StylesheetUserPreferencesServiceImpl.java

/**
 * Licensed to Apereo under one or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information regarding copyright ownership. Apereo
 * licenses this file to you 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 the
 * following location:
 *
 * <p>http://www.apache.org/licenses/LICENSE-2.0
 *
 * <p>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.apereo.portal.layout;

import com.google.common.collect.ImmutableMap;
import com.google.common.collect.ImmutableMap.Builder;
import java.util.LinkedHashSet;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import org.apache.commons.lang3.StringUtils;
import org.apereo.portal.IUserPreferencesManager;
import org.apereo.portal.IUserProfile;
import org.apereo.portal.layout.dao.IStylesheetDescriptorDao;
import org.apereo.portal.layout.dao.IStylesheetUserPreferencesDao;
import org.apereo.portal.layout.om.ILayoutAttributeDescriptor;
import org.apereo.portal.layout.om.IOutputPropertyDescriptor;
import org.apereo.portal.layout.om.IStylesheetData;
import org.apereo.portal.layout.om.IStylesheetData.Scope;
import org.apereo.portal.layout.om.IStylesheetDescriptor;
import org.apereo.portal.layout.om.IStylesheetParameterDescriptor;
import org.apereo.portal.layout.om.IStylesheetUserPreferences;
import org.apereo.portal.security.IPerson;
import org.apereo.portal.user.IUserInstance;
import org.apereo.portal.user.IUserInstanceManager;
import org.apereo.portal.utils.IFragmentDefinitionUtils;
import org.apereo.portal.utils.Populator;
import org.apereo.portal.utils.web.PortalWebUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.web.util.WebUtils;

/**
 * Handles retrieving and storing the various scopes of stylesheet user preference data.
 *
 */
@Service
public class StylesheetUserPreferencesServiceImpl implements IStylesheetUserPreferencesService {
    private static final String OUTPUT_PROPERTIES_KEY =
            StylesheetUserPreferencesServiceImpl.class.getName() + ".OUTPUT_PROPERTIES";
    private static final String STYLESHEET_PARAMETERS_KEY =
            StylesheetUserPreferencesServiceImpl.class.getName() + ".STYLESHEET_PARAMETERS";
    private static final String LAYOUT_ATTRIBUTES_KEY =
            StylesheetUserPreferencesServiceImpl.class.getName() + ".LAYOUT_ATTRIBUTES";

    public static final String STYLESHEET_STRUCTURE_OVERRIDE_REQUEST_ATTRIBUTE =
            StylesheetUserPreferencesServiceImpl.class.getCanonicalName()
                    + ".STYLESHEET_STRUCTURE_NAME";
    public static final String STYLESHEET_THEME_OVERRIDE_REQUEST_ATTRIBUTE_NAME =
            StylesheetUserPreferencesServiceImpl.class.getCanonicalName()
                    + ".STYLESHEET_THEME_NAME";

    protected final Logger logger = LoggerFactory.getLogger(getClass());

    private IFragmentDefinitionUtils fragmentUtils;
    private IUserInstanceManager userInstanceManager;
    private IStylesheetDescriptorDao stylesheetDescriptorDao;
    private IStylesheetUserPreferencesDao stylesheetUserPreferencesDao;

    @Autowired
    public void setUserInstanceManager(IUserInstanceManager userInstanceManager) {
        this.userInstanceManager = userInstanceManager;
    }

    @Autowired
    public void setStylesheetDescriptorDao(IStylesheetDescriptorDao stylesheetDescriptorDao) {
        this.stylesheetDescriptorDao = stylesheetDescriptorDao;
    }

    @Autowired
    public void setStylesheetUserPreferencesDao(
            IStylesheetUserPreferencesDao stylesheetUserPreferencesDao) {
        this.stylesheetUserPreferencesDao = stylesheetUserPreferencesDao;
    }

    @Autowired
    public void setFragmentDefinitionUtils(final IFragmentDefinitionUtils utils) {
        this.fragmentUtils = utils;
    }

    protected static final class StylesheetPreferencesKey {
        private final IPerson person;
        private final IUserProfile userProfile;
        private final IStylesheetDescriptor stylesheetDescriptor;
        private final String str;

        private StylesheetPreferencesKey(
                IPerson person,
                IUserProfile userProfile,
                IStylesheetDescriptor stylesheetDescriptor) {
            this.person = person;
            this.userProfile = userProfile;
            this.stylesheetDescriptor = stylesheetDescriptor;

            this.str =
                    "["
                            + stylesheetDescriptor.getId()
                            + ","
                            + person.getUserName()
                            + ","
                            + userProfile.getProfileId()
                            + "]";
        }

        public String toString() {
            return this.str;
        }
    }

    protected final StylesheetPreferencesKey getStylesheetPreferencesKey(
            HttpServletRequest request, PreferencesScope prefScope) {
        final IUserInstance userInstance = this.userInstanceManager.getUserInstance(request);

        final IPerson person = userInstance.getPerson();

        final IUserPreferencesManager preferencesManager = userInstance.getPreferencesManager();
        final IUserProfile userProfile = preferencesManager.getUserProfile();

        final IStylesheetDescriptor stylesheetDescriptor =
                getStylesheetDescriptor(request, prefScope);

        return new StylesheetPreferencesKey(person, userProfile, stylesheetDescriptor);
    }

