from datetime import datetime
from fastapi import Depends, HTTPException, status
from fastapi.security import HTTPBearer, HTTPAuthorizationCredentials
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy.future import select
from src.database import get_session
from src.models import User, Session

security = HTTPBearer()

async def get_current_user(auth: HTTPAuthorizationCredentials = Depends(security), session: AsyncSession = Depends(get_session)) -> User:
    token = auth.credentials
    
    # Query Better Auth session table
    stmt = select(Session).where(Session.token == token)
    result = await session.execute(stmt)
    db_session = result.scalars().first()
    
    if not db_session:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Invalid session token",
            headers={"WWW-Authenticate": "Bearer"},
        )
    
    if db_session.expiresAt < datetime.utcnow():
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Session expired",
            headers={"WWW-Authenticate": "Bearer"},
        )
        
    user = await session.get(User, db_session.userId)
    if user is None:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="User not found",
            headers={"WWW-Authenticate": "Bearer"},
        )
    return user