/*
 * Copyright 2016 Red Hat, Inc. and/or its affiliates
 * and other contributors as indicated by the @author tags.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
function Keycloak (config) {
    if (!(this instanceof Keycloak)) {
        throw new Error("The 'Keycloak' constructor must be invoked with 'new'.")
    }

    var kc = this;
    var adapter;
    var refreshQueue = [];
    var callbackStorage;

    var loginIframe = {
        enable: true,
        callbackList: [],
        interval: 5
    };

    kc.didInitialize = false;

    var useNonce = true;
    var logInfo = createLogger(console.info);
    var logWarn = createLogger(console.warn);

    kc.init = function (initOptions) {
        if (kc.didInitialize) {
            throw new Error("A 'Keycloak' instance can only be initialized once.");
        }

        kc.didInitialize = true;

        kc.authenticated = false;

        callbackStorage = createCallbackStorage();
        var adapters = ['default', 'cordova', 'cordova-native'];

        if (initOptions && adapters.indexOf(initOptions.adapter) > -1) {
            adapter = loadAdapter(initOptions.adapter);
        } else if (initOptions && typeof initOptions.adapter === "object") {
            adapter = initOptions.adapter;
        } else {
            if (window.Cordova || window.cordova) {
                adapter = loadAdapter('cordova');
            } else {
                adapter = loadAdapter();
            }
        }

        if (initOptions) {
            if (typeof initOptions.useNonce !== 'undefined') {
                useNonce = initOptions.useNonce;
            }

            if (typeof initOptions.checkLoginIframe !== 'undefined') {
                loginIframe.enable = initOptions.checkLoginIframe;
            }

            if (initOptions.checkLoginIframeInterval) {
                loginIframe.interval = initOptions.checkLoginIframeInterval;
            }

            if (initOptions.onLoad === 'login-required') {
                kc.loginRequired = true;
            }

            if (initOptions.responseMode) {
                if (initOptions.responseMode === 'query' || initOptions.responseMode === 'fragment') {
                    kc.responseMode = initOptions.responseMode;
                } else {
                    throw 'Invalid value for responseMode';
                }
            }

            if (initOptions.flow) {
                switch (initOptions.flow) {
                    case 'standard':
                        kc.responseType = 'code';
                        break;
                    case 'implicit':
                        kc.responseType = 'id_token token';
                        break;
                    case 'hybrid':
                        kc.responseType = 'code id_token token';
                        break;
                    default:
                        throw 'Invalid value for flow';
                }
                kc.flow = initOptions.flow;
            }

            if (initOptions.timeSkew != null) {
                kc.timeSkew = initOptions.timeSkew;
            }

            if(initOptions.redirectUri) {
                kc.redirectUri = initOptions.redirectUri;
            }

            if (initOptions.silentCheckSsoRedirectUri) {
                kc.silentCheckSsoRedirectUri = initOptions.silentCheckSsoRedirectUri;
            }

            if (typeof initOptions.silentCheckSsoFallback === 'boolean') {
                kc.silentCheckSsoFallback = initOptions.silentCheckSsoFallback;
            } else {
                kc.silentCheckSsoFallback = true;
            }

            if (typeof initOptions.pkceMethod !== "undefined") {
                if (initOptions.pkceMethod !== "S256" && initOptions.pkceMethod !== false) {
                    throw new TypeError(`Invalid value for pkceMethod', expected 'S256' or false but got ${initOptions.pkceMethod}.`);
                }

                kc.pkceMethod = initOptions.pkceMethod;
            } else {
                kc.pkceMethod = "S256";
            }

            if (typeof initOptions.enableLogging === 'boolean') {
                kc.enableLogging = initOptions.enableLogging;
            } else {
                kc.enableLogging = false;
            }

            if (initOptions.logoutMethod === 'POST') {
                kc.logoutMethod = 'POST';
            } else {
                kc.logoutMethod = 'GET';
            }

            if (typeof initOptions.scope === 'string') {
                kc.scope = initOptions.scope;
            }

            if (typeof initOptions.acrValues === 'string') {
                kc.acrValues = initOptions.acrValues;
            }

            if (typeof initOptions.messageReceiveTimeout === 'number' && initOptions.messageReceiveTimeout > 0) {
                kc.messageReceiveTimeout = initOptions.messageReceiveTimeout;
            } else {
                kc.messageReceiveTimeout = 10000;
            }
        }

        if (!kc.responseMode) {
            kc.responseMode = 'fragment';
        }
        if (!kc.responseType) {
            kc.responseType = 'code';
            kc.flow = 'standard';
        }

        var promise = createPromise();

        var initPromise = createPromise();
        initPromise.promise.then(function() {
            kc.onReady && kc.onReady(kc.authenticated);
            promise.setSuccess(kc.authenticated);
        }).catch(function(error) {
            promise.setError(error);
        });

        var configPromise = loadConfig(config);

        function onLoad() {
            var doLogin = function(prompt) {
                if (!prompt) {
                    options.prompt = 'none';
                }

                if (initOptions && initOptions.locale) {
                    options.locale = initOptions.locale;
                }
                kc.login(options).then(function () {
                    initPromise.setSuccess();
                }).catch(function (error) {
                    initPromise.setError(error);
                });
            }

            var checkSsoSilently = async function() {
                var ifrm = document.createElement("iframe");
                var src = await kc.createLoginUrl({prompt: 'none', redirectUri: kc.silentCheckSsoRedirectUri});
                ifrm.setAttribute("src", src);
                ifrm.setAttribute("sandbox", "allow-storage-access-by-user-activation allow-scripts allow-same-origin");
                ifrm.setAttribute("title", "keycloak-silent-check-sso");
                ifrm.style.display = "none";
                document.body.appendChild(ifrm);

                var messageCallback = function(event) {
                    if (event.origin !== window.location.origin || ifrm.contentWindow !== event.source) {
                        return;
                    }

                    var oauth = parseCallback(event.data);
                    processCallback(oauth, initPromise);

                    document.body.removeChild(ifrm);
                    window.removeEventListener("message", messageCallback);
                };

                window.addEventListener("message", messageCallback);
            };

            var options = {};
            switch (initOptions.onLoad) {
                case 'check-sso':
                    if (loginIframe.enable) {
                        setupCheckLoginIframe().then(function() {
                            checkLoginIframe().then(function (unchanged) {
                                if (!unchanged) {
                                    kc.silentCheckSsoRedirectUri ? checkSsoSilently() : doLogin(false);
                                } else {
                                    initPromise.setSuccess();
                                }
                            }).catch(function (error) {
                                initPromise.setError(error);
                            });
                        });
                    } else {
                        kc.silentCheckSsoRedirectUri ? checkSsoSilently() : doLogin(false);
                    }
                    break;
                case 'login-required':
                    doLogin(true);
                    break;
                default:
                    throw 'Invalid value for onLoad';
            }
        }