    protected final IStylesheetUserPreferences getDistributedStylesheetUserPreferences(
            HttpServletRequest request, PreferencesScope prefScope) {
        final IUserInstance userInstance = this.userInstanceManager.getUserInstance(request);
        final IUserPreferencesManager preferencesManager = userInstance.getPreferencesManager();
        final IUserLayoutManager userLayoutManager = preferencesManager.getUserLayoutManager();
        final IUserLayout userLayout = userLayoutManager.getUserLayout();

        return prefScope.getDistributedIStylesheetUserPreferences(userLayout);
    }

    protected final Scope getWriteScope(
            HttpServletRequest request,
            PreferencesScope prefScope,
            StylesheetPreferencesKey stylesheetPreferencesKey,
            IStylesheetData descriptor) {
        final Scope scope = descriptor.getScope();
        final boolean persistentScopeReadOnly = stylesheetPreferencesKey.person.isGuest();
        if (persistentScopeReadOnly && Scope.PERSISTENT == scope) {
            return Scope.SESSION;
        }
        return scope;
    }

    protected final boolean compareValues(String value, String defaultValue) {
        return value == defaultValue || (value != null && value.equals(defaultValue));
    }

    protected final <T> T getDataValue(
            HttpServletRequest request,
            StylesheetPreferencesKey stylesheetPreferencesKey,
            Scope scope,
            String mapKey,
            String name) {
        switch (scope) {
            case SESSION:
                {
                    final HttpSession session = request.getSession(false);
                    if (session == null) {
                        return null;
                    }

                    final Map<String, T> outputProperties =
                            PortalWebUtils.getMapSessionAttribute(
                                    session, mapKey + stylesheetPreferencesKey.toString(), false);
                    if (outputProperties == null) {
                        return null;
                    }

                    return outputProperties.get(name);
                }
            case REQUEST:
                {
                    final Map<String, T> outputProperties =
                            PortalWebUtils.getMapRequestAttribute(
                                    request, mapKey + stylesheetPreferencesKey.toString(), false);
                    if (outputProperties == null) {
                        return null;
                    }

                    return outputProperties.get(name);
                }
            default:
                {
                    return null;
                }
        }
    }

    protected final <T> T putDataValue(
            HttpServletRequest request,
            StylesheetPreferencesKey stylesheetPreferencesKey,
            Scope scope,
            String mapKey,
            String name,
            T value) {
        switch (scope) {
            case SESSION:
                {
                    final HttpSession session = request.getSession();
                    final Map<String, T> outputProperties =
                            PortalWebUtils.getMapSessionAttribute(
                                    session, mapKey + stylesheetPreferencesKey.toString());

                    return outputProperties.put(name, value);
                }
            case REQUEST:
                {
                    final Map<String, T> outputProperties =
                            PortalWebUtils.getMapRequestAttribute(
                                    request, mapKey + stylesheetPreferencesKey.toString());

                    return outputProperties.put(name, value);
                }
            default:
                {
                    return null;
                }
        }
    }

    protected final <T> T removeDataValue(
            HttpServletRequest request,
            StylesheetPreferencesKey stylesheetPreferencesKey,
            Scope scope,
            String mapKey,
            String name) {
        switch (scope) {
            case SESSION:
                {
                    final HttpSession session = request.getSession(false);
                    if (session == null) {
                        return null;
                    }

                    final Map<String, T> outputProperties =
                            PortalWebUtils.getMapSessionAttribute(
                                    session, mapKey + stylesheetPreferencesKey.toString(), false);
                    if (outputProperties == null) {
                        return null;
                    }

                    return outputProperties.remove(name);
                }
            case REQUEST:
                {
                    final Map<String, T> outputProperties =
                            PortalWebUtils.getMapRequestAttribute(
                                    request, mapKey + stylesheetPreferencesKey.toString(), false);
                    if (outputProperties == null) {
                        return null;
                    }

                    return outputProperties.remove(name);
                }
            default:
                {
                    return null;
                }
        }
    }

    @Override
    public IStylesheetDescriptor getStylesheetDescriptor(
            HttpServletRequest request, PreferencesScope prefScope) {
        String stylesheetName = this.getStyleSheetName(request, prefScope);
        if (!StringUtils.isBlank(stylesheetName)) {
            return this.stylesheetDescriptorDao.getStylesheetDescriptorByName(stylesheetName);
        } else {
            final IUserInstance userInstance = this.userInstanceManager.getUserInstance(request);

            final IUserPreferencesManager preferencesManager = userInstance.getPreferencesManager();
            final IUserProfile userProfile = preferencesManager.getUserProfile();

            final int stylesheetId = prefScope.getStylesheetId(userProfile);
            return this.stylesheetDescriptorDao.getStylesheetDescriptor(stylesheetId);
        }
    }

    @Transactional
    @Override
    public String removeOutputProperty(
            HttpServletRequest request, PreferencesScope prefScope, String name) {
        final StylesheetPreferencesKey stylesheetPreferencesKey =
                this.getStylesheetPreferencesKey(request, prefScope);
        final IStylesheetDescriptor stylesheetDescriptor =
                stylesheetPreferencesKey.stylesheetDescriptor;
        final IOutputPropertyDescriptor outputPropertyDescriptor =
                stylesheetDescriptor.getOutputPropertyDescriptor(name);
        if (outputPropertyDescriptor == null) {
            logger.warn(
                    "Attempted to remove output property '{}' but no such output property is defined in stylesheet descriptor '{}'. It will be ignored",
                    new Object[] {name, stylesheetDescriptor.getName()});
            return null;
        }

        final Scope scope =
                this.getWriteScope(
                        request, prefScope, stylesheetPreferencesKey, outputPropertyDescriptor);
        switch (scope) {
            case PERSISTENT:
                {
                    final IStylesheetUserPreferences stylesheetUserPreferences =
                            this.getStylesheetUserPreferences(request, stylesheetPreferencesKey);
                    if (stylesheetUserPreferences == null) {
                        return null;
                    }

                    final String oldValue = stylesheetUserPreferences.removeOutputProperty(name);
                    this.stylesheetUserPreferencesDao.storeStylesheetUserPreferences(
                            stylesheetUserPreferences);
                    this.clearStylesheetUserPreferencesCache(request, stylesheetPreferencesKey);
                    return oldValue;
                }
            default:
                {
                    return removeDataValue(
                            request, stylesheetPreferencesKey, scope, OUTPUT_PROPERTIES_KEY, name);
                }
        }
    }

