from datetime import datetime, timedelta
from jose import JWTError, jwt
from passlib.context import CryptContext
from fastapi import Depends, HTTPException, status
from fastapi.security import OAuth2PasswordBearer
from sqlalchemy.orm import Session
from app.database import get_db
from app.models.models import User

SECRET_KEY = "your-secret-key-change-in-production-make-it-very-long-and-secure"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 1440  # 24 часа

pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")
oauth2_scheme = OAuth2PasswordBearer(tokenUrl="api/auth/login")

def verify_password(plain_password, hashed_password):
    return pwd_context.verify(plain_password, hashed_password)

def get_password_hash(password):
    return pwd_context.hash(password)

def create_access_token(data: dict):
    to_encode = data.copy()
    expire = datetime.utcnow() + timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    to_encode.update({"exp": expire})
    return jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)

def get_current_user(token: str = Depends(oauth2_scheme), db: Session = Depends(get_db)):
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": "Bearer"},
    )
    
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username: str = payload.get("sub")
        if username is None:
            raise credentials_exception
    except JWTError as e:
        print(f"JWT Error: {e}")
        raise credentials_exception
    
    user = db.query(User).filter(User.username == username).first()
    if user is None:
        raise credentials_exception
    
    if user.is_banned:
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="Ваш аккаунт заблокирован"
        )
    
    return user