        function processInit() {
            var callback = parseCallback(window.location.href);

            if (callback) {
                window.history.replaceState(window.history.state, null, callback.newUrl);
            }

            if (callback && callback.valid) {
                return setupCheckLoginIframe().then(function() {
                    processCallback(callback, initPromise);
                }).catch(function (error) {
                    initPromise.setError(error);
                });
            } else if (initOptions) {
                if (initOptions.token && initOptions.refreshToken) {
                    setToken(initOptions.token, initOptions.refreshToken, initOptions.idToken);

                    if (loginIframe.enable) {
                        setupCheckLoginIframe().then(function() {
                            checkLoginIframe().then(function (unchanged) {
                                if (unchanged) {
                                    kc.onAuthSuccess && kc.onAuthSuccess();
                                    initPromise.setSuccess();
                                    scheduleCheckIframe();
                                } else {
                                    initPromise.setSuccess();
                                }
                            }).catch(function (error) {
                                initPromise.setError(error);
                            });
                        });
                    } else {
                        kc.updateToken(-1).then(function() {
                            kc.onAuthSuccess && kc.onAuthSuccess();
                            initPromise.setSuccess();
                        }).catch(function(error) {
                            kc.onAuthError && kc.onAuthError();
                            if (initOptions.onLoad) {
                                onLoad();
                            } else {
                                initPromise.setError(error);
                            }
                        });
                    }
                } else if (initOptions.onLoad) {
                    onLoad();
                } else {
                    initPromise.setSuccess();
                }
            } else {
                initPromise.setSuccess();
            }
        }

        configPromise.then(function () {
            check3pCookiesSupported()
                .then(processInit)
                .catch(function (error) {
                    promise.setError(error);
                });
        });
        configPromise.catch(function (error) {
            promise.setError(error);
        });

        return promise.promise;
    }

    kc.login = function (options) {
        return adapter.login(options);
    }

    function generateRandomData(len) {
        // use web crypto APIs if possible
        var array = null;
        var crypto = window.crypto || window.msCrypto;
        if (crypto && crypto.getRandomValues && window.Uint8Array) {
            array = new Uint8Array(len);
            crypto.getRandomValues(array);
            return array;
        }

        // fallback to Math random
        array = new Array(len);
        for (var j = 0; j < array.length; j++) {
            array[j] = Math.floor(256 * Math.random());
        }
        return array;
    }

    function generateCodeVerifier(len) {
        return generateRandomString(len, 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789');
    }

    function generateRandomString(len, alphabet){
        var randomData = generateRandomData(len);
        var chars = new Array(len);
        for (var i = 0; i < len; i++) {
            chars[i] = alphabet.charCodeAt(randomData[i] % alphabet.length);
        }
        return String.fromCharCode.apply(null, chars);
    }

    async function generatePkceChallenge(pkceMethod, codeVerifier) {
        if (pkceMethod !== "S256") {
            throw new TypeError(`Invalid value for 'pkceMethod', expected 'S256' but got '${pkceMethod}'.`);
        }

        // hash codeVerifier, then encode as url-safe base64 without padding
        const hashBytes = new Uint8Array(await sha256Digest(codeVerifier));
        const encodedHash = bytesToBase64(hashBytes)
            .replace(/\+/g, '-')
            .replace(/\//g, '_')
            .replace(/\=/g, '');

        return encodedHash;
    }

    function buildClaimsParameter(requestedAcr){
        var claims = {
            id_token: {
                acr: requestedAcr
            }
        }
        return JSON.stringify(claims);
    }

    kc.createLoginUrl = async function(options) {
        var state = createUUID();
        var nonce = createUUID();

        var redirectUri = adapter.redirectUri(options);

        var callbackState = {
            state: state,
            nonce: nonce,
            redirectUri: encodeURIComponent(redirectUri),
            loginOptions: options
        };

        if (options && options.prompt) {
            callbackState.prompt = options.prompt;
        }

        var baseUrl;
        if (options && options.action == 'register') {
            baseUrl = kc.endpoints.register();
        } else {
            baseUrl = kc.endpoints.authorize();
        }

        var scope = options && options.scope || kc.scope;
        if (!scope) {
            // if scope is not set, default to "openid"
            scope = "openid";
        } else if (scope.indexOf("openid") === -1) {
            // if openid scope is missing, prefix the given scopes with it
            scope = "openid " + scope;
        }

        var url = baseUrl
            + '?client_id=' + encodeURIComponent(kc.clientId)
            + '&redirect_uri=' + encodeURIComponent(redirectUri)
            + '&state=' + encodeURIComponent(state)
            + '&response_mode=' + encodeURIComponent(kc.responseMode)
            + '&response_type=' + encodeURIComponent(kc.responseType)
            + '&scope=' + encodeURIComponent(scope);
        if (useNonce) {
            url = url + '&nonce=' + encodeURIComponent(nonce);
        }

        if (options && options.prompt) {
            url += '&prompt=' + encodeURIComponent(options.prompt);
        }

        if (options && typeof options.maxAge === 'number') {
            url += '&max_age=' + encodeURIComponent(options.maxAge);
        }

        if (options && options.loginHint) {
            url += '&login_hint=' + encodeURIComponent(options.loginHint);
        }

        if (options && options.idpHint) {
            url += '&kc_idp_hint=' + encodeURIComponent(options.idpHint);
        }

        if (options && options.action && options.action != 'register') {
            url += '&kc_action=' + encodeURIComponent(options.action);
        }

        if (options && options.locale) {
            url += '&ui_locales=' + encodeURIComponent(options.locale);
        }

        if (options && options.acr) {
            var claimsParameter = buildClaimsParameter(options.acr);
            url += '&claims=' + encodeURIComponent(claimsParameter);
        }

        if ((options && options.acrValues) || kc.acrValues) {
            url += '&acr_values=' + encodeURIComponent(options.acrValues || kc.acrValues);
        }

        if (kc.pkceMethod) {
            if (!globalThis.isSecureContext) {
                logWarn('[KEYCLOAK] PKCE is only supported in secure contexts (HTTPS)');
            } else {
                var codeVerifier = generateCodeVerifier(96);
                callbackState.pkceCodeVerifier = codeVerifier;
                var pkceChallenge = await generatePkceChallenge(kc.pkceMethod, codeVerifier);
                url += '&code_challenge=' + pkceChallenge;
                url += '&code_challenge_method=' + kc.pkceMethod;
            }
        }

