/*
 * This library is part of OpenCms -
 * the Open Source Content Management System
 *
 * Copyright (c) Alkacon Software GmbH (http://www.alkacon.com)
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * For further information about Alkacon Software GmbH, please see the
 * company website: http://www.alkacon.com
 *
 * For further information about OpenCms, please see the
 * project website: http://www.opencms.org
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package org.opencms.module;

import org.opencms.db.CmsExportPoint;
import org.opencms.file.CmsObject;
import org.opencms.file.types.I_CmsResourceType;
import org.opencms.main.CmsIllegalArgumentException;
import org.opencms.main.CmsLog;
import org.opencms.main.OpenCms;
import org.opencms.security.CmsRole;
import org.opencms.security.CmsRoleViolationException;
import org.opencms.util.CmsFileUtil;
import org.opencms.util.CmsStringUtil;
import org.opencms.workplace.explorer.CmsExplorerTypeSettings;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.SortedMap;
import java.util.StringTokenizer;
import java.util.TreeMap;

import org.apache.commons.logging.Log;

/**
 * Describes an OpenCms module.<p>
 * 
 * OpenCms modules provide a standard mechanism to extend the OpenCms functionality.
 * Modules can contain VFS data, Java classes and a number of configuration options.<p> 
 * 
 * @since 6.0.0 
 * 
 * @see org.opencms.module.I_CmsModuleAction
 * @see org.opencms.module.A_CmsModuleAction
 */
public class CmsModule implements Comparable<CmsModule> {

    /** The default date for module created / installed if not provided. */
    public static final long DEFAULT_DATE = 0L;

    /** The log object for this class. */
    private static final Log LOG = CmsLog.getLog(CmsModule.class);

    /**
     * The module property key name to specifiy additional resources which are
     * part of a module outside of {system/modules}.
     */
    private static final String MODULE_PROPERTY_ADDITIONAL_RESOURCES = "additionalresources";

    /** Character to separate additional resources specified in the module properties.  */
    private static final String MODULE_PROPERTY_ADDITIONAL_RESOURCES_SEPARATOR = ";";

    /** The module action class name. */
    private String m_actionClass;

    /** Initialized module action instance. */
    private I_CmsModuleAction m_actionInstance;

    /** The email of the author of this module. */
    private String m_authorEmail;

    /** The name of the author of this module. */
    private String m_authorName;

    /** Flag to create the classes folders when creating the module. */
    private boolean m_createClassesFolder;

    /** Flag to create the elements folder when creating the module. */
    private boolean m_createElementsFolder;

    /** Flag to create the formatters folder when creating the module. */
    private boolean m_createFormattersFolder;

    /** Flag to create the lib folder when creating the module. */
    private boolean m_createLibFolder;

    /** Flag to create the module folder when creating the module. */
    private boolean m_createModuleFolder;

    /** Flag to create the resources folder when creating the module. */
    private boolean m_createResourcesFolder;

    /** Flag to create the schemas folder when creating the module. */
    private boolean m_createSchemasFolder;

    /** Flag to create the template folder when creating the module. */
    private boolean m_createTemplateFolder;

    /** The date this module was created by the author. */
    private long m_dateCreated;

    /** The date this module was installed. */
    private long m_dateInstalled;

    /** List of dependencies of this module. */
    private List<CmsModuleDependency> m_dependencies;

    /** The description of this module. */
    private String m_description;

    /** The explorer type settings. */
    private List<CmsExplorerTypeSettings> m_explorerTypeSettings;

    /** List of export points added by this module. */
    private List<CmsExportPoint> m_exportPoints;

    /** Indicates if this modules configuration has already been frozen. */
    private boolean m_frozen;

    /** The group of the module. */
    private String m_group;

    /** The name of this module, must be a valid Java package name. */
    private String m_name;

    /** The "nice" display name of this module. */
    private String m_niceName;

    /** The additional configuration parameters of this module. */
    private SortedMap<String, String> m_parameters;

    /** List of VFS resources that belong to this module. */
    private List<String> m_resources;

    /** The list of additional resource types. */
    private List<I_CmsResourceType> m_resourceTypes;

    /** The name of the user who installed this module. */
    private String m_userInstalled;

    /** The version of this module. */
    private CmsModuleVersion m_version;

