export interface Options {
  /**
   * URL to the OIDC server.
   * This URL is used to locate the OIDC discovery document (typically found
   * at /.well-known/openid-configuration), which specifies the provider's
   * OAuth endpoints and public keys.
   */
  url: string;
  /**
   * Name of the realm (applies only to keycloak servers)
   */
  realm?: string;
  /**
   * Client identifier example: 'my-app'
   */
  clientId: string;
  /**
   * Client Secret (for servers which require basic-auth)
   * token_endpoint_auth_methods_supported: ['client_secret_basic']
   */
  clientSecret?: string;
  /**
   * Send Client Secret in POST body. 
   * token_endpoint_auth_methods_supported: ['client_secret_post']
   */
  clientSecretPost?: boolean;
  /**
   * Specifies a default uri to redirect to after login or logout.
   */
  redirectUri?: Url;
  /**
   * Specifies a default uri to redirect to after logout.
   * if not specified than value from `redirectUri` is used.
   */
  postLogoutRedirectUri?: Url;
  /**
   * Replaces the settings which are usually loaded from
   * `.well-known/openid-configuration`.
   * Needs to follow the conventions defined in the standard.
   * https://openid.net/specs/openid-connect-discovery-1_0.html#ProviderMetadata
   * If type is string than configuration is loaded from this url.
   */
  oidcConfig?: OidcConfig | string;
  /**
   * calls login on client initialization if no valid tokens are present
   * @default false
   */
  forceLogin?: boolean;
  /**
   * calls logout if event 'logout' was emitted.
   * @default true
   */
  forceLogout?: boolean;
  /**
   * OpenID Connect scopes.
   * Scope `openid` is always added per default.
   */
  scope?: string|string[];
  /**
   * Adds a [cryptographic nonce](https://en.wikipedia.org/wiki/Cryptographic_nonce)
   * to verify that the authentication response matches the request.
   * @default true
   */
  useNonce?: boolean;
  /**
   * storage used to store received tokens.
   * @default 'session'
   */
  storage?: 'session'|'local'|'cookie'|'memory'|'none';
  /**
   * minimum validity of an access_token before expiry.
   * If expiry is less than minValidity new access_token is requested using a
   * refresh_token.
   * @default 15
   */
  minValidity?: number;
  /**
   * timer interval (in seconds) to check if token needs update
   * @default 5
   */
  expiryInterval?: number;
  /**
   * Set the OpenID Connect response mode upon login.
   * @default fragment After successful authentication the OIDC server will
   *                   redirect to JavaScript application with OpenID Connect
   *                   parameters added in URL fragment. This is generally safer
   *                   and recommended over 'query'.
   */
  responseMode?: ResponseMode;
  /**
   * Set the OpenID Connect response type upon login
   * @default code
   */
  responseType?: ResponseType;
  /**
   * Set the OpenID Connect flow.
   * @default standard
   */
  flow?: 'standard'|'implicit'|'hybrid';
  /**
   * Configures the Proof Key for Code Exchange (PKCE) method to use.
   * The currently allowed method is 'S256'.
   * If not configured, PKCE will not be used.
   */
  pkceMethod?: PkceMethod;
  /**
   * external function which implements the PKCE challenge.
   * If not configured, PKCE will not be used.
   */
  pkce?: (pkceMethod: PkceMethod) => { codeVerifier: string, challenge: string };
  /**
   * Set to enable/disable session monitoring login state.
   * @default true
   */
  useStatusIframe?: boolean;
  /**
   * Set the interval to check login state (in seconds).
   * @default 5
   */
  statusIframeInterval?: number;
  /**
   * define a custom adapter e.g. for use with cordova
   * @default as defined in adapters/default.js
   */
  adapter?: Adapter;
  /**
   * Set an initial value for the token.
   */
  token?: string;
  /**
   * Set an initial value for the refresh token.
   */
  refreshToken?: string;
  /**
   * Set an initial value for the id token
   */
  idToken?: string;
  /**
   * Specifies an uri to redirect to after silent login was triggered.
   * Silent login will only happen, when this redirect uri is given and the
   * specified uri is available within the application.
   * The url must deliver a page with the following content.
   * ```
   * <html><body><script>
   *   parent.postMessage(location.href, location.origin);
   * </script></body></html>
   * ```
   */
  silentLoginRedirectUri?: string;
  /**
   * Seconds to wait for the silent login redirect iframe to load
   * @default 5
   */
  silentLoginWait?: number;
  /**
   * log output using `log.info` and `log.error`
   * example: {log: console, ...}
   */
  log?: Logger;
  /**
   * By default the login screen is displayed if the user is not logged in.
   * To only authenticate to the application if the user is already
   * logged in and not display the login page if the user is not logged in, set
   * this option to `'none'`. To always require re-authentication and ignore
   * SSO, set this option to `'login'`.
   */
  prompt?: 'none'|'login';
  /**
   * Used just if user is already authenticated. Specifies maximum time since
   * the authentication of user happened. If user is already authenticated for
   * longer time than `'maxAge'`, the SSO is ignored and he will need to
   * authenticate again.
   */
  maxAge?: number;
  /**
   * Used to pre-fill the username/email field on the login form.
   */
  loginHint?: string;
  /**
   * Used to tell then OIDC server which Identity Provider (IDP) the user wants
   * to authenticate with. Needs to be supported by OIDC server
   */
  idpHint?: string;
  /**
   * Sets the 'ui_locales' query param in compliance with section 3.1.2.1
   * of the OIDC 1.0 specification.
   */
  locale?: string;
  /**
   * additional authorization paramaters added on authorization request
   */
  authorizationParams?: object;
  /**
   * registration endpoint for users
   */
  userRegistrationEndpoint?: Url;
  /**
   * account endpoint for users
   */
  userAccountEndpoint?: Url;
}

