from __future__ import annotations
import asyncio
import traceback
import uuid
from .services import parser, chunker
from pkg.core import app
from pkg.rag.knowledge.services.embedder import Embedder
from pkg.rag.knowledge.services.retriever import Retriever
import sqlalchemy
from ...entity.persistence import rag as persistence_rag
from pkg.core import taskmgr
from ...entity.rag import retriever as retriever_entities


class RuntimeKnowledgeBase:
    ap: app.Application

    knowledge_base_entity: persistence_rag.KnowledgeBase

    parser: parser.FileParser

    chunker: chunker.Chunker

    embedder: Embedder

    retriever: Retriever

    def __init__(self, ap: app.Application, knowledge_base_entity: persistence_rag.KnowledgeBase):
        self.ap = ap
        self.knowledge_base_entity = knowledge_base_entity
        self.parser = parser.FileParser(ap=self.ap)
        self.chunker = chunker.Chunker(ap=self.ap)
        self.embedder = Embedder(ap=self.ap)
        self.retriever = Retriever(ap=self.ap)
        # 传递kb_id给retriever
        self.retriever.kb_id = knowledge_base_entity.uuid

    async def initialize(self):
        pass

    async def _store_file_task(self, file: persistence_rag.File, task_context: taskmgr.TaskContext):
        try:
            # set file status to processing
            await self.ap.persistence_mgr.execute_async(
                sqlalchemy.update(persistence_rag.File)
                .where(persistence_rag.File.uuid == file.uuid)
                .values(status='processing')
            )

            task_context.set_current_action('Parsing file')
            # parse file
            text = await self.parser.parse(file.file_name, file.extension)
            if not text:
                raise Exception(f'No text extracted from file {file.file_name}')

            task_context.set_current_action('Chunking file')
            # chunk file
            chunks_texts = await self.chunker.chunk(text)
            if not chunks_texts:
                raise Exception(f'No chunks extracted from file {file.file_name}')

            task_context.set_current_action('Embedding chunks')

            embedding_model = await self.ap.model_mgr.get_embedding_model_by_uuid(
                self.knowledge_base_entity.embedding_model_uuid
            )
            # embed chunks
            await self.embedder.embed_and_store(
                kb_id=self.knowledge_base_entity.uuid,
                file_id=file.uuid,
                chunks=chunks_texts,
                embedding_model=embedding_model,
            )

            # set file status to completed
            await self.ap.persistence_mgr.execute_async(
                sqlalchemy.update(persistence_rag.File)
                .where(persistence_rag.File.uuid == file.uuid)
                .values(status='completed')
            )

        except Exception as e:
            self.ap.logger.error(f'Error storing file {file.uuid}: {e}')
            traceback.print_exc()
            # set file status to failed
            await self.ap.persistence_mgr.execute_async(
                sqlalchemy.update(persistence_rag.File)
                .where(persistence_rag.File.uuid == file.uuid)
                .values(status='failed')
            )

            raise

    async def store_file(self, file_id: str) -> str:
        # pre checking
        if not await self.ap.storage_mgr.storage_provider.exists(file_id):
            raise Exception(f'File {file_id} not found')

        file_uuid = str(uuid.uuid4())
        kb_id = self.knowledge_base_entity.uuid
        file_name = file_id
        extension = file_name.split('.')[-1]

        file_obj_data = {
            'uuid': file_uuid,
            'kb_id': kb_id,
            'file_name': file_name,
            'extension': extension,
            'status': 'pending',
        }

        file_obj = persistence_rag.File(**file_obj_data)

        await self.ap.persistence_mgr.execute_async(sqlalchemy.insert(persistence_rag.File).values(file_obj_data))

        # run background task asynchronously
        ctx = taskmgr.TaskContext.new()
        wrapper = self.ap.task_mgr.create_user_task(
            self._store_file_task(file_obj, task_context=ctx),
            kind='knowledge-operation',
            name=f'knowledge-store-file-{file_id}',
            label=f'Store file {file_id}',
            context=ctx,
        )
        return wrapper.id

    async def retrieve(self, query: str) -> list[retriever_entities.RetrieveResultEntry]:
        embedding_model = await self.ap.model_mgr.get_embedding_model_by_uuid(
            self.knowledge_base_entity.embedding_model_uuid
        )
        return await self.retriever.retrieve(self.knowledge_base_entity.uuid, query, embedding_model)

    async def dispose(self):
        pass


class RAGManager:
    ap: app.Application

    knowledge_bases: list[RuntimeKnowledgeBase]

    def __init__(self, ap: app.Application):
        self.ap = ap
        self.knowledge_bases = []

    async def initialize(self):
        await self.load_knowledge_bases_from_db()

    async def load_knowledge_bases_from_db(self):
        self.ap.logger.info('Loading knowledge bases from db...')

