"""阿里云 OSS 上传：往固定目录上传，返回下载地址"""

import asyncio
import base64
import os
from uuid import uuid4

import oss2

from app.config import settings
from app.core.logger import log

_auth = oss2.Auth(settings.oss_access_key_id, settings.oss_access_key_secret)
_bucket = oss2.Bucket(_auth, f"https://{settings.oss_endpoint}", settings.oss_bucket)


async def upload(data: bytes, file_name: str) -> str:
    """上传字节内容到固定目录，返回下载地址"""
    key = f"{settings.oss_upload_dir}/{uuid4().hex[:18]}{os.path.splitext(file_name)[1]}"
    await asyncio.to_thread(_bucket.put_object, key, data)
    url = f"{settings.oss_domain}/{key}"
    log.info("OSS 上传成功 [{}] -> {}", file_name, url)
    return url


async def upload_base64(b64: str, file_name: str = "image.png") -> str | None:
    """上传 base64 图片到固定目录，返回下载地址；空值或解码失败返回 None

    :param b64: base64 字符串，兼容 data URI 前缀（data:image/png;base64,xxx）
    :param file_name: 用于取后缀，默认 png
    """
    if not b64 or not b64.strip():
        return None
    # 去掉 data URI 前缀
    if "," in b64 and b64.strip().startswith("data:"):
        b64 = b64.split(",", 1)[1]
    try:
        data = base64.b64decode(b64)
    except Exception as e:
        log.warning("base64 解码失败: {}", e)
        return None
    return await upload(data, file_name)