    /**
     * Creates a new, empty CmsModule object.<p>
     */
    public CmsModule() {

        m_version = new CmsModuleVersion(CmsModuleVersion.DEFAULT_VERSION);
        m_resources = Collections.emptyList();
        m_exportPoints = Collections.emptyList();
        m_dependencies = Collections.emptyList();
    }

    /**
     * Creates a new module description with the specified values.<p>
     * 
     * @param name the name of this module, must be a valid Java package name
     * @param niceName the "nice" display name of this module
     * @param group the group of this module
     * @param actionClass the (optional) module class name
     * @param description the description of this module
     * @param version the version of this module
     * @param authorName the name of the author of this module
     * @param authorEmail the email of the author of this module
     * @param dateCreated the date this module was created by the author
     * @param userInstalled the name of the user who uploaded this module
     * @param dateInstalled the date this module was uploaded
     * @param dependencies a list of dependencies of this module
     * @param exportPoints a list of export point added by this module
     * @param resources a list of VFS resources that belong to this module
     * @param parameters the parameters for this module
     */
    public CmsModule(
        String name,
        String niceName,
        String group,
        String actionClass,
        String description,
        CmsModuleVersion version,
        String authorName,
        String authorEmail,
        long dateCreated,
        String userInstalled,
        long dateInstalled,
        List<CmsModuleDependency> dependencies,
        List<CmsExportPoint> exportPoints,
        List<String> resources,
        Map<String, String> parameters) {

        super();
        m_name = name;
        setNiceName(niceName);
        setActionClass(actionClass);
        setGroup(group);

        if (CmsStringUtil.isEmpty(description)) {
            m_description = "";
        } else {
            m_description = description;
        }
        m_version = version;
        if (CmsStringUtil.isEmpty(authorName)) {
            m_authorName = "";
        } else {
            m_authorName = authorName;
        }
        if (CmsStringUtil.isEmpty(authorEmail)) {
            m_authorEmail = "";
        } else {
            m_authorEmail = authorEmail;
        }
        // remove milisecounds
        m_dateCreated = (dateCreated / 1000L) * 1000L;
        if (CmsStringUtil.isEmpty(userInstalled)) {
            m_userInstalled = "";
        } else {
            m_userInstalled = userInstalled;
        }
        m_dateInstalled = (dateInstalled / 1000L) * 1000L;
        if (dependencies == null) {
            m_dependencies = Collections.emptyList();
        } else {
            m_dependencies = Collections.unmodifiableList(dependencies);
        }
        if (exportPoints == null) {
            m_exportPoints = Collections.emptyList();
        } else {
            m_exportPoints = Collections.unmodifiableList(exportPoints);
        }
        if (resources == null) {
            m_resources = Collections.emptyList();
        } else {
            m_resources = Collections.unmodifiableList(resources);
        }
        if (parameters == null) {
            m_parameters = new TreeMap<String, String>();
        } else {
            m_parameters = new TreeMap<String, String>(parameters);
        }

        initOldAdditionalResources();

        if (LOG.isDebugEnabled()) {
            LOG.debug(Messages.get().getBundle().key(Messages.LOG_MODULE_INSTANCE_CREATED_1, m_name));
        }
        m_resourceTypes = Collections.emptyList();
        m_explorerTypeSettings = Collections.emptyList();
    }

    /**
     * Checks if this module depends on another given module,
     * will return the dependency, or <code>null</code> if no dependency was found.<p>
     * 
     * @param module the other module to check against
     * @return the dependency, or null if no dependency was found
     */
    public CmsModuleDependency checkDependency(CmsModule module) {

        CmsModuleDependency otherDepdendency = new CmsModuleDependency(module.getName(), module.getVersion());

        // loop through all the dependencies
        for (int i = 0; i < m_dependencies.size(); i++) {
            CmsModuleDependency dependency = m_dependencies.get(i);
            if (dependency.dependesOn(otherDepdendency)) {
                // short circuit here
                return dependency;
            }
        }

        // no dependency was found
        return null;
    }

    /**
     * Checks if all resources of the module are present.<p>
     * 
     * @param cms an initialized OpenCms user context which must have read access to all module resources
     * 
     * @throws CmsIllegalArgumentException in case not all module resources exist or can be read with the given OpenCms user context
     */
    public void checkResources(CmsObject cms) throws CmsIllegalArgumentException {

