package com.c2kernel.lookup;

import com.c2kernel.common.ObjectCannotBeUpdated;
import com.c2kernel.common.ObjectNotFoundException;
import com.c2kernel.persistency.ClusterStorageException;
import com.c2kernel.process.Gateway;
import com.c2kernel.utils.Logger;
import com.novell.ldap.LDAPEntry;

/**************************************************************************
 *
 * $Revision: 1.2 $
 * $Date: 2005/04/27 13:47:24 $
 *
 * Copyright (C) 2003 CERN - European Organization for Nuclear Research
 * All rights reserved.
 **************************************************************************/

//    public static final String codeRevision = "$Revision: 1.2 $ $Date: 2005/04/27 13:47:24 $ $Author: abranson $";
public class NextKeyManager {

    LDAPLookup ldap;
    String lastKeyPath;

    public NextKeyManager(LDAPLookup ldap, String lastKeyPath) {
        super();
        this.ldap = ldap;
        this.lastKeyPath = lastKeyPath;
    }

    public synchronized EntityPath generateNextEntityKey()
    throws ObjectCannotBeUpdated, ObjectNotFoundException
    {
        EntityPath lastKey = getLastEntityPath();

        try {
            lastKey.setSysKey(lastKey.getSysKey()+1);
        } catch (InvalidEntityPathException ex) {
            throw new ObjectCannotBeUpdated("Invalid syskey "+(lastKey.getSysKey()+1)+". Maybe centre is full.");
        }
        //test that storage is empty for that key
        try {
			if (Gateway.getStorage().getClusterContents(lastKey.getSysKey(), "").length > 0)
				throw new ObjectCannotBeUpdated("NextKeyManager: Storage already contains data for syskey "+lastKey.getSysKey()+
						". Storage is out of sync with nextkey. Please contact an administrator", "");
		} catch (ClusterStorageException e) {
			Logger.error(e);
			throw new ObjectCannotBeUpdated("Could not check storage for prior data for the next generated systemKey: "+e.getMessage());
		}
        
        //set the last key
        writeLastEntityKey(lastKey.getSysKey());

        return lastKey;
    }

    public synchronized AgentPath generateNextAgentKey()
    throws ObjectCannotBeUpdated, ObjectNotFoundException {
        EntityPath newEntity = generateNextEntityKey();
        return new AgentPath(newEntity);
    }

    public void writeLastEntityKey(int sysKey) throws ObjectCannotBeUpdated, ObjectNotFoundException {
        LDAPEntry lastKeyEntry = LDAPLookupUtils.getEntry(ldap.getConnection(),lastKeyPath);
        LDAPLookupUtils.setAttributeValue(ldap.getConnection(), lastKeyEntry,"intsyskey",Integer.toString(sysKey));
    }

    public EntityPath getLastEntityPath() throws ObjectNotFoundException
    {
        LDAPEntry lastKeyEntry = LDAPLookupUtils.getEntry(ldap.getConnection(),lastKeyPath);
        String lastKey = LDAPLookupUtils.getFirstAttributeValue(lastKeyEntry,"intsyskey");
        try {
            int sysKey = Integer.parseInt(lastKey);
            EntityPath sysPath = new EntityPath(sysKey);
            return sysPath;
        } catch (InvalidEntityPathException ex) {
            throw new ObjectNotFoundException("Invalid syskey. Maybe centre is full.");
        } catch (NumberFormatException ex) {
            throw new ObjectNotFoundException("Invalid syskey in lastkey.");
        }

    }

}