package org.gcube.informationsystem.collector.impl.xmlstorage.exist;

import org.gcube.informationsystem.collector.impl.contexts.ICServiceContext;
import org.gcube.informationsystem.collector.impl.persistence.AggregatorPersistentResource;

import org.globus.wsrf.config.ContainerConfig;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.List;
import java.util.Collections;

/**
 * This class groups the data globally scoped in an active RI
 * 
 * @author manuele simi
 * 
 */
public class State {

    /**
     * Connection to eXist used to store data
     */
    public static XMLStorageManager storage_manager;

    /**
     * Connection to eXist used to query the database
     */
    public static XMLStorageManager query_manager;

    /**
     * DIS-IC's JNDI resource name as declared in the JNDI file
     */
    public static final String JNDIResourceName = "DISICConfiguration";

    /**
     * Prefix to prepend to any log message
     */
    public static final String logPrefix = "";

    /**
     * Thread that periodically sweeps the database from expired resources
     */
    public static Thread sweeperT;

    /**
     * List of recently deleted resources. It is used to avoid the storage of RPs of a deleted
     * resource
     */
    public static List<AggregatorPersistentResource> deletedResources = Collections.synchronizedList(new ArrayList<AggregatorPersistentResource>());

    private static Log logger = LogFactory.getLog(State.class.getName());

    /**
     * Initializes the eXist DB connections using during the service life
     * 
     * @param configuration
     *            the RI configuration loaded from the JNDI resource
     * @throws Exception
     *             if the intialization fails
     */
    public static void initialize() throws Exception {
	logger.info("starting IC service initialization...");
	State.initializeStorageManager();
	State.initializeQueryManager();
	if (Boolean.valueOf((String) ICServiceContext.getContext().getProperty("deleteRPsOnStartup", true))) { 
	    // cleanup the RPs collection
	    logger.info("deleting all RPs...");
	    State.storage_manager.deleteAllProperties();
	} else {
	    logger.info("all RPs previously stored are keept in the storage");
	}

	// start the sweeper to periodically cleanup the storage and some data structures
	Sweeper sweeper = new Sweeper(Long.valueOf((String) ICServiceContext.getContext().getProperty("sweeperIntervalinMillis", true)), Long.valueOf((String) ICServiceContext.getContext()
		.getProperty("resourceExpirationTimeInMillis", true)));
	State.sweeperT = new Thread(sweeper);
	State.sweeperT.start();

	logger.info("IC service initialization completed");
    }

    private static void initializeStorageManager() throws Exception {
	// open the connection used to store resources
	State.storage_manager = new XMLStorageManager();
	storage_manager.initialize();
    }

    private static void initializeQueryManager() throws Exception {
	// open the connection used to query stored resources
	State.query_manager = new XMLStorageManager();
	query_manager.initialize();
    }

    /**
     * 
     * @return the container base dir
     */
    public static String getBaseDirectory() {
	return ContainerConfig.getBaseDirectory();
    }

    /**
     * Releases all the State resources
     * 
     * @throws Exception if the shutdown fails
     */
    public static void dispose() throws Exception {
	logger.info("Disposing IC service's resources...");
	State.storage_manager.shutdown();
	State.query_manager.shutdown();
    }

    /**
     * Prints the enviromnet variables
     */
    public void printEnv() {
	java.util.Properties p = System.getProperties();
	Enumeration<Object> keys = p.keys();
	while (keys.hasMoreElements()) {
	    logger.debug(keys.nextElement());
	}
	logger.debug("Exist home: " + System.getProperty("exist.home"));
	logger.debug("Class path: " + System.getProperty("java.class.path"));
    }
}