import datetime
import json
import logging
import re
import threading
import time
import uuid
from typing import Optional, cast

from flask import Flask, current_app
from flask_login import current_user
from langchain.schema import Document
from langchain.text_splitter import TextSplitter
from sqlalchemy.orm.exc import ObjectDeletedError

from core.data_loader.file_extractor import FileExtractor
from core.data_loader.loader.notion import NotionLoader
from core.docstore.dataset_docstore import DatasetDocumentStore
from core.errors.error import ProviderTokenNotInitError
from core.generator.llm_generator import LLMGenerator
from core.index.index import IndexBuilder
from core.model_manager import ModelInstance, ModelManager
from core.model_runtime.entities.model_entities import ModelType, PriceType
from core.model_runtime.model_providers.__base.large_language_model import LargeLanguageModel
from core.model_runtime.model_providers.__base.text_embedding_model import TextEmbeddingModel
from core.splitter.fixed_text_splitter import EnhanceRecursiveCharacterTextSplitter, FixedRecursiveCharacterTextSplitter
from extensions.ext_database import db
from extensions.ext_redis import redis_client
from extensions.ext_storage import storage
from libs import helper
from models.dataset import Dataset, DatasetProcessRule, DocumentSegment
from models.dataset import Document as DatasetDocument
from models.model import UploadFile
from models.source import DataSourceBinding


class IndexingRunner:

    def __init__(self):
        self.storage = storage
        self.model_manager = ModelManager()

    def run(self, dataset_documents: list[DatasetDocument]):
        """Run the indexing process."""
        for dataset_document in dataset_documents:
            try:
                # get dataset
                dataset = Dataset.query.filter_by(
                    id=dataset_document.dataset_id
                ).first()

                if not dataset:
                    raise ValueError("no dataset found")

                # get the process rule
                processing_rule = db.session.query(DatasetProcessRule). \
                    filter(DatasetProcessRule.id == dataset_document.dataset_process_rule_id). \
                    first()

                # load file
                text_docs = self._load_data(dataset_document, processing_rule.mode == 'automatic')

                # get embedding model instance
                embedding_model_instance = None
                if dataset.indexing_technique == 'high_quality':
                    if dataset.embedding_model_provider:
                        embedding_model_instance = self.model_manager.get_model_instance(
                            tenant_id=dataset.tenant_id,
                            provider=dataset.embedding_model_provider,
                            model_type=ModelType.TEXT_EMBEDDING,
                            model=dataset.embedding_model
                        )
                    else:
                        embedding_model_instance = self.model_manager.get_default_model_instance(
                            tenant_id=dataset.tenant_id,
                            model_type=ModelType.TEXT_EMBEDDING,
                        )

                # get splitter
                splitter = self._get_splitter(processing_rule, embedding_model_instance)

                # split to documents
                documents = self._step_split(
                    text_docs=text_docs,
                    splitter=splitter,
                    dataset=dataset,
                    dataset_document=dataset_document,
                    processing_rule=processing_rule
                )
                self._build_index(
                    dataset=dataset,
                    dataset_document=dataset_document,
                    documents=documents
                )
            except DocumentIsPausedException:
                raise DocumentIsPausedException('Document paused, document id: {}'.format(dataset_document.id))
            except ProviderTokenNotInitError as e:
                dataset_document.indexing_status = 'error'
                dataset_document.error = str(e.description)
                dataset_document.stopped_at = datetime.datetime.utcnow()
                db.session.commit()
            except ObjectDeletedError:
                logging.warning('Document deleted, document id: {}'.format(dataset_document.id))
            except Exception as e:
                logging.exception("consume document failed")
                dataset_document.indexing_status = 'error'
                dataset_document.error = str(e)
                dataset_document.stopped_at = datetime.datetime.utcnow()
                db.session.commit()

    def run_in_splitting_status(self, dataset_document: DatasetDocument):
        """Run the indexing process when the index_status is splitting."""
        try:
            # get dataset
            dataset = Dataset.query.filter_by(
                id=dataset_document.dataset_id
            ).first()

            if not dataset:
                raise ValueError("no dataset found")

