import json
import logging
import os
import shutil
import zipfile
from datetime import datetime
from pathlib import Path
import asyncio

import torch
from fastapi import BackgroundTasks, HTTPException, UploadFile
from components.dbo.models.entity import EntityModel
from ntr_fileparser import ParsedDocument, UniversalParser
from sqlalchemy.orm import Session

from common.common import get_source_format
from common.configuration import Configuration
from components.dbo.models.dataset import Dataset
from components.dbo.models.dataset_document import DatasetDocument
from components.dbo.models.document import Document
from components.services.entity import EntityService
from schemas.dataset import Dataset as DatasetSchema
from schemas.dataset import DatasetExpanded as DatasetExpandedSchema
from schemas.dataset import DatasetProcessing
from schemas.dataset import DocumentsPage as DocumentsPageSchema
from schemas.dataset import SortQueryList
from schemas.document import Document as DocumentSchema

logger = logging.getLogger(__name__)


class DatasetService:
    """
    Сервис для работы с датасетами.
    """

    def __init__(
        self,
        entity_service: EntityService,
        config: Configuration,
        db: Session,
    ) -> None:
        """
        Инициализация сервиса.

        Args:
            entity_service: Сервис для работы с сущностями
            config: Конфигурация приложения
            db: SQLAlchemy сессия
        """
        logger.info("DatasetService initializing")
        self.db = db
        self.config = config
        self.parser = UniversalParser()
        self.entity_service = entity_service
        self.documents_path = Path(config.db_config.files.documents_path)
        self.tmp_path = Path(os.environ.get("APP_TMP_PATH", '.'))
        logger.info("DatasetService initialized")

    def get_dataset(
        self,
        dataset_id: int,
        page: int = 1,
        page_size: int = 20,
        search: str = '',
        sort: SortQueryList = [],
    ) -> DatasetExpandedSchema:
        """
        Получить пагинированную информацию о датасете и его документах.
        """
        logger.info(
            f"Getting dataset {dataset_id} (page={page}, size={page_size}, search='{search}')"
        )
        self.raise_if_processing()

        with self.db() as session:
            dataset: Dataset = (
                session.query(Dataset).filter(Dataset.id == dataset_id).first()
            )
            if not dataset:
                raise HTTPException(status_code=404, detail='Dataset not found')

            query = (
                session.query(Document)
                .join(DatasetDocument, DatasetDocument.document_id == Document.id)
                .filter(DatasetDocument.dataset_id == dataset_id)
                .filter(Document.title.like(f'%{search}%'))
            )

            query = self.sort_documents(query, sort)

            documents = query.offset((page - 1) * page_size).limit(page_size).all()

            total_documents = (
                session.query(Document)
                .join(DatasetDocument, DatasetDocument.document_id == Document.id)
                .filter(DatasetDocument.dataset_id == dataset_id)
                .filter(Document.title.like(f'%{search}%'))
                .count()
            )

            dataset_expanded = DatasetExpandedSchema(
                id=dataset.id,
                name=dataset.name,
                isDraft=dataset.is_draft,
                isActive=dataset.is_active,
                dateCreated=dataset.date_created,
                data=DocumentsPageSchema(
                    page=[
                        DocumentSchema(
                            id=document.id,
                            name=document.title,
                            owner=document.owner,
                            status=document.status,
                        )
                        for document in documents
                    ],
                    total=total_documents,
                    pageNumber=page,
                    pageSize=page_size,
                ),
            )

        return dataset_expanded

    def get_datasets(self) -> list[DatasetSchema]:
        """
        Получить список всех датасетов.
        """
        self.raise_if_processing()

        with self.db() as session:
            datasets: list[Dataset] = session.query(Dataset).all()
        return [
            DatasetSchema(
                id=dataset.id,
                name=dataset.name,
                isDraft=dataset.is_draft,
                isActive=dataset.is_active,
                dateCreated=dataset.date_created,
            )
            for dataset in datasets
        ]

    def create_draft(self, parent_id: int) -> DatasetSchema:
        """
        Создать черновик датасета на основе родительского датасета.
        """
        logger.info(f"Creating draft dataset from parent {parent_id}")
        self.raise_if_processing()

        with self.db() as session:
            parent = session.query(Dataset).filter(Dataset.id == parent_id).first()
            if not parent:
                raise HTTPException(status_code=404, detail='Parent dataset not found')

