/* 
    Licensed to the Apache Software Foundation (ASF) under one
    or more contributor license agreements.  See the NOTICE file
    distributed with this work for additional information
    regarding copyright ownership.  The ASF 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

       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.apache.wiki.modules;

import java.io.BufferedInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.net.URL;

import org.jdom2.Element;

import org.apache.wiki.util.FileUtil;

/**
 *  A WikiModule describes whatever JSPWiki plugin there is: it can be a plugin,
 *  an editor, a filter, etc.
 *
 *  @since 2.4
 */
public class WikiModuleInfo
    implements Comparable<WikiModuleInfo>
{
    protected String m_name;
    protected String m_description;
    protected String m_moduleUrl;
    protected String m_moduleVersion;
    protected String m_htmlTemplate;
    protected String m_scriptLocation;
    protected String m_scriptText;
    protected String m_stylesheetLocation;
    protected String m_stylesheetText;
    protected String m_author;
    protected String m_authorUrl;
    protected URL    m_resource;
    protected String m_minVersion;
    protected String m_maxVersion;
    protected String m_adminBeanClass;
    
    /**
     *  Create a new info container.
     *  
     *  @param name The name of the module.
     */
    public WikiModuleInfo( String name ) {
        m_name = name;
    }
    
    /**
     *  The WikiModuleInfo is equal to another WikiModuleInfo, if the name is equal.  All
     *  objects are unique across JSPWiki.
     *  
     *  @param obj {@inheritDoc}
     *  @return {@inheritDoc}
     */
    @Override
    public boolean equals(Object obj) {
        if( obj instanceof WikiModuleInfo )
        {
            return ((WikiModuleInfo)obj).m_name.equals( m_name );
        }
        
        return false;
    }

    /**
     *  {@inheritDoc}
     */
    @Override
    public int hashCode() {
        return m_name.hashCode();
    }

    /**
     *  Initializes the ModuleInfo from some standard XML elements
     *  which are under the given element.
     *  
     *  @param el The element to parse.
     */
    protected void initializeFromXML( Element el ) {
        m_description        = el.getChildText("description");
        m_moduleUrl          = el.getChildText("url");
        m_moduleVersion      = el.getChildText("version");
        m_htmlTemplate       = el.getChildText("template");
        m_scriptLocation     = el.getChildText("script");
        m_stylesheetLocation = el.getChildText("stylesheet");
        m_author             = el.getChildText("author");
        m_authorUrl          = el.getChildText("authorUrl");
        m_minVersion         = el.getChildText("minVersion");
        m_maxVersion         = el.getChildText("maxVersion");
        m_adminBeanClass     = el.getChildText("adminBean");
    }

    /**
     *  Returns the AdminBean class which is supposed to manage this module.
     *  
     *  @return A class name.
     */
    public String getAdminBeanClass() {
        return m_adminBeanClass;
    }
    
    /**
     *  Returns the common name for this particular module.  Note that
     *  this is not the class name, nor is it an alias.  For different modules
     *  the name may have different meanings.
     *  <p>
     *  Every module defines a name, so this method should never return null.
     *  
     *  @return A module name.
     */
    public String getName() {
        return m_name;
    }
    
    /**
     *  The description of what this module does.
     *  
     *  @return A module description.
     */
    public String getDescription() {
        return m_description;
    }
    
    /**
     *  The URL for this getting more information about this module.
     *  
     *  @return A module URL.
     */
    public String getModuleUrl() {
        return m_moduleUrl;
    }
    
    /**
     *  The current version of the implemented module
     *  
     *  @return A module version.
     */
    public String getModuleVersion() {
        return m_moduleVersion;
    }
    
    /**
     *  Return the location of the html template for this module.
     *  
     *  @return The path to the location.
     */
    public String getHtmlTemplate() {
        return m_htmlTemplate;
    }

    /**
     *  Returns the style sheet location for this module.
     *  
     *  @return The path to the location.
     */
    public String getStylesheetLocation() {
        return m_stylesheetLocation;
    }

    /**
     *  Return the location of the script for this module.
     *  
     *  @return The path to the location.
     */
    public String getScriptLocation() {
        return m_scriptLocation;
    }

    /**
     *  Returns the name of the author of this plugin (if defined).
     * @return Author name, or null.
     */
    public String getAuthor() {
        return m_author;
    }

    /**
     *  Returns the url of the author of this plugin (if defined).
     */
    public String getAuthorUrl() {
        return m_authorUrl;
    }
    
    /**
     *  Returns the minimum version of JSPWiki that this module supports.
     *  
     *  @return The minimum version.
     */
    public String getMinVersion() {
        return m_minVersion;
    }
    
    /**
     *  Returns the maximum version of JSPWiki that this module supports.
     *  
     *  @return The maximum version.
     */
    public String getMaxVersion() {
        return m_maxVersion;
    }

    /**
     *  Attempts to locate a resource from a JAR file and returns it as a string.
     *  
     *  @param resourceLocation an URI of the resource
     *  @return The content of the file
     *  
     *  @throws IOException if the JAR file or the resource cannot be read
     */
    protected String getTextResource(String resourceLocation) 
        throws IOException
    {
        if(m_resource == null)
        {
            return "";
        }
    
        // The text of this resource should be loaded from the same
        //   jar-file as the jspwiki_modules.xml -file! This is because 2 plugins
        //   could have the same name of the resourceLocation!
        //   (2 plugins could have their stylesheet-files in 'ini/jspwiki.css')
    
        // So try to construct a resource that loads this resource from the
        //   same jar-file.
        String spec = m_resource.toString();
    
        // Replace the 'PLUGIN_RESOURCE_LOCATION' with the requested
        //   resourceLocation.
        int length = ModuleManager.PLUGIN_RESOURCE_LOCATION.length();
        spec = spec.substring(0, spec.length() - length) + resourceLocation;
    
        URL url = new URL(spec);
        BufferedInputStream   in  = new BufferedInputStream(url.openStream());
        ByteArrayOutputStream out = new ByteArrayOutputStream(1024);
        
        FileUtil.copyContents( in, out );
    
        in.close();
        String text = out.toString();
        out.close();
        
        return text;
    }

    /**
     *  {@inheritDoc}
     */
    public int compareTo(WikiModuleInfo arg0)
    {
        return m_name.compareTo( arg0.getName() );
    }

}