/**
 * Copyright (c) 2011, 2015 - Lunifera GmbH (Gross Enzersdorf, Austria), Loetz GmbH&Co.KG (69115 Heidelberg, Germany)
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *         Florian Pirchner - Initial implementation
 */
package org.eclipse.osbp.runtime.web.ecview.presentation.vaadin.common;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Date;
import java.util.List;

import org.eclipse.osbp.ecview.core.common.dnd.IDropTargetStrategy;
import org.eclipse.osbp.ecview.core.common.editpart.IEmbeddableEditpart;
import org.eclipse.osbp.ecview.core.common.editpart.ILayoutEditpart;
import org.eclipse.osbp.ecview.core.common.model.core.CoreModelFactory;
import org.eclipse.osbp.ecview.core.common.model.core.YElement;
import org.eclipse.osbp.ecview.core.common.model.core.YEmbeddable;
import org.eclipse.osbp.ecview.core.common.model.core.YEmbeddableEvent;
import org.eclipse.osbp.ecview.core.common.model.core.YLayout;
import org.eclipse.osbp.ecview.core.common.model.core.YMarginable;
import org.eclipse.osbp.ecview.core.common.model.core.YSpacingable;
import org.eclipse.osbp.ecview.core.common.presentation.ILayoutPresentation;
import org.eclipse.osbp.runtime.designer.api.IDesignerService.DesignEvent;
import org.eclipse.osbp.runtime.designer.api.IDesignerService.EventType;
import org.eclipse.osbp.runtime.designer.api.IDesignerService.IDesignListener;
import org.eclipse.osbp.runtime.designer.api.IWidgetDesignConfigurator;

import com.vaadin.ui.Component;
import com.vaadin.ui.HasComponents.ComponentAttachDetachNotifier;
import com.vaadin.ui.Layout.MarginHandler;
import com.vaadin.ui.Layout.SpacingHandler;

import fi.jasoft.dragdroplayouts.client.ui.LayoutDragMode;
import fi.jasoft.dragdroplayouts.interfaces.DragFilter;
import fi.jasoft.dragdroplayouts.interfaces.LayoutDragSource;

// TODO: Auto-generated Javadoc
/**
 * An abstract base class implementing {@link ILayoutPresentation}.
 *
 * @param <A>
 *            the generic type
 */
public abstract class AbstractLayoutPresenter<A extends Component> extends AbstractVaadinWidgetPresenter<A>
		implements ILayoutPresentation<A>, IDesignListener {

	/** The children. */
	private List<IEmbeddableEditpart> children;

	/** The render lock. */
	private boolean renderLock;

	/**
	 * Instantiates a new abstract layout presenter.
	 *
	 * @param editpart
	 *            the editpart
	 */
	public AbstractLayoutPresenter(ILayoutEditpart editpart) {
		super(editpart);
	}

	/**
	 * Returns the editpart the presenter will render for.
	 * 
	 * @return the editpart
	 */
	protected ILayoutEditpart getEditpart() {
		return (ILayoutEditpart) super.getEditpart();
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.osbp.runtime.web.ecview.presentation.vaadin.common.
	 * AbstractVaadinWidgetPresenter#getModel()
	 */
	@Override
	public YLayout getModel() {
		return (YLayout) getEditpart().getModel();
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see
	 * org.eclipse.osbp.ecview.core.common.presentation.ILayoutPresentation#
	 * getChildren()
	 */
	@Override
	public List<IEmbeddableEditpart> getChildren() {
		return children != null ? Collections.unmodifiableList(children) : Collections.<IEmbeddableEditpart>emptyList();
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see
	 * org.eclipse.osbp.ecview.core.common.presentation.ILayoutPresentation#
	 * contains(org.eclipse.osbp.ecview.core.common.editpart.
	 * IEmbeddableEditpart)
	 */
	@Override
	public boolean contains(IEmbeddableEditpart presentation) {
		return children != null && children.contains(presentation);
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see
	 * org.eclipse.osbp.ecview.core.common.presentation.ILayoutPresentation#add(
	 * org.eclipse.osbp.ecview.core.common.editpart.IEmbeddableEditpart)
	 */
	@Override
	public void add(IEmbeddableEditpart editPart) {
		ensureChildren();

