/*
Copyright 2017 Red Hat, Inc.

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.
 */
package org.jboss.as.cli.impl.aesh.cmd.security.model;

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Objects;
import java.util.Set;
import org.jboss.as.cli.CommandContext;
import org.jboss.as.cli.Util;
import org.jboss.as.cli.operation.OperationFormatException;
import org.jboss.as.cli.operation.impl.DefaultOperationRequestBuilder;
import org.jboss.as.controller.client.ModelControllerClient;
import org.jboss.dmr.ModelNode;

/**
 * Utility class to interact with Elytron subsystem.
 *
 * @author jdenise@redhat.com
 */
public abstract class ElytronUtil {

    private static final String PLAIN_MECHANISM = "PLAIN";
    private static final String DIGEST_MD5_MECHANISM = "DIGEST-MD5";
    private static final String EXTERNAL_MECHANISM = "EXTERNAL";
    private static final String JBOSS_LOCAL_USER_MECHANISM = "JBOSS-LOCAL-USER";

    private static final String BASIC_MECHANISM = "BASIC";
    private static final String DIGEST_MECHANISM = "DIGEST";
    private static final String FORM_MECHANISM = "FORM";
    private static final String CLIENT_CERT_MECHANISM = "CLIENT_CERT";

    private static final String SCRAM_SHA_1 = "SCRAM-SHA-1";
    private static final String SCRAM_SHA_1_PLUS = "SCRAM-SHA-1-PLUS";
    private static final String SCRAM_SHA_256 = "SCRAM-SHA-256";
    private static final String SCRAM_SHA_256_PLUS = "SCRAM-SHA-256-PLUS";
    private static final String SCRAM_SHA_384 = "SCRAM-SHA-384";
    private static final String SCRAM_SHA_384_PLUS = "SCRAM-SHA-384-PLUS";
    private static final String SCRAM_SHA_512 = "SCRAM-SHA-512";
    private static final String SCRAM_SHA_512_PLUS = "SCRAM-SHA-512-PLUS";

    private static final String DIGEST_SHA = "DIGEST-SHA";
    private static final String DIGEST_SHA_256 = "DIGEST-SHA-256";
    private static final String DIGEST_SHA_384 = "DIGEST-SHA-384";
    private static final String DIGEST_SHA_512 = "DIGEST-SHA-512";

    public static final String JKS = "JKS";
    public static final String PKCS12 = "PKCS12";
    public static final String TLS_V1_2 = "TLSv1.2";

    public static String OOTB_MANAGEMENT_SASL_FACTORY = "management-sasl-authentication";
    public static String OOTB_MANAGEMENT_HTTP_FACTORY = "management-http-authentication";
    public static String OOTB_APPLICATION_HTTP_FACTORY = "application-http-authentication";
    public static String OOTB_APPLICATION_DOMAIN = "ApplicationDomain";

    public static final String SASL_SERVER_CAPABILITY = "org.wildfly.security.sasl-server-factory";
    public static final String HTTP_SERVER_CAPABILITY = "org.wildfly.security.http-server-mechanism-factory";

    private static final Set<String> MECHANISMS_WITH_REALM = new HashSet<>();

    private static final Set<String> MECHANISMS_WITH_TRUST_STORE = new HashSet<>();

    private static final Set<String> MECHANISMS_LOCAL_USER = new HashSet<>();

    static {
        MECHANISMS_WITH_REALM.add(PLAIN_MECHANISM);
        MECHANISMS_WITH_REALM.add(DIGEST_MD5_MECHANISM);
        MECHANISMS_WITH_REALM.add(DIGEST_MECHANISM);
        MECHANISMS_WITH_REALM.add(FORM_MECHANISM);
        MECHANISMS_WITH_REALM.add(BASIC_MECHANISM);

        MECHANISMS_WITH_REALM.add(SCRAM_SHA_1);
        MECHANISMS_WITH_REALM.add(SCRAM_SHA_1_PLUS);
        MECHANISMS_WITH_REALM.add(SCRAM_SHA_256);
        MECHANISMS_WITH_REALM.add(SCRAM_SHA_256_PLUS);
        MECHANISMS_WITH_REALM.add(SCRAM_SHA_384);
        MECHANISMS_WITH_REALM.add(SCRAM_SHA_384_PLUS);
        MECHANISMS_WITH_REALM.add(SCRAM_SHA_512);
        MECHANISMS_WITH_REALM.add(SCRAM_SHA_512_PLUS);

        MECHANISMS_WITH_REALM.add(DIGEST_SHA);
        MECHANISMS_WITH_REALM.add(DIGEST_SHA_256);
        MECHANISMS_WITH_REALM.add(DIGEST_SHA_384);
        MECHANISMS_WITH_REALM.add(DIGEST_SHA_512);

        MECHANISMS_WITH_TRUST_STORE.add(EXTERNAL_MECHANISM);
        MECHANISMS_WITH_TRUST_STORE.add(CLIENT_CERT_MECHANISM);

        MECHANISMS_LOCAL_USER.add(JBOSS_LOCAL_USER_MECHANISM);
    }

    private ElytronUtil() {
    }

    static String retrieveKeyStorePassword(CommandContext ctx, String name) throws OperationFormatException, IOException {
        DefaultOperationRequestBuilder builder = new DefaultOperationRequestBuilder();
        builder.setOperationName(Util.READ_ATTRIBUTE);
        builder.addNode(Util.SUBSYSTEM, Util.ELYTRON);
        builder.addNode(Util.KEY_STORE, name);
        builder.addProperty(Util.NAME, Util.CREDENTIAL_REFERENCE);
        ModelNode request = builder.buildRequest();
        ModelNode response = ctx.getModelControllerClient().execute(request);
        String password = null;
        if (Util.isSuccess(response)) {
            if (response.hasDefined(Util.RESULT)) {
                ModelNode res = response.get(Util.RESULT);
                if (res.hasDefined(Util.CLEAR_TEXT)) {
                    password = res.get(Util.CLEAR_TEXT).asString();
                }
            }
        }
        return password;
    }

    static String findMatchingKeyStore(CommandContext ctx, File path, String relativeTo, String password, String type, Boolean required, String alias) throws OperationFormatException, IOException {
        ModelNode resource = buildKeyStoreResource(path, relativeTo, password, type, required, alias);
        List<String> names = findMatchingResources(ctx, Util.KEY_STORE, resource);
        if (names.isEmpty()) {
            return null;
        }
        return names.get(0);
    }

    static List<String> findMatchingKeyStores(CommandContext ctx, File path, String relativeTo) throws OperationFormatException, IOException {
        ModelNode resource = buildKeyStoreResource(path, relativeTo, null, null, null, null);
        return findMatchingResources(ctx, Util.KEY_STORE, resource);
    }

