package events.internal;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;

import core.VSInternalProcess;
import core.VSTask;
import core.VSTaskManager;
import events.VSAbstractEvent;
import events.VSCopyableEvent;
import events.VSRegisteredEvents;
import protocols.VSAbstractProtocol;
import serialize.VSSerialize;

/**
 * The class VSProtocolEvent, this event is used if a protocol (server or
 * client part) of a process gets enabled or disabled, an object of this class
 * can be for 4 different purporses! Activation of the client protocol,
 * deactivation of the client protocol, activation of the server protocol,
 * deactivation of the server protocol.
 *
 * @author Paul C. Buetow
 */
public class VSProtocolEvent extends VSAbstractInternalEvent
    implements VSCopyableEvent {
    /** The protocol classname. */
    private String protocolClassname;

    /** The event is a client protocol if true. Else it is a server protocol */
    private boolean isClientProtocol;
    
    @Override
    public boolean isProtocolEvent() {
        return true;
    }
    
    @Override
    public int getEventPriority() {
        return PRIORITY_MEDIUM;
    }

    /** The event is a protocol activation if true. Else it is a deactivation */
    private boolean isProtocolActivation;

    /* (non-Javadoc)
     * @see events.VSCopyableEvent#initCopy(events.VSAbstractEvent)
     */
    public void initCopy(VSAbstractEvent copy) {
        VSProtocolEvent protocolEventCopy = (VSProtocolEvent) copy;
        protocolEventCopy.isClientProtocol(isClientProtocol);
        protocolEventCopy.isProtocolActivation(isProtocolActivation);
        protocolEventCopy.setProtocolClassname(protocolClassname);
    }

    /* (non-Javadoc)
     * @see events.VSAbstractEvent#onInit()
     */
    public void onInit() {
        setClassname(getClass().toString());
    }

    /**
     * Sets if it is a client protocol activation/deactivation.
     *
     * @param isClientProtocol the event is client protocol if true. the event
     * is a server protocol if false.
     */
    public void isClientProtocol(boolean isClientProtocol) {
        this.isClientProtocol = isClientProtocol;
    }

    /**
     * Checks if it is a client protocol activation/deactivation.
     *
     * @return the event is client protocol if true. the event
     * is a server protocol if false.
     */
    public boolean isClientProtocol() {
        return isClientProtocol;
    }

    /**
     * Sets if it is protocol activation.
     *
     * @param isProtocolActivation true, if it is a protocol activation. false,
     *	if it is a protocol deactivation.
     */
    public void isProtocolActivation(boolean isProtocolActivation) {
        this.isProtocolActivation = isProtocolActivation;
    }

    /**
     * Checks if it is protocol activation.
     *
     * @return true, if it is a protocol activation. false, if it is a protocol
     *	deactivation.
     */
    public boolean isProtocolActivation() {
        return isProtocolActivation;
    }

    /**
     * Sets the protocol classname.
     *
     * @param protocolClassname the new protocol classname
     */
    public void setProtocolClassname(String protocolClassname) {
        this.protocolClassname = protocolClassname;
    }
    
    /**
     * Checks if we should schedule a protocol start task.
     * We should NOT schedule if the protocol is already scheduled at the current time.
     * This prevents duplicate execution when loading saved simulations.
     *
     * @param process the process to check
     * @param protocol the protocol to check for
     * @return true if we should schedule, false if already scheduled
     */
    private boolean shouldScheduleProtocolStart(VSInternalProcess process, VSAbstractProtocol protocol) {
        // Check process-local tasks
        for (VSTask task : process.getTasks()) {
            if (task.getEvent() == protocol && task.getTaskTime() == process.getTime()) {
                // Protocol is already scheduled at this time
                return false;
            }
        }
        
        // Check global tasks  
        VSTaskManager taskManager = process.getSimulatorCanvas().getTaskManager();
        try {
            // Use reflection to access global tasks
            java.lang.reflect.Field globalTasksField = VSTaskManager.class.getDeclaredField("globalTasks");
            globalTasksField.setAccessible(true);
            @SuppressWarnings("unchecked")
            java.util.Queue<VSTask> globalTasks = (java.util.Queue<VSTask>) globalTasksField.get(taskManager);
            
            for (VSTask task : globalTasks) {
                if (task.getEvent() == protocol && task.getTaskTime() == process.getGlobalTime()) {
                    // Protocol is already scheduled at this time
                    return false;
                }
            }
        } catch (Exception e) {
            // If we can't check, assume we should schedule
            System.err.println("Warning: Could not check for duplicate protocol tasks: " + e.getMessage());
        }
        
        return true;
    }

    /* (non-Javadoc)
     * @see events.VSAbstractEvent#onStart()
     */
    public void onStart() {
        VSInternalProcess internalProcess = (VSInternalProcess) process;
        VSAbstractProtocol protocol =
            internalProcess.getProtocolObject(protocolClassname);

        if (isClientProtocol)
            protocol.isClient(isProtocolActivation);
        else
            protocol.isServer(isProtocolActivation);

