/*
 * JBoss, Home of Professional Open Source.
 *
 * See the LEGAL.txt file distributed with this work for information regarding copyright ownership and licensing.
 *
 * See the AUTHORS.txt file distributed with this work for a full listing of individual contributors.
 */
package org.teiid.designer.ui.actions;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.IExtension;
import org.eclipse.core.runtime.IExtensionPoint;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Platform;
import org.eclipse.jface.action.Action;
import org.eclipse.jface.action.MenuManager;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.ui.ISelectionListener;
import org.teiid.designer.ui.PluginConstants;
import org.teiid.designer.ui.UiConstants;
import org.teiid.designer.ui.UiPlugin;


/**
 * 
 *
 * @since 8.0
 */
public class ModelProjectActionManager {
    /** Array of all extensions to the DiagramHelper extension point */
    private static final String PROJECTS_LABEL = UiConstants.Util.getString("ModelProjectActionManager.projectLabel"); //$NON-NLS-1$
    private static Collection actions;
    private static boolean actionsLoaded = false;

    public static Collection getActions( Object selection ) {
        if (!actionsLoaded) {
            loadExtensions();
        }
        return actions;
    }

    private static void loadExtensions() {
        HashMap actionExtList = new HashMap();
        actionsLoaded = true;

        // get the NewChildAction extension point from the plugin class
        String id = UiConstants.ExtensionPoints.ModelProjectActionExtension.ID;
        String actionTag = UiConstants.ExtensionPoints.ModelProjectActionExtension.RESOURCE_ACTION;
        String className = UiConstants.ExtensionPoints.ModelProjectActionExtension.CLASSNAME;
        String labelTag = UiConstants.ExtensionPoints.ModelProjectActionExtension.LABEL;
        IExtensionPoint extensionPoint = Platform.getExtensionRegistry().getExtensionPoint(UiConstants.PLUGIN_ID, id);

        // get the all extensions to the NewChildAction extension point
        IExtension[] extensions = extensionPoint.getExtensions();

        // walk through the extensions and find all INewChildAction implementations
        for (int i = 0; i < extensions.length; ++i) {
            IConfigurationElement[] elements = extensions[i].getConfigurationElements();
            try {

                // first, find the content provider instance and add it to the instance list
                for (int j = 0; j < elements.length; ++j) {
                    if (elements[j].getName().equals(actionTag)) {
                        Object helper = elements[j].createExecutableExtension(className);
                        // Set the text label
                        String label = elements[j].getAttribute(labelTag);
                        if (label != null) {
                            ((Action)helper).setText(label);
                        }

                        actionExtList.put(elements[j].getAttribute(className), helper);
                    }
                }

            } catch (Exception e) {
                // catch any Exception that occurred obtaining the configuration and log it
                String message = UiConstants.Util.getString("ModelProjectActionManager.loadingExtensionsErrorMessage", //$NON-NLS-1$
                                                            extensions[i].getUniqueIdentifier());
                UiConstants.Util.log(IStatus.ERROR, e, message);
            }
        }

        Object[] actionsArray = actionExtList.values().toArray();
        Arrays.sort(actionsArray);
        // Now we need to set the actual map
        actions = new ArrayList(actionsArray.length);
        Collection keys = actionExtList.keySet();
        for (int i = 0; i < actionsArray.length; i++) {
            Object key = null;
            for (Iterator iter = keys.iterator(); iter.hasNext();) {
                key = iter.next();
                if (actionExtList.get(key) == (actionsArray[i])) {
                    actions.add(actionsArray[i]);
                    break;
                }
            }
        }

    }

    public static MenuManager getModelProjectActionMenu( final ISelection theSelection ) {
        MenuManager menu = new MenuManager(PROJECTS_LABEL,
                                           UiPlugin.getDefault().getImageDescriptor(PluginConstants.Images.MODEL_PROJECT),
                                           "projectActions"); //$NON-NLS-1$

        Collection modelProjectActions = getActions(theSelection);

        // create a NewChildAction for every new child type
        Iterator iter = modelProjectActions.iterator();
        Action nextAction = null;

        while (iter.hasNext()) {
            nextAction = (Action)iter.next();
            if (nextAction instanceof ISelectionAction) {
                if (((ISelectionAction)nextAction).isApplicable(theSelection)) {
                    if (nextAction instanceof ISelectionListener) {
                        ((ISelectionListener)nextAction).selectionChanged(null, theSelection);
                    }
                    menu.add(nextAction);
                }
            } else {
                if (nextAction instanceof ISelectionListener) {
                    ((ISelectionListener)nextAction).selectionChanged(null, theSelection);
                }
                menu.add(nextAction);
            }
        }
        if (menu.getItems().length == 0) return null;

        return menu;
    }
}