        CmsFileUtil.checkResources(cms, getResources());
    }

    /**
     * Clones a CmsModule which is not set to frozen.<p>
     * This clones module can be used to be update the module information.
     * 
     * @see java.lang.Object#clone()
     */
    @Override
    public Object clone() {

        // create a copy of the module
        CmsModule result = new CmsModule(
            m_name,
            m_niceName,
            m_group,
            m_actionClass,
            m_description,
            m_version,
            m_authorName,
            m_authorEmail,
            m_dateCreated,
            m_userInstalled,
            m_dateInstalled,
            m_dependencies,
            m_exportPoints,
            m_resources,
            m_parameters);
        // and set its frozen state to false
        result.m_frozen = false;

        if (getExplorerTypes() != null) {
            List<CmsExplorerTypeSettings> settings = new ArrayList<CmsExplorerTypeSettings>();
            for (CmsExplorerTypeSettings setting : getExplorerTypes()) {
                settings.add((CmsExplorerTypeSettings)setting.clone());
            }
            result.setExplorerTypes(settings);
        }
        if (getResourceTypes() != null) {
            // TODO: The resource types must be cloned also, otherwise modification will effect the origin also
            result.setResourceTypes(new ArrayList<I_CmsResourceType>(getResourceTypes()));
        }
        if (getDependencies() != null) {
            List<CmsModuleDependency> deps = new ArrayList<CmsModuleDependency>();
            for (CmsModuleDependency dep : getDependencies()) {
                deps.add((CmsModuleDependency)dep.clone());
            }
            result.setDependencies(new ArrayList<CmsModuleDependency>(getDependencies()));
        }
        if (getExportPoints() != null) {
            List<CmsExportPoint> exps = new ArrayList<CmsExportPoint>();
            for (CmsExportPoint exp : getExportPoints()) {
                exps.add((CmsExportPoint)exp.clone());
            }
            result.setExportPoints(exps);
        }

        result.setCreateClassesFolder(m_createClassesFolder);
        result.setCreateElementsFolder(m_createElementsFolder);
        result.setCreateLibFolder(m_createLibFolder);
        result.setCreateModuleFolder(m_createModuleFolder);
        result.setCreateResourcesFolder(m_createResourcesFolder);
        result.setCreateSchemasFolder(m_createSchemasFolder);
        result.setCreateTemplateFolder(m_createTemplateFolder);
        result.setCreateFormattersFolder(m_createFormattersFolder);

        result.setResources(new ArrayList<String>(m_resources));

        return result;
    }

    /**
     * @see java.lang.Comparable#compareTo(java.lang.Object)
     */
    public int compareTo(CmsModule obj) {

        if (obj == this) {
            return 0;
        }
        return m_name.compareTo(obj.m_name);
    }

    /**
     * Two instances of a module are considered equal if their name is equal.<p>
     *
     * @param obj the object to compare
     * 
     * @return true if the objects are equal
     *  
     * @see java.lang.Object#equals(java.lang.Object)
     * @see #isIdentical(CmsModule)
     */
    @Override
    public boolean equals(Object obj) {

        if (obj == this) {
            return true;
        }
        if (obj instanceof CmsModule) {
            return ((CmsModule)obj).m_name.equals(m_name);
        }
        return false;
    }

    /**
     * Returns the class name of this modules (optional) action class.<p>
     *
     * If this module does not use an action class,
     * <code>null</code> is returned.<p>
     *
     * @return the class name of this modules (optional) action class
     */
    public String getActionClass() {

        return m_actionClass;
    }

    /**
     * Returns the module action instance of this module, or <code>null</code>
     * if no module action instance is configured.<p>
     * 
     * @return the module action instance of this module
     */
    public I_CmsModuleAction getActionInstance() {

        return m_actionInstance;
    }

    /**
     * Returns the email of the module author.<p>
     *
     * @return the email of the module author
     */
    public String getAuthorEmail() {

        return m_authorEmail;
    }

    /**
     * Returns the name of the author of this module.<p>
     *
     * @return the name of the author of this module
     */
    public String getAuthorName() {

        return m_authorName;
    }

    /**
     * Gets the module configuration path.<p>
     * 
     * @return the module configuration path
     */
    public String getConfigurationPath() {