            # get exist document_segment list and delete
            document_segments = DocumentSegment.query.filter_by(
                dataset_id=dataset.id,
                document_id=dataset_document.id
            ).all()

            for document_segment in document_segments:
                db.session.delete(document_segment)
            db.session.commit()
            # get the process rule
            processing_rule = db.session.query(DatasetProcessRule). \
                filter(DatasetProcessRule.id == dataset_document.dataset_process_rule_id). \
                first()

            # load file
            text_docs = self._load_data(dataset_document, processing_rule.mode == 'automatic')

            # get embedding model instance
            embedding_model_instance = None
            if dataset.indexing_technique == 'high_quality':
                if dataset.embedding_model_provider:
                    embedding_model_instance = self.model_manager.get_model_instance(
                        tenant_id=dataset.tenant_id,
                        provider=dataset.embedding_model_provider,
                        model_type=ModelType.TEXT_EMBEDDING,
                        model=dataset.embedding_model
                    )
                else:
                    embedding_model_instance = self.model_manager.get_default_model_instance(
                        tenant_id=dataset.tenant_id,
                        model_type=ModelType.TEXT_EMBEDDING,
                    )

            # get splitter
            splitter = self._get_splitter(processing_rule, embedding_model_instance)

            # split to documents
            documents = self._step_split(
                text_docs=text_docs,
                splitter=splitter,
                dataset=dataset,
                dataset_document=dataset_document,
                processing_rule=processing_rule
            )

            # build index
            self._build_index(
                dataset=dataset,
                dataset_document=dataset_document,
                documents=documents
            )
        except DocumentIsPausedException:
            raise DocumentIsPausedException('Document paused, document id: {}'.format(dataset_document.id))
        except ProviderTokenNotInitError as e:
            dataset_document.indexing_status = 'error'
            dataset_document.error = str(e.description)
            dataset_document.stopped_at = datetime.datetime.utcnow()
            db.session.commit()
        except Exception as e:
            logging.exception("consume document failed")
            dataset_document.indexing_status = 'error'
            dataset_document.error = str(e)
            dataset_document.stopped_at = datetime.datetime.utcnow()
            db.session.commit()

    def run_in_indexing_status(self, dataset_document: DatasetDocument):
        """Run the indexing process when the index_status is indexing."""
        try:
            # get dataset
            dataset = Dataset.query.filter_by(
                id=dataset_document.dataset_id
            ).first()

            if not dataset:
                raise ValueError("no dataset found")

            # get exist document_segment list and delete
            document_segments = DocumentSegment.query.filter_by(
                dataset_id=dataset.id,
                document_id=dataset_document.id
            ).all()

            documents = []
            if document_segments:
                for document_segment in document_segments:
                    # transform segment to node
                    if document_segment.status != "completed":
                        document = Document(
                            page_content=document_segment.content,
                            metadata={
                                "doc_id": document_segment.index_node_id,
                                "doc_hash": document_segment.index_node_hash,
                                "document_id": document_segment.document_id,
                                "dataset_id": document_segment.dataset_id,
                            }
                        )

                        documents.append(document)

            # build index
            self._build_index(
                dataset=dataset,
                dataset_document=dataset_document,
                documents=documents
            )
        except DocumentIsPausedException:
            raise DocumentIsPausedException('Document paused, document id: {}'.format(dataset_document.id))
        except ProviderTokenNotInitError as e:
            dataset_document.indexing_status = 'error'
            dataset_document.error = str(e.description)
            dataset_document.stopped_at = datetime.datetime.utcnow()
            db.session.commit()
        except Exception as e:
            logging.exception("consume document failed")
            dataset_document.indexing_status = 'error'
            dataset_document.error = str(e)
            dataset_document.stopped_at = datetime.datetime.utcnow()
            db.session.commit()

