// Copyright Inrupt Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal in
// the Software without restriction, including without limitation the rights to use,
// copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
// Software, and to permit persons to whom the Software is furnished to do so,
// subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
// PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
// SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//

import { Session } from "./Session";

let defaultSession: Session | undefined;

/**
 * Obtain the {@link Session} used when not explicitly instantiating one yourself.
 *
 * When using the top-level exports {@link fetch}, {@link login}, {@link logout},
 * {@link handleIncomingRedirect}, {@link onLogin} and {@link onLogout}, these apply to an
 * implicitly-instantiated {@link Session}.
 * This function returns a reference to that Session in order to obtain e.g. the current user's
 * WebID.
 * @since 1.3.0
 */
export function getDefaultSession(): Session {
  if (typeof defaultSession === "undefined") {
    defaultSession = new Session();
  }
  return defaultSession;
}

/**
 * This function's signature is equal to `window.fetch`, but if the current user is authenticated
 * (see [[login]] and [[handleIncomingRedirect]]), requests made using it will include that user's
 * credentials. If not, this will behave just like the regular `window.fetch`.
 *
 * @see {@link https://developer.mozilla.org/en-US/docs/Web/API/WindowOrWorkerGlobalScope/fetch}
 * @since 1.3.0
 */

export function fetch(
  ...args: Parameters<Session["fetch"]>
): ReturnType<Session["fetch"]> {
  const session = getDefaultSession();
  return session.fetch(...args);
}

/**
 * Triggers the login process. Note that this method will redirect the user away from your app.
 *
 * @param options Parameter to customize the login behaviour. In particular, two options are mandatory: `options.oidcIssuer`, the user's identity provider, and `options.redirectUrl`, the URL to which the user will be redirected after logging in their identity provider.
 * @returns This method should redirect the user away from the app: it does not return anything. The login process is completed by [[handleIncomingRedirect]].
 * @since 1.3.0
 */
export function login(
  ...args: Parameters<Session["login"]>
): ReturnType<Session["login"]> {
  const session = getDefaultSession();
  return session.login(...args);
}

/**
 * Logs the user out of the application.
 *
 * By default this does not log the user out of their Solid identity provider.
 * In order to do so, you must set the logoutType to `idp`. For usage details
 * see {@link Session.logout}.
 *
 * @since 1.3.0
 */
export function logout(
  ...args: Parameters<Session["logout"]>
): ReturnType<Session["logout"]> {
  const session = getDefaultSession();
  return session.logout(...args);
}

/**
 * Completes the login process by processing the information provided by the Solid identity provider through redirect.
 *
 * @param url The URL of the page handling the redirect, including the query parameters — these contain the information to process the login.
 * @since 1.3.0
 */
export function handleIncomingRedirect(
  ...args: Parameters<Session["handleIncomingRedirect"]>
): ReturnType<Session["handleIncomingRedirect"]> {
  const session = getDefaultSession();
  return session.handleIncomingRedirect(...args);
}

/**
 * {@link SessionEventEmitter} instance to subscribe to events by the default session.
 *
 * @since 1.14.0
 */
export function events(): Session["events"] {
  return getDefaultSession().events;
}