    private static ModelNode buildKeyStoreResource(File path, String relativeTo,
            String password, String type, Boolean required, String alias) throws IOException {
        ModelNode localKS = new ModelNode();
        if (path != null) {
            localKS.get(Util.PATH).set(path.getPath());
        }
        if (relativeTo != null) {
            localKS.get(Util.RELATIVE_TO).set(relativeTo);
        } else {
            localKS.get(Util.RELATIVE_TO);
        }
        if (password != null) {
            localKS.get(Util.CREDENTIAL_REFERENCE).set(buildCredentialReferences(password));
        }
        if (type != null) {
            localKS.get(Util.TYPE).set(type);
        }
        if (required != null) {
            localKS.get(Util.REQUIRED).set(required);
        }
        if (alias != null) {
            localKS.get(Util.ALIAS_FILTER, alias);
        } else {
            localKS.get(Util.ALIAS_FILTER);
        }
        return localKS;
    }

    private static ModelNode buildKeyManagerResource(KeyStore keyStore, String alias, String algorithm) {
        ModelNode localKM = new ModelNode();
        if (keyStore.getPassword() != null) {
            localKM.get(Util.CREDENTIAL_REFERENCE).set(buildCredentialReferences(keyStore.getPassword()));
        }
        localKM.get(Util.KEY_STORE).set(keyStore.getName());
        if (alias != null) {
            localKM.get(Util.ALIAS_FILTER, alias);
        } else {
            localKM.get(Util.ALIAS_FILTER);
        }
        if (algorithm != null) {
            localKM.get(Util.ALGORITHM, algorithm);
        } else {
            localKM.get(Util.ALGORITHM);
        }
        return localKM;
    }

    private static ModelNode buildTrustManagerResource(KeyStore keyStore, String alias, String algorithm) {
        // No password in trust-store
        ModelNode mn = buildKeyManagerResource(keyStore, alias, algorithm);
        mn.remove(Util.CREDENTIAL_REFERENCE);
        return mn;
    }

    private static List<String> findMatchingResources(CommandContext ctx, String type,
            ModelNode resource) throws OperationFormatException, IOException {
        DefaultOperationRequestBuilder builder = new DefaultOperationRequestBuilder();
        builder.setOperationName(Util.READ_CHILDREN_RESOURCES);
        builder.addNode(Util.SUBSYSTEM, Util.ELYTRON);
        builder.addProperty(Util.CHILD_TYPE, type);
        ModelNode request = builder.buildRequest();
        ModelNode response = ctx.getModelControllerClient().execute(request);
        List<String> matches = new ArrayList<>();
        if (Util.isSuccess(response)) {
            if (response.hasDefined(Util.RESULT)) {
                ModelNode res = response.get(Util.RESULT);
                for (String ksName : res.keys()) {
                    ModelNode ks = res.get(ksName);
                    List<String> meaninglessKeys = new ArrayList<>();
                    for (String k : ks.keys()) {
                        if (!resource.keys().contains(k)) {
                            meaninglessKeys.add(k);
                        }
                    }
                    for (String s : meaninglessKeys) {
                        ks.remove(s);
                    }
                    if (resource.equals(ks)) {
                        matches.add(ksName);
                    }
                }
            }
        }
        return matches;
    }

    static String findMatchingKeyManager(CommandContext ctx, KeyStore keyStore,
            String alias, String algorithm) throws OperationFormatException, IOException {
        ModelNode resource = buildKeyManagerResource(keyStore, alias, algorithm);
        List<String> names = findMatchingResources(ctx, Util.KEY_MANAGER, resource);
        if (names.isEmpty()) {
            return null;
        }
        return names.get(0);
    }

    static String findMatchingTrustManager(CommandContext ctx, KeyStore keyStore,
            String alias, String algorithm) throws OperationFormatException, IOException {
        ModelNode resource = buildTrustManagerResource(keyStore, alias, algorithm);
        List<String> names = findMatchingResources(ctx, Util.TRUST_MANAGER, resource);
        if (names.isEmpty()) {
            return null;
        }
        return names.get(0);
    }

    static String findMatchingSSLContext(CommandContext ctx, ServerSSLContext sslCtx) throws OperationFormatException, IOException {
        List<String> names = findMatchingResources(ctx, Util.SERVER_SSL_CONTEXT, sslCtx.buildResource());
        if (names.isEmpty()) {
            return null;
        }
        return names.get(0);
    }

    static ModelNode addKeyStore(CommandContext ctx, String name, File path,
            String relativeTo, String password, String type, Boolean required, String alias) throws Exception {
        ModelNode mn = buildKeyStoreResource(path, relativeTo, password, type, required, alias);
        DefaultOperationRequestBuilder builder = new DefaultOperationRequestBuilder();
        builder.setOperationName(Util.ADD);
        builder.addNode(Util.SUBSYSTEM, Util.ELYTRON);
        builder.addNode(Util.KEY_STORE, name);
        for (String k : mn.keys()) {
            builder.getModelNode().get(k).set(mn.get(k));
        }
        return builder.buildRequest();
    }

    static ModelNode generateKeyPair(CommandContext ctx, String name, String dn, String alias, Long validity, String keyAlg, int keySize) throws Exception {
        DefaultOperationRequestBuilder builder = new DefaultOperationRequestBuilder();
        builder.setOperationName(Util.GENERATE_KEY_PAIR);
        builder.addNode(Util.SUBSYSTEM, Util.ELYTRON);
        builder.addNode(Util.KEY_STORE, name);
        builder.getModelNode().get(Util.DISTINGUISHED_NAME).set(dn);
        builder.getModelNode().get(Util.ALGORITHM).set(keyAlg);
        builder.getModelNode().get(Util.KEY_SIZE).set(keySize);
        builder.getModelNode().get(Util.ALIAS).set(alias);
        if (validity != null) {
            builder.getModelNode().get(Util.VALIDITY).set(validity);
        }
        return builder.buildRequest();
    }

    static ModelNode importCertificate(CommandContext ctx, File trustedCertificate,
            String alias, boolean validate, KeyStore trustStore, boolean trust) throws OperationFormatException {
        DefaultOperationRequestBuilder builder = new DefaultOperationRequestBuilder();
        builder.setOperationName(Util.IMPORT_CERTIFICATE);
        builder.addNode(Util.SUBSYSTEM, Util.ELYTRON);
        builder.addNode(Util.KEY_STORE, trustStore.getName());
        builder.getModelNode().get(Util.ALIAS).set(alias);
        builder.getModelNode().get(Util.PATH).set(trustedCertificate.getAbsolutePath());
        builder.getModelNode().get(Util.TRUST_CACERTS).set(trust);
        builder.getModelNode().get(Util.VALIDATE).set(validate);
        return builder.buildRequest();
    }

    static ModelNode storeKeyStore(CommandContext ctx, String name) throws OperationFormatException {
        DefaultOperationRequestBuilder builder = new DefaultOperationRequestBuilder();
        builder.setOperationName(Util.STORE);
        builder.addNode(Util.SUBSYSTEM, Util.ELYTRON);
        builder.addNode(Util.KEY_STORE, name);
        return builder.buildRequest();
    }