    def file_indexing_estimate(self, tenant_id: str, file_details: list[UploadFile], tmp_processing_rule: dict,
                               doc_form: str = None, doc_language: str = 'English', dataset_id: str = None,
                               indexing_technique: str = 'economy') -> dict:
        """
        Estimate the indexing for the document.
        """
        embedding_model_instance = None
        if dataset_id:
            dataset = Dataset.query.filter_by(
                id=dataset_id
            ).first()
            if not dataset:
                raise ValueError('Dataset not found.')
            if dataset.indexing_technique == 'high_quality' or indexing_technique == 'high_quality':
                if dataset.embedding_model_provider:
                    embedding_model_instance = self.model_manager.get_model_instance(
                        tenant_id=tenant_id,
                        provider=dataset.embedding_model_provider,
                        model_type=ModelType.TEXT_EMBEDDING,
                        model=dataset.embedding_model
                    )
                else:
                    embedding_model_instance = self.model_manager.get_default_model_instance(
                        tenant_id=tenant_id,
                        model_type=ModelType.TEXT_EMBEDDING,
                    )
        else:
            if indexing_technique == 'high_quality':
                embedding_model_instance = self.model_manager.get_default_model_instance(
                    tenant_id=tenant_id,
                    model_type=ModelType.TEXT_EMBEDDING,
                )
        tokens = 0
        preview_texts = []
        total_segments = 0
        total_price = 0
        currency = 'USD'
        for file_detail in file_details:

            processing_rule = DatasetProcessRule(
                mode=tmp_processing_rule["mode"],
                rules=json.dumps(tmp_processing_rule["rules"])
            )

            # load data from file
            text_docs = FileExtractor.load(file_detail, is_automatic=processing_rule.mode == 'automatic')

            # get splitter
            splitter = self._get_splitter(processing_rule, embedding_model_instance)

            # split to documents
            documents = self._split_to_documents_for_estimate(
                text_docs=text_docs,
                splitter=splitter,
                processing_rule=processing_rule
            )

            total_segments += len(documents)

            for document in documents:
                if len(preview_texts) < 5:
                    preview_texts.append(document.page_content)
                if indexing_technique == 'high_quality' or embedding_model_instance:
                    embedding_model_type_instance = embedding_model_instance.model_type_instance
                    embedding_model_type_instance = cast(TextEmbeddingModel, embedding_model_type_instance)
                    tokens += embedding_model_type_instance.get_num_tokens(
                        model=embedding_model_instance.model,
                        credentials=embedding_model_instance.credentials,
                        texts=[self.filter_string(document.page_content)]
                    )

        if doc_form and doc_form == 'qa_model':
            model_instance = self.model_manager.get_default_model_instance(
                tenant_id=tenant_id,
                model_type=ModelType.LLM
            )

            model_type_instance = model_instance.model_type_instance
            model_type_instance = cast(LargeLanguageModel, model_type_instance)

            if len(preview_texts) > 0:
                # qa model document
                response = LLMGenerator.generate_qa_document(current_user.current_tenant_id, preview_texts[0],
                                                             doc_language)
                document_qa_list = self.format_split_text(response)
                price_info = model_type_instance.get_price(
                    model=model_instance.model,
                    credentials=model_instance.credentials,
                    price_type=PriceType.INPUT,
                    tokens=total_segments * 2000,
                )
                return {
                    "total_segments": total_segments * 20,
                    "tokens": total_segments * 2000,
                    "total_price": '{:f}'.format(price_info.total_amount),
                    "currency": price_info.currency,
                    "qa_preview": document_qa_list,
                    "preview": preview_texts
                }
        if embedding_model_instance:
            embedding_model_type_instance = cast(TextEmbeddingModel, embedding_model_instance.model_type_instance)
            embedding_price_info = embedding_model_type_instance.get_price(
                model=embedding_model_instance.model,
                credentials=embedding_model_instance.credentials,
                price_type=PriceType.INPUT,
                tokens=tokens
            )
            total_price = '{:f}'.format(embedding_price_info.total_amount)
            currency = embedding_price_info.currency
        return {
            "total_segments": total_segments,
            "tokens": tokens,
            "total_price": total_price,
            "currency": currency,
            "preview": preview_texts
        }