        callbackStorage.add(callbackState);

        return url;
    }

    kc.logout = function(options) {
        return adapter.logout(options);
    }

    kc.createLogoutUrl = function(options) {

        const logoutMethod = options?.logoutMethod ?? kc.logoutMethod;
        if (logoutMethod === 'POST') {
            return kc.endpoints.logout();
        }

        var url = kc.endpoints.logout()
            + '?client_id=' + encodeURIComponent(kc.clientId)
            + '&post_logout_redirect_uri=' + encodeURIComponent(adapter.redirectUri(options, false));

        if (kc.idToken) {
            url += '&id_token_hint=' + encodeURIComponent(kc.idToken);
        }

        return url;
    }

    kc.register = function (options) {
        return adapter.register(options);
    }

    kc.createRegisterUrl = async function(options) {
        if (!options) {
            options = {};
        }
        options.action = 'register';
        return await kc.createLoginUrl(options);
    }

    kc.createAccountUrl = function(options) {
        var realm = getRealmUrl();
        var url = undefined;
        if (typeof realm !== 'undefined') {
            url = realm
            + '/account'
            + '?referrer=' + encodeURIComponent(kc.clientId)
            + '&referrer_uri=' + encodeURIComponent(adapter.redirectUri(options));
        }
        return url;
    }

    kc.accountManagement = function() {
        return adapter.accountManagement();
    }

    kc.hasRealmRole = function (role) {
        var access = kc.realmAccess;
        return !!access && access.roles.indexOf(role) >= 0;
    }

    kc.hasResourceRole = function(role, resource) {
        if (!kc.resourceAccess) {
            return false;
        }

        var access = kc.resourceAccess[resource || kc.clientId];
        return !!access && access.roles.indexOf(role) >= 0;
    }

    kc.loadUserProfile = function() {
        var url = getRealmUrl() + '/account';
        var req = new XMLHttpRequest();
        req.open('GET', url, true);
        req.setRequestHeader('Accept', 'application/json');
        req.setRequestHeader('Authorization', 'bearer ' + kc.token);

        var promise = createPromise();

        req.onreadystatechange = function () {
            if (req.readyState == 4) {
                if (req.status == 200) {
                    kc.profile = JSON.parse(req.responseText);
                    promise.setSuccess(kc.profile);
                } else {
                    promise.setError();
                }
            }
        }

        req.send();

        return promise.promise;
    }

    kc.loadUserInfo = function() {
        var url = kc.endpoints.userinfo();
        var req = new XMLHttpRequest();
        req.open('GET', url, true);
        req.setRequestHeader('Accept', 'application/json');
        req.setRequestHeader('Authorization', 'bearer ' + kc.token);

        var promise = createPromise();

        req.onreadystatechange = function () {
            if (req.readyState == 4) {
                if (req.status == 200) {
                    kc.userInfo = JSON.parse(req.responseText);
                    promise.setSuccess(kc.userInfo);
                } else {
                    promise.setError();
                }
            }
        }

        req.send();

        return promise.promise;
    }

    kc.isTokenExpired = function(minValidity) {
        if (!kc.tokenParsed || (!kc.refreshToken && kc.flow != 'implicit' )) {
            throw 'Not authenticated';
        }

        if (kc.timeSkew == null) {
            logInfo('[KEYCLOAK] Unable to determine if token is expired as timeskew is not set');
            return true;
        }

        var expiresIn = kc.tokenParsed['exp'] - Math.ceil(new Date().getTime() / 1000) + kc.timeSkew;
        if (minValidity) {
            if (isNaN(minValidity)) {
                throw 'Invalid minValidity';
            }
            expiresIn -= minValidity;
        }
        return expiresIn < 0;
    }

    kc.updateToken = function(minValidity) {
        var promise = createPromise();

        if (!kc.refreshToken) {
            promise.setError();
            return promise.promise;
        }

        minValidity = minValidity || 5;

        var exec = function() {
            var refreshToken = false;
            if (minValidity == -1) {
                refreshToken = true;
                logInfo('[KEYCLOAK] Refreshing token: forced refresh');
            } else if (!kc.tokenParsed || kc.isTokenExpired(minValidity)) {
                refreshToken = true;
                logInfo('[KEYCLOAK] Refreshing token: token expired');
            }

            if (!refreshToken) {
                promise.setSuccess(false);
            } else {
                var params = 'grant_type=refresh_token&' + 'refresh_token=' + kc.refreshToken;
                var url = kc.endpoints.token();

                refreshQueue.push(promise);

                if (refreshQueue.length == 1) {
                    var req = new XMLHttpRequest();
                    req.open('POST', url, true);
                    req.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');
                    req.withCredentials = true;

                    params += '&client_id=' + encodeURIComponent(kc.clientId);

                    var timeLocal = new Date().getTime();

                    req.onreadystatechange = function () {
                        if (req.readyState == 4) {
                            if (req.status == 200) {
                                logInfo('[KEYCLOAK] Token refreshed');

                                timeLocal = (timeLocal + new Date().getTime()) / 2;

                                var tokenResponse = JSON.parse(req.responseText);

                                setToken(tokenResponse['access_token'], tokenResponse['refresh_token'], tokenResponse['id_token'], timeLocal);

                                kc.onAuthRefreshSuccess && kc.onAuthRefreshSuccess();
                                for (var p = refreshQueue.pop(); p != null; p = refreshQueue.pop()) {
                                    p.setSuccess(true);
                                }
                            } else {
                                logWarn('[KEYCLOAK] Failed to refresh token');

                                if (req.status == 400) {
                                    kc.clearToken();
                                }

