from datetime import datetime, timedelta
from typing import Optional
from passlib.context import CryptContext
from jose import JWTError, jwt
from app.config import settings
from app.models import User
from sqlalchemy.orm import Session

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


def verify_password(plain_password: str, hashed_password: str) -> bool:
    return pwd_context.verify(plain_password, hashed_password)


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


def create_access_token(data: dict, expires_delta: Optional[timedelta] = None) -> str:
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.utcnow() + expires_delta
    else:
        expire = datetime.utcnow() + timedelta(
            minutes=settings.access_token_expire_minutes
        )
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(
        to_encode, settings.jwt_secret_key, algorithm=settings.jwt_algorithm
    )
    return encoded_jwt


def verify_token(token: str) -> Optional[int]:
    try:
        payload = jwt.decode(
            token, settings.jwt_secret_key, algorithms=[settings.jwt_algorithm]
        )
        user_id: int = payload.get("sub")
        if user_id is None:
            return None
        return user_id
    except JWTError:
        return None


def authenticate_user(db: Session, email: str, password: str) -> Optional[User]:
    user = db.query(User).filter(User.email == email).first()
    if not user or not verify_password(password, user.hashed_password):
        return None
    return user