    static ModelNode removeKeyStore(CommandContext ctx, String name) throws Exception {
        DefaultOperationRequestBuilder builder = new DefaultOperationRequestBuilder();
        builder.setOperationName(Util.REMOVE);
        builder.addNode(Util.SUBSYSTEM, Util.ELYTRON);
        builder.addNode(Util.KEY_STORE, name);
        return builder.buildRequest();
    }

    static ModelNode exportCertificate(CommandContext ctx, String name, File path, String relativeTo, String alias, boolean pem) throws Exception {
        DefaultOperationRequestBuilder builder = new DefaultOperationRequestBuilder();
        builder.setOperationName(Util.EXPORT_CERTIFICATE);
        builder.addNode(Util.SUBSYSTEM, Util.ELYTRON);
        builder.addNode(Util.KEY_STORE, name);
        builder.getModelNode().get(Util.PATH).set(path.getPath());
        builder.getModelNode().get(Util.ALIAS).set(alias);
        if (relativeTo != null) {
            builder.getModelNode().get(Util.RELATIVE_TO).set(relativeTo);
        }
        builder.getModelNode().get(Util.PEM).set(pem);
        return builder.buildRequest();
    }

    static ModelNode generateSigningRequest(CommandContext ctx, String name,
            File path, String relativeTo, String alias) throws Exception {
        DefaultOperationRequestBuilder builder = new DefaultOperationRequestBuilder();
        builder.setOperationName(Util.GENERATE_CERTIFICATE_SIGNING_REQUEST);
        builder.addNode(Util.SUBSYSTEM, Util.ELYTRON);
        builder.addNode(Util.KEY_STORE, name);
        builder.getModelNode().get(Util.PATH).set(path.getPath());
        builder.getModelNode().get(Util.ALIAS).set(alias);
        if (relativeTo != null) {
            builder.getModelNode().get(Util.RELATIVE_TO).set(relativeTo);
        }
        return builder.buildRequest();
    }

    static ModelNode addKeyManager(CommandContext ctx, KeyStore keyStore, String name, String alias, String algorithm) throws Exception {
        DefaultOperationRequestBuilder builder = new DefaultOperationRequestBuilder();
        builder.setOperationName(Util.ADD);
        builder.addNode(Util.SUBSYSTEM, Util.ELYTRON);
        builder.addNode(Util.KEY_MANAGER, name);
        ModelNode mn = buildKeyManagerResource(keyStore, alias, algorithm);
        for (String k : mn.keys()) {
            builder.getModelNode().get(k).set(mn.get(k));
        }
        builder.getModelNode().get(Util.CREDENTIAL_REFERENCE).set(buildCredentialReferences(keyStore.getPassword()));
        return builder.buildRequest();
    }

    static ModelNode addTrustManager(CommandContext ctx, KeyStore keyStore, String name, String alias, String algorithm) throws Exception {
        DefaultOperationRequestBuilder builder = new DefaultOperationRequestBuilder();
        builder.setOperationName(Util.ADD);
        builder.addNode(Util.SUBSYSTEM, Util.ELYTRON);
        builder.addNode(Util.TRUST_MANAGER, name);
        ModelNode mn = buildKeyManagerResource(keyStore, alias, algorithm);
        for (String k : mn.keys()) {
            builder.getModelNode().get(k).set(mn.get(k));
        }
        if (keyStore.getPassword() != null) {
            builder.getModelNode().get(Util.CREDENTIAL_REFERENCE).set(buildCredentialReferences(keyStore.getPassword()));
        }
        return builder.buildRequest();
    }

    static ModelNode addServerSSLContext(CommandContext ctx, ServerSSLContext sslCtx, String name) throws Exception {
        DefaultOperationRequestBuilder builder = new DefaultOperationRequestBuilder();
        builder.setOperationName(Util.ADD);
        builder.addNode(Util.SUBSYSTEM, Util.ELYTRON);
        builder.addNode(Util.SERVER_SSL_CONTEXT, name);
        ModelNode mn = sslCtx.buildResource();
        for (String k : mn.keys()) {
            builder.getModelNode().get(k).set(mn.get(k));
        }
        return builder.buildRequest();
    }

    private static ModelNode buildCredentialReferences(String password) {
        ModelNode mn = new ModelNode();
        mn.get(Util.CLEAR_TEXT).set(password);
        return mn;
    }

    static boolean keyManagerExists(CommandContext ctx, String name) throws IOException, OperationFormatException {
        DefaultOperationRequestBuilder builder = new DefaultOperationRequestBuilder();
        builder.setOperationName(Util.READ_RESOURCE);
        builder.addNode(Util.SUBSYSTEM, Util.ELYTRON);
        builder.addNode(Util.KEY_MANAGER, name);
        return Util.isSuccess(ctx.getModelControllerClient().execute(builder.buildRequest()));
    }

    public static boolean trustManagerExists(CommandContext ctx, String name) throws IOException, OperationFormatException {
        DefaultOperationRequestBuilder builder = new DefaultOperationRequestBuilder();
        builder.setOperationName(Util.READ_RESOURCE);
        builder.addNode(Util.SUBSYSTEM, Util.ELYTRON);
        builder.addNode(Util.TRUST_MANAGER, name);
        return Util.isSuccess(ctx.getModelControllerClient().execute(builder.buildRequest()));
    }

    public static boolean keyStoreExists(CommandContext ctx, String name) throws OperationFormatException, IOException {
        DefaultOperationRequestBuilder builder = new DefaultOperationRequestBuilder();
        builder.setOperationName(Util.READ_RESOURCE);
        builder.addNode(Util.SUBSYSTEM, Util.ELYTRON);
        builder.addNode(Util.KEY_STORE, name);
        return Util.isSuccess(ctx.getModelControllerClient().execute(builder.buildRequest()));
    }

    public static boolean serverSSLContextExists(CommandContext ctx, String name) throws OperationFormatException, IOException {
        DefaultOperationRequestBuilder builder = new DefaultOperationRequestBuilder();
        builder.setOperationName(Util.READ_RESOURCE);
        builder.addNode(Util.SUBSYSTEM, Util.ELYTRON);
        builder.addNode(Util.SERVER_SSL_CONTEXT, name);
        return Util.isSuccess(ctx.getModelControllerClient().execute(builder.buildRequest()));
    }

    public static List<String> getKeyStoreNames(ModelControllerClient client) {
        return getNames(client, Util.KEY_STORE);
    }

    public static List<String> getSecurityDomainNames(ModelControllerClient client) {
        return getNames(client, Util.SECURITY_DOMAIN);
    }

    public static List<String> getConstantRoleMappers(ModelControllerClient client) {
        return getNames(client, Util.CONSTANT_ROLE_MAPPER);
    }