            if parent.is_draft:
                raise HTTPException(status_code=400, detail='Parent dataset is draft')

            date = datetime.now()
            dataset = Dataset(
                name=f"{date.strftime('%Y-%m-%d %H:%M:%S')}",
                is_draft=True,
                is_active=False,
            )

            parent_documents = (
                session.query(DatasetDocument)
                .filter(DatasetDocument.dataset_id == parent_id)
                .all()
            )
            new_dataset_documents = [
                DatasetDocument(
                    dataset_id=dataset.id,
                    document_id=document.id,
                )
                for document in parent_documents
            ]

            dataset.documents = new_dataset_documents

            session.add(dataset)
            session.commit()
            session.refresh(dataset)

        return self.get_dataset(dataset.id)

    def delete_dataset(self, dataset_id: int) -> None:
        """
        Удалить черновик датасета.
        """
        logger.info(f"Deleting dataset {dataset_id}")
        self.raise_if_processing()

        with self.db() as session:
            dataset: Dataset = (
                session.query(Dataset).filter(Dataset.id == dataset_id).first()
            )

            if not dataset:
                raise HTTPException(status_code=404, detail='Dataset not found')

            if dataset.name == 'default':
                raise HTTPException(
                    status_code=400, detail='Default dataset cannot be deleted'
                )

            if dataset.is_active:
                raise HTTPException(
                    status_code=403, detail='Active dataset cannot be deleted'
                )
            
            session.query(EntityModel).filter(EntityModel.dataset_id == dataset_id).delete()
            session.delete(dataset)
            session.commit()

    def apply_draft_task(self, dataset_id: int):
        """
        Метод для выполнения в отдельном процессе.
        """
        logger.info(f"apply_draft_task started")
        try:
            with self.db() as session:
                dataset = (
                    session.query(Dataset).filter(Dataset.id == dataset_id).first()
                )
                if not dataset:
                    raise HTTPException(
                        status_code=404,
                        detail=f"Dataset with id {dataset_id} not found",
                    )

                active_dataset = (
                    session.query(Dataset).filter(Dataset.is_active == True).first()
                )

                self.apply_draft(dataset)
                dataset.is_draft = False
                dataset.is_active = True
                if active_dataset:
                    active_dataset.is_active = False

                session.commit()
            logger.info(f"apply_draft_task finished")
        except Exception as e:
            logger.error(f"Error applying draft: {e}")
            raise

    def activate_dataset(
        self, dataset_id: int, background_tasks: BackgroundTasks
    ) -> DatasetExpandedSchema:
        """
        Активировать датасет в фоновой задаче.
        """

        logger.info(f"Activating dataset {dataset_id}")
        self.raise_if_processing()

        with self.db() as session:
            dataset = session.query(Dataset).filter(Dataset.id == dataset_id).first()
            active_dataset = session.query(Dataset).filter(Dataset.is_active).first()
            if not dataset:
                raise HTTPException(status_code=404, detail='Dataset not found')

            if dataset.is_active:
                raise HTTPException(status_code=400, detail='Dataset is already active')

            if dataset.is_draft:
                background_tasks.add_task(self.apply_draft_task, dataset_id)
            else:
                dataset.is_active = True

                if active_dataset:
                    active_dataset.is_active = False

                session.commit()

            return self.get_dataset(dataset_id)

    def get_processing(self) -> DatasetProcessing:
        """
        Получить информацию о процессе обработки датасета.
        """
        tmp_file = Path(self.tmp_path / 'tmp.json')
        if tmp_file.exists():
            try:
                with open(tmp_file, 'r', encoding='utf-8') as f:
                    info = json.load(f)
            except Exception as e:
                logger.warning(f"Error loading processing info: {e}")
                return DatasetProcessing(
                    status='in_progress',
                    total=None,
                    current=None,
                    datasetName=None,
                )

            with self.db() as session:
                dataset_name = (
                    session.query(Dataset)
                    .filter(Dataset.id == info['dataset_id'])
                    .first()
                    .name
                )

            return DatasetProcessing(
                status='in_progress',
                total=info['total'],
                current=info['current'],
                datasetName=dataset_name,
            )

        return DatasetProcessing(
            status='ready',
            total=None,
            current=None,
            datasetName=None,
        )

