from datetime import datetime, timezone, timedelta
from typing import Dict, Any, Optional

import jwt
from fastapi import Request

from core.settings import jwt_settings


class JwtUtil:
    """
    JWT工具类
    """

    @staticmethod
    def generate_token(user_id: int, username: str) -> str:
        payload = {
            "user_id": user_id,
            "username": username,
            "exp": datetime.now(timezone.utc)
            + timedelta(minutes=jwt_settings.expire_minutes),
        }
        return jwt.encode(
            payload, jwt_settings.secret_key, algorithm=jwt_settings.algorithm
        )

    @staticmethod
    def verify_token(token: str) -> Dict[str, Any]:
        return jwt.decode(
            token, jwt_settings.secret_key, algorithm=[jwt_settings.algorithm]
        )

    @staticmethod
    def get_token_from_request(request: Request) -> Optional[str]:
        # 从Authorization头中获取
        auth_header = request.headers.get("Authorization")
        if auth_header and auth_header.startswith("Bearer "):
            return auth_header.split(" ")[1]

        # 从查询参数中获取
        token = request.query_params.get("token")
        if token:
            return token

        return None

    @classmethod
    def get_current_user_from_token(cls, request: Request) -> Optional[Dict[str, Any]]:
        token = cls.get_token_from_request(request)
        if not token:
            return None

        try:
            return cls.verify_token(token)
        except (jwt.ExpiredSignatureError, jwt.InvalidTokenError):
            return None