    private static List<String> getNames(ModelControllerClient client, String type) {
        final DefaultOperationRequestBuilder builder = new DefaultOperationRequestBuilder();
        final ModelNode request;
        try {
            builder.setOperationName(Util.READ_CHILDREN_NAMES);
            builder.addNode(Util.SUBSYSTEM, Util.ELYTRON);
            builder.addProperty(Util.CHILD_TYPE, type);
            request = builder.buildRequest();
        } catch (OperationFormatException e) {
            throw new IllegalStateException("Failed to build operation", e);
        }

        try {
            final ModelNode outcome = client.execute(request);
            if (Util.isSuccess(outcome)) {
                return Util.getList(outcome);
            }
        } catch (Exception e) {
        }

        return Collections.emptyList();
    }

    private static ModelNode getChildResource(String name, String type, CommandContext ctx) {
        final DefaultOperationRequestBuilder builder = new DefaultOperationRequestBuilder();
        final ModelNode request;
        try {
            builder.setOperationName(Util.READ_RESOURCE);
            builder.addNode(Util.SUBSYSTEM, Util.ELYTRON);
            builder.addNode(type, name);
            request = builder.buildRequest();
        } catch (OperationFormatException e) {
            throw new IllegalStateException("Failed to build operation", e);
        }

        try {
            final ModelNode outcome = ctx.getModelControllerClient().execute(request);
            if (Util.isSuccess(outcome)) {
                return outcome.get(Util.RESULT);
            }
        } catch (Exception e) {
        }
        return null;
    }

    public static ServerSSLContext getServerSSLContext(CommandContext context, String sslContextName) {
        ModelNode sslContext = getChildResource(sslContextName, Util.SERVER_SSL_CONTEXT, context);
        ServerSSLContext ctx = null;
        if (sslContext != null) {
            String kmName = sslContext.get(Util.KEY_MANAGER).asString();
            ModelNode km = getChildResource(kmName, Util.KEY_MANAGER, context);
            String ksName = km.get(Util.KEY_STORE).asString();
            KeyStore keyStore = new KeyStore(ksName, null, true);
            KeyManager keyManager = new KeyManager(kmName, keyStore, true);
            KeyManager trustManager = null;
            if (sslContext.hasDefined(Util.TRUST_MANAGER)) {
                trustManager = new KeyManager(sslContext.get(Util.TRUST_MANAGER).asString(), keyStore, true);
            }
            ctx = new ServerSSLContext(ksName, keyManager, trustManager, true);
        }
        return ctx;
    }

    public static KeyStore getKeyStore(CommandContext ctx, String name) throws OperationFormatException, IOException {
        String password;
        password = ElytronUtil.retrieveKeyStorePassword(ctx, name);

        if (password == null) {
            // Can be null for trust-store, inconcistency in API.
            //throw new OperationFormatException("Can't retrieve password for " + name);
        }
        return new KeyStore(name, password, true);
    }

    public static boolean isElytronSupported(CommandContext commandContext) throws IOException, OperationFormatException {
        final DefaultOperationRequestBuilder builder = new DefaultOperationRequestBuilder();
        builder.setOperationName(Util.READ_RESOURCE);
        builder.addNode(Util.SUBSYSTEM, Util.ELYTRON);
        ModelNode response = commandContext.getModelControllerClient().execute(builder.buildRequest());
        return Util.isSuccess(response);
    }

    public static boolean isKeyStoreManagementSupported(CommandContext commandContext) throws IOException, OperationFormatException {
        final DefaultOperationRequestBuilder builder = new DefaultOperationRequestBuilder();
        builder.setOperationName(Util.READ_OPERATION_DESCRIPTION);
        builder.addNode(Util.SUBSYSTEM, Util.ELYTRON);
        builder.addNode(Util.KEY_STORE, "?");
        builder.addProperty(Util.NAME, Util.GENERATE_KEY_PAIR);
        ModelNode response = commandContext.getModelControllerClient().execute(builder.buildRequest());
        return Util.isSuccess(response);
    }

    public static ModelNode getAuthFactoryResource(String authFactory, AuthFactorySpec spec, CommandContext ctx) {
        final DefaultOperationRequestBuilder builder = new DefaultOperationRequestBuilder();
        final ModelNode request;
        try {
            builder.setOperationName(Util.READ_RESOURCE);
            builder.addNode(Util.SUBSYSTEM, Util.ELYTRON);
            builder.addNode(spec.getResourceType(), authFactory);
            request = builder.buildRequest();
        } catch (OperationFormatException e) {
            throw new IllegalStateException("Failed to build operation", e);
        }

        try {
            final ModelNode outcome = ctx.getModelControllerClient().execute(request);
            if (Util.isSuccess(outcome)) {
                return outcome.get(Util.RESULT);
            }
        } catch (Exception e) {
        }
        return null;
    }

    public static ModelNode reorderSASLFactory(CommandContext ctx, List<String> order, String factoryName) throws Exception {
        ModelNode factory = getAuthFactoryResource(factoryName, AuthFactorySpec.SASL, ctx);
        if (factory == null) {
            throw new Exception("Invalid factory name " + factoryName);
        }
        if (factory.hasDefined(Util.MECHANISM_CONFIGURATIONS)) {
            ModelNode mechanisms = factory.get(Util.MECHANISM_CONFIGURATIONS);
            Set<String> seen = new HashSet<>();
            List<ModelNode> newOrder = new ArrayList<>();
            for (String o : order) {
                for (ModelNode m : mechanisms.asList()) {
                    String name = m.get(Util.MECHANISM_NAME).asString();
                    if (o.equals(name)) {
                        newOrder.add(m);
                    }
                    seen.add(name);
                }
            }
            for (String r : order) {
                if (!seen.contains(r)) {
                    throw new Exception("Mechanism " + r
                            + " is not contained in SASL factory " + factoryName);
                }
            }
            if (!order.containsAll(seen)) {
                throw new Exception("Mechanism list is not complete, existing mechanisms are:" + seen);
            }

            if (newOrder.isEmpty()) {
                throw new Exception("Error: All mechanisms would be removed, this would fully disable access.");
            }
            ModelNode newValue = new ModelNode();
            newValue.set(newOrder);
            DefaultOperationRequestBuilder builder = new DefaultOperationRequestBuilder();
            builder.setOperationName(Util.WRITE_ATTRIBUTE);
            builder.addNode(Util.SUBSYSTEM, Util.ELYTRON);
            builder.addNode(AuthFactorySpec.SASL.getResourceType(), factoryName);
            builder.addProperty(Util.NAME, Util.MECHANISM_CONFIGURATIONS);
            builder.getModelNode().get(Util.VALUE).set(newValue);
            return builder.buildRequest();
        } else {
            throw new Exception("No mechanism to re-order in Factory " + factoryName);
        }
    }