    def upload_zip(self, file: UploadFile) -> DatasetExpandedSchema:
        """
        Загрузить архив с датасетом.
        """
        logger.info(f"Uploading ZIP file {file.filename}")
        self.raise_if_processing()

        file_location = Path(self.tmp_path / 'tmp' / 'tmp.zip')
        logger.debug(f"Saving uploaded file to {file_location}")
        file_location.parent.mkdir(parents=True, exist_ok=True)
        with open(file_location, 'wb') as f:
            f.write(file.file.read())

        with zipfile.ZipFile(file_location, 'r') as zip_ref:
            zip_ref.extractall(file_location.parent)

        dataset = self.create_dataset_from_directory(
            is_default=False,
            directory_with_documents=file_location.parent,
        )

        file_location.unlink()
        shutil.rmtree(file_location.parent)

        return self.get_dataset(dataset.id)

    def apply_draft(
        self,
        dataset: Dataset,
    ) -> None:
        """
        Сохранить черновик как полноценный датасет.
        Вызывает асинхронную обработку документов.

        Args:
            dataset: Датасет для применения
        """
        torch.set_num_threads(1)
        logger.info(f"Applying draft dataset {dataset.id}")
        if not dataset.is_draft:
            logger.error(f"Dataset {dataset.id} is not a draft")
            raise HTTPException(
                status_code=400, detail='Dataset is not draft but trying to apply it'
            )

        TMP_PATH = Path(self.tmp_path / 'tmp.json')

        def progress_callback(current: int, total: int) -> None:
            log_step = total // 100
            if log_step == 0:
                log_step = 1
            if current % log_step != 0:
                return
            if (total > 10) and (current % (total // 10) == 0):
                logger.info(f"Processing dataset {dataset.id}: {current}/{total}")
            with open(TMP_PATH, 'w', encoding='utf-8') as f:
                json.dump(
                    {
                        'total': total,
                        'current': current,
                        'dataset_id': dataset.id,
                    },
                    f,
                )

        TMP_PATH.touch()

        documents: list[Document] = [
            doc_dataset_link.document for doc_dataset_link in dataset.documents
        ]

        async def process_single_document(document: Document):
            path = self.documents_path / f'{document.id}.{document.source_format}'
            try:
                parsed = self.parser.parse_by_path(str(path))
                if parsed is None:
                    logger.warning(
                        f"Failed to parse document {document.id} at path {path}"
                    )
                    return
                parsed.name = document.title
                await self.entity_service.process_document(
                    parsed,
                    dataset.id,
                    progress_callback=progress_callback,  # Callback остается синхронным
                )
            except Exception as e:
                logger.error(
                    f"Error processing document {document.id} in apply_draft: {e}",
                    exc_info=True,
                )

        async def main_processing():
            tasks = [process_single_document(doc) for doc in documents]
            await asyncio.gather(*tasks)

        try:
            asyncio.run(main_processing())
        finally:
            if TMP_PATH.exists():
                TMP_PATH.unlink()

    def raise_if_processing(self) -> None:
        """
        Поднять ошибку, если процесс обработки датасета еще не завершен.
        """
        if self.get_processing().status == 'in_progress':
            logger.error("Dataset processing is already in progress")
            raise HTTPException(
                status_code=409, detail='Dataset processing is in progress'
            )

    def create_dataset_from_directory(
        self,
        is_default: bool,
        directory_with_documents: Path,
    ) -> Dataset:
        """
        Создать датасет из директории с xml-документами.

        Args:
            is_default: Создать ли датасет по умолчанию.
            directory_with_xmls: Путь к директории с xml-документами.
            directory_with_processed_dataset: Путь к директории с обработанным датасетом - если не передан, будет произведена полная обработка (например, при создании датасета из скриптов).