    def notion_indexing_estimate(self, tenant_id: str, notion_info_list: list, tmp_processing_rule: dict,
                                 doc_form: str = None, doc_language: str = 'English', dataset_id: str = None,
                                 indexing_technique: str = 'economy') -> dict:
        """
        Estimate the indexing for the document.
        """
        embedding_model_instance = None
        if dataset_id:
            dataset = Dataset.query.filter_by(
                id=dataset_id
            ).first()
            if not dataset:
                raise ValueError('Dataset not found.')
            if dataset.indexing_technique == 'high_quality' or indexing_technique == 'high_quality':
                if dataset.embedding_model_provider:
                    embedding_model_instance = self.model_manager.get_model_instance(
                        tenant_id=tenant_id,
                        provider=dataset.embedding_model_provider,
                        model_type=ModelType.TEXT_EMBEDDING,
                        model=dataset.embedding_model
                    )
                else:
                    embedding_model_instance = self.model_manager.get_default_model_instance(
                        tenant_id=tenant_id,
                        model_type=ModelType.TEXT_EMBEDDING,
                    )
        else:
            if indexing_technique == 'high_quality':
                embedding_model_instance = self.model_manager.get_default_model_instance(
                    tenant_id=tenant_id,
                    model_type=ModelType.TEXT_EMBEDDING
                )
        # load data from notion
        tokens = 0
        preview_texts = []
        total_segments = 0
        total_price = 0
        currency = 'USD'
        for notion_info in notion_info_list:
            workspace_id = notion_info['workspace_id']
            data_source_binding = DataSourceBinding.query.filter(
                db.and_(
                    DataSourceBinding.tenant_id == current_user.current_tenant_id,
                    DataSourceBinding.provider == 'notion',
                    DataSourceBinding.disabled == False,
                    DataSourceBinding.source_info['workspace_id'] == f'"{workspace_id}"'
                )
            ).first()
            if not data_source_binding:
                raise ValueError('Data source binding not found.')

            for page in notion_info['pages']:
                loader = NotionLoader(
                    notion_access_token=data_source_binding.access_token,
                    notion_workspace_id=workspace_id,
                    notion_obj_id=page['page_id'],
                    notion_page_type=page['type']
                )
                documents = loader.load()

                processing_rule = DatasetProcessRule(
                    mode=tmp_processing_rule["mode"],
                    rules=json.dumps(tmp_processing_rule["rules"])
                )

                # get splitter
                splitter = self._get_splitter(processing_rule, embedding_model_instance)

                # split to documents
                documents = self._split_to_documents_for_estimate(
                    text_docs=documents,
                    splitter=splitter,
                    processing_rule=processing_rule
                )
                total_segments += len(documents)

                embedding_model_type_instance = None
                if embedding_model_instance:
                    embedding_model_type_instance = embedding_model_instance.model_type_instance
                    embedding_model_type_instance = cast(TextEmbeddingModel, embedding_model_type_instance)

                for document in documents:
                    if len(preview_texts) < 5:
                        preview_texts.append(document.page_content)
                    if indexing_technique == 'high_quality' and embedding_model_type_instance:
                        tokens += embedding_model_type_instance.get_num_tokens(
                            model=embedding_model_instance.model,
                            credentials=embedding_model_instance.credentials,
                            texts=[document.page_content]
                        )

        if doc_form and doc_form == 'qa_model':
            model_instance = self.model_manager.get_default_model_instance(
                tenant_id=tenant_id,
                model_type=ModelType.LLM
            )

            model_type_instance = model_instance.model_type_instance
            model_type_instance = cast(LargeLanguageModel, model_type_instance)
            if len(preview_texts) > 0:
                # qa model document
                response = LLMGenerator.generate_qa_document(current_user.current_tenant_id, preview_texts[0],
                                                             doc_language)
                document_qa_list = self.format_split_text(response)

