from typing import Optional

from fastapi import Depends, Header, HTTPException, status
from fastapi.security import HTTPAuthorizationCredentials, HTTPBearer
from sqlalchemy.orm import Session

from app.database import SessionLocal
from app.models.user import User
from app.utils.jwt import get_user_from_token

# Define security scheme for JWT
security = HTTPBearer()


async def get_token_header(x_token: Optional[str] = Header(None)):
    """
    Dependency to validate token from header.
    Modify this according to your authentication requirements.
    """
    if x_token is None:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED, detail="X-Token header missing"
        )
    # Add your token validation logic here
    return x_token


def get_db():
    """Database session dependency"""
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()


async def get_current_user(
    credentials: HTTPAuthorizationCredentials = Depends(security),
    db: Session = Depends(get_db),
) -> User:
    """
    Dependency to get current user from JWT token.

    Args:
        credentials: HTTP Authorization credentials containing the JWT token
        db: Database session

    Returns:
        User object if authenticated

    Raises:
        HTTPException: If token is invalid or user not found
    """
    token = credentials.credentials

    # Get user ID from token
    user_id = get_user_from_token(token)
    if user_id is None:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Could not validate credentials",
            headers={"WWW-Authenticate": "Bearer"},
        )

    # Get user from database
    user = db.query(User).filter(User.id == user_id).first()
    if user is None:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="User not found",
            headers={"WWW-Authenticate": "Bearer"},
        )

    if user.is_active is False:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST, detail="Inactive user"
        )

    return user