/*
 *  Copyright 2010 Anyware Services
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */
package org.ametys.web.cocoon;

import java.io.File;
import java.io.IOException;
import java.util.Map;
import java.util.MissingResourceException;

import org.apache.avalon.framework.component.ComponentException;
import org.apache.avalon.framework.configuration.Configuration;
import org.apache.avalon.framework.configuration.ConfigurationException;
import org.apache.avalon.framework.configuration.DefaultConfiguration;
import org.apache.avalon.framework.parameters.Parameters;
import org.apache.avalon.framework.service.ServiceException;
import org.apache.avalon.framework.service.ServiceManager;
import org.apache.cocoon.ProcessingException;
import org.apache.cocoon.environment.ObjectModelHelper;
import org.apache.cocoon.environment.Request;
import org.apache.cocoon.environment.SourceResolver;
import org.apache.cocoon.xml.ParamSaxBuffer;
import org.apache.commons.lang.StringUtils;
import org.xml.sax.SAXException;

import org.ametys.core.cocoon.XMLResourceBundle;
import org.ametys.web.skin.SkinsManager;

/**
 * CMS version of the I18nTransformer, dealing with skin catalogues.<br>
 * It is also able to reconfigure itself dynamically, to reflect changes.
 */
public class I18nTransformer extends org.ametys.core.cocoon.I18nTransformer
{
    // The last time, "needsReload" was called
    private static long _needsReloadTime;

    /** the avalon service manager */
    protected ServiceManager _manager;
    
    private Configuration _conf;
    
    /** The time the configure method was lastly called on this instance */
    private long _lastConfigureTime;

    private SkinsManager _skinsManager;
    
    @Override
    public void configure(Configuration conf) throws ConfigurationException
    {
        _conf = conf;
        _configure();
    }
    
    @Override
    public void service(ServiceManager smanager) throws ServiceException
    {
        super.service(smanager);
        _manager = smanager;
        _skinsManager = (SkinsManager) smanager.lookup(SkinsManager.ROLE);
    }
    
    private void _configure() throws ConfigurationException
    {
        _lastConfigureTime = System.currentTimeMillis();
        
        // Modification de la configuration pour faire apparaitre les sites
        DefaultConfiguration newConf = new DefaultConfiguration("i18n");

        Configuration cataloguesConf = _conf.getChild("catalogues", false);
        DefaultConfiguration catalogues = new DefaultConfiguration("catalogues");
        newConf.addChild(catalogues);

        if (cataloguesConf != null)
        {
            catalogues.addAll(cataloguesConf);
        }

        _configureCatalogue(catalogues, "skins", "skin");
        _configureCatalogue(catalogues, "models", "model");
        
        super.configure(newConf);
    }

    private void _configureCatalogue(DefaultConfiguration catalogues, String dirName, String catalogName)
    {
        File skinsBaseDir = new File(_context.getRealPath("/" + dirName));

        if (skinsBaseDir.exists())
        {
            File[] skinsDir = skinsBaseDir.listFiles();

            for (int i = 0; i < skinsDir.length; i++)
            {
                File skinDir = skinsDir[i];

                // On filtre les non-repertoires, non-plugins, et les plugins sans i18n
                if (skinDir.isDirectory() && new File(skinDir, "i18n/messages.xml").exists())
                {
                    String name = skinDir.getName();
                    String id = catalogName + "." + name;

                    DefaultConfiguration catalogue = new DefaultConfiguration("catalogue");
                    catalogue.setAttribute("id", id);
                    catalogue.setAttribute("name", "messages");
                    catalogue.setAttribute("location", "context://" + dirName + "/" + name + "/i18n");

                    catalogues.addChild(catalogue);
                }
            }
        }
    }
    
    @Override
    protected ParamSaxBuffer getMessage(String catalogueID, String key)
    {
        Request request = ObjectModelHelper.getRequest(objectModel);
        
        String skinLocation = (String) request.getAttribute("skin-location");
        if (skinLocation != null && catalogueID != null && catalogueID.startsWith("skin"))
        {
            ParamSaxBuffer message = null;
            
            String skinName = _skinsManager.getSkinNameFromRequest (request);
            
            if (StringUtils.isNotEmpty(skinName))
            {
                message = _getExternalMessage ("ametys-home://" + skinLocation + "/" + skinName + "/i18n", key);
            }
            
            if (message == null)
            {
                message = getUntranslatedMessage (catalogueID, key);
            }
            
            return message;
        }
        else
        {
            return super.getMessage(catalogueID, key);
        }
    }
    
    private ParamSaxBuffer _getExternalMessage (String externalLocation, String key)
    {
        try
        {
            XMLResourceBundle bundle = (XMLResourceBundle) factory.select(externalLocation, "messages", locale);
            if (bundle == null) 
            {
                // Can't translate
                if (getLogger().isDebugEnabled())
                {
                    getLogger().debug("No bundle found for catalogue location '" + externalLocation + "'");
                }
                return null;
            }
            
            try 
            {
                return (ParamSaxBuffer) bundle.getObject(key);
            } 
            catch (MissingResourceException e)  
            {
                if (getLogger().isDebugEnabled())
                {
                    getLogger().debug("Untranslated key: '" + key + "'");
                }
            }
        }
        catch (ComponentException e)
        {
            if (getLogger().isDebugEnabled())
            {
                getLogger().debug("Untranslated key: '" + key + "'");
            }
        }
        
        return null;
        
    }

    /**
     * Call this method when you change the list of i18n catalogues <br> by adding a new skin for example.
     */
    public static void needsReload()
    {
        _needsReloadTime = System.currentTimeMillis();
    }
    
    @Override
    public void setup(SourceResolver resolver, Map objModel, String source, Parameters parameters) throws ProcessingException, SAXException, IOException
    {
        try
        {
            if (_needsReloadTime > _lastConfigureTime)
            {
                _configure();
            }
        }
        catch (ConfigurationException e)
        {
            String errorMessage = "Error with i18n on work dir";
            getLogger().error(errorMessage, e);
            throw new SAXException(errorMessage, e);
        }
        
        super.setup(resolver, objModel, source, parameters);
    }
}