        String parameter = getParameter("config.sitemap");
        if (parameter != null) {
            return parameter;
        } else {
            return "/system/modules/" + getName() + "/.config";
        }
    }

    /**
     * Returns the date this module was created by the author.<p>
     *
     * @return the date this module was created by the author
     */
    public long getDateCreated() {

        return m_dateCreated;
    }

    /**
     * Returns the date this module was uploaded.<p>
     *
     * @return the date this module was uploaded
     */
    public long getDateInstalled() {

        return m_dateInstalled;
    }

    /**
     * Returns the list of dependencies of this module.<p>
     *
     * @return the list of dependencies of this module
     */
    public List<CmsModuleDependency> getDependencies() {

        return m_dependencies;
    }

    /**
     * Returns the description of this module.<p>
     *
     * @return the description of this module
     */
    public String getDescription() {

        return m_description;
    }

    /**
     * Returns the list of explorer resource types that belong to this module.<p>
     *
     * @return the list of explorer resource types that belong to this module
     */
    public List<CmsExplorerTypeSettings> getExplorerTypes() {

        return m_explorerTypeSettings;
    }

    /**
     * Returns the list of export point added by this module.<p>
     *
     * @return the list of export point added by this module
     */
    public List<CmsExportPoint> getExportPoints() {

        return m_exportPoints;
    }

    /**
     * Returns the group name of this module.<p>
     *
     * @return the group name of this module
     */
    public String getGroup() {

        return m_group;
    }

    /**
     * Returns the name of this module.<p>
     * 
     * The module name must be a valid java package name.<p>
     *
     * @return the name of this module
     */
    public String getName() {

        return m_name;
    }

    /**
     * Returns the "nice" display name of this module.<p>
     *
     * @return the "nice" display name of this module
     */
    public String getNiceName() {

        return m_niceName;
    }

    /**
     * Returns a parameter value from the module parameters.<p>
     * 
     * @param key the parameter to return the value for
     * @return the parameter value from the module parameters
     */
    public String getParameter(String key) {

        return m_parameters.get(key);
    }

    /**
     * Returns a parameter value from the module parameters,
     * or a given default value in case the parameter is not set.<p>
     * 
     * @param key the parameter to return the value for
     * @param defaultValue the default value in case there is no value stored for this key
     * @return the parameter value from the module parameters
     */
    public String getParameter(String key, String defaultValue) {

        String value = m_parameters.get(key);
        return (value != null) ? value : defaultValue;
    }

    /**
     * Returns the configured (immutable) module parameters.<p>
     * 
     * @return the configured (immutable) module parameters
     */
    public SortedMap<String, String> getParameters() {

        return m_parameters;
    }

    /**
     * Returns the list of VFS resources that belong to this module.<p>
     *
     * @return the list of VFS resources that belong to this module
     */
    public List<String> getResources() {

        return m_resources;
    }

    /**
     * Returns the list of additional resource types that belong to this module.<p>
     *
     * @return the list of additional resource types that belong to this module
     */
    public List<I_CmsResourceType> getResourceTypes() {

        return m_resourceTypes;
    }

    /**
     * Returns the name of the user who uploaded this module.<p>
     *
     * @return the name of the user who uploaded this module
     */
    public String getUserInstalled() {

        return m_userInstalled;
    }

    /**
     * Returns the version of this module.<p>
     *
     * @return the version of this module
     */
    public CmsModuleVersion getVersion() {

        return m_version;
    }

    /**
     * @see java.lang.Object#hashCode()
     */
    @Override
    public int hashCode() {

        return m_name.hashCode();
    }

    /**
     * Returns the createClassesFolder flag.<p>
     *
     * @return the createClassesFolder flag
     */
    public boolean isCreateClassesFolder() {

        return m_createClassesFolder;
    }

    /**
     * Returns the createElementsFolder flag.<p>
     *
     * @return the createElementsFolder flag
     */
    public boolean isCreateElementsFolder() {

        return m_createElementsFolder;
    }

    /**
     * Returns the createFormattersFolder flag.<p>
     * 
     * @return the createFormattersFolder flag 
     */
    public boolean isCreateFormattersFolder() {

        return m_createFormattersFolder;
    }

    /**
     * Returns the createLibFolder flag.<p>
     *
     * @return the createLibFolder flag
     */
    public boolean isCreateLibFolder() {