                price_info = model_type_instance.get_price(
                    model=model_instance.model,
                    credentials=model_instance.credentials,
                    price_type=PriceType.INPUT,
                    tokens=total_segments * 2000,
                )

                return {
                    "total_segments": total_segments * 20,
                    "tokens": total_segments * 2000,
                    "total_price": '{:f}'.format(price_info.total_amount),
                    "currency": price_info.currency,
                    "qa_preview": document_qa_list,
                    "preview": preview_texts
                }
        if embedding_model_instance:
            embedding_model_type_instance = embedding_model_instance.model_type_instance
            embedding_model_type_instance = cast(TextEmbeddingModel, embedding_model_type_instance)
            embedding_price_info = embedding_model_type_instance.get_price(
                model=embedding_model_instance.model,
                credentials=embedding_model_instance.credentials,
                price_type=PriceType.INPUT,
                tokens=tokens
            )
            total_price = '{:f}'.format(embedding_price_info.total_amount)
            currency = embedding_price_info.currency
        return {
            "total_segments": total_segments,
            "tokens": tokens,
            "total_price": total_price,
            "currency": currency,
            "preview": preview_texts
        }

    def _load_data(self, dataset_document: DatasetDocument, automatic: bool = False) -> list[Document]:
        # load file
        if dataset_document.data_source_type not in ["upload_file", "notion_import"]:
            return []

        data_source_info = dataset_document.data_source_info_dict
        text_docs = []
        if dataset_document.data_source_type == 'upload_file':
            if not data_source_info or 'upload_file_id' not in data_source_info:
                raise ValueError("no upload file found")

            file_detail = db.session.query(UploadFile). \
                filter(UploadFile.id == data_source_info['upload_file_id']). \
                one_or_none()

            if file_detail:
                text_docs = FileExtractor.load(file_detail, is_automatic=automatic)
        elif dataset_document.data_source_type == 'notion_import':
            loader = NotionLoader.from_document(dataset_document)
            text_docs = loader.load()

        # update document status to splitting
        self._update_document_index_status(
            document_id=dataset_document.id,
            after_indexing_status="splitting",
            extra_update_params={
                DatasetDocument.word_count: sum([len(text_doc.page_content) for text_doc in text_docs]),
                DatasetDocument.parsing_completed_at: datetime.datetime.utcnow()
            }
        )

        # replace doc id to document model id
        text_docs = cast(list[Document], text_docs)
        for text_doc in text_docs:
            # remove invalid symbol
            text_doc.page_content = self.filter_string(text_doc.page_content)
            text_doc.metadata['document_id'] = dataset_document.id
            text_doc.metadata['dataset_id'] = dataset_document.dataset_id

        return text_docs

    def filter_string(self, text):
        text = re.sub(r'<\|', '<', text)
        text = re.sub(r'\|>', '>', text)
        text = re.sub(r'[\x00-\x08\x0B\x0C\x0E-\x1F\x7F\xEF\xBF\xBE]', '', text)
        # Unicode  U+FFFE
        text = re.sub('\uFFFE', '', text)
        return text

    def _get_splitter(self, processing_rule: DatasetProcessRule,
                      embedding_model_instance: Optional[ModelInstance]) -> TextSplitter:
        """
        Get the NodeParser object according to the processing rule.
        """
        if processing_rule.mode == "custom":
            # The user-defined segmentation rule
            rules = json.loads(processing_rule.rules)
            segmentation = rules["segmentation"]
            if segmentation["max_tokens"] < 50 or segmentation["max_tokens"] > 1000:
                raise ValueError("Custom segment length should be between 50 and 1000.")