    @Override
    public <P extends Populator<String, String>> P populateOutputProperties(
            HttpServletRequest request, PreferencesScope prefScope, P properties) {
        final StylesheetPreferencesKey stylesheetPreferencesKey =
                this.getStylesheetPreferencesKey(request, prefScope);
        final IStylesheetDescriptor stylesheetDescriptor =
                stylesheetPreferencesKey.stylesheetDescriptor;

        //Get the scoped sources once
        final IStylesheetUserPreferences stylesheetUserPreferences =
                this.getStylesheetUserPreferences(request, stylesheetPreferencesKey);

        final Map<String, String> sessionOutputProperties;
        final HttpSession session = request.getSession(false);
        if (session == null) {
            sessionOutputProperties = null;
        } else {
            sessionOutputProperties =
                    PortalWebUtils.getMapSessionAttribute(
                            session,
                            OUTPUT_PROPERTIES_KEY + stylesheetPreferencesKey.toString(),
                            false);
        }

        final Map<String, String> requestOutputProperties =
                PortalWebUtils.getMapRequestAttribute(
                        request,
                        OUTPUT_PROPERTIES_KEY + stylesheetPreferencesKey.toString(),
                        false);

        //Try getting each output property to populate the Properties
        for (final IOutputPropertyDescriptor outputPropertyDescriptor :
                stylesheetDescriptor.getOutputPropertyDescriptors()) {
            final String name = outputPropertyDescriptor.getName();

            final String value;
            final Scope scope = outputPropertyDescriptor.getScope();
            switch (scope) {
                case PERSISTENT:
                    {
                        if (stylesheetUserPreferences == null) {
                            value = null;
                            break;
                        }

                        value = stylesheetUserPreferences.getOutputProperty(name);
                        break;
                    }
                case SESSION:
                    {
                        if (sessionOutputProperties == null) {
                            value = null;
                            break;
                        }

                        value = sessionOutputProperties.get(name);
                        break;
                    }
                case REQUEST:
                    {
                        if (requestOutputProperties == null) {
                            value = null;
                            break;
                        }

                        value = requestOutputProperties.get(name);
                        break;
                    }
                default:
                    {
                        value = null;
                        break;
                    }
            }

            //Don't add unset properties
            if (value == null) {
                continue;
            }

            //If the value is equal to the default value remove the property and return null
            if (this.compareValues(value, outputPropertyDescriptor.getDefaultValue())) {
                this.removeOutputProperty(request, prefScope, name);
                continue;
            }

            properties.put(name, value);
        }

        return properties;
    }

    @Override
    public String getStylesheetParameter(
            HttpServletRequest request, PreferencesScope prefScope, String name) {
        final StylesheetPreferencesKey stylesheetPreferencesKey =
                this.getStylesheetPreferencesKey(request, prefScope);
        final IStylesheetDescriptor stylesheetDescriptor =
                stylesheetPreferencesKey.stylesheetDescriptor;
        final IStylesheetParameterDescriptor stylesheetParameterDescriptor =
                stylesheetDescriptor.getStylesheetParameterDescriptor(name);
        if (stylesheetParameterDescriptor == null) {
            logger.warn(
                    "Attempted to get stylesheet parameter '{}' but no such stylesheet parameter is defined in stylesheet descriptor '{}'. null will be returned",
                    new Object[] {name, stylesheetDescriptor.getName()});
            return null;
        }

        final String value;
        final Scope scope = stylesheetParameterDescriptor.getScope();
        switch (scope) {
            case PERSISTENT:
                {
                    final IStylesheetUserPreferences stylesheetUserPreferences =
                            this.getStylesheetUserPreferences(request, stylesheetPreferencesKey);
                    if (stylesheetUserPreferences == null) {
                        return null;
                    }

                    value = stylesheetUserPreferences.getStylesheetParameter(name);
                    break;
                }
            default:
                {
                    value =
                            this.getDataValue(
                                    request,
                                    stylesheetPreferencesKey,
                                    scope,
                                    STYLESHEET_PARAMETERS_KEY,
                                    name);
                    break;
                }
        }

        if (value == null) {
            return null;
        }

        //If the value is equal to the default value remove the property and return null
        if (this.compareValues(value, stylesheetParameterDescriptor.getDefaultValue())) {
            this.removeStylesheetParameter(request, prefScope, name);
            return null;
        }

        return value;
    }

    @Transactional
    @Override
    public String setStylesheetParameter(
            HttpServletRequest request, PreferencesScope prefScope, String name, String value) {

        logger.trace(
                "Setting stylesheet parameter {} with scope {} to {}.", name, prefScope, value);

