"""
OAuth2 统一认证平台 SSO 路由
"""
import logging
import uuid
import os
from typing import Optional

import httpx
from fastapi import APIRouter, Depends, HTTPException
from pydantic import BaseModel
from sqlalchemy.orm import Session

from app.database import get_db
from app.models.user import User
from app.services.auth_service import AuthService
from app.services.user_service import UserService
from app.schemas.user_schema import UserCreate
from app.services import local_config_service

logger = logging.getLogger(__name__)

router = APIRouter(tags=["OAuth2 SSO"])

SSO_BASE_URL = os.getenv("SSO_BASE_URL", "http://192.168.92.61:8200")
SSO_CLIENT_ID = os.getenv("SSO_CLIENT_ID", "")
SSO_CLIENT_SECRET = os.getenv("SSO_CLIENT_SECRET", "")
SSO_REDIRECT_URI = os.getenv("SSO_REDIRECT_URI", "http://localhost:3000/#/auth/callback")
SSO_SCOPE = os.getenv("SSO_SCOPE", "profile email")
SSO_LOGOUT_REDIRECT_URL = os.getenv("SSO_LOGOUT_REDIRECT_URL", "http://192.168.92.61:9200/login")


def _get_sso_config() -> dict:
    try:
        data = local_config_service.get_all()
        sso = data.get("sso", {})
    except Exception:
        sso = {}
    # sso_enable_redirect 控制是否启用SSO重定向
    enabled = sso.get("sso_enable_redirect")
    if enabled is None:
        enabled = True  # 默认启用SSO
    return {
        "base_url": (sso.get("sso_base_url") or SSO_BASE_URL).rstrip("/"),
        "client_id": sso.get("sso_client_id") or SSO_CLIENT_ID,
        "client_secret": sso.get("sso_client_secret") or SSO_CLIENT_SECRET,
        "redirect_uri": sso.get("sso_redirect_uri") or SSO_REDIRECT_URI,
        "scope": sso.get("sso_scope") or SSO_SCOPE,
        "logout_redirect_url": sso.get("sso_logout_redirect_url") or SSO_LOGOUT_REDIRECT_URL,
        "enabled": bool(enabled),
    }


class ExchangeCodeRequest(BaseModel):
    code: str


@router.get("/api/sso/config")
def get_sso_public_config():
    """Return SSO config for frontend."""
    cfg = _get_sso_config()
    authorize_url = (
        f"{cfg['base_url']}/oauth/authorize"
        f"?response_type=code"
        f"&client_id={cfg['client_id']}"
        f"&redirect_uri={cfg['redirect_uri']}"
        f"&scope={cfg['scope']}"
    )
    return {
        "sso_enabled": cfg["enabled"] and bool(cfg["client_id"]),
        "authorize_url": authorize_url,
        "logout_redirect_url": cfg["logout_redirect_url"],
    }


@router.post("/api/oauth/exchange-code")
async def exchange_code(request: ExchangeCodeRequest, db: Session = Depends(get_db)):
    """
    OAuth2 authorization code exchange endpoint.
    Frontend calls this with the code from SSO callback to get a local JWT.
    """
    cfg = _get_sso_config()

    if not cfg["client_id"] or not cfg["client_secret"]:
        raise HTTPException(status_code=500, detail="SSO not configured")

    async with httpx.AsyncClient(timeout=15) as client:
        # Exchange code for access_token
        token_url = f"{cfg['base_url']}/oauth/token"
        token_data = {
            "grant_type": "authorization_code",
            "code": request.code,
            "redirect_uri": cfg["redirect_uri"],
            "client_id": cfg["client_id"],
            "client_secret": cfg["client_secret"],
        }

        try:
            token_resp = await client.post(
                token_url,
                data=token_data,
                headers={"Content-Type": "application/x-www-form-urlencoded"}
            )
        except httpx.RequestError as e:
            logger.error("SSO token exchange failed: %s", e)
            raise HTTPException(status_code=502, detail="Cannot connect to SSO server")

        if token_resp.status_code != 200:
            error_data = {}
            try:
                error_data = token_resp.json()
            except Exception:
                pass
            error_msg = error_data.get("error_description") or error_data.get("error") or "Invalid code"
            raise HTTPException(status_code=401, detail=f"SSO login failed: {error_msg}")

        token_result = token_resp.json()
        access_token = token_result.get("access_token")
        if not access_token:
            raise HTTPException(status_code=502, detail="SSO did not return access_token")

        # Get user info
        userinfo_url = f"{cfg['base_url']}/oauth/userinfo"
        try:
            userinfo_resp = await client.get(
                userinfo_url,
                headers={"Authorization": f"Bearer {access_token}"}
            )
        except httpx.RequestError as e:
            logger.error("SSO userinfo failed: %s", e)
            raise HTTPException(status_code=502, detail="Failed to get user info")

        if userinfo_resp.status_code != 200:
            raise HTTPException(status_code=502, detail="Failed to get user info")

        userinfo = userinfo_resp.json()

    # Sync user to local database
    username = userinfo.get("username") or userinfo.get("sub") or ""
    if not username:
        raise HTTPException(status_code=400, detail="SSO did not return username")

    user = db.query(User).filter(User.username == username).first()

    if not user:
        email = userinfo.get("email") or None
        nickname = userinfo.get("real_name") or userinfo.get("username") or username
        random_password = uuid.uuid4().hex[:16]

        user_service = UserService(db)
        user_payload = {"username": username, "password": random_password, "nickname": nickname}
        if email:
            user_payload["email"] = email

        user_create = UserCreate(**user_payload)
        user = user_service.create_user(user_create)
        logger.info("SSO created new user: %s (id=%s)", username, user.id)
    else:
        updated = False
        if userinfo.get("email") and user.email != userinfo["email"]:
            user.email = userinfo["email"]
            updated = True
        if userinfo.get("real_name") and user.nickname != userinfo["real_name"]:
            user.nickname = userinfo["real_name"]
            updated = True
        if updated:
            db.commit()

    # Issue local JWT
    local_token = AuthService.create_access_token(user.id)

    return {
        "code": 200,
        "message": "success",
        "data": {
            "token": local_token,
            "user": {
                "id": user.id,
                "username": user.username,
                "nickname": user.nickname,
                "email": user.email,
                "phone": user.phone,
                "avatar": user.avatar,
            }
        }
    }