package org.eclipse.wst.wsdl.internal.generator.extension;

import java.net.URL;

import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.IExtensionPoint;
import org.eclipse.core.runtime.IPluginRegistry;
import org.eclipse.core.runtime.Platform;
import org.eclipse.wst.wsdl.WSDLPlugin;

public class ContentGeneratorExtensionRegistryReader {
	  protected static final String PLUGIN_ID = WSDLPlugin.getPlugin().getDescriptor().getUniqueIdentifier();
	  protected static final String EXTENSION_POINT_ID = "contentGenerators";
	  protected static final String ELEMENT_NAME = "contentGenerator";
	  protected static final String ATT_NAMESPACE = "namespace";
	  protected static final String ATT_NAME = "name";
	  protected static final String ATT_CLASS = "class";
	  protected ContentGeneratorExtensionFactoryRegistry contentGeneratorExtensionFactoryRegistry;

	  public ContentGeneratorExtensionRegistryReader(ContentGeneratorExtensionFactoryRegistry generatorExtensionFactoryRegistry) {
	    this.contentGeneratorExtensionFactoryRegistry = generatorExtensionFactoryRegistry;
	  }
	
	
	  /**
	   * read from plugin registry and parse it.
	   */
	  public void readRegistry() {
	    IPluginRegistry pluginRegistry = Platform.getPluginRegistry();
	    IExtensionPoint point = pluginRegistry.getExtensionPoint(PLUGIN_ID, EXTENSION_POINT_ID);
	    if (point != null) {
	      IConfigurationElement[] elements = point.getConfigurationElements();
	      for (int i = 0; i < elements.length; i++) {
	        readElement(elements[i]);
	      }
	    }
	  }

	  public String resolve(URL platformURL, String relativePath) throws Exception {
	    URL resolvedURL = Platform.resolve(platformURL);
	    return resolvedURL.toString() + relativePath;
	  }

	  protected void readElement(IConfigurationElement element) {
	    if (element.getName().equals(ELEMENT_NAME)) {
	      try {
	        IConfigurationElement childElement = (IConfigurationElement) element;
			String name = childElement.getAttribute(ATT_NAME);
	        String namespace = childElement.getAttribute(ATT_NAMESPACE);
			
	        if (namespace != null) {
	          ClassLoader pluginClasssLoader = element.getDeclaringExtension().getDeclaringPluginDescriptor().getPluginClassLoader();
	          String className = childElement.getAttribute(ATT_CLASS);
	          ContentGeneratorExtensionDescriptor descriptor = new ContentGeneratorExtensionDescriptor(pluginClasssLoader, className, namespace, name);
	          contentGeneratorExtensionFactoryRegistry.put(namespace, name, descriptor);
	        }
	      }
	      catch (Exception e) {
			  e.printStackTrace();
	      }
	    }
	  }
}