        final StylesheetPreferencesKey stylesheetPreferencesKey =
                this.getStylesheetPreferencesKey(request, prefScope);
        final IStylesheetDescriptor stylesheetDescriptor =
                stylesheetPreferencesKey.stylesheetDescriptor;
        final IStylesheetParameterDescriptor stylesheetParameterDescriptor =
                stylesheetDescriptor.getStylesheetParameterDescriptor(name);
        if (stylesheetParameterDescriptor == null) {
            logger.warn(
                    "Attempted to set stylesheet parameter {}={} but no such stylesheet parameter is defined in stylesheet descriptor {}. It will be ignored",
                    new Object[] {name, value, stylesheetDescriptor.getName()});
            return null;
        }

        if (this.compareValues(value, stylesheetParameterDescriptor.getDefaultValue())) {
            return this.removeStylesheetParameter(request, prefScope, name);
        }

        final Scope scope =
                this.getWriteScope(
                        request,
                        prefScope,
                        stylesheetPreferencesKey,
                        stylesheetParameterDescriptor);
        switch (scope) {
            case PERSISTENT:
                {
                    IStylesheetUserPreferences stylesheetUserPreferences =
                            this.getStylesheetUserPreferences(request, stylesheetPreferencesKey);
                    if (stylesheetUserPreferences == null) {
                        stylesheetUserPreferences =
                                this.stylesheetUserPreferencesDao.createStylesheetUserPreferences(
                                        stylesheetDescriptor,
                                        stylesheetPreferencesKey.person,
                                        stylesheetPreferencesKey.userProfile);
                        this.clearStylesheetUserPreferencesCache(request, stylesheetPreferencesKey);
                    }

                    final String oldValue =
                            stylesheetUserPreferences.setStylesheetParameter(name, value);
                    this.stylesheetUserPreferencesDao.storeStylesheetUserPreferences(
                            stylesheetUserPreferences);
                    return oldValue;
                }
            default:
                {
                    return this.putDataValue(
                            request,
                            stylesheetPreferencesKey,
                            scope,
                            STYLESHEET_PARAMETERS_KEY,
                            name,
                            value);
                }
        }
    }

    @Transactional
    @Override
    public String removeStylesheetParameter(
            HttpServletRequest request, PreferencesScope prefScope, String name) {
        final StylesheetPreferencesKey stylesheetPreferencesKey =
                this.getStylesheetPreferencesKey(request, prefScope);
        final IStylesheetDescriptor stylesheetDescriptor =
                stylesheetPreferencesKey.stylesheetDescriptor;
        final IStylesheetParameterDescriptor stylesheetParameterDescriptor =
                stylesheetDescriptor.getStylesheetParameterDescriptor(name);
        if (stylesheetParameterDescriptor == null) {
            logger.warn(
                    "Attempted to remove stylesheet parameter {} but no such stylesheet parameter is defined in stylesheet descriptor {}. It will be ignored",
                    new Object[] {name, stylesheetDescriptor.getName()});
            return null;
        }

        final Scope scope =
                this.getWriteScope(
                        request,
                        prefScope,
                        stylesheetPreferencesKey,
                        stylesheetParameterDescriptor);
        switch (scope) {
            case PERSISTENT:
                {
                    final IStylesheetUserPreferences stylesheetUserPreferences =
                            this.getStylesheetUserPreferences(request, stylesheetPreferencesKey);
                    if (stylesheetUserPreferences == null) {
                        return null;
                    }

                    final String oldValue =
                            stylesheetUserPreferences.removeStylesheetParameter(name);
                    this.stylesheetUserPreferencesDao.storeStylesheetUserPreferences(
                            stylesheetUserPreferences);
                    return oldValue;
                }
            default:
                {
                    return removeDataValue(
                            request,
                            stylesheetPreferencesKey,
                            scope,
                            STYLESHEET_PARAMETERS_KEY,
                            name);
                }
        }
    }

    @Override
    public <P extends Populator<String, String>> P populateStylesheetParameters(
            HttpServletRequest request, PreferencesScope prefScope, P stylesheetParameters) {
        final StylesheetPreferencesKey stylesheetPreferencesKey =
                this.getStylesheetPreferencesKey(request, prefScope);
        final IStylesheetDescriptor stylesheetDescriptor =
                stylesheetPreferencesKey.stylesheetDescriptor;

        //Get the scoped sources once
        final IStylesheetUserPreferences stylesheetUserPreferences =
                this.getStylesheetUserPreferences(request, stylesheetPreferencesKey);
        final Map<String, String> sessionStylesheetParameters;
        final HttpSession session = request.getSession(false);
        if (session == null) {
            sessionStylesheetParameters = null;
        } else {
            sessionStylesheetParameters =
                    PortalWebUtils.getMapSessionAttribute(
                            session,
                            STYLESHEET_PARAMETERS_KEY + stylesheetPreferencesKey.toString(),
                            false);
        }
        final Map<String, String> requestStylesheetParameters =
                PortalWebUtils.getMapRequestAttribute(
                        request,
                        STYLESHEET_PARAMETERS_KEY + stylesheetPreferencesKey.toString(),
                        false);

        //Try getting each stylesheet parameter to populate the Map
        for (final IStylesheetParameterDescriptor stylesheetParameterDescriptor :
                stylesheetDescriptor.getStylesheetParameterDescriptors()) {
            final String name = stylesheetParameterDescriptor.getName();

            final String value;
            final Scope scope = stylesheetParameterDescriptor.getScope();
            switch (scope) {
                case PERSISTENT:
                    {
                        if (stylesheetUserPreferences == null) {
                            value = null;
                            break;
                        }