    public static AuthFactory findMatchingAuthFactory(AuthMechanism newMechanism,
            AuthFactorySpec spec, CommandContext ctx) throws OperationFormatException, IOException {
        DefaultOperationRequestBuilder builder = new DefaultOperationRequestBuilder();
        builder.setOperationName(Util.READ_CHILDREN_RESOURCES);
        builder.addNode(Util.SUBSYSTEM, Util.ELYTRON);
        builder.addProperty(Util.CHILD_TYPE, spec.getResourceType());
        ModelNode request = builder.buildRequest();
        ModelNode response = ctx.getModelControllerClient().execute(request);
        AuthFactory factory = null;
        if (Util.isSuccess(response)) {
            if (response.hasDefined(Util.RESULT)) {
                ModelNode res = response.get(Util.RESULT);
                for (String ksName : res.keys()) {
                    ModelNode ks = res.get(ksName);
                    AuthFactory fact = getAuthFactory(ks, ksName, spec, ctx);
                    List<AuthMechanism> mecs = fact.getMechanisms();
                    if (mecs.isEmpty() || mecs.size() > 1) {
                        continue;
                    }
                    AuthMechanism mec = mecs.get(0);
                    // Only compare, type, realmName and realmMapper.
                    if (newMechanism.getType().equals(mec.getType())) {
                        if (newMechanism.getConfig().getRealmMapper() == null) {
                            if (Objects.equals(newMechanism.getConfig().getRealmName(),
                                    mec.getConfig().getRealmName())) {
                                factory = fact;
                                break;
                            }
                        } else if (Objects.equals(newMechanism.getConfig().getRealmMapper(),
                                mec.getConfig().getRealmMapper())) {
                            factory = fact;
                            break;
                        }
                    }
                }
            }
        }
        return factory;
    }

    public static AuthFactory getAuthFactory(String authFactory, AuthFactorySpec spec, CommandContext ctx) {
        ModelNode mn = getAuthFactoryResource(authFactory, spec, ctx);
        return getAuthFactory(mn, authFactory, spec, ctx);
    }

    public static AuthFactory getAuthFactory(ModelNode mn, String authFactory, AuthFactorySpec spec, CommandContext ctx) {
        AuthFactory factory = null;
        if (mn != null) {
            SecurityDomain sc = new SecurityDomain(mn.get(Util.SECURITY_DOMAIN).asString());
            factory = new AuthFactory(authFactory, sc, spec);
            if (mn.hasDefined(Util.MECHANISM_CONFIGURATIONS)) {
                ModelNode lst = mn.get(Util.MECHANISM_CONFIGURATIONS);
                for (ModelNode m : lst.asList()) {
                    String name = m.get(Util.MECHANISM_NAME).asString();
                    String realmMapper = null;
                    String realmName = null;
                    if (m.hasDefined(Util.REALM_MAPPER)) {
                        realmMapper = m.get(Util.REALM_MAPPER).asString();
                    }
                    // XXX This could be evolved with new exposed attributes
                    if (m.hasDefined(Util.MECHANISM_REALM_CONFIGURATIONS)) {
                        ModelNode config = m.get(Util.MECHANISM_REALM_CONFIGURATIONS);
                        for (ModelNode c : config.asList()) {
                            if (c.hasDefined(Util.REALM_NAME)) {
                                realmName = c.get(Util.REALM_NAME).asString();
                                break;
                            }
                        }
                    }
                    String finalRealmName = realmName;
                    String finalRealmMapper = realmMapper;
                    AuthMechanism mec = new AuthMechanism(name, new MechanismConfiguration() {
                        @Override
                        public String getRealmName() {
                            return finalRealmName;
                        }

                        @Override
                        public String getRoleDecoder() {
                            return null;
                        }

                        @Override
                        public String getRoleMapper() {
                            return null;
                        }

                        @Override
                        public String getRealmMapper() {
                            return finalRealmMapper;
                        }

                        @Override
                        public String getExposedRealmName() {
                            return finalRealmName;
                        }

                        @Override
                        public void setRealmMapperName(String constantMapper) {
                            // NO-OP
                        }
                    });
                    factory.addMechanism(mec);
                }
            }
        }
        return factory;
    }

    public static String findMatchingUsersPropertiesRealm(CommandContext ctx,
            PropertiesRealmConfiguration config) throws Exception {
        ModelNode resource = buildRealmResource(config);
        List<String> names = findMatchingResources(ctx, Util.PROPERTIES_REALM, resource);
        if (names.isEmpty()) {
            return null;
        }
        return names.get(0);
    }

    private static ModelNode buildRealmResource(Realm realm) {
        ModelNode mn = new ModelNode();
        mn.get(Util.REALM).set(realm.getResourceName());
        if (realm.getConfig().getRoleDecoder() != null) {
            mn.get(Util.ROLE_DECODER).set(realm.getConfig().getRoleDecoder());
        }
        if (realm.getConfig().getRoleMapper() != null) {
            mn.get(Util.ROLE_MAPPER).set(realm.getConfig().getRoleMapper());
        }
        return mn;
    }

    private static ModelNode buildRealmResource(PropertiesRealmConfiguration config) throws Exception {
        ModelNode localRealm = new ModelNode();
        localRealm.get(Util.GROUPS_ATTRIBUTE).set(Util.GROUPS);
        if (config.getGroupPropertiesFile() != null) {
            localRealm.get(Util.GROUPS_PROPERTIES).set(buildGroupsResource(config));
        }
        localRealm.get(Util.USERS_PROPERTIES).set(buildUsersResource(config));
        return localRealm;
    }

    private static ModelNode buildGroupsResource(PropertiesRealmConfiguration config) throws IOException {
        ModelNode mn = new ModelNode();
        mn.get(Util.PATH).set(config.getGroupPropertiesFile());
        if (config.getRelativeTo() != null) {
            mn.get(Util.RELATIVE_TO).set(config.getRelativeTo());
        }
        return mn;
    }

    private static ModelNode buildUsersResource(PropertiesRealmConfiguration config) throws IOException {
        ModelNode mn = new ModelNode();
        mn.get(Util.PATH).set(config.getUserPropertiesFile());
        if (config.getRelativeTo() != null) {
            mn.get(Util.RELATIVE_TO).set(config.getRelativeTo());
        }
        mn.get(Util.DIGEST_REALM_NAME).set(config.getExposedRealmName());
        return mn;
    }

    public static boolean serverPropertiesRealmExists(CommandContext ctx, String name) throws OperationFormatException, IOException {
        DefaultOperationRequestBuilder builder = new DefaultOperationRequestBuilder();
        builder.setOperationName(Util.READ_RESOURCE);
        builder.addNode(Util.SUBSYSTEM, Util.ELYTRON);
        builder.addNode(Util.PROPERTIES_REALM, name);
        return Util.isSuccess(ctx.getModelControllerClient().execute(builder.buildRequest()));
    }

