import logging
import os

from fastapi import APIRouter, Depends, File, HTTPException, UploadFile

from .. import db, oss_store
from ..user import user_payload
from .auth import get_current_user

logger = logging.getLogger(__name__)

router = APIRouter(prefix="/api/v1/profile", tags=["profile"])

MAX_AVATAR_SIZE = 4 * 1024 * 1024
ALLOWED_AVATAR_EXT = {".png", ".jpg", ".jpeg", ".webp"}

LEGACY_AVATAR_PREFIX = "/clock/static/"


def avatar_key(path):
    """头像路径 -> OSS 对象 key。

    兼容两种格式，因为老数据还在用旧的那种：
    - `avatars/{uid}/avatar.jpg`               新格式（2026-09-22 起），等于对象 key
    - `/clock/static/avatars/{uid}/avatar.jpg` 旧格式，原本是 nginx 静态路径

    ⚠️ 旧格式**不能删**：库里仍有这种值，而它对应的文件现在也在 OSS 上，
    对象 key 就是剥掉 `/clock/static/` 之后的那串 —— 剥离这一步是它唯一的读法。
    两种格式指向同一个对象。不是头像路径则返回空串。
    """
    text = (path or "").strip()
    if text.startswith(LEGACY_AVATAR_PREFIX):
        text = text[len(LEGACY_AVATAR_PREFIX):]
    text = text.lstrip("/")
    if not text.startswith("avatars/") or ".." in text:
        return ""
    return text


def avatar_url(path):
    """头像规范路径 -> 可直接喂给 `<image>` 的签名地址（OSS 未启用时为空串）。"""
    text = (path or "").strip()
    if not text:
        return ""
    if text.startswith(("http://", "https://")):
        return text
    key = avatar_key(text)
    if not key or not oss_store.is_enabled():
        return ""
    return oss_store.signed_url(key)


def _profile(user):
    payload = user_payload(user)
    return {
        "name": payload["name"],
        "student_id": payload["student_id"],
        "display_name": payload["display_name"],
        "phone": user.get("phone_display", "") or "",
        "group": payload["group"],
        "role": payload["role"],
        "class_groups": payload["class_groups"],
        # wechat_avatar 保持规范路径不变（会写回库），avatar_url 是展示专用的签名地址
        "wechat_avatar": user.get("wechat_avatar", ""),
        "avatar_url": avatar_url(user.get("wechat_avatar", "")),
        "login_type": user.get("login_type", ""),
    }


@router.get("")
def get_profile(user=Depends(get_current_user)):
    return {"success": True, **_profile(user)}


@router.post("/avatar")
def upload_avatar(file: UploadFile = File(...), user=Depends(get_current_user)):
    data = file.file.read()
    if len(data) > MAX_AVATAR_SIZE:
        raise HTTPException(status_code=400, detail="头像不能超过4MB")

    safe_name = os.path.basename(file.filename or "")
    ext = os.path.splitext(safe_name)[1].lower()
    if ext not in ALLOWED_AVATAR_EXT:
        raise HTTPException(status_code=400, detail="不支持的文件类型")

    uid = str(user["id"])
    filename = "avatar" + ext
    # 新格式：直接就是 OSS 对象 key，去掉 /clock/static 这层 nginx 前缀
    url_path = "avatars/" + uid + "/" + filename

    if not oss_store.is_enabled():
        # OSS 是现在唯一的头像存储，没有磁盘兜底了。
        # 未配置就明确报错，而不是悄悄写本地 —— 本地文件取不到，写了等于丢。
        raise HTTPException(status_code=503, detail="对象存储未配置，无法上传头像")

    try:
        oss_store.put_bytes(url_path, data, content_type=oss_store.guess_content_type(filename))
    except Exception:
        # 写失败就明确报错让用户重试，**不落磁盘**：磁盘上的文件已经没有任何读路径
        # 能取到（前端取头像走的是 OSS 签名 URL），落盘只是留下一份永远没人读的副本。
        logger.exception("头像上传到 OSS 失败: %s", url_path)
        raise HTTPException(status_code=500, detail="头像保存失败，请重试")

    # 换扩展名时清掉同目录下其它扩展名的旧头像，否则 avatar.jpg / avatar.png 会并存
    for other in ALLOWED_AVATAR_EXT:
        other_name = "avatar" + other
        if other_name != filename:
            try:
                oss_store.delete("avatars/" + uid + "/" + other_name)
            except Exception:
                logger.debug("清理旧头像对象失败: %s", other_name, exc_info=True)

    db.execute("UPDATE auth_users SET wechat_avatar=%s WHERE id=%s", (url_path, user["id"]))
    return {"success": True, "wechat_avatar": url_path, "avatar_url": avatar_url(url_path)}