                        value = stylesheetUserPreferences.getStylesheetParameter(name);
                        break;
                    }
                case SESSION:
                    {
                        if (sessionStylesheetParameters == null) {
                            value = null;
                            break;
                        }

                        value = sessionStylesheetParameters.get(name);
                        break;
                    }
                case REQUEST:
                    {
                        if (requestStylesheetParameters == null) {
                            value = null;
                            break;
                        }

                        value = requestStylesheetParameters.get(name);
                        break;
                    }
                default:
                    {
                        value = null;
                        break;
                    }
            }

            //Don't add unset properties
            if (value == null) {
                continue;
            }

            //If the value is equal to the default value remove the property and return null
            if (this.compareValues(value, stylesheetParameterDescriptor.getDefaultValue())) {
                this.removeStylesheetParameter(request, prefScope, name);
                continue;
            }

            stylesheetParameters.put(name, value);
        }

        return stylesheetParameters;
    }

    @Override
    public String getLayoutAttribute(
            HttpServletRequest request, PreferencesScope prefScope, String nodeId, String name) {
        final StylesheetPreferencesKey stylesheetPreferencesKey =
                this.getStylesheetPreferencesKey(request, prefScope);
        final IStylesheetDescriptor stylesheetDescriptor =
                stylesheetPreferencesKey.stylesheetDescriptor;
        final ILayoutAttributeDescriptor layoutAttributeDescriptor =
                stylesheetDescriptor.getLayoutAttributeDescriptor(name);
        if (layoutAttributeDescriptor == null) {
            logger.warn(
                    "Attempted to get layout attribute {} for ID=\"{}\" but no such stylesheet parameter is defined in stylesheet descriptor {}. Null will be returned",
                    new Object[] {name, nodeId, stylesheetDescriptor.getName()});
            return null;
        }

        //Load the default value
        String defaultValue = null;
        final IStylesheetUserPreferences distributedStylesheetUserPreferences =
                this.getDistributedStylesheetUserPreferences(request, prefScope);

        if (distributedStylesheetUserPreferences != null) {
            defaultValue = distributedStylesheetUserPreferences.getLayoutAttribute(nodeId, name);

            // special handling for fragment owner
            if (this.isFragmentOwnerStylesheetPreferencesKey(stylesheetPreferencesKey)) {
                return defaultValue;
            }

            if (this.compareValues(defaultValue, layoutAttributeDescriptor.getDefaultValue())) {
                //DLM attribute value matches the stylesheet descriptor default, remove the DLM value
                distributedStylesheetUserPreferences.removeLayoutAttribute(nodeId, name);
                defaultValue = null;
            }
        }

        final String value;
        final Scope scope = layoutAttributeDescriptor.getScope();
        switch (scope) {
            case PERSISTENT:
                {
                    final IStylesheetUserPreferences stylesheetUserPreferences =
                            this.getStylesheetUserPreferences(request, stylesheetPreferencesKey);
                    if (stylesheetUserPreferences == null) {
                        value = null;
                        break;
                    }

                    value = stylesheetUserPreferences.getLayoutAttribute(nodeId, name);
                    break;
                }
            default:
                {
                    final Map<String, String> nodeAttributes =
                            this.getDataValue(
                                    request,
                                    stylesheetPreferencesKey,
                                    scope,
                                    LAYOUT_ATTRIBUTES_KEY,
                                    nodeId);
                    if (nodeAttributes == null) {
                        value = null;
                        break;
                    }

                    value = nodeAttributes.get(name);
                    break;
                }
        }

        if (value == null) {
            return defaultValue;
        }

        if (!this.isFragmentOwnerStylesheetPreferencesKey(stylesheetPreferencesKey)) {
            if (this.compareValues(value, layoutAttributeDescriptor.getDefaultValue())
                    || //Value is equal to stylesheet descriptor default
                    (defaultValue != null
                            && this.compareValues(
                                    value,
                                    defaultValue))) { //Value is equal to DLM stylesheet preferences default

                //Remove the user's customized value
                this.removeLayoutAttribute(request, prefScope, nodeId, name);
                return null;
            }
        }

        return value;
    }

    private static final String NO_PERSISTENT_IStylesheetUserPreferences =
            StylesheetUserPreferencesServiceImpl.class.getName()
                    + ".NO_PERSISTENT_IStylesheetUserPreferences";

    private String getCacheKey(StylesheetPreferencesKey stylesheetPreferencesKey) {
        return NO_PERSISTENT_IStylesheetUserPreferences + "." + stylesheetPreferencesKey.toString();
    }

    private IStylesheetUserPreferences getStylesheetUserPreferences(
            HttpServletRequest request, StylesheetPreferencesKey stylesheetPreferencesKey) {
        final String key = getCacheKey(stylesheetPreferencesKey);

        if (request.getAttribute(key) != null) {
            return null;
        }

        final HttpSession session = request.getSession();
        if (session.getAttribute(key) != null) {
            request.setAttribute(key, Boolean.TRUE);
            return null;
        }

        final IStylesheetUserPreferences stylesheetUserPreferences =
                this.stylesheetUserPreferencesDao.getStylesheetUserPreferences(
                        stylesheetPreferencesKey.stylesheetDescriptor,
                        stylesheetPreferencesKey.person,
                        stylesheetPreferencesKey.userProfile);

        if (stylesheetUserPreferences == null) {
            session.setAttribute(key, Boolean.TRUE);
            request.setAttribute(key, Boolean.TRUE);
        }

        return stylesheetUserPreferences;
    }

    private void clearStylesheetUserPreferencesCache(
            HttpServletRequest request, StylesheetPreferencesKey stylesheetPreferencesKey) {
        final String key = getCacheKey(stylesheetPreferencesKey);

        request.removeAttribute(key);

        final HttpSession session = request.getSession();
        session.removeAttribute(key);
    }

