import requests
from fastapi import UploadFile
from app.core.biz_exception import NotFoundError, PermissionDeniedError, BizLogicError
from app.core.logger import logger


class SeaweedFSService:
    MASTER_URL = "http://127.0.0.1:9333"  # 你的 SeaweedFS master 地址

    @classmethod
    def upload(cls, file: UploadFile):
        """上传文件到 SeaweedFS"""
        try:
            # 1️⃣ 获取可上传的 volume 地址
            assign_resp = requests.get(f"{cls.MASTER_URL}/dir/assign", timeout=5)
            assign_data = assign_resp.json()
            fid = assign_data["fid"]
            public_url = assign_data["publicUrl"]

            # 2️⃣ 上传文件数据
            upload_url = f"http://{public_url}/{fid}"
            
            download_url = f"http://45.137.220.138:8888/api/resource/download_file?fid={fid}"
            files = {"file": (file.filename, file.file, file.content_type)}
            upload_resp = requests.post(upload_url, files=files, timeout=10)

            if upload_resp.status_code == 201:
                return {"fid": fid, "url": download_url}
            else:
                raise BizLogicError(f"file upload error: {upload_resp.text}")
        except Exception as e:
            raise BizLogicError(f"file upload exception: {e}")

    @classmethod
    def get(cls, fid: str):
        """根据 fid 读取文件"""
        try:
            resp = requests.get(f"{cls.MASTER_URL}/dir/lookup?volumeId={fid.split(',')[0]}", timeout=5)
            data = resp.json()
            if not data.get("locations"):
                return None

            public_url = data["locations"][0]["publicUrl"]
            file_url = f"http://{public_url}/{fid}"

            file_resp = requests.get(file_url, timeout=10)
            if file_resp.status_code == 200:
                return file_resp.content, file_resp.headers.get("Content-Type", "application/octet-stream")
            else:
                return None
        except Exception as e:
            logger.exception(f"SeaweedFS 读取异常, 原因={e}")
            return None

    @classmethod
    def delete(cls, fid: str):
        """删除文件"""
        try:
            resp = requests.get(f"{cls.MASTER_URL}/dir/lookup?volumeId={fid.split(',')[0]}", timeout=5)
            data = resp.json()
            if not data.get("locations"):
                return False

            public_url = data["locations"][0]["publicUrl"]
            delete_url = f"http://{public_url}/{fid}"

            del_resp = requests.delete(delete_url, timeout=10)
            return del_resp.status_code == 202
        except Exception as e:
            logger.exception(f"SeaweedFS 删除异常, 原因={e}")
            return False