                                kc.onAuthRefreshError && kc.onAuthRefreshError();
                                for (var p = refreshQueue.pop(); p != null; p = refreshQueue.pop()) {
                                    p.setError(true);
                                }
                            }
                        }
                    };

                    req.send(params);
                }
            }
        }

        if (loginIframe.enable) {
            var iframePromise = checkLoginIframe();
            iframePromise.then(function() {
                exec();
            }).catch(function(error) {
                promise.setError(error);
            });
        } else {
            exec();
        }

        return promise.promise;
    }

    kc.clearToken = function() {
        if (kc.token) {
            setToken(null, null, null);
            kc.onAuthLogout && kc.onAuthLogout();
            if (kc.loginRequired) {
                kc.login();
            }
        }
    }

    function getRealmUrl() {
        if (typeof kc.authServerUrl !== 'undefined') {
            if (kc.authServerUrl.charAt(kc.authServerUrl.length - 1) == '/') {
                return kc.authServerUrl + 'realms/' + encodeURIComponent(kc.realm);
            } else {
                return kc.authServerUrl + '/realms/' + encodeURIComponent(kc.realm);
            }
        } else {
            return undefined;
        }
    }

    function getOrigin() {
        if (!window.location.origin) {
            return window.location.protocol + "//" + window.location.hostname + (window.location.port ? ':' + window.location.port: '');
        } else {
            return window.location.origin;
        }
    }

    function processCallback(oauth, promise) {
        var code = oauth.code;
        var error = oauth.error;
        var prompt = oauth.prompt;

        var timeLocal = new Date().getTime();

        if (oauth['kc_action_status']) {
            kc.onActionUpdate && kc.onActionUpdate(oauth['kc_action_status'], oauth['kc_action']);
        }

        if (error) {
            if (prompt != 'none') {
                if (oauth.error_description && oauth.error_description === "authentication_expired") {
                    kc.login(oauth.loginOptions);
                } else {
                    var errorData = { error: error, error_description: oauth.error_description };
                    kc.onAuthError && kc.onAuthError(errorData);
                    promise && promise.setError(errorData);
                }
            } else {
                promise && promise.setSuccess();
            }
            return;
        } else if ((kc.flow != 'standard') && (oauth.access_token || oauth.id_token)) {
            authSuccess(oauth.access_token, null, oauth.id_token, true);
        }

        if ((kc.flow != 'implicit') && code) {
            var params = 'code=' + code + '&grant_type=authorization_code';
            var url = kc.endpoints.token();

            var req = new XMLHttpRequest();
            req.open('POST', url, true);
            req.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');

            params += '&client_id=' + encodeURIComponent(kc.clientId);
            params += '&redirect_uri=' + oauth.redirectUri;

            if (oauth.pkceCodeVerifier) {
                params += '&code_verifier=' + oauth.pkceCodeVerifier;
            }

            req.withCredentials = true;

            req.onreadystatechange = function() {
                if (req.readyState == 4) {
                    if (req.status == 200) {

                        var tokenResponse = JSON.parse(req.responseText);
                        authSuccess(tokenResponse['access_token'], tokenResponse['refresh_token'], tokenResponse['id_token'], kc.flow === 'standard');
                        scheduleCheckIframe();
                    } else {
                        kc.onAuthError && kc.onAuthError();
                        promise && promise.setError();
                    }
                }
            };

            req.send(params);
        }

        function authSuccess(accessToken, refreshToken, idToken, fulfillPromise) {
            timeLocal = (timeLocal + new Date().getTime()) / 2;

            setToken(accessToken, refreshToken, idToken, timeLocal);

            if (useNonce && (kc.idTokenParsed && kc.idTokenParsed.nonce != oauth.storedNonce)) {
                logInfo('[KEYCLOAK] Invalid nonce, clearing token');
                kc.clearToken();
                promise && promise.setError();
            } else {
                if (fulfillPromise) {
                    kc.onAuthSuccess && kc.onAuthSuccess();
                    promise && promise.setSuccess();
                }
            }
        }

    }

    function loadConfig(url) {
        var promise = createPromise();
        var configUrl;

        if (!config) {
            configUrl = 'keycloak.json';
        } else if (typeof config === 'string') {
            configUrl = config;
        }

        function setupOidcEndoints(oidcConfiguration) {
            if (! oidcConfiguration) {
                kc.endpoints = {
                    authorize: function() {
                        return getRealmUrl() + '/protocol/openid-connect/auth';
                    },
                    token: function() {
                        return getRealmUrl() + '/protocol/openid-connect/token';
                    },
                    logout: function() {
                        return getRealmUrl() + '/protocol/openid-connect/logout';
                    },
                    checkSessionIframe: function() {
                        return getRealmUrl() + '/protocol/openid-connect/login-status-iframe.html';
                    },
                    thirdPartyCookiesIframe: function() {
                        return getRealmUrl() + '/protocol/openid-connect/3p-cookies/step1.html';
                    },
                    register: function() {
                        return getRealmUrl() + '/protocol/openid-connect/registrations';
                    },
                    userinfo: function() {
                        return getRealmUrl() + '/protocol/openid-connect/userinfo';
                    }
                };
            } else {
                kc.endpoints = {
                    authorize: function() {
                        return oidcConfiguration.authorization_endpoint;
                    },
                    token: function() {
                        return oidcConfiguration.token_endpoint;
                    },
                    logout: function() {
                        if (!oidcConfiguration.end_session_endpoint) {
                            throw "Not supported by the OIDC server";
                        }
                        return oidcConfiguration.end_session_endpoint;
                    },
                    checkSessionIframe: function() {
                        if (!oidcConfiguration.check_session_iframe) {
                            throw "Not supported by the OIDC server";
                        }
                        return oidcConfiguration.check_session_iframe;
                    },
                    register: function() {
                        throw 'Redirection to "Register user" page not supported in standard OIDC mode';
                    },
                    userinfo: function() {
                        if (!oidcConfiguration.userinfo_endpoint) {
                            throw "Not supported by the OIDC server";
                        }
                        return oidcConfiguration.userinfo_endpoint;
                    }
                }
            }
        }

        if (configUrl) {
            var req = new XMLHttpRequest();
            req.open('GET', configUrl, true);
            req.setRequestHeader('Accept', 'application/json');

            req.onreadystatechange = function () {
                if (req.readyState == 4) {
                    if (req.status == 200 || fileLoaded(req)) {
                        var config = JSON.parse(req.responseText);