        return m_createLibFolder;
    }

    /**
     * Returns the createModuleFolder flag.<p>
     *
     * @return the createModuleFolder flag
     */
    public boolean isCreateModuleFolder() {

        return m_createModuleFolder;
    }

    /**
     * Returns the createResourcesFolder flag.<p>
     *
     * @return the createResourcesFolder flag
     */
    public boolean isCreateResourcesFolder() {

        return m_createResourcesFolder;
    }

    /**
     * Returns the createSchemasFolder flag.<p>
     *
     * @return the createSchemasFolder flag
     */
    public boolean isCreateSchemasFolder() {

        return m_createSchemasFolder;
    }

    /**
     * Returns the createTemplateFolder flag.<p>
     *
     * @return the createTemplateFolder flag
     */
    public boolean isCreateTemplateFolder() {

        return m_createTemplateFolder;
    }

    /**
     * Checks if this module is identical with another module.<p>
     * 
     * Modules A, B are <b>identical</b> if <i>all</i> values of A are equal to B.
     * The values from {@link #getUserInstalled()} and {@link #getDateInstalled()} 
     * are ignored for this test.<p>
     *  
     * Modules A, B are <b>equal</b> if just the name of A is equal to the name of B.<p>
     * 
     * @param other the module to compare with
     * 
     * @return if the modules are identical
     * 
     * @see #equals(Object)
     */
    public boolean isIdentical(CmsModule other) {

        // some code redundancy here but this is easier to debug 
        if (!isEqual(m_name, other.m_name)) {
            return false;
        }
        if (!isEqual(m_niceName, other.m_niceName)) {
            return false;
        }
        if (!isEqual(m_version, other.m_version)) {
            return false;
        }
        if (!isEqual(m_actionClass, other.m_actionClass)) {
            return false;
        }
        if (!isEqual(m_description, other.m_description)) {
            return false;
        }
        if (!isEqual(m_authorName, other.m_authorName)) {
            return false;
        }
        if (!isEqual(m_authorEmail, other.m_authorEmail)) {
            return false;
        }
        if (m_dateCreated != other.m_dateCreated) {
            return false;
        }
        return true;
    }

    /**
     * Sets the class name of this modules (optional) action class.<p>
     * 
     * Providing <code>null</code> as a value indicates that this module does not use an action class.<p>
     * 
     * <i>Please note:</i>It's not possible to set the action class name once the module
     * configuration has been frozen.<p> 
     * 
     * @param value the class name of this modules (optional) action class to set
     */
    public void setActionClass(String value) {

        checkFrozen();
        if (CmsStringUtil.isEmpty(value)) {
            m_actionClass = null;
        } else {
            if (!CmsStringUtil.isValidJavaClassName(value)) {
                throw new CmsIllegalArgumentException(Messages.get().container(
                    Messages.ERR_MODULE_ACTION_CLASS_2,
                    value,
                    getName()));
            }
            m_actionClass = value;
        }
    }

    /**
     * Sets the author email of this module.<p>
     * 
     * 
     * <i>Please note:</i>It's not possible to set the modules author email once the module
     * configuration has been frozen.<p>
     * 
     * @param value the module description to set
     */
    public void setAuthorEmail(String value) {

        checkFrozen();
        m_authorEmail = value.trim();
    }

    /**
     * Sets the author name of this module.<p>
     * 
     * 
     * <i>Please note:</i>It's not possible to set the modules author name once the module
     * configuration has been frozen.<p>
     * 
     * @param value the module description to set
     */
    public void setAuthorName(String value) {

        checkFrozen();
        m_authorName = value.trim();
    }

    /**
     * Sets the createClassesFolder flag.<p>
     *
     * @param createClassesFolder the createClassesFolder flag to set
     */
    public void setCreateClassesFolder(boolean createClassesFolder) {

        m_createClassesFolder = createClassesFolder;
    }

    /**
     * Sets the createElementsFolder flag.<p>
     *
     * @param createElementsFolder the createElementsFolder flag to set
     */
    public void setCreateElementsFolder(boolean createElementsFolder) {

        m_createElementsFolder = createElementsFolder;
    }

    /**
     * Sets the createFormattersFolder flag.<p>
     * 
     * @param createFormattersFolder the createFormattersFolder flag to set
     */
    public void setCreateFormattersFolder(boolean createFormattersFolder) {