    /** @return Map<nodeId, Map<name, value>> */
    protected ConcurrentMap<String, Map<String, String>> getRequestLayoutAttributes(
            HttpServletRequest request, StylesheetPreferencesKey stylesheetPreferencesKey) {
        return PortalWebUtils.getMapRequestAttribute(
                request, LAYOUT_ATTRIBUTES_KEY + stylesheetPreferencesKey.toString(), false);
    }

    /** @return Map<nodeId, Map<name, value>> */
    protected ConcurrentMap<String, Map<String, String>> getSessionLayoutAttributes(
            HttpSession session, StylesheetPreferencesKey stylesheetPreferencesKey) {
        return PortalWebUtils.getMapSessionAttribute(
                session, LAYOUT_ATTRIBUTES_KEY + stylesheetPreferencesKey.toString(), false);
    }

    @Transactional
    @Override
    public String setLayoutAttribute(
            HttpServletRequest request,
            PreferencesScope prefScope,
            String nodeId,
            String name,
            String value) {
        final StylesheetPreferencesKey stylesheetPreferencesKey =
                this.getStylesheetPreferencesKey(request, prefScope);
        final IStylesheetDescriptor stylesheetDescriptor =
                stylesheetPreferencesKey.stylesheetDescriptor;
        final ILayoutAttributeDescriptor layoutAttributeDescriptor =
                stylesheetDescriptor.getLayoutAttributeDescriptor(name);
        if (layoutAttributeDescriptor == null) {
            logger.warn(
                    "Attempted to set layout attribute {}={} on node with ID=\"{}\" but no such stylesheet parameter is defined in stylesheet descriptor {}. It will be ignored.",
                    new Object[] {name, value, nodeId, stylesheetDescriptor.getName()});
            return null;
        }

        if (this.compareValues(value, layoutAttributeDescriptor.getDefaultValue())) {
            //Value matches the default value, remove the attribute
            return this.removeLayoutAttribute(request, prefScope, nodeId, name);
        }

        final IStylesheetUserPreferences distributedStylesheetUserPreferences =
                this.getDistributedStylesheetUserPreferences(request, prefScope);
        if (distributedStylesheetUserPreferences != null) {
            final String defaultValue =
                    distributedStylesheetUserPreferences.getLayoutAttribute(nodeId, name);
            if (this.compareValues(value, defaultValue)) {
                //Value matches the DLM preferences value, remove the value
                return this.removeLayoutAttribute(request, prefScope, nodeId, name);
            }
        }

        final Scope scope =
                this.getWriteScope(
                        request, prefScope, stylesheetPreferencesKey, layoutAttributeDescriptor);
        switch (scope) {
            case PERSISTENT:
                {
                    IStylesheetUserPreferences stylesheetUserPreferences =
                            this.getStylesheetUserPreferences(request, stylesheetPreferencesKey);
                    if (stylesheetUserPreferences == null) {
                        stylesheetUserPreferences =
                                this.stylesheetUserPreferencesDao.createStylesheetUserPreferences(
                                        stylesheetDescriptor,
                                        stylesheetPreferencesKey.person,
                                        stylesheetPreferencesKey.userProfile);
                        this.clearStylesheetUserPreferencesCache(request, stylesheetPreferencesKey);
                    }

                    final String oldValue =
                            stylesheetUserPreferences.setLayoutAttribute(nodeId, name, value);
                    this.stylesheetUserPreferencesDao.storeStylesheetUserPreferences(
                            stylesheetUserPreferences);
                    return oldValue;
                }
            default:
                {

                    //Determine the mutex to use for accessing the nodeAttributes map
                    final Object mutex;
                    switch (scope) {
                        case REQUEST:
                            {
                                mutex = PortalWebUtils.getRequestAttributeMutex(request);
                                break;
                            }
                        case SESSION:
                            {
                                final HttpSession session = request.getSession();
                                mutex = WebUtils.getSessionMutex(session);
                                break;
                            }
                        default:
                            {
                                mutex = new Object();
                                break;
                            }
                    }

                    //Get/Create the nodeAttributes map
                    Map<String, String> nodeAttributes;
                    synchronized (mutex) {
                        nodeAttributes =
                                this.getDataValue(
                                        request,
                                        stylesheetPreferencesKey,
                                        scope,
                                        LAYOUT_ATTRIBUTES_KEY,
                                        nodeId);
                        if (nodeAttributes == null) {
                            nodeAttributes = new ConcurrentHashMap<String, String>();
                            this.putDataValue(
                                    request,
                                    stylesheetPreferencesKey,
                                    scope,
                                    LAYOUT_ATTRIBUTES_KEY,
                                    nodeId,
                                    nodeAttributes);
                        }
                    }

                    return nodeAttributes.put(name, value);
                }
        }
    }

    @Transactional
    @Override
    public String removeLayoutAttribute(
            HttpServletRequest request, PreferencesScope prefScope, String nodeId, String name) {
        final StylesheetPreferencesKey stylesheetPreferencesKey =
                this.getStylesheetPreferencesKey(request, prefScope);
        final IStylesheetDescriptor stylesheetDescriptor =
                stylesheetPreferencesKey.stylesheetDescriptor;
        final ILayoutAttributeDescriptor layoutAttributeDescriptor =
                stylesheetDescriptor.getLayoutAttributeDescriptor(name);
        if (layoutAttributeDescriptor == null) {
            logger.warn(
                    "Attempted to remove layout attribute {} for ID=\"{}\" but no such stylesheet parameter is defined in stylesheet descriptor {}. It will be ignored.",
                    new Object[] {name, nodeId, stylesheetDescriptor.getName()});
            return null;
        }

