package com.c2kernel.process;

/**
 * @version $Revision: 1.17 $ $Date: 2005/10/12 12:51:54 $
 * @author  $Author: abranson $
 */

import java.net.MalformedURLException;
import java.util.Enumeration;
import java.util.Properties;

import com.c2kernel.common.InvalidDataException;
import com.c2kernel.common.ObjectNotFoundException;
import com.c2kernel.entity.CorbaServer;
import com.c2kernel.entity.proxy.AgentProxy;
import com.c2kernel.entity.proxy.EntityProxyManager;
import com.c2kernel.lookup.AgentPath;
import com.c2kernel.lookup.LDAPLookup;
import com.c2kernel.lookup.LDAPProperties;
import com.c2kernel.persistency.ClusterStorageException;
import com.c2kernel.persistency.TransactionManager;
import com.c2kernel.process.module.ModuleManager;
import com.c2kernel.process.resource.Resource;
import com.c2kernel.process.resource.ResourceLoader;
import com.c2kernel.utils.CastorXMLUtility;
import com.c2kernel.utils.FileStringUtility;
import com.c2kernel.utils.Language;
import com.c2kernel.utils.Logger;
import com.c2kernel.utils.ObjectProperties;


/**************************************************************************
 * The Gateway is the central object of a CRISTAL process. It initializes,
 * maintains and shuts down every other subsystem in both the client and the
 * server.
 *
 * Child objects:
 * <ul>
 * <li>LDAPLookup - Provides access to the CRISTAL directory. Find or
 * search for Items or Agents.
 * <li>EntityProxyManager - Gives a local proxy object for Entities found
 * in LDAP. Execute activities in Items, query or subscribe to Entity data.
 * <li>TransactionManager - Access to the configured CRISTAL databases
 * <li>CorbaServer - Manages the memory pool of active Entities
 * <li>mORB - the Orbacus CORBA ORB
 * </ul>
 *
 * @author $Author: abranson $ $Date: 2005/10/12 12:51:54 $
 * @version $Revision: 1.17 $
 **************************************************************************/

public class Gateway
{
    static private ObjectProperties     mC2KProps;
    static private ModuleManager   		mModules;
    static private org.omg.CORBA.ORB    mORB;
    static private boolean				orbDestroyed = false;
    static private LDAPLookup           mLDAPLookup;
    static private TransactionManager   mStorage;
    static private EntityProxyManager   mProxyManager;
    static private CorbaServer          mCorbaServer;
    static private CastorXMLUtility		mMarshaller;
    static private AgentProxy			mCurrentUser = null;
    static private ResourceLoader		mResource;



    private Gateway() { }

    /**
     * Initialises the Gateway and all of the client objects it holds, with
     * the exception of the LDAPLookup, which is initialised during connect()
     *
     * @param props - java.util.Properties containing all application properties.
     * If null, the java system properties are used
     * @throws InvalidDataException - invalid properties caused a failure in initialisation
     */
    static public void init(Properties props) throws InvalidDataException {
    	init(props, null);
    }
    
    /**
     * Initialises the Gateway and all of the client objects it holds, with
     * the exception of the LDAPLookup, which is initialised during connect()
     *
     * @param props - java.util.Properties containing all application properties.
     * If null, the java system properties are used
     * @param res - ResourceLoader for the kernel to use to resolve all class resource requests
     * such as for bootstrap descriptions and version information
     * @throws InvalidDataException - invalid properties caused a failure in initialisation
     */    
    static public void init(Properties props, ResourceLoader res) throws InvalidDataException {
    	
        // Init properties & resources
        mC2KProps = new ObjectProperties();
        mResource = res;
        if (mResource == null) mResource = new Resource();

        // report version info
        Logger.msg("Kernel version: "+getKernelVersion());

        // load kernel mapfiles
        try {
        	mMarshaller = new CastorXMLUtility(mResource.getKernelResourceURL("mapFiles/"));
        } catch (MalformedURLException e1) {
            throw new InvalidDataException("Invalid Resource Location", "");
        }
        
        // init module manager
        try {
			mModules = new ModuleManager(mResource.getModuleDefURLs(), AbstractMain.runningAsWrapper);
		} catch (Exception e) {
			Logger.error(e);
			throw new InvalidDataException("Could not load module definitions.", "");
		}

        // merge in module props
        Properties moduleProperties = mModules.getAllModuleProperties();
        for (Enumeration<?> e = moduleProperties.propertyNames(); e.hasMoreElements();) {
            String propName = (String)e.nextElement();
            mC2KProps.put(propName, moduleProperties.get(propName));
        }

        // Overwrite with argument props
        if (props != null) mC2KProps.putAll(props);

        // dump properties
        dumpC2KProps(7);