		if (!children.contains(editPart)) {
			children.add(editPart);

			if (!renderLock) {
				internalAdd(editPart);
			}
		}
	}

	/**
	 * This method is called after the editpart was successfully added to the
	 * children collection.<br>
	 * Subclasses should handle the add of the UI element in that method.
	 *
	 * @param presentation
	 *            the presentation
	 */
	protected void internalAdd(IEmbeddableEditpart presentation) {

	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see
	 * org.eclipse.osbp.ecview.core.common.presentation.ILayoutPresentation#
	 * remove(org.eclipse.osbp.ecview.core.common.editpart.IEmbeddableEditpart)
	 */
	@Override
	public void remove(IEmbeddableEditpart editPart) {
		if (children == null) {
			return;
		}

		if (children.remove(editPart) && !renderLock) {
			internalRemove(editPart);
		}
	}

	/**
	 * This method is called after the editpart was successfully removed from
	 * the children collection.<br>
	 * Subclasses should handle the removal of the UI element in that method.
	 * 
	 * @param presentation
	 *            The presentation to be removed
	 */
	protected void internalRemove(IEmbeddableEditpart presentation) {

	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see
	 * org.eclipse.osbp.ecview.core.common.presentation.ILayoutPresentation#
	 * insert(org.eclipse.osbp.ecview.core.common.editpart.IEmbeddableEditpart,
	 * int)
	 */
	@Override
	public void insert(IEmbeddableEditpart editPart, int index) {
		ensureChildren();

		int currentIndex = children.indexOf(editPart);
		if (currentIndex > -1 && currentIndex != index) {
			throw new RuntimeException(
					String.format("Insert at index %d not possible since presentation already contained at index %d",
							index, currentIndex));
		}

		children.add(index, editPart);

		if (!renderLock) {
			internalInsert(editPart, index);
		}
	}

	/**
	 * This method is called after the editpart was successfully inserted to the
	 * children collection.<br>
	 * Subclasses should handle the insert of the UI element in that method.
	 * 
	 * @param editpart
	 *            The editpart to be inserted
	 * @param index
	 *            The index where the editpart should be inserted
	 */
	protected void internalInsert(IEmbeddableEditpart editpart, int index) {

	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see
	 * org.eclipse.osbp.ecview.core.common.presentation.ILayoutPresentation#move
	 * (org.eclipse.osbp.ecview.core.common.editpart.IEmbeddableEditpart, int)
	 */
	@Override
	public void move(IEmbeddableEditpart editpart, int index) {
		if (children == null) {
			throw new RuntimeException("Move not possible. No children present.");
		}

		if (!children.contains(editpart)) {
			throw new RuntimeException(
					String.format("Move to index %d not possible since presentation not added yet!", index));
		}

		int currentIndex = children.indexOf(editpart);
		children.remove(editpart);
		children.add(index, editpart);

		if (!renderLock) {
			internalMove(editpart, currentIndex, index);
		}
	}

	/**
	 * This method is called after the presentation was successfully moved
	 * inside the children collection.<br>
	 * Subclasses should handle the move of the UI element in that method.
	 * 
	 * @param presentation
	 *            The presentation to be moved.
	 * @param oldIndex
	 *            The old index where the control was located.
	 * @param newIndex
	 *            The new index where the control should be located after the
	 *            move operation.
	 */
	protected void internalMove(IEmbeddableEditpart presentation, int oldIndex, int newIndex) {

