package org.ovirt.engine.ui.common.editor;

import java.util.Map;

import org.ovirt.engine.ui.uicommonweb.models.Model;
import org.ovirt.engine.ui.uicompat.IEventListener;
import org.ovirt.engine.ui.uicompat.PropertyChangedEventArgs;
import com.google.gwt.editor.client.Editor;
import com.google.gwt.editor.client.EditorVisitor;
import com.google.gwt.editor.client.impl.BaseEditorDriver;

/**
 * Base class for generated UiCommonEditorDriver implementations for editing EntityModel and ListModel instances.
 *
 * @param <T>
 *            the type being edited
 * @param <E>
 *            the Editor type
 */
public abstract class AbstractUiCommonModelEditorDriver<T extends Model, E extends Editor<T>>
        extends BaseEditorDriver<T, E> implements UiCommonEditorDriver<T, E> {

    private IEventListener<PropertyChangedEventArgs> propertyChangeListener;
    private EditorVisitor visitor;

    /**
     * {@inheritDoc} <BR>
     * Register listeners for EntityModel changes, according to the Event Map created by the Driver
     */
    @Override
    public void edit(T object) {
        doEdit(object);

        if (propertyChangeListener != null) {
            object.getPropertyChangedEvent().removeListener(propertyChangeListener);
        }

        final UiCommonListenerMap listenerMap = getListenerMap();

        propertyChangeListener = (ev, sender, args) -> {
            String propName = args.propertyName;
            listenerMap.callListener(propName, "PropertyChanged"); //$NON-NLS-1$
        };

        // Register a "PropertyChangedEvent" to get Model changes
        object.getPropertyChangedEvent().addListener(propertyChangeListener);

        accept(getEditorVisitor());
    }

    /**
     * Get the {@code EditorVisitor}, creating one if it doesn't exist yet.
     * @return THe {@code EditorVisitor}
     */
    protected EditorVisitor getEditorVisitor() {
        // Visit editors
        if (visitor == null) {
            visitor = new UiCommonEditorVisitor<>(getEventMap(), getOwnerModels());
        }
        return visitor;
    }

    @Override
    public T flush() {
        doFlush();
        return getObject();
    }

    @Override
    public void initialize(E editor) {
        doInitialize(editor);
    }

    /**
     * Returns a {@link UiCommonListenerMap} that contains a PropertyChanged Listener for each Property in the edited
     * Model
     */
    protected abstract UiCommonListenerMap getListenerMap();

    /**
     * Returns a {@link UiCommonEventMap} for the edited Model
     */
    protected abstract UiCommonEventMap getEventMap();

    /**
     * Returns a Map of the parent ListModel for all the ListModelBoxes being edited.
     */
    protected abstract Map<String, Model> getOwnerModels();

}