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

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import org.eclipse.wst.wsdl.internal.generator.ContentGenerator;


public class ContentGeneratorExtensionFactoryRegistry {
	protected Map map;
	protected static ContentGeneratorExtensionFactoryRegistry instance;
	
	public static ContentGeneratorExtensionFactoryRegistry getInstance() {
		if (instance == null) {
			instance = new ContentGeneratorExtensionFactoryRegistry();
			
			// TODO... don't read the registry until an 'get'occurs
			//
			ContentGeneratorExtensionRegistryReader reader = new ContentGeneratorExtensionRegistryReader(instance); 
			reader.readRegistry();
		}
		
		return instance;
	}
	
	protected ContentGeneratorExtensionFactoryRegistry() {
		map = new HashMap();
	}
	
	public void put(String namespace, String name, ContentGeneratorExtensionDescriptor descriptor) {
		// Check if this namespace/name key is already in the Map
		List foundKey = findExistingKey(namespace, name);
		
		// Did we find an existing key with the same namespace/key pairing?
		if (foundKey != null) {
			// Simply add the descriptor to the list of descriptors associated
			// with this namespace/name key
			List descriptorList = (List) map.get(foundKey);
			descriptorList.add(descriptor);
		}
		else {
			// We need to create a new entry in the Map for this namespace/name key
			List newKey = new ArrayList(2);
			newKey.add(namespace);
			newKey.add(name);
			
			List newDescriptorList = new ArrayList();
			newDescriptorList.add(descriptor);
			
			map.put(newKey, newDescriptorList);
		}		
	}
	
	/*
	 * Returns the 'name' attribute for this extension.
	 */
	public List getBindingExtensionNames() {
		List list = new ArrayList();
		
		Iterator keyIt = map.keySet().iterator();
		List key = null;
		while (keyIt.hasNext()) {
			key = (List) keyIt.next();
			list.add(key.get(1));
		}
		
		return list;
	}
	
	/*
	 * Return the class specified for this extension based on the namespace
	 * attribute.
	 */
	public ContentGenerator getGeneratorClassFromNamespace(String namespace) {
		ContentGenerator generatorClass = null;
		List key = findExistingKeyFromNamespace(namespace);
		
		if (key != null) {
			List descriptors = (List) map.get(key);
			
			// Grab the first descriptor available
			if (descriptors.size() > 0) {
				ContentGeneratorExtensionDescriptor extensionDescriptor = (ContentGeneratorExtensionDescriptor) descriptors.get(0);
				generatorClass = (ContentGenerator) extensionDescriptor.getContentGenerator();
			}
		}
		
		return generatorClass;
	}

	/*
	 * Return the class specified for this extension based on the name
	 * attribute.
	 */
	public ContentGenerator getGeneratorClassFromName(String name) {
		ContentGenerator generatorClass = null;
		List key = findExistingKeyFromName(name);
		
		if (key != null) {
			List descriptors = (List) map.get(key);
			
			// Grab the first descriptor available
			if (descriptors.size() > 0) {
				ContentGeneratorExtensionDescriptor extensionDescriptor = (ContentGeneratorExtensionDescriptor) descriptors.get(0);
				generatorClass = (ContentGenerator) extensionDescriptor.getContentGenerator();
			}
		}
		
		return generatorClass;
	}
	
	// TODO: We need to common the following three methods up.......
	private List findExistingKeyFromNamespace(String namespace) {
		Iterator keyIt = map.keySet().iterator();
		List foundKey = null;
		while (keyIt.hasNext()) {
			foundKey = (List) keyIt.next();
			if (namespace.equals(foundKey.get(0))) {
				break;
			}
			foundKey = null;
		}

		return foundKey;
	}
	
	private List findExistingKeyFromName(String name) {
		Iterator keyIt = map.keySet().iterator();
		List foundKey = null;
		while (keyIt.hasNext()) {
			foundKey = (List) keyIt.next();
			if (name.equals(foundKey.get(1))) {
				break;
			}
			foundKey = null;
		}

		return foundKey;
	}
	
	private List findExistingKey(String namespace, String name) {
		Iterator keyIt = map.keySet().iterator();
		List foundKey = null;
		while (keyIt.hasNext()) {
			foundKey = (List) keyIt.next();
			if (namespace.equals(foundKey.get(0)) && name.equals(foundKey.get(1))) {
				break;
			}
			foundKey = null;
		}

		return foundKey;
	}
}