package org.apache.wiki.ui.stripes;

import java.io.IOException;
import java.io.InputStream;
import java.util.HashSet;
import java.util.Properties;
import java.util.Set;

import net.sourceforge.stripes.action.ActionBean;
import net.sourceforge.stripes.config.Configuration;
import net.sourceforge.stripes.config.DontAutoLoad;
import net.sourceforge.stripes.controller.NameBasedActionResolver;
import net.sourceforge.stripes.controller.UrlBinding;
import net.sourceforge.stripes.controller.UrlBindingFactory;

import org.apache.wiki.api.WikiException;

/**
 * Resolves Stripes ActionBeans in an identical fashion to {@link NameBasedActionResolver}, but allows
 * UrlBindings to be defined in an external file.
 */
@DontAutoLoad
public class FileBasedActionResolver extends NameBasedActionResolver
{
    
    private Set<Class<? extends ActionBean>> m_processed = new HashSet<Class<? extends ActionBean>>();
    private Properties m_urlBindings = new Properties();
    private static final String URL_BINDINGS = "/WEB-INF/urlpattern.properties";
    
    @Override
    public void init( Configuration configuration ) throws Exception
    {
        // Get the url bindings file
        m_urlBindings.clear();
        InputStream in = configuration.getServletContext().getResourceAsStream( URL_BINDINGS );
        if ( in == null )
        {
            throw new IOException( "Resource not returned by servlet context: " + URL_BINDINGS );
        }
        
        // Load the URL patterns from the config file
        try
        {
            m_urlBindings.load( in );
            in.close();
        }
        catch( IOException e )
        {
            throw new WikiException( "Could not find file " + URL_BINDINGS + ". Reason: " + e.getMessage(), e );
        }
        
        // Initialize the URL bindings factory
        super.init( configuration );
    }

    /**
     * 
     */
    @Override
    public String getUrlBinding( Class<? extends ActionBean> clazz )
    {
        // See if we've processed the class first.
        if ( m_processed.contains( clazz  ) )
        {
            return super.getUrlBinding( clazz );
        }
        
        // Have we defined a binding string somewhere? If not, delegate to Stripes
        String binding = m_urlBindings.getProperty( clazz.getName() );
        if ( binding == null )
        {
            return super.getUrlBinding( clazz );
        }
        
        // Must be a new ActionBean we haven't processed yet, AND we have a binding for it.
        UrlBinding prototype = UrlBindingFactory.parseUrlBinding( clazz, binding );
        UrlBindingFactory.getInstance().addBinding( clazz, prototype );
        m_processed.add( clazz );
        return prototype.toString();
    }

}