            separator = segmentation["separator"]
            if separator:
                separator = separator.replace('\\n', '\n')

            character_splitter = FixedRecursiveCharacterTextSplitter.from_encoder(
                chunk_size=segmentation["max_tokens"],
                chunk_overlap=segmentation.get('chunk_overlap', 0),
                fixed_separator=separator,
                separators=["\n\n", "。", ".", " ", ""],
                embedding_model_instance=embedding_model_instance
            )
        else:
            # Automatic segmentation
            character_splitter = EnhanceRecursiveCharacterTextSplitter.from_encoder(
                chunk_size=DatasetProcessRule.AUTOMATIC_RULES['segmentation']['max_tokens'],
                chunk_overlap=DatasetProcessRule.AUTOMATIC_RULES['segmentation']['chunk_overlap'],
                separators=["\n\n", "。", ".", " ", ""],
                embedding_model_instance=embedding_model_instance
            )

        return character_splitter

    def _step_split(self, text_docs: list[Document], splitter: TextSplitter,
                    dataset: Dataset, dataset_document: DatasetDocument, processing_rule: DatasetProcessRule) \
            -> list[Document]:
        """
        Split the text documents into documents and save them to the document segment.
        """
        documents = self._split_to_documents(
            text_docs=text_docs,
            splitter=splitter,
            processing_rule=processing_rule,
            tenant_id=dataset.tenant_id,
            document_form=dataset_document.doc_form,
            document_language=dataset_document.doc_language
        )

        # save node to document segment
        doc_store = DatasetDocumentStore(
            dataset=dataset,
            user_id=dataset_document.created_by,
            document_id=dataset_document.id
        )

        # add document segments
        doc_store.add_documents(documents)

        # update document status to indexing
        cur_time = datetime.datetime.utcnow()
        self._update_document_index_status(
            document_id=dataset_document.id,
            after_indexing_status="indexing",
            extra_update_params={
                DatasetDocument.cleaning_completed_at: cur_time,
                DatasetDocument.splitting_completed_at: cur_time,
            }
        )

        # update segment status to indexing
        self._update_segments_by_document(
            dataset_document_id=dataset_document.id,
            update_params={
                DocumentSegment.status: "indexing",
                DocumentSegment.indexing_at: datetime.datetime.utcnow()
            }
        )

        return documents

    def _split_to_documents(self, text_docs: list[Document], splitter: TextSplitter,
                            processing_rule: DatasetProcessRule, tenant_id: str,
                            document_form: str, document_language: str) -> list[Document]:
        """
        Split the text documents into nodes.
        """
        all_documents = []
        all_qa_documents = []
        for text_doc in text_docs:
            # document clean
            document_text = self._document_clean(text_doc.page_content, processing_rule)
            text_doc.page_content = document_text

            # parse document to nodes
            documents = splitter.split_documents([text_doc])
            split_documents = []
            for document_node in documents:

                if document_node.page_content.strip():
                    doc_id = str(uuid.uuid4())
                    hash = helper.generate_text_hash(document_node.page_content)
                    document_node.metadata['doc_id'] = doc_id
                    document_node.metadata['doc_hash'] = hash
                    # delete Spliter character
                    page_content = document_node.page_content
                    if page_content.startswith(".") or page_content.startswith("。"):
                        page_content = page_content[1:]
                    else:
                        page_content = page_content
                    document_node.page_content = page_content

                    if document_node.page_content:
                        split_documents.append(document_node)
            all_documents.extend(split_documents)
        # processing qa document
        if document_form == 'qa_model':
            for i in range(0, len(all_documents), 10):
                threads = []
                sub_documents = all_documents[i:i + 10]
                for doc in sub_documents:
                    document_format_thread = threading.Thread(target=self.format_qa_document, kwargs={
                        'flask_app': current_app._get_current_object(),
                        'tenant_id': tenant_id, 'document_node': doc, 'all_qa_documents': all_qa_documents,
                        'document_language': document_language})
                    threads.append(document_format_thread)
                    document_format_thread.start()
                for thread in threads:
                    thread.join()
            return all_qa_documents
        return all_documents