        self.knowledge_bases = []

        result = await self.ap.persistence_mgr.execute_async(sqlalchemy.select(persistence_rag.KnowledgeBase))

        knowledge_bases = result.all()

        for knowledge_base in knowledge_bases:
            try:
                await self.load_knowledge_base(knowledge_base)
            except Exception as e:
                self.ap.logger.error(
                    f'Error loading knowledge base {knowledge_base.uuid}: {e}\n{traceback.format_exc()}'
                )

    async def load_knowledge_base(
        self,
        knowledge_base_entity: persistence_rag.KnowledgeBase | sqlalchemy.Row | dict,
    ) -> RuntimeKnowledgeBase:
        if isinstance(knowledge_base_entity, sqlalchemy.Row):
            knowledge_base_entity = persistence_rag.KnowledgeBase(**knowledge_base_entity._mapping)
        elif isinstance(knowledge_base_entity, dict):
            knowledge_base_entity = persistence_rag.KnowledgeBase(**knowledge_base_entity)

        runtime_knowledge_base = RuntimeKnowledgeBase(ap=self.ap, knowledge_base_entity=knowledge_base_entity)

        await runtime_knowledge_base.initialize()

        self.knowledge_bases.append(runtime_knowledge_base)

        return runtime_knowledge_base

    async def get_knowledge_base_by_uuid(self, kb_uuid: str) -> RuntimeKnowledgeBase | None:
        for kb in self.knowledge_bases:
            if kb.knowledge_base_entity.uuid == kb_uuid:
                return kb
        return None

    async def remove_knowledge_base(self, kb_uuid: str):
        for kb in self.knowledge_bases:
            if kb.knowledge_base_entity.uuid == kb_uuid:
                await kb.dispose()
                self.knowledge_bases.remove(kb)
                return

    async def delete_data_by_file_id(self, file_id: str):
        """
        Deletes all data associated with a specific file ID, including its chunks and vectors,
        and the file record itself.
        """
        self.ap.logger.info(f'Starting data deletion process for file_id: {file_id}')
        session = SessionLocal()
        try:
            # delete vectors
            await asyncio.to_thread(self.ap.vector_db_mgr.vector_db.delete_by_file_id_sync, file_id)
            self.ap.logger.info(f'Deleted embeddings from ChromaDB for file_id: {file_id}')

            chunks_to_delete = session.query(Chunk).filter_by(file_id=file_id).all()
            for chunk in chunks_to_delete:
                session.delete(chunk)
            self.ap.logger.info(f'Deleted {len(chunks_to_delete)} chunk records for file_id: {file_id}')

            file_to_delete = session.query(File).filter_by(id=file_id).first()
            if file_to_delete:
                session.delete(file_to_delete)
                try:
                    await self.ap.storage_mgr.storage_provider.delete(file_id)
                except Exception as e:
                    self.ap.logger.error(
                        f'Error deleting file from storage for file_id {file_id}: {str(e)}',
                        exc_info=True,
                    )
                self.ap.logger.info(f'Deleted file record for file_id: {file_id}')
            else:
                self.ap.logger.warning(
                    f'File with ID {file_id} not found in database. Skipping deletion of file record.'
                )
            session.commit()
            self.ap.logger.info(f'Successfully completed data deletion for file_id: {file_id}')
        except Exception as e:
            session.rollback()
            self.ap.logger.error(f'Error deleting data for file_id {file_id}: {str(e)}', exc_info=True)
            raise
        finally:
            session.close()

    async def delete_kb_by_id(self, kb_id: str):
        """
        Deletes a knowledge base and all associated files, chunks, and vectors.
        This involves querying for associated files and then deleting them.
        """
        self.ap.logger.info(f'Starting deletion of knowledge base with ID: {kb_id}')
        session = SessionLocal()

        try:
            kb_to_delete = session.query(KnowledgeBase).filter_by(id=kb_id).first()
            if not kb_to_delete:
                self.ap.logger.warning(f'Knowledge Base with ID {kb_id} not found.')
                return

            files_to_delete = session.query(File).filter_by(kb_id=kb_id).all()

            session.close()

            for file_obj in files_to_delete:
                try:
                    await self.delete_data_by_file_id(file_obj.id)
                except Exception as file_del_e:
                    self.ap.logger.error(f'Failed to delete file ID {file_obj.id} during KB deletion: {file_del_e}')

            session = SessionLocal()
            try:
                kb_final_delete = session.query(KnowledgeBase).filter_by(id=kb_id).first()
                if kb_final_delete:
                    session.delete(kb_final_delete)
                    session.commit()
                    self.ap.logger.info(f'Successfully deleted knowledge base with ID: {kb_id}')
                else:
                    self.ap.logger.warning(
                        f'Knowledge Base with ID {kb_id} not found after file deletion, skipping KB deletion.'
                    )
            except Exception as kb_del_e:
                session.rollback()
                self.ap.logger.error(
                    f'Error deleting KnowledgeBase record for ID {kb_id}: {kb_del_e}',
                    exc_info=True,
                )
                raise
            finally:
                session.close()

        except Exception as e:
            # 如果在最初获取 KB 或文件列表时出错
            if session.is_active:
                session.rollback()
            self.ap.logger.error(
                f'Error during overall knowledge base deletion for ID {kb_id}: {str(e)}',
                exc_info=True,
            )
            raise
        finally:
            if session.is_active:
                session.close()

    # async def get_file_content_by_file_id(self, file_id: str) -> str:
    #     file_bytes = await self.ap.storage_mgr.storage_provider.load(file_id)

    #     _, ext = os.path.splitext(file_id.lower())
    #     ext = ext.lstrip('.')

    #     try:
    #         text = file_bytes.decode('utf-8')
    #     except UnicodeDecodeError:
    #         return '[非文本文件或编码无法识别]'

    #     if ext in ['txt', 'md', 'csv', 'log', 'py', 'html']:
    #         return text
    #     else:
    #         return f'[未知类型: .{ext}]'