> KnowledgeRetrievalService:
    """Return retrieval service."""
    retriever = DenseRetriever(
        embedding_provider=get_embedding_provider(),
        vector_index=get_vector_index(),
    )
    return KnowledgeRetrievalService(
        retriever=retriever,
        bm25_retriever=get_bm25_retriever(),
        reranker=get_reranker(),
        reranker_top_k=settings.reranker_top_k,
    )


@lru_cache
def get_document_command_service() -> DocumentCommandService:
    """Return document command service."""
    return DocumentCommandService(
        document_repository=get_document_repository(),
        binary_store=get_binary_store(),
        parser=get_parser(),
        chunk_builder=get_chunk_builder(),
        embedding_provider=get_embedding_provider(),
        vector_index=get_vector_index(),
        parse_artifact_store=get_parse_artifact_store(),
    )


@lru_cache
def get_document_query_service() -> DocumentQueryService:
    """Return document query service."""
    return DocumentQueryService(
        document_repository=get_document_repository(),
        binary_store=get_binary_store(),
        vector_index=get_vector_index(),
    )


@lru_cache
def get_conversation_store() -> InMemoryConversationStore:
    """Return conversation store."""
    return InMemoryConversationStore(
        max_sessions=settings.session_max_sessions,
        timeout_minutes=settings.session_timeout_minutes,
    )


@lru_cache
def get_agent_conversation_service() -> AgentConversationService:
    """Return agent conversation service."""
    return AgentConversationService(
        retrieval_service=get_retrieval_service(),
        answer_generator=OpenAICompatibleAnswerGenerator(),
        conversation_store=get_conversation_store(),
    )


@lru_cache
def get_perception_service() -> PerceptionService:
    """Return perception service for regulatory intelligence."""
    return PerceptionService(
        event_store=MockEventStore(),
        retrieval_service=get_retrieval_service(),
    )
def get_agent_session_service() -> AgentSessionService:
    """Return agent session service."""
    return AgentSessionService(conversation_store=get_conversation_store())