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

from jose import jwt, JWTError
from fastapi import Depends, HTTPException, status, Request
from fastapi.security import HTTPBearer, HTTPAuthorizationCredentials
from sqlalchemy.orm import Session

from app.config import get_settings
from app.database import get_db

settings = get_settings()
security = HTTPBearer(auto_error=False)


def create_access_token(
    data: dict,
    expires_delta: Optional[timedelta] = None,
) -> str:
    to_encode = data.copy()
    expire = datetime.utcnow() + (expires_delta or timedelta(minutes=settings.JWT_ACCESS_TOKEN_EXPIRE_MINUTES))
    to_encode.update({"exp": expire})
    return jwt.encode(to_encode, settings.JWT_SECRET_KEY, algorithm=settings.JWT_ALGORITHM)


def decode_access_token(token: str) -> dict:
    try:
        payload = jwt.decode(token, settings.JWT_SECRET_KEY, algorithms=[settings.JWT_ALGORITHM])
        return payload
    except JWTError:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="无效的认证凭证",
        )


async def get_current_user(request: Request) -> dict:
    credentials: Optional[HTTPAuthorizationCredentials] = await security(request)
    if not credentials:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="未提供认证凭证",
        )
    token = credentials.credentials
    payload = decode_access_token(token)
    return payload


async def get_optional_user(request: Request) -> Optional[dict]:
    try:
        return await get_current_user(request)
    except HTTPException:
        return None