    public static ModelNode addUsersPropertiesRealm(CommandContext ctx, String realmName,
            PropertiesRealmConfiguration config) throws Exception {
        ModelNode mn = buildRealmResource(config);
        DefaultOperationRequestBuilder builder = new DefaultOperationRequestBuilder();
        builder.setOperationName(Util.ADD);
        builder.addNode(Util.SUBSYSTEM, Util.ELYTRON);
        builder.addNode(Util.PROPERTIES_REALM, realmName);
        for (String k : mn.keys()) {
            builder.getModelNode().get(k).set(mn.get(k));
        }
        return builder.buildRequest();
    }

    public static String findKeyStoreRealm(CommandContext ctx, String trustStore) throws IOException, OperationFormatException {
        DefaultOperationRequestBuilder builder = new DefaultOperationRequestBuilder();
        String name = null;
        builder.setOperationName(Util.READ_CHILDREN_RESOURCES);
        builder.addNode(Util.SUBSYSTEM, Util.ELYTRON);
        builder.addProperty(Util.CHILD_TYPE, Util.KEY_STORE_REALM);
        ModelNode response = ctx.getModelControllerClient().execute(builder.buildRequest());
        if (Util.isSuccess(response)) {
            if (response.hasDefined(Util.RESULT)) {
                ModelNode mn = response.get(Util.RESULT);
                for (String key : mn.keys()) {
                    ModelNode ksr = mn.get(key);
                    if (ksr.hasDefined(Util.KEY_STORE)) {
                        String ks = ksr.get(Util.KEY_STORE).asString();
                        if (ks.equals(trustStore)) {
                            name = key;
                            break;
                        }
                    }
                }
            }
        }
        return name;
    }

    public static ModelNode addKeyStoreRealm(CommandContext ctx, String ksRealmName, String keyStore) throws OperationFormatException {
        DefaultOperationRequestBuilder builder = new DefaultOperationRequestBuilder();
        builder.setOperationName(Util.ADD);
        builder.addNode(Util.SUBSYSTEM, Util.ELYTRON);
        builder.addNode(Util.KEY_STORE_REALM, ksRealmName);
        builder.addProperty(Util.KEY_STORE, keyStore);
        return builder.buildRequest();
    }

    public static String findConstantRealmMapper(CommandContext ctx, String realmName) throws IOException, OperationFormatException {
        DefaultOperationRequestBuilder builder = new DefaultOperationRequestBuilder();
        builder.setOperationName(Util.READ_CHILDREN_RESOURCES);
        builder.addNode(Util.SUBSYSTEM, Util.ELYTRON);
        builder.addProperty(Util.CHILD_TYPE, Util.CONSTANT_REALM_MAPPER);
        ModelNode request = builder.buildRequest();
        ModelNode response = ctx.getModelControllerClient().execute(request);
        if (Util.isSuccess(response)) {
            if (response.hasDefined(Util.RESULT)) {
                ModelNode res = response.get(Util.RESULT);
                for (String csName : res.keys()) {
                    ModelNode mn = res.get(csName);
                    String constantName = mn.get(Util.REALM_NAME).asString();
                    if (realmName.equals(constantName)) {
                        return csName;
                    }
                }
            }
        }
        return null;
    }

    public static ModelNode addConstantRealmMapper(CommandContext ctx, String realmName) throws OperationFormatException, IOException {
        DefaultOperationRequestBuilder builder = new DefaultOperationRequestBuilder();
        builder.setOperationName(Util.ADD);
        builder.addNode(Util.SUBSYSTEM, Util.ELYTRON);
        builder.addNode(Util.CONSTANT_REALM_MAPPER, realmName);
        builder.addProperty(Util.REALM_NAME, realmName);
        return builder.buildRequest();
    }

    public static boolean securityDomainExists(CommandContext ctx, String name) throws OperationFormatException, IOException {
        DefaultOperationRequestBuilder builder = new DefaultOperationRequestBuilder();
        builder.setOperationName(Util.READ_RESOURCE);
        builder.addNode(Util.SUBSYSTEM, Util.ELYTRON);
        builder.addNode(Util.SECURITY_DOMAIN, name);
        return Util.isSuccess(ctx.getModelControllerClient().execute(builder.buildRequest()));
    }

    public static ModelNode addSecurityDomain(CommandContext ctx, Realm realm,
            String newSecurityDomain) throws OperationFormatException {
        DefaultOperationRequestBuilder builder = new DefaultOperationRequestBuilder();
        builder.setOperationName(Util.ADD);
        builder.addNode(Util.SUBSYSTEM, Util.ELYTRON);
        builder.addNode(Util.SECURITY_DOMAIN, newSecurityDomain);
        ModelNode mn = buildSecurityDomainResource(realm);
        for (String k : mn.keys()) {
            builder.getModelNode().get(k).set(mn.get(k));
        }
        return builder.buildRequest();
    }

    private static ModelNode buildSecurityDomainResource(Realm realm) {
        ModelNode sd = new ModelNode();
        if (realm != null) {
            sd.get(Util.REALMS).add(buildRealmResource(realm));
        }
        sd.get(Util.PERMISSION_MAPPER).set(Util.DEFAULT_PERMISSION_MAPPER);

        return sd;
    }

    public static boolean factoryExists(CommandContext ctx, String name, AuthFactorySpec spec) throws OperationFormatException, IOException {
        DefaultOperationRequestBuilder builder = new DefaultOperationRequestBuilder();
        builder.setOperationName(Util.READ_RESOURCE);
        builder.addNode(Util.SUBSYSTEM, Util.ELYTRON);
        builder.addNode(spec.getResourceType(), name);
        return Util.isSuccess(ctx.getModelControllerClient().execute(builder.buildRequest()));
    }

    public static ModelNode addAuthFactory(CommandContext ctx, SecurityDomain securityDomain,
            String newAuthFactoryName, AuthFactorySpec spec) throws OperationFormatException {
        DefaultOperationRequestBuilder builder = new DefaultOperationRequestBuilder();
        builder.setOperationName(Util.ADD);
        builder.addNode(Util.SUBSYSTEM, Util.ELYTRON);
        builder.addNode(spec.getResourceType(), newAuthFactoryName);
        ModelNode mn = buildAuthFactoryResource(securityDomain, spec);
        for (String k : mn.keys()) {
            builder.getModelNode().get(k).set(mn.get(k));
        }
        return builder.buildRequest();
    }

    private static ModelNode buildAuthFactoryResource(SecurityDomain domain, AuthFactorySpec spec) {
        ModelNode sd = new ModelNode();
        sd.get(spec.getServerType()).set(spec.getServerValue());
        sd.get(Util.SECURITY_DOMAIN).set(domain.getName());
        return sd;
    }

    public static void addAuthMechanism(CommandContext ctx, AuthFactory authFactory,
            AuthMechanism mechanism, ModelNode steps) throws OperationFormatException {
        ModelNode mechanisms = retrieveMechanisms(ctx, authFactory);
        ModelNode newMechanism = buildMechanismResource(mechanism);
        // check if a mechanism with the same name exists, replace it.
        int index = 0;
        boolean found = false;
        for (ModelNode m : mechanisms.asList()) {
            if (m.hasDefined(Util.MECHANISM_NAME)) {
                String name = m.get(Util.MECHANISM_NAME).asString();
                if (name.equals(mechanism.getType())) {
                    // Already have the exact same mechanism, no need to add it.
                    if (newMechanism.equals(m)) {
                        return;
                    }
                    found = true;
                    break;
                }
            }
            index += 1;
        }

        if (found) {
            mechanisms.remove(index);
            mechanisms.insert(newMechanism, index);
        } else {
            mechanisms.add(newMechanism);
        }