        m_createFormattersFolder = createFormattersFolder;
    }

    /**
     * Sets the createLibFolder flag.<p>
     *
     * @param createLibFolder the createLibFolder flag to set
     */
    public void setCreateLibFolder(boolean createLibFolder) {

        m_createLibFolder = createLibFolder;
    }

    /**
     * Sets the createModuleFolder flag.<p>
     *
     * @param createModuleFolder the createModuleFolder flag to set
     */
    public void setCreateModuleFolder(boolean createModuleFolder) {

        m_createModuleFolder = createModuleFolder;
    }

    /**
     * Sets the createResourcesFolder flag.<p>
     *
     * @param createResourcesFolder the createResourcesFolder flag to set
     */
    public void setCreateResourcesFolder(boolean createResourcesFolder) {

        m_createResourcesFolder = createResourcesFolder;
    }

    /**
     * Sets the createSchemasFolder flag .<p>
     *
     * @param createSchemasFolder the createSchemasFolder flag to set
     */
    public void setCreateSchemasFolder(boolean createSchemasFolder) {

        m_createSchemasFolder = createSchemasFolder;
    }

    /**
     * Sets the createTemplateFolder flag .<p>
     *
     * @param createTemplateFolder the createTemplateFolder flag to set
     */
    public void setCreateTemplateFolder(boolean createTemplateFolder) {

        m_createTemplateFolder = createTemplateFolder;
    }

    /**
     * Sets the date created of this module.<p>
     * 
     * 
     * <i>Please note:</i>It's not possible to set the module date created once the module
     * configuration has been frozen.<p>
     * 
     * @param value the date created to set
     */
    public void setDateCreated(long value) {

        checkFrozen();
        m_dateCreated = value;
    }

    /**
     * Sets the installation date of this module.<p>
     * 
     * 
     * <i>Please note:</i>It's not possible to set the installation date once the module
     * configuration has been frozen.<p>
     * 
     * @param value the installation date this module
     */
    public void setDateInstalled(long value) {

        checkFrozen();
        m_dateInstalled = value;
    }

    /**
     * Sets the list of module dependencies.<p>
     *
     * @param dependencies list of module dependencies
     */
    public void setDependencies(List<CmsModuleDependency> dependencies) {

        checkFrozen();
        m_dependencies = dependencies;
    }

    /**
     * Sets the description of this module.<p>
     * 
     * 
     * <i>Please note:</i>It's not possible to set the modules description once the module
     * configuration has been frozen.<p>
     * 
     * @param value the module description to set
     */
    public void setDescription(String value) {

        checkFrozen();
        m_description = value.trim();
    }

    /**
     * Sets the additional explorer types that belong to this module.<p>
     *
     * @param explorerTypeSettings the explorer type settings.
     */
    public void setExplorerTypes(List<CmsExplorerTypeSettings> explorerTypeSettings) {

        m_explorerTypeSettings = explorerTypeSettings;
    }

    /**
     * Sets the export points of this module.<p>
     *
     * @param exportPoints the export points of this module.
     */
    public void setExportPoints(List<CmsExportPoint> exportPoints) {

        m_exportPoints = exportPoints;
    }

    /**
     * Sets the group name of this module.<p>
     * 
     * 
     * <i>Please note:</i>It's not possible to set the modules group name once the module
     * configuration has been frozen.<p>
     * 
     * @param value the module group name to set
     */
    public void setGroup(String value) {

        checkFrozen();
        m_group = value;
    }

    /**
     * Sets the name of this module.<p>
     * 
     * The module name must be a valid java package name.<p>
     * 
     * <i>Please note:</i>It's not possible to set the modules name once the module
     * configuration has been frozen.<p>
     * 
     * @param value the module name to set
     */
    public void setName(String value) {

        checkFrozen();
        if (!CmsStringUtil.isValidJavaClassName(value)) {
            throw new CmsIllegalArgumentException(Messages.get().container(Messages.ERR_MODULE_NAME_1, value));
        }
        m_name = value;
    }

