from pathlib import Path
from typing import Any

from fastapi import UploadFile
from app.config import get_settings
from app.core.logging import logger
from app.schemas.dataset import DatasetDownloadRequest, DatasetDownloadResponse

settings = get_settings()


async def download_dataset(req: DatasetDownloadRequest) -> DatasetDownloadResponse:
    """从 HuggingFace 或 ModelScope 下载数据集。"""
    import os
    import uuid

    download_dir = settings.processed_dir
    download_dir.mkdir(parents=True, exist_ok=True)

    if req.use_modelscope:
        try:
            from modelscope.msdatasets import MsDataset
            MsDataset.load(req.dataset_id, split="train")
            path = str(download_dir / f"ms_{req.dataset_id.replace('/', '_')}")
            logger.info(f"Downloaded dataset from ModelScope: {req.dataset_id}")
            return DatasetDownloadResponse(dataset_id=req.dataset_id, status="downloading", path=path)
        except Exception as e:
            logger.error(f"ModelScope dataset download failed: {e}")
            return DatasetDownloadResponse(dataset_id=req.dataset_id, status="failed", error=str(e))
    else:
        try:
            from datasets import load_dataset
            load_dataset(req.dataset_id)
            path = str(download_dir / f"hf_{req.dataset_id.replace('/', '_')}")
            logger.info(f"Downloaded dataset from HuggingFace: {req.dataset_id}")
            return DatasetDownloadResponse(dataset_id=req.dataset_id, status="downloading", path=path)
        except Exception as e:
            logger.error(f"HuggingFace dataset download failed: {e}")
            return DatasetDownloadResponse(dataset_id=req.dataset_id, status="failed", error=str(e))


async def upload_dataset(file: UploadFile) -> dict[str, Any]:
    """保存上传文件并检测格式。"""
    upload_dir = settings.uploads_dir
    upload_dir.mkdir(parents=True, exist_ok=True)

    file_path = upload_dir / file.filename
    content = await file.read()
    file_path.write_bytes(content)

    fmt = _detect_format(file.filename or "")
    logger.info(f"Uploaded dataset: {file_path} (format={fmt})")
    return {"path": str(file_path), "format": fmt, "size": len(content)}


def _detect_format(filename: str) -> str:
    ext = Path(filename).suffix.lower().lstrip(".")
    if ext in ("jsonl", "csv", "parquet", "json"):
        return ext
    return "unknown"