        DefaultOperationRequestBuilder builder = new DefaultOperationRequestBuilder();
        builder.setOperationName(Util.WRITE_ATTRIBUTE);
        builder.addNode(Util.SUBSYSTEM, Util.ELYTRON);
        builder.addNode(authFactory.getSpec().getResourceType(), authFactory.getName());
        builder.getModelNode().get(Util.VALUE).set(mechanisms);
        builder.getModelNode().get(Util.NAME).set(Util.MECHANISM_CONFIGURATIONS);
        steps.add(builder.buildRequest());
    }

    private static ModelNode buildMechanismResource(AuthMechanism mechanism) {
        ModelNode mn = new ModelNode();
        mn.get(Util.MECHANISM_NAME).set(mechanism.getType());
        if (mechanism.getConfig().getRealmMapper() != null) {
            mn.get(Util.REALM_MAPPER).set(mechanism.getConfig().getRealmMapper());
        }
        if (mechanism.getConfig().getExposedRealmName() != null) {
            ModelNode realmConfig = new ModelNode();
            realmConfig.get(Util.REALM_NAME).set(mechanism.getConfig().getExposedRealmName());
            mn.get(Util.MECHANISM_REALM_CONFIGURATIONS).add(realmConfig);
        }
        return mn;
    }

    public static void addRealm(CommandContext ctx, SecurityDomain securityDomain, Realm realm, ModelNode steps) throws OperationFormatException {
        ModelNode realms = retrieveSecurityDomainRealms(ctx, securityDomain);
        ModelNode newRealm = buildRealmResource(realm);
        int index = 0;
        boolean found = false;
        for (ModelNode r : realms.asList()) {
            if (r.hasDefined(Util.REALM)) {
                String n = r.get(Util.REALM).asString();
                // Already present, skip....
                if (n.equals(realm.getResourceName())) {
                    if (newRealm.equals(r)) {
                        return;
                    }
                    // We need to replace it with the new one.
                    found = true;
                    break;
                }
            }
            index += 1;
        }
        if (found) {
            realms.remove(index);
            realms.insert(newRealm, index);
        } else {
            realms.add(newRealm);
        }
        DefaultOperationRequestBuilder builder = new DefaultOperationRequestBuilder();
        builder.setOperationName(Util.WRITE_ATTRIBUTE);
        builder.addNode(Util.SUBSYSTEM, Util.ELYTRON);
        builder.addNode(Util.SECURITY_DOMAIN, securityDomain.getName());
        builder.getModelNode().get(Util.VALUE).set(realms);
        builder.getModelNode().get(Util.NAME).set(Util.REALMS);
        steps.add(builder.buildRequest());
    }

    private static ModelNode retrieveSecurityDomainRealms(CommandContext ctx, SecurityDomain domain) {
        ModelNode mn = getSecurityDomainResource(domain, ctx);
        if (mn == null) {
            return new ModelNode().setEmptyList();
        } else if (mn.hasDefined(Util.REALMS)) {
            return mn.get(Util.REALMS);
        } else {
            return new ModelNode().setEmptyList();
        }
    }

    public static ModelNode getSecurityDomainResource(SecurityDomain domain, CommandContext ctx) {
        final DefaultOperationRequestBuilder builder = new DefaultOperationRequestBuilder();
        final ModelNode request;
        try {
            builder.setOperationName(Util.READ_RESOURCE);
            builder.addNode(Util.SUBSYSTEM, Util.ELYTRON);
            builder.addNode(Util.SECURITY_DOMAIN, domain.getName());
            request = builder.buildRequest();
        } catch (OperationFormatException e) {
            throw new IllegalStateException("Failed to build operation", e);
        }

        try {
            final ModelNode outcome = ctx.getModelControllerClient().execute(request);
            if (Util.isSuccess(outcome)) {
                return outcome.get(Util.RESULT);
            }
        } catch (Exception e) {
        }
        return null;
    }

    private static ModelNode retrieveMechanisms(CommandContext ctx, AuthFactory authFactory) {
        ModelNode mn = getAuthFactoryResource(authFactory.getName(), authFactory.getSpec(), ctx);
        if (mn == null) {
            return new ModelNode().setEmptyList();
        } else if (mn.hasDefined(Util.MECHANISM_CONFIGURATIONS)) {
            return mn.get(Util.MECHANISM_CONFIGURATIONS);
        } else {
            return new ModelNode().setEmptyList();
        }
    }

    public static final Set<String> getMechanismsWithRealm() {
        return MECHANISMS_WITH_REALM;
    }

    public static final Set<String> getMechanismsWithTrustStore() {
        return MECHANISMS_WITH_TRUST_STORE;
    }

    public static final Set<String> getMechanismsLocalUser() {
        return MECHANISMS_LOCAL_USER;
    }

    private static boolean isMechanismSupported(String name) {
        return getMechanismsWithRealm().contains(name) || getMechanismsWithTrustStore().contains(name) || getMechanismsLocalUser().contains(name);
    }

    public static List<String> getMechanisms(CommandContext ctx, AuthFactorySpec spec) throws OperationFormatException, IOException {
        List<String> lst = new ArrayList<>();
        for (String m : getAvailableMechanisms(ctx, spec)) {
            if (isMechanismSupported(m)) {
                lst.add(m);
            }
        }
        return lst;
    }

    public static List<String> getAvailableMechanisms(CommandContext ctx, AuthFactorySpec spec) throws OperationFormatException, IOException {
        List<String> lst = new ArrayList<>();
        ModelNode resource = getServerFactory(spec.getServerValue(), spec, ctx);
        if (resource == null) {
            return null;
        }
        for (ModelNode m : resource.get(Util.AVAILABLE_MECHANISMS).asList()) {
            lst.add(m.asString());
        }
        return lst;
    }

    public static List<String> getFileSystemRealmNames(ModelControllerClient client) {
        return getNames(client, Util.FILESYSTEM_REALM);
    }

    public static List<String> getPropertiesRealmNames(ModelControllerClient client) {
        return getNames(client, Util.PROPERTIES_REALM);
    }

    public static List<String> getKeyStoreRealmNames(ModelControllerClient client) {
        return getNames(client, Util.KEY_STORE_REALM);
    }