        Returns:
            Dataset: Созданный датасет.
        """
        logger.info(
            f"Creating {'default' if is_default else 'new'} dataset from directory {directory_with_documents}"
        )
        with self.db() as session:
            documents = []

            date = datetime.now()
            name = 'default' if is_default else f'{date.strftime("%Y-%m-%d %H:%M:%S")}'

            dataset = Dataset(
                name=name,
                is_draft=True,
                is_active=True if is_default else False,
            )
            session.add(dataset)

            for subpath in self._get_recursive_dirlist(directory_with_documents):
                document, relation = self._create_document(
                    directory_with_documents, subpath, dataset
                )
                if document is None:
                    continue
                documents.append(document)
                session.add(document)
                session.add(relation)

            logger.info(f"Created {len(documents)} documents")

            session.flush()

            self.documents_path.mkdir(parents=True, exist_ok=True)

            for document in documents:
                session.refresh(document)
                old_filename = document.filename
                new_filename = '{}.{}'.format(document.id, document.source_format)
                shutil.copy(
                    directory_with_documents / old_filename,
                    self.documents_path / new_filename,
                )
                document.filename = new_filename

            logger.info(f"Documents renamed with ids")

            session.commit()
            session.refresh(dataset)

            dataset_id = dataset.id

        logger.info(f"Dataset {dataset_id} created")

        return dataset

    def create_empty_dataset(self, is_default: bool) -> Dataset:
        """
        Создать пустой датасет.
        """
        with self.db() as session:
            name = (
                'default'
                if is_default
                else f'{datetime.now().strftime("%Y-%m-%d %H:%M:%S")}'
            )
            dataset = Dataset(
                name=name,
                is_active=True if is_default else False,
                is_draft=False,
            )
            session.add(dataset)
            session.commit()
            session.refresh(dataset)

        return dataset

    @staticmethod
    def _get_recursive_dirlist(path: Path) -> list[Path]:
        """
        Возвращает список всех xml и docx файлов на всех уровнях вложенности.

        Args:
            path: Путь к директории.

        Returns:
            list[Path]: Список путей к xml-файлам относительно path.
        """
        xml_files = set()  # set для отбрасывания неуникальных путей
        for ext in ('*.xml', '*.XML', '*.docx', '*.DOCX'):
            xml_files.update(path.glob(f'**/{ext}'))

        return [p.relative_to(path) for p in xml_files]

    def _create_document(
        self,
        documents_path: Path,
        subpath: os.PathLike,
        dataset: Dataset,
    ) -> tuple[Document | None, DatasetDocument | None]:
        """
        Создаёт документ в базе данных.

        Args:
            documents_path: Путь к директории с документами.
            subpath: Путь к документу относительно documents_path.
            dataset: Датасет, к которому относится документ.

        Returns:
            tuple[Document, DatasetDocument]: Кортеж из документа и его связи с датасетом.
        """
        logger.debug(f"Creating document from {subpath}")

        try:
            source_format = get_source_format(str(subpath))
            path = documents_path / subpath
            parsed: ParsedDocument | None = self.parser.parse_by_path(
                str(path)
            )
            
            if 'Приложение' in parsed.name:
                parsed.name = path.parent.name + ' ' + parsed.name

            if not parsed:
                logger.warning(f"Failed to parse file: {subpath}")
                return None, None

            document = Document(
                filename=str(subpath),
                title=parsed.name,
                status=parsed.meta.status,
                owner=parsed.meta.owner,
                source_format=source_format,
            )
            relation = DatasetDocument(
                document=document,
                dataset=dataset,
            )

            return document, relation

        except Exception as e:
            logger.error(f"Error creating document from {subpath}: {e}")
            return None, None

    def get_current_dataset(self) -> Dataset | None:
        with self.db() as session:
            result = session.query(Dataset).filter(Dataset.is_active == True).first()
        return result

    def get_default_dataset(self) -> Dataset | None:
        with self.db() as session:
            result = session.query(Dataset).filter(Dataset.name == 'default').first()
        return result

    def sort_documents(
        self,
        query: "Query",  # type: ignore
        sort: SortQueryList,
    ) -> "Query":  # type: ignore
        """
        Сортирует документы по заданным полям и направлениям сортировки.
        """
        if sort and (len(sort.sorts) > 0):
            for sort_query in sort.sorts:
                field = sort_query.field
                direction = sort_query.direction

                if field == 'name':
                    column = Document.title
                elif field == 'status':
                    column = Document.status
                elif field == 'owner':
                    column = Document.owner
                elif field == 'id':
                    column = Document.id
                else:
                    raise HTTPException(
                        status_code=400, detail=f'Invalid sort field: {field}'
                    )

                query = query.order_by(
                    column.desc() if direction.lower() == 'desc' else column
                )
        else:
            query = query.order_by(Document.id.desc())  # Default sorting

        return query