    def format_qa_document(self, flask_app: Flask, tenant_id: str, document_node, all_qa_documents, document_language):
        format_documents = []
        if document_node.page_content is None or not document_node.page_content.strip():
            return
        with flask_app.app_context():
            try:
                # qa model document
                response = LLMGenerator.generate_qa_document(tenant_id, document_node.page_content, document_language)
                document_qa_list = self.format_split_text(response)
                qa_documents = []
                for result in document_qa_list:
                    qa_document = Document(page_content=result['question'], metadata=document_node.metadata.copy())
                    doc_id = str(uuid.uuid4())
                    hash = helper.generate_text_hash(result['question'])
                    qa_document.metadata['answer'] = result['answer']
                    qa_document.metadata['doc_id'] = doc_id
                    qa_document.metadata['doc_hash'] = hash
                    qa_documents.append(qa_document)
                format_documents.extend(qa_documents)
            except Exception as e:
                logging.exception(e)

            all_qa_documents.extend(format_documents)

    def _split_to_documents_for_estimate(self, text_docs: list[Document], splitter: TextSplitter,
                                         processing_rule: DatasetProcessRule) -> list[Document]:
        """
        Split the text documents into nodes.
        """
        all_documents = []
        for text_doc in text_docs:
            # document clean
            document_text = self._document_clean(text_doc.page_content, processing_rule)
            text_doc.page_content = document_text

            # parse document to nodes
            documents = splitter.split_documents([text_doc])

            split_documents = []
            for document in documents:
                if document.page_content is None or not document.page_content.strip():
                    continue
                doc_id = str(uuid.uuid4())
                hash = helper.generate_text_hash(document.page_content)

                document.metadata['doc_id'] = doc_id
                document.metadata['doc_hash'] = hash

                split_documents.append(document)

            all_documents.extend(split_documents)

        return all_documents

    def _document_clean(self, text: str, processing_rule: DatasetProcessRule) -> str:
        """
        Clean the document text according to the processing rules.
        """
        if processing_rule.mode == "automatic":
            rules = DatasetProcessRule.AUTOMATIC_RULES
        else:
            rules = json.loads(processing_rule.rules) if processing_rule.rules else {}

        if 'pre_processing_rules' in rules:
            pre_processing_rules = rules["pre_processing_rules"]
            for pre_processing_rule in pre_processing_rules:
                if pre_processing_rule["id"] == "remove_extra_spaces" and pre_processing_rule["enabled"] is True:
                    # Remove extra spaces
                    pattern = r'\n{3,}'
                    text = re.sub(pattern, '\n\n', text)
                    pattern = r'[\t\f\r\x20\u00a0\u1680\u180e\u2000-\u200a\u202f\u205f\u3000]{2,}'
                    text = re.sub(pattern, ' ', text)
                elif pre_processing_rule["id"] == "remove_urls_emails" and pre_processing_rule["enabled"] is True:
                    # Remove email
                    pattern = r'([a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+)'
                    text = re.sub(pattern, '', text)

                    # Remove URL
                    pattern = r'https?://[^\s]+'
                    text = re.sub(pattern, '', text)

        return text

    def format_split_text(self, text):
        regex = r"Q\d+:\s*(.*?)\s*A\d+:\s*([\s\S]*?)(?=Q\d+:|$)"
        matches = re.findall(regex, text, re.UNICODE)

        return [
            {
                "question": q,
                "answer": re.sub(r"\n\s*", "\n", a.strip())
            }
            for q, a in matches if q and a
        ]

    def _build_index(self, dataset: Dataset, dataset_document: DatasetDocument, documents: list[Document]) -> None:
        """
        Build the index for the document.
        """
        vector_index = IndexBuilder.get_index(dataset, 'high_quality')
        keyword_table_index = IndexBuilder.get_index(dataset, 'economy')
        embedding_model_instance = None
        if dataset.indexing_technique == 'high_quality':
            embedding_model_instance = self.model_manager.get_model_instance(
                tenant_id=dataset.tenant_id,
                provider=dataset.embedding_model_provider,
                model_type=ModelType.TEXT_EMBEDDING,
                model=dataset.embedding_model
            )

