import json
import uuid

from fastapi import UploadFile
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy.inspection import inspect
from loguru import logger

from src.core.clients import S3Storage
from src.schemas.enums import FileStatus, FileType, RecognitionStatus, RecognitionPipeline

def get_dict(obj):
    return {c.key: getattr(obj, c.key) for c in inspect(obj).mapper.column_attrs}

class FileService:
    def __init__(self, storage: S3Storage, session: AsyncSession, file_repository, recognition_job_repo, nats_conn):
        self.storage = storage
        self.file_repo = file_repository
        self.rec_job_repo = recognition_job_repo
        self.nats_conn = nats_conn
        self.session = session
    
    async def save_file(self, file: UploadFile, legal_entity_id: uuid.UUID, quarter: str, year: int):
        try:
            db_payload = {
                'original_name': file.filename,
                'legal_entity_id': legal_entity_id,
                'period_quarter': quarter,
                'period_year': year,
                'size_bytes': file.size,
            }
            file_ext = file.filename.lower().split('.')[-1]
            db_payload['file_type'] = FileType[file_ext.upper()]
            new_file = await self.file_repo.insert_one(db_payload)
            
            s3_key = f'{str(new_file.id)}.{file_ext}'
            await self.storage.put_object(s3_key, await file.read())
            new_file.s3_key = s3_key
            # new_file.status = FileStatus.UPLOADED

            job_pipeline = RecognitionPipeline.IMAGE
            if (file_ext in ['xlsx', 'xls']):
                job_pipeline = RecognitionPipeline.TABULAR
            
            rec_job_db_payload = {
                'file_id': new_file.id,
                'legal_entity_id': legal_entity_id,
                'status': RecognitionStatus.QUEUED,
                'attempt': 1,
                'pipeline': job_pipeline,
            }
            
            rec_job = await self.rec_job_repo.insert_one(rec_job_db_payload)
            new_file.current_recognition_job_id = rec_job.id

            await self.session.commit()


            return {'file': get_dict(new_file), 'rec_job': get_dict(rec_job)}

            
        except Exception as e:
            await self.session.rollback()
            logger.exception("Ошибка при сохранении файла в БД")
            
            raise

    async def get_files_by_legal_entity(self, legal_entity_id: uuid.UUID):
        result = await self.file_repo.get_by_legal_entity(legal_entity_id)
        return [self._get_transformed_file_job_info(new_file) for new_file in result]

    async def get_file_bytes(self, file_id):
        result = await self.file_repo.get_by_id(file_id)
        return (await self.storage.get_object(result.s3_key))
    
    def _get_transformed_file_job_info(self, stored_file_db_obj):
        return {
            'id': stored_file_db_obj.id,
            'legal_entity_id': stored_file_db_obj.legal_entity_id,
            'status': stored_file_db_obj.status,
            'file_type': stored_file_db_obj.file_type,
            'original_name': stored_file_db_obj.original_name,
            'document_type': stored_file_db_obj.document_type
        }