package com.onaro.sanscreen.client.view.init;

import java.util.Collection;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Stack;

import org.apache.commons.lang3.StringUtils;
import org.w3c.dom.Element;
import com.onaro.commons.xml.xpath.XPathUtils;
import com.onaro.sanscreen.client.view.ActionFactory;
import com.onaro.sanscreen.client.view.ActionFactory.ActionInitInfo;
import com.onaro.util.InvalidConfigException;
import com.onaro.util.xml.XmlIterator;

public class ActionsInitInfo implements Cloneable {

	/**
	 * Caches pointers into the configuration to allow the configuratoin to refer to previously defined blocks.
	 */
	private final static Map<String,ActionFactory.ActionInitInfo> cachedInitInfos = new HashMap<String,ActionFactory.ActionInitInfo>();

	private Map<String,ActionFactory.ActionInitInfo> nameToActionInitInfo = new HashMap<String,ActionFactory.ActionInitInfo>();

	private String targetViewType;

	public ActionsInitInfo(String targetViewType) {
		this.targetViewType = targetViewType;
	}

	public ActionsInitInfo(XmlIterator xmlIterator2, String targetViewType) throws InvalidConfigException {
		this(targetViewType);

		Element xmlIteratorNode = (Element)xmlIterator2.getNode();
		List<Element> actionElements = getActionElements(xmlIteratorNode);
		
		if(actionElements != null) {
			for (Element actionElement : actionElements) {
				/**
				 * Create the actionInitInfo and save it.
				 */
				String actionType = actionElement.getAttribute("type"); //$NON-NLS-1$
				if (StringUtils.isBlank(actionType)) {
					String actionElementPath = XPathUtils.getPath(actionElement);
					throw new InvalidConfigException("Mandatory attribute 'type' is missing at '" + actionElementPath + "'"); //$NON-NLS-1$ //$NON-NLS-2$
				}
	
				String actionName = actionElement.getAttribute("name"); //$NON-NLS-1$
				if (StringUtils.isBlank(actionName)) {
					String actionElementPath = XPathUtils.getPath(actionElement);
					throw new InvalidConfigException("Mandatory attribute 'name' is missing in '" + actionElementPath + "'"); //$NON-NLS-1$ //$NON-NLS-2$
				}
	
				boolean clone = Boolean.parseBoolean(actionElement.getAttribute("clone")); //$NON-NLS-1$
	
				XmlIterator actionXmlIterator = new XmlIterator(actionElement);
	
				ActionFactory.ActionInitInfo actionInitInfo;
				if (clone) {
					// should be used only for the properties configuration
					actionInitInfo = getCachedActionInfo(actionXmlIterator, actionType, actionName);
				} else {
					actionInitInfo = ActionFactory.getActionInitInfo(actionName, actionType, targetViewType,
							actionXmlIterator);
					addCacheActionInfo(actionInitInfo);
				}
	
				nameToActionInitInfo.put(actionName, actionInitInfo);
	
			}
		}
	}

	/* Returns a list of action element nodes from the given parent of a menuactions element or null if none could
	 * be found.  This method assumes that the <menuactions> element only has <action> elements.
	 */
	private static List<Element> getActionElements(Element menuActionsParent) {
		// We expect to only find one menuactions child element
		Element menuActions = XPathUtils.getFirstChildElementByTagName(menuActionsParent, "menuactions"); //$NON-NLS-1$
		
		if(menuActions == null) {
			return null;
		}
		return(XPathUtils.getChildElementsByTagName(menuActions, "action")); //$NON-NLS-1$
	}
	
	private static String getCacheKey(String type, String name) {
		return type + "#" + name; //$NON-NLS-1$
	}

	private static void addCacheActionInfo(ActionFactory.ActionInitInfo actionInitInfo) {
		String cacheKey = getCacheKey(actionInitInfo.getActionType(), actionInitInfo.getActionName());
		cachedInitInfos.put(cacheKey, actionInitInfo);
	}

	private static ActionFactory.ActionInitInfo getCachedActionInfo(XmlIterator confItr, String type, String name)
			throws InvalidConfigException {
		ActionFactory.ActionInitInfo cached = cachedInitInfos.get(getCacheKey(type, name));
		if (cached != null) {
			return cached;
		}

		XmlIterator rootItr = new XmlIterator(confItr);
		while (rootItr.hasUp())
			rootItr.up();

		/**
		 * Search for the block that defines the requested type and name
		 */
		Stack<XmlIterator> parents = new Stack<XmlIterator>();
		parents.push(rootItr);
		while (!parents.isEmpty()) {
			XmlIterator itr = parents.pop();

			/**
			 * For each node, test if its of the requested type and nama and isn't a clone.
			 */
			if (itr.getName().equals(type)) {
				String currentName = itr.getAttribute("name"); //$NON-NLS-1$
				boolean clone = itr.getBooleanAttribute("clone"); //$NON-NLS-1$
				if (!clone && name.equals(currentName)) {
					ActionFactory.ActionInitInfo actionInitInfo = ActionFactory.getActionInitInfo(name, type, null,
							confItr);
					cachedInitInfos.put(getCacheKey(type, name), actionInitInfo);
					return actionInitInfo;
				}
			}

			/**
			 * Push the childs of this node to the stack.
			 */
			for (XmlIterator child = (new XmlIterator(itr)).down(); child.isValid(); child.next()) {
				parents.push(new XmlIterator(child));
			}
		}

		throw new InvalidConfigException("Couldn't find the block to clone for type='" + type + "' name='" + name + "'"); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
	}

	public Collection<String> getActionNames() {
		return nameToActionInitInfo.keySet();
	}

	public ActionFactory.ActionInitInfo getActionInitInfo(String actionName) {
		return nameToActionInitInfo.get(actionName);
	}

	public ActionFactory.ActionInitInfo addAction(String actionName, String actionType) {
		ActionInitInfo actionInitInfo = ActionFactory.getActionInitInfo(actionName, actionType, targetViewType, null);
		addCacheActionInfo(actionInitInfo);
		nameToActionInitInfo.put(actionName, actionInitInfo);
		return actionInitInfo;
	}

	public static ActionFactory.ActionInitInfo getCachedActionInitInfo(String type, String name) {
		return cachedInitInfos.get(getCacheKey(type, name));

	}

	@Override
	public ActionsInitInfo clone() throws CloneNotSupportedException {
		return (ActionsInitInfo) super.clone();
	}
}