        StringBuffer buffer = new StringBuffer();
        buffer.append(VSRegisteredEvents.getShortnameByClassname(protocolClassname));
        if (buffer.length() == 0) {
            buffer.append(protocolClassname);
        }

        buffer.append(" ");
        buffer.append(isClientProtocol
                      ? prefs.getString("lang.client")
                      : prefs.getString("lang.server"));

        buffer.append(" ");
        buffer.append(isProtocolActivation
                      ? prefs.getString("lang.activated")
                      : prefs.getString("lang.deactivated"));

        log(buffer.toString());
        
        // If this is an activation, schedule the protocol to start immediately
        // This ensures that protocols with HAS_ON_SERVER_START or HAS_ON_CLIENT_START
        // will have their onServerStart() or onClientStart() methods called
        // 
        // However, we should NOT schedule if the protocol is already scheduled to run.
        // This can happen when loading from a saved simulation where both the activation
        // event and the resulting protocol task were saved.
        if (isProtocolActivation && shouldScheduleProtocolStart(internalProcess, protocol)) {
            // Create a task to start the protocol at the current time
            VSTask startTask = new VSTask(internalProcess.getTime(), 
                                         internalProcess, 
                                         protocol, 
                                         VSTask.LOCAL);
            internalProcess.getSimulatorCanvas().getTaskManager().addTask(startTask);
        }
    }

    /* (non-Javadoc)
     * @see serialize.VSSerializable#serialize(serialize.VSSerialize,
     *	java.io.ObjectOutputStream)
     */
    public synchronized void serialize(VSSerialize serialize,
                                       ObjectOutputStream objectOutputStream)
    throws IOException {
        super.serialize(serialize, objectOutputStream);

        /** For later backwards compatibility, to add more stuff */
        objectOutputStream.writeObject(Boolean.valueOf(false));

        objectOutputStream.writeObject(protocolClassname);
        objectOutputStream.writeObject(Boolean.valueOf(isClientProtocol));
        objectOutputStream.writeObject(Boolean.valueOf(isProtocolActivation));

        /** For later backwards compatibility, to add more stuff */
        objectOutputStream.writeObject(Boolean.valueOf(false));
    }

    /* (non-Javadoc)
     * @see serialize.VSSerializable#deserialize(serialize.VSSerialize,
     *	java.io.ObjectInputStream)
     */
    public synchronized void deserialize(VSSerialize serialize,
                                         ObjectInputStream objectInputStream)
    throws IOException, ClassNotFoundException {
        super.deserialize(serialize, objectInputStream);

        if (VSSerialize.DEBUG)
            System.out.println("Deserializing: VSProtocolEvent");

        /** For later backwards compatibility, to add more stuff */
        objectInputStream.readObject();

        // Set protocolClassname before calling createShortname
        protocolClassname = (String) objectInputStream.readObject();
        isClientProtocol = ((Boolean) objectInputStream.readObject()).booleanValue();
        isProtocolActivation = ((Boolean) objectInputStream.readObject()).booleanValue();

        // Set the event shortname using current localization
        this.setShortname(createShortname(null));

        /** For later backwards compatibility, to add more stuff */
        objectInputStream.readObject();
    }

    protected String createShortname(String savedShortname) {
        // Handle case where this is called during parent deserialization
        // before our fields are initialized
        if (protocolClassname == null || prefs == null) {
            return savedShortname != null ? savedShortname : "Protocol Event";
        }
        
        // Always use current localization strings
        String protocolShortname = VSRegisteredEvents.getShortnameByClassname(protocolClassname);
        if (protocolShortname == null) {
            protocolShortname = protocolClassname;
        }
        
        String clientServer = isClientProtocol ? 
            prefs.getString("lang.client") : 
            prefs.getString("lang.server");
        String activateDeactivate = isProtocolActivation ?
            prefs.getString("lang.activated") :
            prefs.getString("lang.deactivated");
        return protocolShortname + " " + clientServer + " " + activateDeactivate;
    }
}