        //Initialise language file
        String languageFile = getProperty("language.file");
        if (languageFile != null && languageFile.length() > 0) {
            Language.isTranlated=true;
            Language.mTableOfTranslation = FileStringUtility.loadLanguageFile(languageFile);
        }
        
        // if client, run module startup scripts. Otherwise bootstrap will do it after all imports
        if (!AbstractMain.runningAsWrapper) mModules.runScripts("startup");
    }

    /**
     * Makes this process capable of creating and managing server entities. Runs the
     * bootstrap to create the root LDAP contexts, initialises the CORBA server and
     * time-out manager.
     *
     * @throws InvalidDataException - error initialising
     */
    static public void startServer() throws InvalidDataException {
        try {
            // check top level LDAP contexts
            mLDAPLookup.install();

            // start entity proxy server
            EntityProxyManager.initServer();

            // Init ORB - set various config 
            String serverName = getProperty("ItemServer.name");
            if (serverName != null)
            	mC2KProps.put("com.sun.CORBA.ORBServerHost", serverName);
            String serverPort = getProperty("ItemServer.iiop", "1500");
            mC2KProps.put("com.sun.CORBA.ORBServerPort", serverPort);
            //TODO: externalize this (or replace corba completely)
            mC2KProps.put("com.sun.CORBA.POA.ORBServerId", "1");
            mC2KProps.put("com.sun.CORBA.POA.ORBPersistentServerPort", serverPort);

            //Standard initialisation of the ORB
            mORB = org.omg.CORBA.ORB.init(new String[0], mC2KProps);

            Logger.msg("Gateway.init() - ORB initialised. ORB is " + mORB.getClass().getName() );

            // start corba server components
            mCorbaServer = new CorbaServer();

            // start checking bootstrap & module items
            Bootstrap.run();
            
        } catch (Exception ex) {
            Logger.error(ex);
            Logger.die("Exception starting server components. Shutting down.");
        }

        System.out.println("Server '"+Gateway.getCentreId()+"' initialised.");
    }

    public static ModuleManager getModuleManager() {
		return mModules;
	}

	/**
     * Connects to the LDAP server in an administrative context - using the admin username and
     * password given in the LDAP.user and LDAP.password props of the kernel properties.
     *
     * @throws InvalidDataException - bad params
     * @throws ClusterStorageException - error starting storages
     */
    static public void connect()
        throws InvalidDataException,
               ClusterStorageException
    {
        LDAPProperties ldapProps = new LDAPProperties();

        if( ldapProps.mHost != null && ldapProps.mPort     != null &&
            ldapProps.mUser != null && ldapProps.mPassword != null )
        {
            try
            {
				mLDAPLookup = new LDAPLookup(ldapProps);
            }
            catch (Exception ex)
            {
                Logger.error(ex);
                throw new InvalidDataException("Cannot authenticate. Name and/or password invalid.", "");
            }
        }
        else
        {
            Logger.error("LDAP properties not set for server login.");
            throw new InvalidDataException("Cannot authenticate with LDAP.", "");
        }

        setup();
    }

    /**
     * Authenticates a user and returns and AgentProxy on them without overriding the system LDAP context.
     * Useful for handling multiple users in one context e.g. on a web server
     *
     * @param agentName - username
     * @param agentPassword - password
     * @return AgentProxy on that user
     * @throws InvalidDataException
     * @throws ObjectNotFoundException
     */
    static public AgentProxy login(String agentName, String agentPassword) throws InvalidDataException, ObjectNotFoundException {
        LDAPProperties ldapProps = new LDAPProperties();
        AgentPath agentPath;
        try {
            agentPath = mLDAPLookup.getRoleManager().getAgentPath(agentName);
        } catch (Exception ex) {
            Logger.error(ex);
            throw new ObjectNotFoundException("Could not resolve agent", "");
        }
        String agentDN = agentPath.getFullDN();
        ldapProps.mUser = agentDN;
        ldapProps.mPassword = agentPassword;

        try {
            LDAPLookup.createConnection(ldapProps);
            return (AgentProxy)getProxyManager().getProxy(mLDAPLookup.getRoleManager().getAgentPath(agentName));
        } catch (Exception ex) {
            Logger.error(ex);
            throw new InvalidDataException("Could not log in", "");
        }
    }


    /**
     * Logs into the LDAP server with the given username and password, and initialises the lookup.
     *
     * @param agentName - username
     * @param agentPassword - password
     * @return an AgentProxy on the requested user
     * @throws InvalidDataException
     */
    static public AgentProxy connect(String agentName, String agentPassword)
    throws InvalidDataException, ObjectNotFoundException
    {