        # chunk nodes by chunk size
        indexing_start_at = time.perf_counter()
        tokens = 0
        chunk_size = 100

        embedding_model_type_instance = None
        if embedding_model_instance:
            embedding_model_type_instance = embedding_model_instance.model_type_instance
            embedding_model_type_instance = cast(TextEmbeddingModel, embedding_model_type_instance)

        for i in range(0, len(documents), chunk_size):
            # check document is paused
            self._check_document_paused_status(dataset_document.id)
            chunk_documents = documents[i:i + chunk_size]
            if dataset.indexing_technique == 'high_quality' or embedding_model_type_instance:
                tokens += sum(
                    embedding_model_type_instance.get_num_tokens(
                        embedding_model_instance.model,
                        embedding_model_instance.credentials,
                        [document.page_content]
                    )
                    for document in chunk_documents
                )

            # save vector index
            if vector_index:
                vector_index.add_texts(chunk_documents)

            # save keyword index
            keyword_table_index.add_texts(chunk_documents)

            document_ids = [document.metadata['doc_id'] for document in chunk_documents]
            db.session.query(DocumentSegment).filter(
                DocumentSegment.document_id == dataset_document.id,
                DocumentSegment.index_node_id.in_(document_ids),
                DocumentSegment.status == "indexing"
            ).update({
                DocumentSegment.status: "completed",
                DocumentSegment.enabled: True,
                DocumentSegment.completed_at: datetime.datetime.utcnow()
            })

            db.session.commit()

        indexing_end_at = time.perf_counter()

        # update document status to completed
        self._update_document_index_status(
            document_id=dataset_document.id,
            after_indexing_status="completed",
            extra_update_params={
                DatasetDocument.tokens: tokens,
                DatasetDocument.completed_at: datetime.datetime.utcnow(),
                DatasetDocument.indexing_latency: indexing_end_at - indexing_start_at,
            }
        )

    def _check_document_paused_status(self, document_id: str):
        indexing_cache_key = 'document_{}_is_paused'.format(document_id)
        result = redis_client.get(indexing_cache_key)
        if result:
            raise DocumentIsPausedException()

    def _update_document_index_status(self, document_id: str, after_indexing_status: str,
                                      extra_update_params: Optional[dict] = None) -> None:
        """
        Update the document indexing status.
        """
        count = DatasetDocument.query.filter_by(id=document_id, is_paused=True).count()
        if count > 0:
            raise DocumentIsPausedException()
        document = DatasetDocument.query.filter_by(id=document_id).first()
        if not document:
            raise DocumentIsDeletedPausedException()

        update_params = {
            DatasetDocument.indexing_status: after_indexing_status
        }

        if extra_update_params:
            update_params.update(extra_update_params)

        DatasetDocument.query.filter_by(id=document_id).update(update_params)
        db.session.commit()

    def _update_segments_by_document(self, dataset_document_id: str, update_params: dict) -> None:
        """
        Update the document segment by document id.
        """
        DocumentSegment.query.filter_by(document_id=dataset_document_id).update(update_params)
        db.session.commit()

    def batch_add_segments(self, segments: list[DocumentSegment], dataset: Dataset):
        """
        Batch add segments index processing
        """
        documents = []
        for segment in segments:
            document = Document(
                page_content=segment.content,
                metadata={
                    "doc_id": segment.index_node_id,
                    "doc_hash": segment.index_node_hash,
                    "document_id": segment.document_id,
                    "dataset_id": segment.dataset_id,
                }
            )
            documents.append(document)
        # save vector index
        index = IndexBuilder.get_index(dataset, 'high_quality')
        if index:
            index.add_texts(documents, duplicate_check=True)

        # save keyword index
        index = IndexBuilder.get_index(dataset, 'economy')
        if index:
            index.add_texts(documents)


class DocumentIsPausedException(Exception):
    pass


class DocumentIsDeletedPausedException(Exception):
    pass