        final Scope scope =
                this.getWriteScope(
                        request, prefScope, stylesheetPreferencesKey, layoutAttributeDescriptor);
        switch (scope) {
            case PERSISTENT:
                {
                    final IStylesheetUserPreferences stylesheetUserPreferences =
                            this.getStylesheetUserPreferences(request, stylesheetPreferencesKey);
                    if (stylesheetUserPreferences == null) {
                        break;
                    }

                    final String oldValue =
                            stylesheetUserPreferences.removeLayoutAttribute(nodeId, name);
                    if (oldValue != null) {
                        this.stylesheetUserPreferencesDao.storeStylesheetUserPreferences(
                                stylesheetUserPreferences);
                        return oldValue;
                    }
                }
            default:
                {
                    final Map<String, String> nodeAttributes =
                            this.getDataValue(
                                    request,
                                    stylesheetPreferencesKey,
                                    scope,
                                    LAYOUT_ATTRIBUTES_KEY,
                                    nodeId);
                    if (nodeAttributes == null) {
                        break;
                    }

                    final String oldValue = nodeAttributes.remove(name);
                    if (oldValue != null) {
                        return oldValue;
                    }
                }
        }

        final IStylesheetUserPreferences distributedStylesheetUserPreferences =
                this.getDistributedStylesheetUserPreferences(request, prefScope);
        if (distributedStylesheetUserPreferences != null) {
            return distributedStylesheetUserPreferences.removeLayoutAttribute(nodeId, name);
        }

        return null;
    }

    @Override
    public Iterable<String> getAllLayoutAttributeNodeIds(
            HttpServletRequest request, PreferencesScope prefScope) {
        final StylesheetPreferencesKey stylesheetPreferencesKey =
                this.getStylesheetPreferencesKey(request, prefScope);

        final LinkedHashSet<String> allNodeIds = new LinkedHashSet<String>();

        final IStylesheetUserPreferences stylesheetUserPreferences =
                this.getStylesheetUserPreferences(request, stylesheetPreferencesKey);
        if (stylesheetUserPreferences != null) {
            allNodeIds.addAll(stylesheetUserPreferences.getAllLayoutAttributeNodeIds());
        }

        final HttpSession session = request.getSession(false);
        if (session != null) {
            final Map<String, Map<String, String>> sessionLayoutAttributes =
                    getSessionLayoutAttributes(session, stylesheetPreferencesKey);
            if (sessionLayoutAttributes != null) {
                allNodeIds.addAll(sessionLayoutAttributes.keySet());
            }
        }

        final Map<String, Map<String, String>> requestLayoutAttributes =
                getRequestLayoutAttributes(request, stylesheetPreferencesKey);
        if (requestLayoutAttributes != null) {
            allNodeIds.addAll(requestLayoutAttributes.keySet());
        }

        final IStylesheetUserPreferences distributedStylesheetUserPreferences =
                this.getDistributedStylesheetUserPreferences(request, prefScope);
        if (distributedStylesheetUserPreferences != null) {
            allNodeIds.addAll(distributedStylesheetUserPreferences.getAllLayoutAttributeNodeIds());
        }

        return allNodeIds;
    }

    @Override
    public Map<String, String> getAllNodesAndValuesForAttribute(
            HttpServletRequest request, PreferencesScope prefScope, String name) {
        final StylesheetPreferencesKey stylesheetPreferencesKey =
                this.getStylesheetPreferencesKey(request, prefScope);
        final Builder<String, String> result = ImmutableMap.builder();
        final boolean isFragmentOwner =
                this.isFragmentOwnerStylesheetPreferencesKey(stylesheetPreferencesKey);

        if (!isFragmentOwner) {
            final IStylesheetUserPreferences distributedStylesheetUserPreferences =
                    this.getDistributedStylesheetUserPreferences(request, prefScope);
            if (distributedStylesheetUserPreferences != null) {
                final Map<String, String> allNodesAndValuesForAttribute =
                        distributedStylesheetUserPreferences.getAllNodesAndValuesForAttribute(name);
                result.putAll(allNodesAndValuesForAttribute);
            }
        }

        final IStylesheetUserPreferences stylesheetUserPreferences =
                this.getStylesheetUserPreferences(request, stylesheetPreferencesKey);
        if (stylesheetUserPreferences != null) {
            final Map<String, String> allNodesAndValuesForAttribute =
                    stylesheetUserPreferences.getAllNodesAndValuesForAttribute(name);
            result.putAll(allNodesAndValuesForAttribute);
        }

        final HttpSession session = request.getSession(false);
        if (session != null) {
            //nodeId, name, value
            final Map<String, Map<String, String>> sessionLayoutAttributes =
                    getSessionLayoutAttributes(session, stylesheetPreferencesKey);
            getAllNodesAndValuesForAttribute(sessionLayoutAttributes, name, result);
        }

        final Map<String, Map<String, String>> requestLayoutAttributes =
                getRequestLayoutAttributes(request, stylesheetPreferencesKey);
        if (requestLayoutAttributes != null) {
            getAllNodesAndValuesForAttribute(requestLayoutAttributes, name, result);
        }

        return result.build();
    }

    protected void getAllNodesAndValuesForAttribute(
            Map<String, Map<String, String>> layoutAttributes,
            String name,
            Builder<String, String> result) {
        if (layoutAttributes == null) {
            return;
        }

        for (Map.Entry<String, Map<String, String>> layoutNodeAttributesEntry :
                layoutAttributes.entrySet()) {
            //name, value
            final Map<String, String> layoutNodeAttribute = layoutNodeAttributesEntry.getValue();
            final String value = layoutNodeAttribute.get(name);
            if (value != null) {
                final String nodeId = layoutNodeAttributesEntry.getKey();
                result.put(nodeId, value);
            }
        }
    }

