package uk.ac.cam.ch.ami.amievents;

import com.thoughtworks.xstream.XStream;
import org.apache.commons.io.FileUtils;
import org.apache.commons.io.IOUtils;
import uk.ac.cam.ch.ami.Experiment;
import uk.ac.cam.ch.ami.amievents.events.AmiEvent;
import uk.ac.cam.ch.ami.amievents.events.ChemicalAmiEvent;
import uk.ac.cam.ch.ami.amievents.log.AmiEventLog;
import uk.ac.cam.ch.ami.events.UpdateStatusBarEvent;
import uk.ac.cam.ch.ami.listeners.ResetLogoutTimerListener;
import uk.ac.cam.ch.ami.listeners.UpdateStatusBarListener;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;

/**
 * Central handler which listens for all AmiEvents and processes them accordingly.
 * <p>
 * Created by IntelliJ IDEA.
 * User: alt36
 * Date: 02-Sep-2010
 * Time: 19:26:08
 */
public class AmiEventHandler implements AmiEventListener {

    AmiEventLog amiEventLog = null;
    protected javax.swing.event.EventListenerList listenerList = new javax.swing.event.EventListenerList();
    Experiment experiment;

    /**
     * Process an incoming AmiEvent. The event is appended to the log, the LogoutTimer (which logs the user out after a period
     * of inactivity) in HomeScreen is reset to zero, and the status bar of ExperimentScreen is updated to provide
     * feedback that the event has occurred.
     * @param event the event to process
     */
    @Override
    public void processAmiEvent(AmiEvent event) {
        amiEventLog.appendEvent(event);
        fireResetLogoutTimerEvent();
        if(!event.isToBeDeleted()) {
            String msg = event.getAmiEventType() + ": " + event.getTimelineText();
            fireUpdateStatusBarEvent(new UpdateStatusBarEvent(this, msg));
            experiment.updateDateLastModified();
        }
    }

    public AmiEventHandler(Experiment experiment) {
        amiEventLog = new AmiEventLog(experiment.getAmiEventLogPath());
        this.experiment = experiment;
        loadLogFile();
    }

    private void loadLogFile(){
        File amiEventLogFile = amiEventLog.getLogFile();

        if (amiEventLogFile.exists()) {
            InputStream is = null;
            try {
                XStream xstream = new XStream();
                xstream.processAnnotations(AmiEventLog.class);
                xstream.processAnnotations(ChemicalAmiEvent.class);
                is = FileUtils.openInputStream(amiEventLogFile);
                amiEventLog = (AmiEventLog) xstream.fromXML(is);
            } catch (IOException e) {
                e.printStackTrace();
                System.err.println("File "+ amiEventLogFile.toString()+ " not found");
            } finally{
                IOUtils.closeQuietly(is);
            }
        }
    }

    public void fireResetLogoutTimerEvent() {
        Object[] listeners = listenerList.getListenerList();
        // Each listener occupies two elements - the first is the listener class
        // and the second is the listener instance
        for (int i = 0; i < listeners.length; i += 2) {
            if (listeners[i] == ResetLogoutTimerListener.class) {
                ((ResetLogoutTimerListener) listeners[i + 1]).processResetLogoutTimer();
            }
        }
    }

    public void addResetLogoutTimerListener(ResetLogoutTimerListener listener) {
        listenerList.add(ResetLogoutTimerListener.class, listener);
    }

    public void removeResetLogoutTimerListener(ResetLogoutTimerListener listener) {
        listenerList.remove(ResetLogoutTimerListener.class, listener);
    }


    public void fireUpdateStatusBarEvent(UpdateStatusBarEvent event) {
        Object[] listeners = listenerList.getListenerList();
        // Each listener occupies two elements - the first is the listener class
        // and the second is the listener instance
        for (int i = 0; i < listeners.length; i += 2) {
            if (listeners[i] == UpdateStatusBarListener.class) {
                ((UpdateStatusBarListener) listeners[i + 1]).processUpdateStatusBar(event);
            }
        }
    }

    public void addUpdateStatusBarListener(UpdateStatusBarListener listener) {
        listenerList.add(UpdateStatusBarListener.class, listener);
    }

    public void removeUpdateStatusBarListener(UpdateStatusBarListener listener) {
        listenerList.remove(UpdateStatusBarListener.class, listener);
    }

    public AmiEventLog getAmiEventLog() {
        return amiEventLog;
    }

}