/**
 * Standard data is taken from `.well-known/oidc-configuration` endpoint
 * non-standard settings can be named here.
 * @see https://openid.net/specs/openid-connect-discovery-1_0.html#ProviderMetadata
 */
export interface OidcConfig {
  /** issuer url shall be the same as `url` */
  issuer?: Url;
  /** certificates endpoint */
  jwks_uri?: Url;
  /** authorization endpoint */
  authorization_endpoint?: Url;
  /** token endpoint */
  token_endpoint?: Url;
  /** userinfo endpoint */
  userinfo_endpoint?: Url;
  /** logout endpoint */
  end_session_endpoint?: Url;
  /** session management endpoint */
  check_session_iframe?: Url;
}

/**
 * logger with log levels. Uses '%s' microformat options
 * Either use with `console` or [debug](https://www.npmjs.com/package/debug)
 */
export interface Logger {
  /** logs info messages */
  info?: (...args: any) => void;
  /** logs error messages */
  error?: (...args: any) => void;
}

export interface Tokens {
  /**
   * raw access token
   */
  token?: string;
  /**
   * payload of access token (only if JWT)
   */
  tokenParsed?: object;
  /**
   * raw id token
   */
  idToken?: string;
  /**
   * payload of id token
   */
  idTokenParsed?: object;
  /**
   * raw refresh token
   */
  refreshToken?: string;
  /**
   * payload of refresh token (only if JWT)
   */
  refreshTokenParsed?: object;
  /**
   * obtain claim by claim name. E.g. `sub` returns subject
   * First id token payload is checked. If not available then access token
   * payload is queried.
   */
  claim: (claimName: string) => string | number | undefined;
}

export type eventName = 'token'|'error'|'logout'|'action'

export class Client extends EventEmitter {
  constructor (options: Options);
  /**
   * initialize the client. Needs to be called on page load.
   */
  init () : Promise<any>;
  /**
   * adds listener to eventName
   */
  on (eventName: eventName, listener: Function) : this;
  /**
   * removes listener to eventName
   */
  off (eventName: eventName, listener: Function) : this;
  /**
   * return all available tokens and its parsed payload
   */
  getTokens(): Tokens;
  /**
   * asynchonously return access token
   */
  accessToken(): Promise<Tokens["token"]>
  /**
   * Starts login procedure
   * User will always be prompted for credentials.
   * Set prompt='none' if login shall not prompt for credentials.
   */
  login(opts?: {prompt?: 'none'}): Promise<undefined>;
  /**
   * Silent login checks via iframe if auth session exists.
   * Requires option `silentLoginRedirectUri` with server side redirect page.
   * May be blocked if 3rd party cookies are rejected by browser.
   * If opts.prompt is set then `login()` will be started.
   * For `{prompt: 'login'}` user is prompted for credentials.
   * With `{prompt: 'none'}` user is not prompted for credentials (has same effect
   * as with `silentLoginRedirectUri` but with page redirects)
   */
  silentLogin (opts?: {prompt?: 'none'|'login'}): Promise<undefined>;
  /**
   * starts logout
   */
  logout (): Promise<any>;
  /**
   * starts registration
   */
  register (): Promise<any>;
  /**
   * redirects to account management
   */
  account (): Promise<any>;
}