                        kc.authServerUrl = config['auth-server-url'];
                        kc.realm = config['realm'];
                        kc.clientId = config['resource'];
                        setupOidcEndoints(null);
                        promise.setSuccess();
                    } else {
                        promise.setError();
                    }
                }
            };

            req.send();
        } else {
            if (!config.clientId) {
                throw 'clientId missing';
            }

            kc.clientId = config.clientId;

            var oidcProvider = config['oidcProvider'];
            if (!oidcProvider) {
                if (!config['url']) {
                    var scripts = document.getElementsByTagName('script');
                    for (var i = 0; i < scripts.length; i++) {
                        if (scripts[i].src.match(/.*keycloak\.js/)) {
                            config.url = scripts[i].src.substr(0, scripts[i].src.indexOf('/js/keycloak.js'));
                            break;
                        }
                    }
                }
                if (!config.realm) {
                    throw 'realm missing';
                }

                kc.authServerUrl = config.url;
                kc.realm = config.realm;
                setupOidcEndoints(null);
                promise.setSuccess();
            } else {
                if (typeof oidcProvider === 'string') {
                    var oidcProviderConfigUrl;
                    if (oidcProvider.charAt(oidcProvider.length - 1) == '/') {
                        oidcProviderConfigUrl = oidcProvider + '.well-known/openid-configuration';
                    } else {
                        oidcProviderConfigUrl = oidcProvider + '/.well-known/openid-configuration';
                    }
                    var req = new XMLHttpRequest();
                    req.open('GET', oidcProviderConfigUrl, true);
                    req.setRequestHeader('Accept', 'application/json');

                    req.onreadystatechange = function () {
                        if (req.readyState == 4) {
                            if (req.status == 200 || fileLoaded(req)) {
                                var oidcProviderConfig = JSON.parse(req.responseText);
                                setupOidcEndoints(oidcProviderConfig);
                                promise.setSuccess();
                            } else {
                                promise.setError();
                            }
                        }
                    };

                    req.send();
                } else {
                    setupOidcEndoints(oidcProvider);
                    promise.setSuccess();
                }
            }
        }

        return promise.promise;
    }

    function fileLoaded(xhr) {
        return xhr.status == 0 && xhr.responseText && xhr.responseURL.startsWith('file:');
    }

    function setToken(token, refreshToken, idToken, timeLocal) {
        if (kc.tokenTimeoutHandle) {
            clearTimeout(kc.tokenTimeoutHandle);
            kc.tokenTimeoutHandle = null;
        }

        if (refreshToken) {
            kc.refreshToken = refreshToken;
            kc.refreshTokenParsed = decodeToken(refreshToken);
        } else {
            delete kc.refreshToken;
            delete kc.refreshTokenParsed;
        }

        if (idToken) {
            kc.idToken = idToken;
            kc.idTokenParsed = decodeToken(idToken);
        } else {
            delete kc.idToken;
            delete kc.idTokenParsed;
        }

        if (token) {
            kc.token = token;
            kc.tokenParsed = decodeToken(token);
            kc.sessionId = kc.tokenParsed.sid;
            kc.authenticated = true;
            kc.subject = kc.tokenParsed.sub;
            kc.realmAccess = kc.tokenParsed.realm_access;
            kc.resourceAccess = kc.tokenParsed.resource_access;

            if (timeLocal) {
                kc.timeSkew = Math.floor(timeLocal / 1000) - kc.tokenParsed.iat;
            }

            if (kc.timeSkew != null) {
                logInfo('[KEYCLOAK] Estimated time difference between browser and server is ' + kc.timeSkew + ' seconds');

                if (kc.onTokenExpired) {
                    var expiresIn = (kc.tokenParsed['exp'] - (new Date().getTime() / 1000) + kc.timeSkew) * 1000;
                    logInfo('[KEYCLOAK] Token expires in ' + Math.round(expiresIn / 1000) + ' s');
                    if (expiresIn <= 0) {
                        kc.onTokenExpired();
                    } else {
                        kc.tokenTimeoutHandle = setTimeout(kc.onTokenExpired, expiresIn);
                    }
                }
            }
        } else {
            delete kc.token;
            delete kc.tokenParsed;
            delete kc.subject;
            delete kc.realmAccess;
            delete kc.resourceAccess;

            kc.authenticated = false;
        }
    }

    function createUUID() {
        var hexDigits = '0123456789abcdef';
        var s = generateRandomString(36, hexDigits).split("");
        s[14] = '4';
        s[19] = hexDigits.substr((s[19] & 0x3) | 0x8, 1);
        s[8] = s[13] = s[18] = s[23] = '-';
        var uuid = s.join('');
        return uuid;
    }

    function parseCallback(url) {
        var oauth = parseCallbackUrl(url);
        if (!oauth) {
            return;
        }

        var oauthState = callbackStorage.get(oauth.state);

        if (oauthState) {
            oauth.valid = true;
            oauth.redirectUri = oauthState.redirectUri;
            oauth.storedNonce = oauthState.nonce;
            oauth.prompt = oauthState.prompt;
            oauth.pkceCodeVerifier = oauthState.pkceCodeVerifier;
            oauth.loginOptions = oauthState.loginOptions;
        }

        return oauth;
    }

    function parseCallbackUrl(url) {
        var supportedParams;
        switch (kc.flow) {
            case 'standard':
                supportedParams = ['code', 'state', 'session_state', 'kc_action_status', 'kc_action', 'iss'];
                break;
            case 'implicit':
                supportedParams = ['access_token', 'token_type', 'id_token', 'state', 'session_state', 'expires_in', 'kc_action_status', 'kc_action', 'iss'];
                break;
            case 'hybrid':
                supportedParams = ['access_token', 'token_type', 'id_token', 'code', 'state', 'session_state', 'expires_in', 'kc_action_status', 'kc_action', 'iss'];
                break;
        }

        supportedParams.push('error');
        supportedParams.push('error_description');
        supportedParams.push('error_uri');

        var queryIndex = url.indexOf('?');
        var fragmentIndex = url.indexOf('#');

        var newUrl;
        var parsed;

        if (kc.responseMode === 'query' && queryIndex !== -1) {
            newUrl = url.substring(0, queryIndex);
            parsed = parseCallbackParams(url.substring(queryIndex + 1, fragmentIndex !== -1 ? fragmentIndex : url.length), supportedParams);
            if (parsed.paramsString !== '') {
                newUrl += '?' + parsed.paramsString;
            }
            if (fragmentIndex !== -1) {
                newUrl += url.substring(fragmentIndex);
            }
        } else if (kc.responseMode === 'fragment' && fragmentIndex !== -1) {
            newUrl = url.substring(0, fragmentIndex);
            parsed = parseCallbackParams(url.substring(fragmentIndex + 1), supportedParams);
            if (parsed.paramsString !== '') {
                newUrl += '#' + parsed.paramsString;
            }
        }

        if (parsed && parsed.oauthParams) {
            if (kc.flow === 'standard' || kc.flow === 'hybrid') {
                if ((parsed.oauthParams.code || parsed.oauthParams.error) && parsed.oauthParams.state) {
                    parsed.oauthParams.newUrl = newUrl;
                    return parsed.oauthParams;
                }
            } else if (kc.flow === 'implicit') {
                if ((parsed.oauthParams.access_token || parsed.oauthParams.error) && parsed.oauthParams.state) {
                    parsed.oauthParams.newUrl = newUrl;
                    return parsed.oauthParams;
                }
            }
        }
    }