    private static ModelNode getServerFactory(String factory, AuthFactorySpec spec, CommandContext ctx) throws OperationFormatException, IOException {
        for (ModelNode point : getServerFactoriesProviderPoints(ctx, spec)) {
            ModelNode fact = getServerfactory(ctx, point.asString(), factory);
            if (fact != null) {
                return fact;
            }
        }
        return null;
    }

    private static List<ModelNode> getServerFactoriesProviderPoints(CommandContext ctx, AuthFactorySpec spec) throws OperationFormatException, IOException {
        DefaultOperationRequestBuilder builder = new DefaultOperationRequestBuilder();
        builder.setOperationName(Util.GET_PROVIDER_POINTS);
        builder.addNode(Util.CORE_SERVICE, Util.CAPABILITY_REGISTRY);
        builder.getModelNode().get(Util.NAME).set(spec.getCapability());
        ModelNode response = ctx.getModelControllerClient().execute(builder.buildRequest());
        if (Util.isSuccess(response)) {
            return response.get(Util.RESULT).asList();
        }
        return null;
    }

    // Simplistic for now, the format is something like: /subsystem=elytron/aggregate-sasl-server-factory=*
    private static ModelNode getServerfactory(CommandContext ctx, String point, String name) throws OperationFormatException, IOException {
        DefaultOperationRequestBuilder builder = new DefaultOperationRequestBuilder();
        builder.setOperationName(Util.READ_RESOURCE);
        for (String p : point.split("/")) {
            if (p.isEmpty()) {
                continue;
            }
            String[] ps = p.split("=");
            if (ps[1].equals("*")) {
                ps[1] = name;
            }
            builder.addNode(ps[0], ps[1]);
        }
        builder.getModelNode().get(Util.INCLUDE_RUNTIME).set(true);
        ModelNode response = ctx.getModelControllerClient().execute(builder.buildRequest());
        if (Util.isSuccess(response)) {
            return response.get(Util.RESULT);
        }
        return null;
    }

    public static List<String> getSimpleDecoderNames(ModelControllerClient client) {
        return getNames(client, Util.SIMPLE_ROLE_DECODER);
    }

    public static boolean localUserExists(CommandContext ctx) throws IOException, OperationFormatException {
        DefaultOperationRequestBuilder builder = new DefaultOperationRequestBuilder();
        builder.setOperationName(Util.READ_RESOURCE);
        builder.addNode(Util.SUBSYSTEM, Util.ELYTRON);
        builder.addNode(Util.IDENTITY_REALM, Util.LOCAL);
        return Util.isSuccess(ctx.getModelControllerClient().execute(builder.buildRequest()));
    }

    public static ModelNode removeMechanisms(CommandContext ctx, ModelNode factory,
            String factoryName, AuthFactorySpec spec, Set<String> toRemove) throws Exception {
        if (factory.hasDefined(Util.MECHANISM_CONFIGURATIONS)) {
            List<ModelNode> remains = new ArrayList<>();
            Set<String> seen = new HashSet<>();
            ModelNode mechanisms = factory.get(Util.MECHANISM_CONFIGURATIONS);
            for (ModelNode m : mechanisms.asList()) {
                String name = m.get(Util.MECHANISM_NAME).asString();
                if (!toRemove.contains(name)) {
                    remains.add(m);
                }
                seen.add(name);
            }
            for (String r : toRemove) {
                if (!seen.contains(r)) {
                    throw new Exception("Mechanism " + r
                            + " is not contained in factory " + factoryName);
                }
            }
            if (remains.isEmpty()) {
                throw new Exception("Error: All mechanisms would be removed, this would fully disable access. "
                        + "To fully disable authentication, don't provide mechanism.");
            }
            ModelNode newValue = new ModelNode();
            newValue.set(remains);
            DefaultOperationRequestBuilder builder = new DefaultOperationRequestBuilder();
            builder.setOperationName(Util.WRITE_ATTRIBUTE);
            builder.addNode(Util.SUBSYSTEM, Util.ELYTRON);
            builder.addNode(spec.getResourceType(), factoryName);
            builder.addProperty(Util.NAME, Util.MECHANISM_CONFIGURATIONS);
            builder.getModelNode().get(Util.VALUE).set(newValue);
            return builder.buildRequest();
        } else {
            throw new Exception("No mechanism to remove in Factory " + factoryName);
        }
    }

    public static List<String> getMechanisms(CommandContext ctx, String factoryName, AuthFactorySpec spec) throws Exception {
        ModelNode factory = getAuthFactoryResource(factoryName, spec, ctx);
        if (factory == null) {
            throw new Exception("Invalid factory name " + factoryName);
        }
        List<String> lst = new ArrayList<>();
        if (factory.hasDefined(Util.MECHANISM_CONFIGURATIONS)) {
            ModelNode mechanisms = factory.get(Util.MECHANISM_CONFIGURATIONS);
            for (ModelNode m : mechanisms.asList()) {
                String name = m.get(Util.MECHANISM_NAME).asString();
                lst.add(name);
            }
        } else {
            throw new Exception("No mechanism in Factory " + factoryName);
        }
        return lst;
    }

    static String findMatchingConstantRoleMapper(List<String> roles,
            CommandContext ctx) throws OperationFormatException, IOException {
        ModelNode resource = buildConstantRoleMapperResource(roles);
        List<String> names = findMatchingResources(ctx, Util.CONSTANT_ROLE_MAPPER, resource);
        if (names.isEmpty()) {
            return null;
        }
        return names.get(0);
    }

    private static ModelNode buildConstantRoleMapperResource(List<String> roles) {
        ModelNode mn = new ModelNode();
        ModelNode r = mn.get(Util.ROLES);
        for (String role : roles) {
            r.add(role);
        }
        return mn;
    }

    static ModelNode buildConstantRoleMapper(List<String> roles, String mapperName, CommandContext ctx) throws OperationFormatException {
        DefaultOperationRequestBuilder builder = new DefaultOperationRequestBuilder();
        builder.setOperationName(Util.ADD);
        builder.addNode(Util.SUBSYSTEM, Util.ELYTRON);
        builder.addNode(Util.CONSTANT_ROLE_MAPPER, mapperName);
        builder.getModelNode().get(Util.ROLES).set(buildConstantRoleMapperResource(roles).get(Util.ROLES));
        return builder.buildRequest();
    }

    public static boolean constantRoleMapperExists(CommandContext ctx, String name) throws OperationFormatException, IOException {
        DefaultOperationRequestBuilder builder = new DefaultOperationRequestBuilder();
        builder.setOperationName(Util.READ_RESOURCE);
        builder.addNode(Util.SUBSYSTEM, Util.ELYTRON);
        builder.addNode(Util.CONSTANT_ROLE_MAPPER, name);
        return Util.isSuccess(ctx.getModelControllerClient().execute(builder.buildRequest()));
    }
}
