import 'package:openid_client/openid_client.dart';

main() async {

  // print a list of known issuers
  print(Issuer.knownIssuers);

  // discover the metadata of the google OP
  var issuer = await Issuer.discover(Issuer.google);
  
  // create a client
  var client = new Client(issuer, "client_id", "client_secret");
  
  // create a credential object from authorization code
  var c = client.createCredential(code: "some received authorization code");

  // or from an access token
  c = client.createCredential(accessToken: "some received access token");

  // or from an id token
  c = client.createCredential(idToken: "some id token");      

  // get userinfo
  var info = await c.getUserInfo();
  print(info.name);
  
  // get claims from id token if present
  print(c.idToken?.claims?.name);
  
  // create an implicit authentication flow
  var f = new Flow.implicit(client);
  
  // or an explicit flow
  f = new Flow.authorizationCode(client);
  
  // set the redirect uri
  f.redirectUri = Uri.parse("http://localhost");
  
  // do something with the authentication url
  print(f.authenticationUrl);
  
  // handle the result and get a credential object
  c = await f.callback({
    "code": "some code",
  });
  
  // validate an id token
  var violations = await c.validateToken();
}

// import the io version
import 'package:openid_client/openid_client_io.dart';
// use url launcher package 
import 'package:url_launcher/url_launcher.dart';

authenticate(Uri uri, String clientId, List<String> scopes) async {   
    
    // create the client
    var issuer = await Issuer.discover(uri);
    var client = new Client(issuer, clientId);
    
    // create a function to open a browser with an url
    urlLauncher(String url) async {
        if (await canLaunch(url)) {
          await launch(url, forceWebView: true);
        } else {
          throw 'Could not launch $url';
        }
    }
    
    // create an authenticator
    var authenticator = new Authenticator(client,
        scopes: scopes,
        port: 4000, urlLancher: urlLauncher);
    
    // starts the authentication
    var c = await authenticator.authorize();
    
    // close the webview when finished
    closeWebView();
    
    // return the user info
    return await c.getUserInfo();

}

// import the io version
import 'package:openid_client/openid_client_io.dart';

authenticate(Uri uri, String clientId, List<String> scopes) async {   
    
    // create the client
    var issuer = await Issuer.discover(uri);
    var client = new Client(issuer, clientId);
    
    // create an authenticator
    var authenticator = new Authenticator(client,
        scopes: scopes,
        port: 4000);
    
    // starts the authentication
    var c = await authenticator.authorize(); // this will open a browser
    
    // return the user info
    return await c.getUserInfo();
}

// import the browser version
import 'package:openid_client/openid_client_browser.dart';

authenticate(Uri uri, String clientId, List<String> scopes) async {   
    
    // create the client
    var issuer = await Issuer.discover(uri);
    var client = new Client(issuer, clientId);
    
    // create an authenticator
    var authenticator = new Authenticator(client, scopes: scopes);
    
    // get the credential
    var c = await authenticator.credential;
    
    if (c==null) {
      // starts the authentication
      authenticator.authorize(); // this will redirect the browser
    } else {
      // return the user info
      return await c.getUserInfo();
    }
}