    function parseCallbackParams(paramsString, supportedParams) {
        var p = paramsString.split('&');
        var result = {
            paramsString: '',
            oauthParams: {}
        }
        for (var i = 0; i < p.length; i++) {
            var split = p[i].indexOf("=");
            var key = p[i].slice(0, split);
            if (supportedParams.indexOf(key) !== -1) {
                result.oauthParams[key] = p[i].slice(split + 1);
            } else {
                if (result.paramsString !== '') {
                    result.paramsString += '&';
                }
                result.paramsString += p[i];
            }
        }
        return result;
    }

    function createPromise() {
        // Need to create a native Promise which also preserves the
        // interface of the custom promise type previously used by the API
        var p = {
            setSuccess: function(result) {
                p.resolve(result);
            },

            setError: function(result) {
                p.reject(result);
            }
        };
        p.promise = new Promise(function(resolve, reject) {
            p.resolve = resolve;
            p.reject = reject;
        });

        return p;
    }

    // Function to extend existing native Promise with timeout
    function applyTimeoutToPromise(promise, timeout, errorMessage) {
        var timeoutHandle = null;
        var timeoutPromise = new Promise(function (resolve, reject) {
            timeoutHandle = setTimeout(function () {
                reject({ "error": errorMessage || "Promise is not settled within timeout of " + timeout + "ms" });
            }, timeout);
        });

        return Promise.race([promise, timeoutPromise]).finally(function () {
            clearTimeout(timeoutHandle);
        });
    }

    function setupCheckLoginIframe() {
        var promise = createPromise();

        if (!loginIframe.enable) {
            promise.setSuccess();
            return promise.promise;
        }

        if (loginIframe.iframe) {
            promise.setSuccess();
            return promise.promise;
        }

        var iframe = document.createElement('iframe');
        loginIframe.iframe = iframe;

        iframe.onload = function() {
            var authUrl = kc.endpoints.authorize();
            if (authUrl.charAt(0) === '/') {
                loginIframe.iframeOrigin = getOrigin();
            } else {
                loginIframe.iframeOrigin = authUrl.substring(0, authUrl.indexOf('/', 8));
            }
            promise.setSuccess();
        }

        var src = kc.endpoints.checkSessionIframe();
        iframe.setAttribute('src', src );
        iframe.setAttribute('sandbox', 'allow-storage-access-by-user-activation allow-scripts allow-same-origin');
        iframe.setAttribute('title', 'keycloak-session-iframe' );
        iframe.style.display = 'none';
        document.body.appendChild(iframe);

        var messageCallback = function(event) {
            if ((event.origin !== loginIframe.iframeOrigin) || (loginIframe.iframe.contentWindow !== event.source)) {
                return;
            }

            if (!(event.data == 'unchanged' || event.data == 'changed' || event.data == 'error')) {
                return;
            }


            if (event.data != 'unchanged') {
                kc.clearToken();
            }

            var callbacks = loginIframe.callbackList.splice(0, loginIframe.callbackList.length);

            for (var i = callbacks.length - 1; i >= 0; --i) {
                var promise = callbacks[i];
                if (event.data == 'error') {
                    promise.setError();
                } else {
                    promise.setSuccess(event.data == 'unchanged');
                }
            }
        };

        window.addEventListener('message', messageCallback, false);

        return promise.promise;
    }

    function scheduleCheckIframe() {
        if (loginIframe.enable) {
            if (kc.token) {
                setTimeout(function() {
                    checkLoginIframe().then(function(unchanged) {
                        if (unchanged) {
                            scheduleCheckIframe();
                        }
                    });
                }, loginIframe.interval * 1000);
            }
        }
    }

    function checkLoginIframe() {
        var promise = createPromise();

        if (loginIframe.iframe && loginIframe.iframeOrigin ) {
            var msg = kc.clientId + ' ' + (kc.sessionId ? kc.sessionId : '');
            loginIframe.callbackList.push(promise);
            var origin = loginIframe.iframeOrigin;
            if (loginIframe.callbackList.length == 1) {
                loginIframe.iframe.contentWindow.postMessage(msg, origin);
            }
        } else {
            promise.setSuccess();
        }

        return promise.promise;
    }

    function check3pCookiesSupported() {
        var promise = createPromise();

        if (loginIframe.enable || kc.silentCheckSsoRedirectUri) {
            var iframe = document.createElement('iframe');
            iframe.setAttribute('src', kc.endpoints.thirdPartyCookiesIframe());
            iframe.setAttribute('sandbox', 'allow-storage-access-by-user-activation allow-scripts allow-same-origin');
            iframe.setAttribute('title', 'keycloak-3p-check-iframe' );
            iframe.style.display = 'none';
            document.body.appendChild(iframe);

            var messageCallback = function(event) {
                if (iframe.contentWindow !== event.source) {
                    return;
                }

                if (event.data !== "supported" && event.data !== "unsupported") {
                    return;
                } else if (event.data === "unsupported") {
                    logWarn(
                        "[KEYCLOAK] Your browser is blocking access to 3rd-party cookies, this means:\n\n" +
                        " - It is not possible to retrieve tokens without redirecting to the Keycloak server (a.k.a. no support for silent authentication).\n" +
                        " - It is not possible to automatically detect changes to the session status (such as the user logging out in another tab).\n\n" +
                        "For more information see: https://www.keycloak.org/docs/latest/securing_apps/#_modern_browsers"
                    );

                    loginIframe.enable = false;
                    if (kc.silentCheckSsoFallback) {
                        kc.silentCheckSsoRedirectUri = false;
                    }
                }

                document.body.removeChild(iframe);
                window.removeEventListener("message", messageCallback);
                promise.setSuccess();
            };

            window.addEventListener('message', messageCallback, false);
        } else {
            promise.setSuccess();
        }

        return applyTimeoutToPromise(promise.promise, kc.messageReceiveTimeout, "Timeout when waiting for 3rd party check iframe message.");
    }

    function loadAdapter(type) {
        if (!type || type == 'default') {
            return {
                login: async function(options) {
                    window.location.assign(await kc.createLoginUrl(options));
                    return createPromise().promise;
                },

                logout: async function(options) {

                    const logoutMethod = options?.logoutMethod ?? kc.logoutMethod;
                    if (logoutMethod === "GET") {
                        window.location.replace(kc.createLogoutUrl(options));
                        return;
                    }

