from datetime import datetime, timedelta, timezone

from fastapi import Depends, HTTPException, status
from fastapi.security import OAuth2PasswordBearer
from jose import JWTError, jwt
from passlib.context import CryptContext
from sqlalchemy.orm import Session

from app.config import settings
from app.models.db import User, get_db

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


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


def verify_password(password: str, password_hash: str) -> bool:
    return pwd_context.verify(password, password_hash)


def create_access_token(subject: str) -> str:
    expire = datetime.now(timezone.utc) + timedelta(minutes=settings.jwt_expire_minutes)
    payload = {"sub": subject, "exp": expire}
    return jwt.encode(payload, settings.jwt_secret_key, algorithm=settings.jwt_algorithm)


def get_current_user(
    token: str = Depends(oauth2_scheme), db: Session = Depends(get_db)
) -> User:
    credentials_error = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Credenciales inválidas o expiradas",
        headers={"WWW-Authenticate": "Bearer"},
    )
    try:
        payload = jwt.decode(token, settings.jwt_secret_key, algorithms=[settings.jwt_algorithm])
        email = payload.get("sub")
        if email is None:
            raise credentials_error
    except JWTError:
        raise credentials_error

    user = db.query(User).filter(User.email == email).first()
    if user is None:
        raise credentials_error
    return user


def require_admin(user: User = Depends(get_current_user)) -> User:
    if not user.is_admin:
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Requiere rol admin")
    return user