import { useState , State } from "thorium-states";
import { TStoreContext } from './store-context';
import { rootContext } from './root-context';

/** The code is using the `useState` hook from the `thorium-states` library to create a state variable
called `appContextState` and a setter function called `setAppContext`. The initial value of
`appContextState` is set to a new instance of a class `AppContext` that extends `StoreContext`. The
type of `appContextState` is specified as `TStoreContext`. */
const [ appContext , setAppContext ] = useState<TStoreContext>( rootContext().extends( 'application-context' ) );

/**
 * The appContextUpdate function alerts the user that the value has been updated.
 * @param value - The value parameter is the new value that will be used to update the app context.
 */
const appContextUpdate = ( value:TStoreContext ) => {
  alert('value update');
  return value;
};

/** The code `appContextState.subscribe( document.body , appContextUpdate );` is subscribing the
`appContextUpdate` function to changes in the `appContextState` state variable. Whenever the value
of `appContextState` changes, the `appContextUpdate` function will be called. The `document.body`
argument specifies the element to which the subscription is attached. */
appContext.subscribe( document.body , appContextUpdate );

/**
 * The above function returns the value of the appContextState.
 * @returns The appContextState.value is being returned.
 */
export const applicationContext = () => { return appContext };