                    const logoutUrl = kc.createLogoutUrl(options);
                    const response = await fetch(logoutUrl, {
                        method: "POST",
                        headers: {
                            "Content-Type": "application/x-www-form-urlencoded"
                        },
                        body: new URLSearchParams({
                            id_token_hint: kc.idToken,
                            client_id: kc.clientId,
                            post_logout_redirect_uri: adapter.redirectUri(options, false)
                        })
                    });

                    if (response.redirected) {
                        window.location.href = response.url;
                        return;
                    }

                    if (response.ok) {
                        window.location.reload();
                        return;
                    }

                    throw new Error("Logout failed, request returned an error code.");
                },

                register: function(options) {
                    window.location.assign(kc.createRegisterUrl(options));
                    return createPromise().promise;
                },

                accountManagement : function() {
                    var accountUrl = kc.createAccountUrl();
                    if (typeof accountUrl !== 'undefined') {
                        window.location.href = accountUrl;
                    } else {
                        throw "Not supported by the OIDC server";
                    }
                    return createPromise().promise;
                },

                redirectUri: function(options, encodeHash) {
                    if (arguments.length == 1) {
                        encodeHash = true;
                    }

                    if (options && options.redirectUri) {
                        return options.redirectUri;
                    } else if (kc.redirectUri) {
                        return kc.redirectUri;
                    } else {
                        return location.href;
                    }
                }
            };
        }

        if (type == 'cordova') {
            loginIframe.enable = false;
            var cordovaOpenWindowWrapper = function(loginUrl, target, options) {
                if (window.cordova && window.cordova.InAppBrowser) {
                    // Use inappbrowser for IOS and Android if available
                    return window.cordova.InAppBrowser.open(loginUrl, target, options);
                } else {
                    return window.open(loginUrl, target, options);
                }
            };

            var shallowCloneCordovaOptions = function (userOptions) {
                if (userOptions && userOptions.cordovaOptions) {
                    return Object.keys(userOptions.cordovaOptions).reduce(function (options, optionName) {
                        options[optionName] = userOptions.cordovaOptions[optionName];
                        return options;
                    }, {});
                } else {
                    return {};
                }
            };

            var formatCordovaOptions = function (cordovaOptions) {
                return Object.keys(cordovaOptions).reduce(function (options, optionName) {
                    options.push(optionName+"="+cordovaOptions[optionName]);
                    return options;
                }, []).join(",");
            };

            var createCordovaOptions = function (userOptions) {
                var cordovaOptions = shallowCloneCordovaOptions(userOptions);
                cordovaOptions.location = 'no';
                if (userOptions && userOptions.prompt == 'none') {
                    cordovaOptions.hidden = 'yes';
                }
                return formatCordovaOptions(cordovaOptions);
            };

            var getCordovaRedirectUri = function() {
                return kc.redirectUri || 'http://localhost';
            }

            return {
                login: async function(options) {
                    var promise = createPromise();

                    var cordovaOptions = createCordovaOptions(options);
                    var loginUrl = await kc.createLoginUrl(options);
                    var ref = cordovaOpenWindowWrapper(loginUrl, '_blank', cordovaOptions);
                    var completed = false;

                    var closed = false;
                    var closeBrowser = function() {
                        closed = true;
                        ref.close();
                    };

                    ref.addEventListener('loadstart', function(event) {
                        if (event.url.indexOf(getCordovaRedirectUri()) == 0) {
                            var callback = parseCallback(event.url);
                            processCallback(callback, promise);
                            closeBrowser();
                            completed = true;
                        }
                    });

                    ref.addEventListener('loaderror', function(event) {
                        if (!completed) {
                            if (event.url.indexOf(getCordovaRedirectUri()) == 0) {
                                var callback = parseCallback(event.url);
                                processCallback(callback, promise);
                                closeBrowser();
                                completed = true;
                            } else {
                                promise.setError();
                                closeBrowser();
                            }
                        }
                    });

                    ref.addEventListener('exit', function(event) {
                        if (!closed) {
                            promise.setError({
                                reason: "closed_by_user"
                            });
                        }
                    });

                    return promise.promise;
                },

                logout: function(options) {
                    var promise = createPromise();

                    var logoutUrl = kc.createLogoutUrl(options);
                    var ref = cordovaOpenWindowWrapper(logoutUrl, '_blank', 'location=no,hidden=yes,clearcache=yes');

                    var error;

                    ref.addEventListener('loadstart', function(event) {
                        if (event.url.indexOf(getCordovaRedirectUri()) == 0) {
                            ref.close();
                        }
                    });

                    ref.addEventListener('loaderror', function(event) {
                        if (event.url.indexOf(getCordovaRedirectUri()) == 0) {
                            ref.close();
                        } else {
                            error = true;
                            ref.close();
                        }
                    });

                    ref.addEventListener('exit', function(event) {
                        if (error) {
                            promise.setError();
                        } else {
                            kc.clearToken();
                            promise.setSuccess();
                        }
                    });

                    return promise.promise;
                },

                register : function(options) {
                    var promise = createPromise();
                    var registerUrl = kc.createRegisterUrl();
                    var cordovaOptions = createCordovaOptions(options);
                    var ref = cordovaOpenWindowWrapper(registerUrl, '_blank', cordovaOptions);
                    ref.addEventListener('loadstart', function(event) {
                        if (event.url.indexOf(getCordovaRedirectUri()) == 0) {
                            ref.close();
                            var oauth = parseCallback(event.url);
                            processCallback(oauth, promise);
                        }
                    });
                    return promise.promise;
                },

                accountManagement : function() {
                    var accountUrl = kc.createAccountUrl();
                    if (typeof accountUrl !== 'undefined') {
                        var ref = cordovaOpenWindowWrapper(accountUrl, '_blank', 'location=no');
                        ref.addEventListener('loadstart', function(event) {
                            if (event.url.indexOf(getCordovaRedirectUri()) == 0) {
                                ref.close();
                            }
                        });
                    } else {
                        throw "Not supported by the OIDC server";
                    }
                },

                redirectUri: function(options) {
                    return getCordovaRedirectUri();
                }
            }
        }

        if (type == 'cordova-native') {
            loginIframe.enable = false;

            return {
                login: async function(options) {
                    var promise = createPromise();
                    var loginUrl = await kc.createLoginUrl(options);

                    universalLinks.subscribe('keycloak', function(event) {
                        universalLinks.unsubscribe('keycloak');
                        window.cordova.plugins.browsertab.close();
                        var oauth = parseCallback(event.url);
                        processCallback(oauth, promise);
                    });

                    window.cordova.plugins.browsertab.openUrl(loginUrl);
                    return promise.promise;
                },

                logout: function(options) {
                    var promise = createPromise();
                    var logoutUrl = kc.createLogoutUrl(options);

                    universalLinks.subscribe('keycloak', function(event) {
                        universalLinks.unsubscribe('keycloak');
                        window.cordova.plugins.browsertab.close();
                        kc.clearToken();
                        promise.setSuccess();
                    });

                    window.cordova.plugins.browsertab.openUrl(logoutUrl);
                    return promise.promise;
                },

                register : function(options) {
                    var promise = createPromise();
                    var registerUrl = kc.createRegisterUrl(options);
                    universalLinks.subscribe('keycloak' , function(event) {
                        universalLinks.unsubscribe('keycloak');
                        window.cordova.plugins.browsertab.close();
                        var oauth = parseCallback(event.url);
                        processCallback(oauth, promise);
                    });
                    window.cordova.plugins.browsertab.openUrl(registerUrl);
                    return promise.promise;