    @Override
    public <P extends Populator<String, String>> P populateLayoutAttributes(
            HttpServletRequest request,
            PreferencesScope prefScope,
            String nodeId,
            P layoutAttributes) {
        final StylesheetPreferencesKey stylesheetPreferencesKey =
                this.getStylesheetPreferencesKey(request, prefScope);
        final IStylesheetDescriptor stylesheetDescriptor =
                stylesheetPreferencesKey.stylesheetDescriptor;

        //Get the scoped sources once
        final IStylesheetUserPreferences stylesheetUserPreferences =
                this.getStylesheetUserPreferences(request, stylesheetPreferencesKey);
        final Map<String, Map<String, String>> sessionLayoutAttributes;
        final HttpSession session = request.getSession(false);
        if (session == null) {
            sessionLayoutAttributes = null;
        } else {
            sessionLayoutAttributes = getSessionLayoutAttributes(session, stylesheetPreferencesKey);
        }
        final Map<String, Map<String, String>> requestLayoutAttributes =
                getRequestLayoutAttributes(request, stylesheetPreferencesKey);

        final IStylesheetUserPreferences distributedStylesheetUserPreferences =
                this.getDistributedStylesheetUserPreferences(request, prefScope);
        if (distributedStylesheetUserPreferences != null) {
            distributedStylesheetUserPreferences.populateLayoutAttributes(nodeId, layoutAttributes);
        }

        //Try getting each layout attribute to populate the Map
        for (final ILayoutAttributeDescriptor layoutAttributeDescriptor :
                stylesheetDescriptor.getLayoutAttributeDescriptors()) {
            final String name = layoutAttributeDescriptor.getName();

            String value;
            final Scope scope = layoutAttributeDescriptor.getScope();
            switch (scope) {
                case PERSISTENT:
                    {
                        if (stylesheetUserPreferences == null) {
                            value = null;
                            break;
                        }

                        value = stylesheetUserPreferences.getLayoutAttribute(nodeId, name);
                        break;
                    }
                case SESSION:
                    {
                        if (sessionLayoutAttributes == null) {
                            value = null;
                            break;
                        }

                        final Map<String, String> nodeAttributes =
                                sessionLayoutAttributes.get(nodeId);
                        if (nodeAttributes == null) {
                            value = null;
                            break;
                        }

                        value = nodeAttributes.get(name);
                        break;
                    }
                case REQUEST:
                    {
                        if (requestLayoutAttributes == null) {
                            value = null;
                            break;
                        }

                        final Map<String, String> nodeAttributes =
                                requestLayoutAttributes.get(nodeId);
                        if (nodeAttributes == null) {
                            value = null;
                            break;
                        }

                        value = nodeAttributes.get(name);
                        break;
                    }
                default:
                    {
                        value = null;
                        break;
                    }
            }

            //Don't add unset properties
            if (value == null) {
                continue;
            }

            //If the value is equal to the default value remove the property and return null
            if (this.compareValues(value, layoutAttributeDescriptor.getDefaultValue())) {
                this.removeLayoutAttribute(request, prefScope, nodeId, name);
                continue;
            }

            layoutAttributes.put(name, value);
        }

        return layoutAttributes;
    }

    @Override
    public void setStructureStylesheetOverride(HttpServletRequest request, String override) {
        request.setAttribute(
                StylesheetUserPreferencesServiceImpl
                        .STYLESHEET_STRUCTURE_OVERRIDE_REQUEST_ATTRIBUTE,
                override);
    }

    @Override
    public void setThemeStyleSheetOverride(HttpServletRequest request, String override) {
        request.setAttribute(
                StylesheetUserPreferencesServiceImpl
                        .STYLESHEET_THEME_OVERRIDE_REQUEST_ATTRIBUTE_NAME,
                override);
    }

    /**
     * Returns the stylesheet name if overridden in the request object.
     *
     * @param request HttpRequest
     * @param scope Scope (Structure or Theme)
     * @return Stylesheet name if set as an override in the request, else null if it was not.
     */
    protected String getStyleSheetName(final HttpServletRequest request, PreferencesScope scope) {
        final String stylesheetNameFromRequest;

        if (scope.equals(PreferencesScope.STRUCTURE)) {
            stylesheetNameFromRequest =
                    (String) request.getAttribute(STYLESHEET_STRUCTURE_OVERRIDE_REQUEST_ATTRIBUTE);
        } else {
            stylesheetNameFromRequest =
                    (String) request.getAttribute(STYLESHEET_THEME_OVERRIDE_REQUEST_ATTRIBUTE_NAME);
        }

        return stylesheetNameFromRequest;
    }

    protected boolean isFragmentOwnerStylesheetPreferencesKey(final StylesheetPreferencesKey key) {
        return this.isFragmentOwner(key.person);
    }

    protected boolean isFragmentOwner(final IPerson person) {
        return this.fragmentUtils.getFragmentDefinitionByOwner(person) != null;
    }
}