from datetime import datetime, timedelta
from typing import Optional

from jose import jwt
from passlib.context import CryptContext
from pydantic import EmailStr
from sqlalchemy.orm import Session

from app.models.user import User

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

# JWT settings
SECRET_KEY = "your-secret-key-here"  # Should be stored securely in env variables
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


def verify_password(plain_password, hashed_password):
    """Verify a password against a hashed password."""
    return pwd_context.verify(plain_password, hashed_password)


def get_password_hash(password):
    """Hash a password."""
    return pwd_context.hash(password)


def create_access_token(data: dict, expires_delta: Optional[timedelta] = None):
    """Create a JWT access token."""
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.utcnow() + expires_delta
    else:
        expire = datetime.utcnow() + timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


def get_user(db: Session, user_id: int):
    """Get a user by ID."""
    return db.query(User).filter(User.id == user_id).first()


def get_user_by_email(db: Session, email: EmailStr):
    """Get a user by email."""
    return db.query(User).filter(User.email == email).first()


def get_user_by_username(db: Session, username: str):
    """Get a user by username."""
    return db.query(User).filter(User.username == username).first()


def create_user(db: Session, email: EmailStr, username: str, password: str):
    """Create a new user."""
    hashed_password = get_password_hash(password)
    db_user = User(email=email, username=username, hashed_password=hashed_password)
    db.add(db_user)
    db.commit()
    db.refresh(db_user)
    return db_user