import logging
import tempfile
import time
import uuid
from pathlib import Path

import click
import pandas as pd
from celery import shared_task
from sqlalchemy import func

from core.db.session_factory import session_factory
from core.model_manager import ModelManager
from dify_graph.model_runtime.entities.model_entities import ModelType
from extensions.ext_redis import redis_client
from extensions.ext_storage import storage
from libs import helper
from libs.datetime_utils import naive_utc_now
from models.dataset import Dataset, Document, DocumentSegment
from models.model import UploadFile
from services.vector_service import VectorService

logger = logging.getLogger(__name__)


@shared_task(queue="dataset")
def batch_create_segment_to_index_task(
    job_id: str,
    upload_file_id: str,
    dataset_id: str,
    document_id: str,
    tenant_id: str,
    user_id: str,
):
    """
    Async batch create segment to index
    :param job_id:
    :param upload_file_id:
    :param dataset_id:
    :param document_id:
    :param tenant_id:
    :param user_id:

    Usage: batch_create_segment_to_index_task.delay(job_id, upload_file_id, dataset_id, document_id, tenant_id, user_id)
    """
    logger.info(click.style(f"Start batch create segment jobId: {job_id}", fg="green"))
    start_at = time.perf_counter()

    indexing_cache_key = f"segment_batch_import_{job_id}"

    # Initialize variables with default values
    upload_file_key: str | None = None
    dataset_config: dict | None = None
    document_config: dict | None = None

    with session_factory.create_session() as session:
        try:
            dataset = session.get(Dataset, dataset_id)
            if not dataset:
                raise ValueError("Dataset not exist.")

            dataset_document = session.get(Document, document_id)
            if not dataset_document:
                raise ValueError("Document not exist.")

            if (
                not dataset_document.enabled
                or dataset_document.archived
                or dataset_document.indexing_status != "completed"
            ):
                raise ValueError("Document is not available.")

            upload_file = session.get(UploadFile, upload_file_id)
            if not upload_file:
                raise ValueError("UploadFile not found.")

            dataset_config = {
                "id": dataset.id,
                "indexing_technique": dataset.indexing_technique,
                "tenant_id": dataset.tenant_id,
                "embedding_model_provider": dataset.embedding_model_provider,
                "embedding_model": dataset.embedding_model,
            }

            document_config = {
                "id": dataset_document.id,
                "doc_form": dataset_document.doc_form,
                "word_count": dataset_document.word_count or 0,
            }

            upload_file_key = upload_file.key

        except Exception:
            logger.exception("Segments batch created index failed")
            redis_client.setex(indexing_cache_key, 600, "error")
            return

    # Ensure required variables are set before proceeding
    if upload_file_key is None or dataset_config is None or document_config is None:
        logger.error("Required configuration not set due to session error")
        redis_client.setex(indexing_cache_key, 600, "error")
        return

    with tempfile.TemporaryDirectory() as temp_dir:
        suffix = Path(upload_file_key).suffix
        file_path = f"{temp_dir}/{next(tempfile._get_candidate_names())}{suffix}"  # type: ignore
        storage.download(upload_file_key, file_path)

        df = pd.read_csv(file_path)
        content = []
        for _, row in df.iterrows():
            if document_config["doc_form"] == "qa_model":
                data = {"content": row.iloc[0], "answer": row.iloc[1]}
            else:
                data = {"content": row.iloc[0]}
            content.append(data)
        if len(content) == 0:
            raise ValueError("The CSV file is empty.")

    document_segments = []
    embedding_model = None
    if dataset_config["indexing_technique"] == "high_quality":
        model_manager = ModelManager()
        embedding_model = model_manager.get_model_instance(
            tenant_id=dataset_config["tenant_id"],
            provider=dataset_config["embedding_model_provider"],
            model_type=ModelType.TEXT_EMBEDDING,
            model=dataset_config["embedding_model"],
        )

    word_count_change = 0
    if embedding_model:
        tokens_list = embedding_model.get_text_embedding_num_tokens(texts=[segment["content"] for segment in content])
    else:
        tokens_list = [0] * len(content)

    with session_factory.create_session() as session, session.begin():
        for segment, tokens in zip(content, tokens_list):
            content = segment["content"]
            doc_id = str(uuid.uuid4())
            segment_hash = helper.generate_text_hash(content)
            max_position = (
                session.query(func.max(DocumentSegment.position))
                .where(DocumentSegment.document_id == document_config["id"])
                .scalar()
            )
            segment_document = DocumentSegment(
                tenant_id=tenant_id,
                dataset_id=dataset_id,
                document_id=document_id,
                index_node_id=doc_id,
                index_node_hash=segment_hash,
                position=max_position + 1 if max_position else 1,
                content=content,
                word_count=len(content),
                tokens=tokens,
                created_by=user_id,
                indexing_at=naive_utc_now(),
                status="completed",
                completed_at=naive_utc_now(),
            )
            if document_config["doc_form"] == "qa_model":
                segment_document.answer = segment["answer"]
                segment_document.word_count += len(segment["answer"])
            word_count_change += segment_document.word_count
            session.add(segment_document)
            document_segments.append(segment_document)

    with session_factory.create_session() as session, session.begin():
        dataset_document = session.get(Document, document_id)
        if dataset_document:
            assert dataset_document.word_count is not None
            dataset_document.word_count += word_count_change
            session.add(dataset_document)

    with session_factory.create_session() as session:
        dataset = session.get(Dataset, dataset_id)
        if dataset:
            VectorService.create_segments_vector(None, document_segments, dataset, document_config["doc_form"])

    redis_client.setex(indexing_cache_key, 600, "completed")
    end_at = time.perf_counter()
    logger.info(
        click.style(
            f"Segment batch created job: {job_id} latency: {end_at - start_at}",
            fg="green",
        )
    )
