# Install auth dependencies
pip install python-jose[cryptography] passlib[bcrypt] python-multipart

# Generate secret key
openssl rand -hex 32

# app/core/security.py
from datetime import datetime, timedelta
from typing import Optional, Union, Any
from jose import JWTError, jwt
from passlib.context import CryptContext
from app.core.config import settings

# Password hashing
pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")

# JWT settings
SECRET_KEY = settings.SECRET_KEY
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30
REFRESH_TOKEN_EXPIRE_DAYS = 7

def create_access_token(
    subject: Union[str, Any], 
    expires_delta: Optional[timedelta] = None
) -> str:
    """Create JWT access token."""
    if expires_delta:
        expire = datetime.utcnow() + expires_delta
    else:
        expire = datetime.utcnow() + timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    
    to_encode = {"exp": expire, "sub": str(subject), "type": "access"}
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt

def create_refresh_token(subject: Union[str, Any]) -> str:
    """Create JWT refresh token."""
    expire = datetime.utcnow() + timedelta(days=REFRESH_TOKEN_EXPIRE_DAYS)
    to_encode = {"exp": expire, "sub": str(subject), "type": "refresh"}
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt

def verify_password(plain_password: str, hashed_password: str) -> bool:
    """Verify password against hash."""
    return pwd_context.verify(plain_password, hashed_password)

def get_password_hash(password: str) -> str:
    """Generate password hash."""
    return pwd_context.hash(password)

def decode_token(token: str) -> Optional[dict]:
    """Decode and verify JWT token."""
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        return payload
    except JWTError:
        return None

# app/api/dependencies/auth.py
from typing import Optional
from fastapi import Depends, HTTPException, status
from fastapi.security import OAuth2PasswordBearer, HTTPBearer, HTTPAuthorizationCredentials
from sqlalchemy.ext.asyncio import AsyncSession
from app.core.security import decode_token
from app.db.database import get_db
from app.models.user import User
from app.repositories.user import UserRepository

# OAuth2 scheme
oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="/api/v1/auth/login",
    scheme_name="JWT"
)

# Bearer token scheme
security = HTTPBearer()

async def get_current_user(
    token: str = Depends(oauth2_scheme),
    db: AsyncSession = Depends(get_db)
) -> User:
    """Get current authenticated user."""
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": "Bearer"},
    )
    
    payload = decode_token(token)
    if payload is None:
        raise credentials_exception
    
    user_id: str = payload.get("sub")
    token_type: str = payload.get("type")
    
    if user_id is None or token_type != "access":
        raise credentials_exception
    
    user_repo = UserRepository(User, db)
    user = await user_repo.get(int(user_id))
    
    if user is None:
        raise credentials_exception
    
    if not user.is_active:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Inactive user"
        )
    
    return user

async def get_current_active_user(
    current_user: User = Depends(get_current_user)
) -> User:
    """Get current active user."""
    if not current_user.is_active:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Inactive user"
        )
    return current_user

async def get_current_superuser(
    current_user: User = Depends(get_current_user)
) -> User:
    """Get current superuser."""
    if not current_user.is_superuser:
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="Not enough permissions"
        )
    return current_user

def require_permissions(*permissions: str):
    """Decorator for permission-based access control."""
    async def permission_checker(
        current_user: User = Depends(get_current_active_user)
    ) -> User:
        # Check if user has required permissions
        user_permissions = set(current_user.permissions or [])
        required_permissions = set(permissions)
        
        if not required_permissions.issubset(user_permissions) and not current_user.is_superuser:
            raise HTTPException(
                status_code=status.HTTP_403_FORBIDDEN,
                detail="Insufficient permissions"
            )
        
        return curr