    /**
     * Sets the "nice" display name of this module.<p>
     * 
     * <i>Please note:</i>It's not possible to set the modules "nice" name once the module
     * configuration has been frozen.<p> 
     * 
     * @param value the "nice" display name of this module to set
     */
    public void setNiceName(String value) {

        checkFrozen();
        if (CmsStringUtil.isEmptyOrWhitespaceOnly(value)) {
            m_niceName = getName();
        } else {
            m_niceName = value.trim();
        }
    }

    /**
     * Sets the parameters of this module.<p>
     * 
     * 
     * <i>Please note:</i>It's not possible to set the module parameters once the module
     * configuration has been frozen.<p>
     * 
     * @param parameters the module parameters to set
     */
    public void setParameters(SortedMap<String, String> parameters) {

        checkFrozen();
        m_parameters = parameters;
    }

    /**
     * Sets the resources of this module.<p>
     * 
     * 
     * <i>Please note:</i>It's not possible to set the module resources once the module
     * configuration has been frozen.<p>
     * 
     * @param value the module resources to set
     */
    public void setResources(List<String> value) {

        checkFrozen();
        m_resources = value;
    }

    /**
     * Sets the list of additional resource types that belong to this module.<p>
     *
     * @param resourceTypes list of additional resource types that belong to this module
     */
    public void setResourceTypes(List<I_CmsResourceType> resourceTypes) {

        m_resourceTypes = Collections.unmodifiableList(resourceTypes);
    }

    /**
     * Sets the user who installed of this module.<p>
     * 
     * 
     * <i>Please note:</i>It's not possible to set the user installed once the module
     * configuration has been frozen.<p>
     * 
     * @param value the user who installed this module
     */
    public void setUserInstalled(String value) {

        checkFrozen();
        m_userInstalled = value.trim();
    }

    /**
     * Checks if this modules configuration is frozen.<p>
     * 
     * @throws CmsIllegalArgumentException in case the configuration is already frozen
     */
    protected void checkFrozen() throws CmsIllegalArgumentException {

        if (m_frozen) {
            throw new CmsIllegalArgumentException(Messages.get().container(Messages.ERR_MODULE_FROZEN_1, getName()));
        }
    }

    /**
     * Initializes this module, also freezing the module configuration.<p>
     * 
     * @param cms an initialized OpenCms user context
     * 
     * @throws CmsRoleViolationException if the given users does not have the <code>{@link CmsRole#DATABASE_MANAGER}</code> role 
     */
    protected void initialize(CmsObject cms) throws CmsRoleViolationException {

        checkFrozen();
        // check if the user has the required permissions
        OpenCms.getRoleManager().checkRole(cms, CmsRole.DATABASE_MANAGER);

        m_frozen = true;
        m_resources = Collections.unmodifiableList(m_resources);
    }

    /**
     * Sets the module action instance for this module.<p>
     * 
     * @param actionInstance the module action instance for this module
     */
    /*package*/void setActionInstance(I_CmsModuleAction actionInstance) {

        m_actionInstance = actionInstance;

    }

    /**
     * Resolves the module property "additionalresources" to the resource list and
     * vice versa.<p>
     * 
     * This "special" module property is required as long as we do not have a new 
     * GUI for editing of module resource entries. Once we have the new GUI, the 
     * handling of "additionalresources" will be moved to the import of the module 
     * and done only if the imported module is a 5.0 module.<p>
     */
    private void initOldAdditionalResources() {

        SortedMap<String, String> parameters = new TreeMap<String, String>(m_parameters);
        List<String> resources = new ArrayList<String>(m_resources);

        String additionalResources;
        additionalResources = parameters.get(MODULE_PROPERTY_ADDITIONAL_RESOURCES);
        if (additionalResources != null) {
            StringTokenizer tok = new StringTokenizer(
                additionalResources,
                MODULE_PROPERTY_ADDITIONAL_RESOURCES_SEPARATOR);
            while (tok.hasMoreTokens()) {
                String resource = tok.nextToken().trim();
                if ((!"-".equals(resource)) && (!resources.contains(resource))) {
                    resources.add(resource);
                }
            }
        }

        m_resources = resources;
    }

    /**
     * Checks if two objects are either both null, or equal.<p>
     * 
     * @param a the first object to check
     * @param b the second object to check 
     * @return true if the two object are either both null, or equal
     */
    private boolean isEqual(Object a, Object b) {

        if (a == null) {
            return (b == null);
        }
        if (b == null) {
            return false;
        }
        return a.equals(b);
    }
}