package com.c2kernel.utils;

import java.util.Enumeration;

import com.c2kernel.common.InvalidDataException;
import com.c2kernel.common.ObjectNotFoundException;
import com.c2kernel.entity.proxy.ItemProxy;
import com.c2kernel.lifecycle.ActivityDef;
import com.c2kernel.lifecycle.instance.stateMachine.StateMachine;
import com.c2kernel.lookup.DomainPath;
import com.c2kernel.lookup.Path;
import com.c2kernel.persistency.ClusterStorage;
import com.c2kernel.persistency.ClusterStorageException;
import com.c2kernel.persistency.outcome.Schema;
import com.c2kernel.persistency.outcome.Viewpoint;
import com.c2kernel.process.Gateway;

public class LocalObjectLoader {
	private static ActDefCache actCache = new ActDefCache();
	private static StateMachineCache smCache = new StateMachineCache();

	static public ItemProxy loadLocalObjectDef(String root, String name)
		throws ObjectNotFoundException
	{
		DomainPath defRoot = new DomainPath(root);
	    Enumeration<Path> e = Gateway.getLDAPLookup().search(defRoot, name);
	    ItemProxy defProxy = null; int currentLayer = -1;
	    while (e.hasMoreElements()) {
	    	DomainPath defPath = (DomainPath)e.nextElement();
	    	ItemProxy thisProxy = Gateway.getProxyManager().getProxy(defPath);
	    	int thisLayer;
	    	try {
	    		String thisLayerProp = thisProxy.getProperty("Layer");
	    		thisLayer = Integer.parseInt(thisLayerProp);
	    	} catch (Exception ex) {
	    		thisLayer = 0;
	    	}
	    	if (thisLayer > currentLayer) {
	    		currentLayer = thisLayer;
	    		defProxy = thisProxy;
	    	}
	    	else if (thisLayer == currentLayer) {
	    		throw new ObjectNotFoundException("Duplicate definition for "+name+" in "+root+" found in Layer "+thisLayer, "");
	    	}
	    }
	    if (defProxy == null)
	    	throw new ObjectNotFoundException("No match for "+name+" in "+root, "");
	    return defProxy;
	}

	static public String getScript(String scriptName, int scriptVersion) throws ObjectNotFoundException {
	    Logger.msg(5, "Loading script "+scriptName+" v"+scriptVersion);
	    try {
	    	ItemProxy script = loadLocalObjectDef("/desc/Script/", scriptName);
   	        Viewpoint scriptView = (Viewpoint)script.getObject(ClusterStorage.VIEWPOINT + "/Script/" + scriptVersion);
	    	return scriptView.getOutcome().getData();
	    } catch (ClusterStorageException ex) {
	    	Logger.error(ex);
	        throw new ObjectNotFoundException("Error loading script " + scriptName + " version " + scriptVersion, "");
	    }

	}

	static public Schema getSchema(String schemaName, int schemaVersion) throws ObjectNotFoundException {
		Logger.msg(5, "Loading schema "+schemaName+" v"+schemaVersion);
	    
	    String docType = schemaName;
	    int docVersion = schemaVersion;
	    String schemaData;

	    // don't bother if this is the Schema schema - for bootstrap esp.
	    if (schemaName.equals("Schema") && schemaVersion == 0)
	        return new Schema(docType, docVersion, "");

        ItemProxy schema = loadLocalObjectDef("/desc/OutcomeDesc/", schemaName);
        Viewpoint schemaView = (Viewpoint)schema.getObject(ClusterStorage.VIEWPOINT + "/Schema/" + schemaVersion);
        try {
        	schemaData = schemaView.getOutcome().getData();
        } catch (ClusterStorageException ex) {
        	Logger.error(ex);
        	throw new ObjectNotFoundException("Problem loading schema "+schemaName+" v"+schemaVersion+": "+ex.getMessage(), "");
        }
	    return new Schema(docType, docVersion, schemaData);
	}

	/**
	 * Retrieves a named version of activity def from the database
	 *
	 * @param actName - activity name
	 * @param version - named version (String)
	 * @return ActivityDef
	 * @throws ObjectNotFoundException - When activity or version does not exist
	 */
	static public ActivityDef getActDef(String actName, int actVersion) throws ObjectNotFoundException, InvalidDataException {
		Logger.msg(5, "Loading activity def "+actName+" v"+actVersion);
		return actCache.get(actName, actVersion);
	}
	
	static public StateMachine getStateMachine(String smName, int smVersion) throws ObjectNotFoundException, InvalidDataException {
		Logger.msg(5, "Loading activity def "+smName+" v"+smVersion);
		return smCache.get(smName, smVersion);
	}
}