"""认证 API"""
import base64
import json
from fastapi import APIRouter, Depends, HTTPException
from pydantic import BaseModel
from sqlalchemy.orm import Session
from app.core.database import get_db
from app.core.casdoor import casdoor_sdk
from app.core.security import create_access_token
from app.core.config import settings
from app.models.user import User
from app.schemas.auth import Token, UserInfo
from datetime import datetime

router = APIRouter(prefix="/api/auth", tags=["认证"])


def decode_jwt_payload(token: str) -> dict:
    """直接解码 JWT payload，不验签（Casdoor 已完成认证）"""
    payload_b64 = token.split(".")[1]
    rem = len(payload_b64) % 4
    if rem:
        payload_b64 += "=" * (4 - rem)
    return json.loads(base64.urlsafe_b64decode(payload_b64))


@router.get("/login")
def login():
    """获取 Casdoor 登录 URL"""
    return {"url": casdoor_sdk.get_auth_link(settings.CASDOOR_REDIRECT_URL)}


class CallbackRequest(BaseModel):
    code: str
    state: str


@router.post("/callback", response_model=Token)
def callback(body: CallbackRequest, db: Session = Depends(get_db)):
    """Casdoor 登录回调"""
    try:
        token_response = casdoor_sdk.get_oauth_token(code=body.code)
        if isinstance(token_response, dict) and "error" in token_response:
            raise HTTPException(status_code=400, detail=token_response.get("error_description", token_response["error"]))

        access_token = token_response.get("access_token") if isinstance(token_response, dict) else token_response
        if not access_token:
            raise HTTPException(status_code=400, detail="Casdoor 未返回 access_token")

        casdoor_user = decode_jwt_payload(access_token)

        user = db.query(User).filter(User.casdoor_id == casdoor_user["sub"]).first()
        if not user:
            user = User(
                casdoor_id=casdoor_user["sub"],
                username=casdoor_user.get("name") or casdoor_user.get("preferred_username", ""),
                email=casdoor_user.get("email"),
                role="user"
            )
            db.add(user)

        user.last_login = datetime.utcnow()
        db.commit()

        jwt_token = create_access_token({"sub": str(user.id), "username": user.username})
        return {"access_token": jwt_token}
    except HTTPException:
        raise
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))


@router.get("/profile", response_model=UserInfo)
def get_profile(token: str, db: Session = Depends(get_db)):
    """获取当前用户信息"""
    from app.core.security import verify_token

    payload = verify_token(token)
    if not payload:
        raise HTTPException(status_code=401, detail="无效的令牌")

    user = db.query(User).filter(User.id == int(payload["sub"])).first()
    if not user:
        raise HTTPException(status_code=404, detail="用户不存在")

    return user