                },

                accountManagement : function() {
                    var accountUrl = kc.createAccountUrl();
                    if (typeof accountUrl !== 'undefined') {
                        window.cordova.plugins.browsertab.openUrl(accountUrl);
                    } else {
                        throw "Not supported by the OIDC server";
                    }
                },

                redirectUri: function(options) {
                    if (options && options.redirectUri) {
                        return options.redirectUri;
                    } else if (kc.redirectUri) {
                        return kc.redirectUri;
                    } else {
                        return "http://localhost";
                    }
                }
            }
        }

        throw 'invalid adapter type: ' + type;
    }

    var LocalStorage = function() {
        if (!(this instanceof LocalStorage)) {
            return new LocalStorage();
        }

        localStorage.setItem('kc-test', 'test');
        localStorage.removeItem('kc-test');

        var cs = this;

        function clearExpired() {
            var time = new Date().getTime();
            for (var i = 0; i < localStorage.length; i++)  {
                var key = localStorage.key(i);
                if (key && key.indexOf('kc-callback-') == 0) {
                    var value = localStorage.getItem(key);
                    if (value) {
                        try {
                            var expires = JSON.parse(value).expires;
                            if (!expires || expires < time) {
                                localStorage.removeItem(key);
                            }
                        } catch (err) {
                            localStorage.removeItem(key);
                        }
                    }
                }
            }
        }

        cs.get = function(state) {
            if (!state) {
                return;
            }

            var key = 'kc-callback-' + state;
            var value = localStorage.getItem(key);
            if (value) {
                localStorage.removeItem(key);
                value = JSON.parse(value);
            }

            clearExpired();
            return value;
        };

        cs.add = function(state) {
            clearExpired();

            var key = 'kc-callback-' + state.state;
            state.expires = new Date().getTime() + (60 * 60 * 1000);
            localStorage.setItem(key, JSON.stringify(state));
        };
    };

    var CookieStorage = function() {
        if (!(this instanceof CookieStorage)) {
            return new CookieStorage();
        }

        var cs = this;

        cs.get = function(state) {
            if (!state) {
                return;
            }

            var value = getCookie('kc-callback-' + state);
            setCookie('kc-callback-' + state, '', cookieExpiration(-100));
            if (value) {
                return JSON.parse(value);
            }
        };

        cs.add = function(state) {
            setCookie('kc-callback-' + state.state, JSON.stringify(state), cookieExpiration(60));
        };

        cs.removeItem = function(key) {
            setCookie(key, '', cookieExpiration(-100));
        };

        var cookieExpiration = function (minutes) {
            var exp = new Date();
            exp.setTime(exp.getTime() + (minutes*60*1000));
            return exp;
        };

        var getCookie = function (key) {
            var name = key + '=';
            var ca = document.cookie.split(';');
            for (var i = 0; i < ca.length; i++) {
                var c = ca[i];
                while (c.charAt(0) == ' ') {
                    c = c.substring(1);
                }
                if (c.indexOf(name) == 0) {
                    return c.substring(name.length, c.length);
                }
            }
            return '';
        };

        var setCookie = function (key, value, expirationDate) {
            var cookie = key + '=' + value + '; '
                + 'expires=' + expirationDate.toUTCString() + '; ';
            document.cookie = cookie;
        }
    };

    function createCallbackStorage() {
        try {
            return new LocalStorage();
        } catch (err) {
        }

        return new CookieStorage();
    }

    function createLogger(fn) {
        return function() {
            if (kc.enableLogging) {
                fn.apply(console, Array.prototype.slice.call(arguments));
            }
        };
    }
}

export default Keycloak;

/**
 * @param {ArrayBuffer} bytes
 * @see https://developer.mozilla.org/en-US/docs/Glossary/Base64#the_unicode_problem
 */
function bytesToBase64(bytes) {
    const binString = String.fromCodePoint(...bytes);
    return btoa(binString);
}

/**
 * @param {string} message
 * @see https://developer.mozilla.org/en-US/docs/Web/API/SubtleCrypto/digest#basic_example
 */
async function sha256Digest(message) {
    const encoder = new TextEncoder();
    const data = encoder.encode(message);
    const hash = await crypto.subtle.digest("SHA-256", data);
    return hash;
}

/**
 * @param {string} token
 */
function decodeToken(token) {
    const [header, payload] = token.split(".");

    if (typeof payload !== "string") {
        throw new Error("Unable to decode token, payload not found.");
    }

    let decoded;

    try {
        decoded = base64UrlDecode(payload);
    } catch (error) {
        throw new Error("Unable to decode token, payload is not a valid Base64URL value.", { cause: error });
    }

    try {
        return JSON.parse(decoded);
    } catch (error) {
        throw new Error("Unable to decode token, payload is not a valid JSON value.", { cause: error });
    }
}

/**
 * @param {string} input
 */
function base64UrlDecode(input) {
    let output = input
        .replaceAll("-", "+")
        .replaceAll("_", "/");

    switch (output.length % 4) {
        case 0:
            break;
        case 2:
            output += "==";
            break;
        case 3:
            output += "=";
            break;
        default:
            throw new Error("Input is not of the correct length.");
    }

    try {
        return b64DecodeUnicode(output);
    } catch (error) {
        return atob(output);
    }
}

/**
 * @param {string} input
 */
function b64DecodeUnicode(input) {
    return decodeURIComponent(atob(input).replace(/(.)/g, (m, p) => {
        let code = p.charCodeAt(0).toString(16).toUpperCase();

        if (code.length < 2) {
            code = "0" + code;
        }

        return "%" + code;
    }));
}