/*
 * 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.
 */
import base64 from 'base64-js';
import sha256 from 'js-sha256';

if (typeof Promise === 'undefined') {
    throw Error('Keycloak requires an environment that supports Promises. Make sure that you include the appropriate polyfill.');
}

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
    };

    var scripts = document.getElementsByTagName('script');
    for (var i = 0; i < scripts.length; i++) {
        if ((scripts[i].src.indexOf('keycloak.js') !== -1 || scripts[i].src.indexOf('keycloak.min.js') !== -1) && scripts[i].src.indexOf('version=') !== -1) {
            kc.iframeVersion = scripts[i].src.substring(scripts[i].src.indexOf('version=') + 8).split('&')[0];
        }
    }

    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 (initOptions.pkceMethod) {
                if (initOptions.pkceMethod !== "S256") {
                    throw 'Invalid value for pkceMethod';
                }
                kc.pkceMethod = initOptions.pkceMethod;
            }

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

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

            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 = function() {
                var ifrm = document.createElement("iframe");
                var src = 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();
            }
        }

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

            var checkReadyState = function () {
                if (document.readyState === 'interactive' || document.readyState === 'complete') {
                    document.removeEventListener('readystatechange', checkReadyState);
                    promise.setSuccess();
                }
            }
            document.addEventListener('readystatechange', checkReadyState);

            checkReadyState(); // just in case the event was already fired and we missed it (in case the init is done later than at the load time, i.e. it's done from code)

            return promise.promise;
        }

        configPromise.then(function () {
            domReady()
                .then(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);
    }

    function generatePkceChallenge(pkceMethod, codeVerifier) {
        switch (pkceMethod) {
            // The use of the "plain" method is considered insecure and therefore not supported.
            case "S256":
                // hash codeVerifier, then encode as url-safe base64 without padding
                var hashBytes = new Uint8Array(sha256.arrayBuffer(codeVerifier));
                var encodedHash = base64.fromByteArray(hashBytes)
                    .replace(/\+/g, '-')
                    .replace(/\//g, '_')
                    .replace(/\=/g, '');
                return encodedHash;
            default:
                throw 'Invalid value for pkceMethod';
        }
    }

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

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

        var redirectUri = adapter.redirectUri(options);

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

        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 && options.maxAge) {
            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 (kc.pkceMethod) {
            var codeVerifier = generateCodeVerifier(96);
            callbackState.pkceCodeVerifier = codeVerifier;
            var pkceChallenge = 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) {
        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 = function(options) {
        if (!options) {
            options = {};
        }
        options.action = 'register';
        return 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']);
        }

        if (error) {
            if (prompt != 'none') {
                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.tokenParsed && kc.tokenParsed.nonce != oauth.storedNonce) ||
                (kc.refreshTokenParsed && kc.refreshTokenParsed.nonce != oauth.storedNonce) ||
                (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() {
                        var src = getRealmUrl() + '/protocol/openid-connect/login-status-iframe.html';
                        if (kc.iframeVersion) {
                            src = src + '?version=' + kc.iframeVersion;
                        }
                        return src;
                    },
                    thirdPartyCookiesIframe: function() {
                        var src = getRealmUrl() + '/protocol/openid-connect/3p-cookies/step1.html';
                        if (kc.iframeVersion) {
                            src = src + '?version=' + kc.iframeVersion;
                        }
                        return src;
                    },
                    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.session_state;
            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 decodeToken(str) {
        str = str.split('.')[1];

        str = str.replace(/-/g, '+');
        str = str.replace(/_/g, '/');
        switch (str.length % 4) {
            case 0:
                break;
            case 2:
                str += '==';
                break;
            case 3:
                str += '=';
                break;
            default:
                throw 'Invalid token';
        }

        str = decodeURIComponent(escape(atob(str)));

        str = JSON.parse(str);
        return str;
    }

    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;
        }

        return oauth;
    }

    function parseCallbackUrl(url) {
        var supportedParams;
        switch (kc.flow) {
            case 'standard':
                supportedParams = ['code', 'state', 'session_state', 'kc_action_status', 'iss'];
                break;
            case 'implicit':
                supportedParams = ['access_token', 'token_type', 'id_token', 'state', 'session_state', 'expires_in', 'kc_action_status', 'iss'];
                break;
            case 'hybrid':
                supportedParams = ['access_token', 'token_type', 'id_token', 'code', 'state', 'session_state', 'expires_in', 'kc_action_status', '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: function(options) {
                    window.location.assign(kc.createLoginUrl(options));
                    return createPromise().promise;
                },

                logout: function(options) {
                    window.location.replace(kc.createLogoutUrl(options));
                    return createPromise().promise;
                },

                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 cordovaRedirectUri = kc.redirectUri || 'http://localhost';
            
            return {
                login: function(options) {
                    var promise = createPromise();

                    var cordovaOptions = createCordovaOptions(options);
                    var loginUrl = 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(cordovaRedirectUri) == 0) {
                            var callback = parseCallback(event.url);
                            processCallback(callback, promise);
                            closeBrowser();
                            completed = true;
                        }
                    });

                    ref.addEventListener('loaderror', function(event) {
                        if (!completed) {
                            if (event.url.indexOf(cordovaRedirectUri) == 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(cordovaRedirectUri) == 0) {
                            ref.close();
                        }
                    });

                    ref.addEventListener('loaderror', function(event) {
                        if (event.url.indexOf(cordovaRedirectUri) == 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(cordovaRedirectUri) == 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(cordovaRedirectUri) == 0) {
                                ref.close();
                            }
                        });
                    } else {
                        throw "Not supported by the OIDC server";
                    }
                },

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

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

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