        LDAPProperties ldapProps = new LDAPProperties();
        if (ldapProps.mHost!=null && ldapProps.mPort!= null && ldapProps.mLocalPath!=null )
        {
            try {
                ldapProps.mUser = "";
                ldapProps.mPassword = "";
                mLDAPLookup = new LDAPLookup(ldapProps);
                String agentDN = mLDAPLookup.getRoleManager().getAgentPath(agentName).getFullDN();

                //found agentDN, try to log in with it
                ldapProps.mUser = agentDN;
                ldapProps.mPassword = agentPassword;
                mLDAPLookup = new LDAPLookup(ldapProps);

                // find agent proxy
                AgentPath agentPath = mLDAPLookup.getRoleManager().getAgentPath(agentName);

                if (agentPath!=null)
                {
                    setup();
                    mCurrentUser = (AgentProxy) mProxyManager.getProxy(agentPath);
                    return mCurrentUser;
                }
                else
                {
                    throw new InvalidDataException("The agentDN " +agentDN+ " is invalid.", "");
                }
            } catch (ClusterStorageException e) {
                throw new InvalidDataException(Language.translate("Error initialising storage")+Language.translate(". See log."), "");
            } catch (ObjectNotFoundException e) {
                throw new ObjectNotFoundException(Language.translate("Invalid username/password"), "");
            } catch (Exception e) {
                throw new InvalidDataException(Language.translate("Could not log in")+": "+Language.translate(e.getMessage()), "");
            }

        }
        else
        {
            throw new InvalidDataException("Cannot log in. Some connection properties are not set.", "");
        }

    }

    /**
	 * @return the mCurrentUser
	 */
	public static AgentProxy getCurrentUser() {
		return mCurrentUser;
	}

	/**
     * Initializes the storage and proxy manager, called during connect.
     *
     * @throws InvalidDataException
     * @throws ClusterStorageException
     */
    static private void setup()
        throws InvalidDataException,
        ClusterStorageException
    {

        // Init storages
        mStorage = new TransactionManager();
        mProxyManager = new EntityProxyManager();

    }

    /**
     * Shuts down all kernel api objects
     */
    public static void close()
    {
    	// run shutdown module scripts
    	mModules.runScripts("shutdown");

        // shut down servers if running
        if (mCorbaServer != null)
            mCorbaServer.close();
        mCorbaServer = null;

        // disconnect from storages
        if (mStorage != null)
            mStorage.close();
        mStorage = null;

        // disconnect from ldap
        if (mLDAPLookup != null)
            mLDAPLookup.disconnect();
        mLDAPLookup = null;

        // shut down proxy manager
        if (mProxyManager != null)
            mProxyManager.shutdown();
        mProxyManager = null;
        EntityProxyManager.shutdownServer();

        // close log consoles
        Logger.closeConsole();

        // finally, destroy the ORB
        if (!orbDestroyed) {
        	getORB().destroy();
        	orbDestroyed = true;
        }
    }

    static public org.omg.CORBA.ORB getORB()
    {
    	if (orbDestroyed) throw new RuntimeException("Gateway has been closed. ORB is destroyed.");
    	if (mORB == null)
    		mORB = org.omg.CORBA.ORB.init(new String[0], mC2KProps);
        return mORB;
    }

    static public LDAPLookup getLDAPLookup()
    {
        return mLDAPLookup;
    }

    static public CorbaServer getCorbaServer()
    {
        return mCorbaServer;
    }

    static public TransactionManager getStorage()
    {
        return mStorage;
    }
    
    static public CastorXMLUtility getMarshaller()
    {
        return mMarshaller;
    }
    
    static public ResourceLoader getResource()
    {
    	return mResource;
    }

    static public EntityProxyManager getProxyManager()
    {
        return mProxyManager;
    }

    static public String getCentreId() {
        return getProperty("LocalCentre");
    }

    @Deprecated
    static public String getProperty(String propName) {
        return getProperty(propName, null);
    }

    @Deprecated
    static public String getProperty(String propName, String defaultValue) {
        if (mC2KProps == null) return defaultValue;
        return mC2KProps.getProperty(propName, defaultValue);
    }

    @Deprecated
    static public void setProperty(String propName, String propValue) {
        if (mC2KProps == null) return;
        mC2KProps.put(propName, propValue);
    }

    static public Enumeration<?> propertyNames() {
        return mC2KProps.propertyNames();
    }

    static public void dumpC2KProps(int logLevel) {
        if (!Logger.doLog(logLevel)) return;
        mC2KProps.dumpProps(logLevel);
    }
    
    static public ObjectProperties getProperties() {
    	return mC2KProps;
    }

    static public String getKernelVersion() {
    	try {
			return mResource.getTextResource(null, "textFiles/version.txt");
    	} catch (Exception ex) {
    		return "No version info found";
    	}

    }
}