"""图片/文件存储抽象：本地文件系统（开发兜底）+ 七牛（生产）。"""
from __future__ import annotations

import mimetypes
import uuid
from pathlib import Path

import httpx

from config import get_settings

# 本地存储根目录（仓库根 data/media/）
_LOCAL_ROOT = Path(__file__).resolve().parents[2] / "data" / "media"


def _ext_from_url(url: str) -> str:
    ext = mimetypes.guess_extension(url.split("?")[0].lower()) or ".jpg"
    if ext == ".jpe":
        ext = ".jpg"
    return ext


def _ext_from_content_type(content_type: str) -> str:
    ctype = (content_type or "").split(";")[0].strip().lower()
    mapping = {
        "image/jpeg": ".jpg",
        "image/png": ".png",
        "image/webp": ".webp",
        "image/gif": ".gif",
        "image/bmp": ".bmp",
        "image/heic": ".heic",
        "video/mp4": ".mp4",
    }
    return mapping.get(ctype, ".jpg")


async def download_bytes(url: str, referer: str | None = None, timeout: float = 60.0) -> tuple[bytes, str]:
    """下载远程字节。返回 (bytes, content_type)。"""
    headers = {"Referer": referer} if referer else {}
    async with httpx.AsyncClient(timeout=timeout, follow_redirects=True) as client:
        resp = await client.get(url, headers=headers)
        resp.raise_for_status()
        ctype = (resp.headers.get("content-type") or "application/octet-stream").split(";")[0].strip()
        return resp.content, ctype


class LocalStorage:
    """开发期：落 data/media/，由 FastAPI /media 静态托管，返回 app_base_url 可访问 URL。"""

    async def save_from_url(self, url: str, key_prefix: str = "", referer: str | None = None) -> str:
        data, _ = await download_bytes(url, referer)
        key = self._write(data, key_prefix, url)
        return self.public_url(key)

    async def save_bytes(self, data: bytes, key: str, content_type: str = "") -> str:
        key = self._write(data, "", key)
        return self.public_url(key)

    def _write(self, data: bytes, key_prefix: str, hint: str) -> str:
        _LOCAL_ROOT.mkdir(parents=True, exist_ok=True)
        ext = _ext_from_url(hint) if hint and not hint.startswith("data:") else ".jpg"
        key = f"{key_prefix + '/' if key_prefix else ''}{uuid.uuid4().hex}{ext}"
        (_LOCAL_ROOT / key).parent.mkdir(parents=True, exist_ok=True)
        (_LOCAL_ROOT / key).write_bytes(data)
        return key

    def public_url(self, key: str) -> str:
        settings = get_settings()
        return f"{settings.app_base_url.rstrip('/')}/media/{key}"


class QiniuStorage:
    """生产：上传七牛，返回绑定域名公网 URL（Ozon 可拉取）。"""

    def _client(self):
        import qiniu

        settings = get_settings()
        return qiniu.Auth(settings.qiniu_access_key, settings.qiniu_secret_key), settings

    async def save_from_url(self, url: str, key_prefix: str = "", referer: str | None = None) -> str:
        data, ctype = await download_bytes(url, referer)
        return await self.save_bytes(data, f"{key_prefix}/{uuid.uuid4().hex}{_ext_from_content_type(ctype)}", ctype)

    async def save_bytes(self, data: bytes, key: str, content_type: str = "") -> str:
        import qiniu

        auth, settings = self._client()
        bucket = settings.qiniu_bucket
        token = auth.upload_token(bucket, key, 3600)
        ret, info = qiniu.put_data(token, key, data)
        if info.status_code not in (200,):
            raise RuntimeError(f"七牛上传失败：{info.error or info.text_body or info.status_code}")
        return self.public_url(key)

    def public_url(self, key: str) -> str:
        settings = get_settings()
        return f"{settings.qiniu_domain.rstrip('/')}/{key}"


def get_storage():
    settings = get_settings()
    if settings.use_qiniu:
        return QiniuStorage()
    return LocalStorage()