	}

	protected void initialize(Component component, YElement model) {

		super.initialize(component, model);

		if (component instanceof ComponentAttachDetachNotifier && model instanceof YLayout) {
			((ComponentAttachDetachNotifier) component).addComponentAttachListener(e -> {
				YEmbeddableEvent event = CoreModelFactory.eINSTANCE.createYEmbeddableEvent();
				event.setTime(new Date());
				event.setEmbeddable((YEmbeddable) getModel());
				event.setRawEvent(e);
				((YLayout) model).setLastComponentAttach(event);
			});
			((ComponentAttachDetachNotifier) component).addComponentDetachListener(e -> {
				YEmbeddableEvent event = CoreModelFactory.eINSTANCE.createYEmbeddableEvent();
				event.setTime(new Date());
				event.setEmbeddable((YEmbeddable) getModel());
				event.setRawEvent(e);
				((YLayout) model).setLastComponentDetach(event);
			});
		}
	}

	/**
	 * Returns true, if rendering should not be done.
	 *
	 * @return true, if is render lock
	 */
	public boolean isRenderLock() {
		return renderLock;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see
	 * org.eclipse.osbp.ecview.core.common.presentation.ILayoutPresentation#
	 * updateCellStyle(org.eclipse.osbp.ecview.core.common.model.core.
	 * YEmbeddable)
	 */
	@Override
	public void updateCellStyle(YEmbeddable child) {
		// can be overridden by sub classes
	}

	/**
	 * True, if rendering should not be done.
	 *
	 * @param renderLock
	 *            the new render lock
	 */
	public void setRenderLock(boolean renderLock) {
		this.renderLock = renderLock;
	}

	/**
	 * Ensures, that the children collection exists.
	 */
	protected void ensureChildren() {
		if (children == null) {
			children = new ArrayList<IEmbeddableEditpart>();
		}
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.osbp.runtime.web.ecview.presentation.vaadin.common.
	 * AbstractVaadinWidgetPresenter#notify(org.eclipse.osbp.runtime.designer.
	 * api.IDesignerService.DesignEvent)
	 */
	@Override
	public void notify(DesignEvent event) {
		super.notify(event);

		if (getWidget() != null && getWidget() instanceof LayoutDragSource) {
			LayoutDragSource dragSource = (LayoutDragSource) getWidget();
			if (event.getType() == EventType.ENABLED) {
				dragSource.setDragMode(getDragMode());
				dragSource.setDragFilter(DragFilter.ALL);
			} else {
				dragSource.setDragMode(LayoutDragMode.NONE);
				dragSource.setDragFilter(DragFilter.NONE);
			}
		}

		IWidgetDesignConfigurator service = getViewContext().getService(IWidgetDesignConfigurator.class.getName());
		if (service != null) {
			if (event.getType() == EventType.ENABLED) {
				service.configure(getWidget(), (YEmbeddable) getCastedModel(), true);
			} else {
				service.configure(getWidget(), (YEmbeddable) getCastedModel(), false);
			}
		}
	}

	/**
	 * Is called to initialize the newly created component.
	 *
	 * @param component
	 *            the component
	 * @param model
	 *            the model
	 */
	protected void setupComponent(Component component, YElement model) {
		super.setupComponent(component, model);

		if (component instanceof LayoutDragSource) {
			LayoutDragSource source = (LayoutDragSource) component;
			LayoutDragMode mode = getDragMode();
			source.setDragMode(getDragMode());
			if (mode == LayoutDragMode.NONE) {
				source.setDragFilter(DragFilter.NONE);
			} else {
				source.setDragFilter(DragFilter.ALL);
			}
		}

		setupDropTarget(component, (YLayout) model);
		
		initialize(component, model);
	}

	/**
	 * Creates a UI-Kit specific drop handler for the component.
	 *
	 * @param component
	 *            the component
	 * @param yLayout
	 *            the y layout
	 */
	protected void setupDropTarget(Component component, YLayout yLayout) {
		IDropTargetStrategy strategy = getViewContext().getService(IDropTargetStrategy.class.getName());
		if (strategy != null) {
			strategy.setupDropTarget(getViewContext(), component, yLayout);
		}
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see
	 * org.eclipse.osbp.ecview.core.common.presentation.ILayoutPresentation#
	 * updateSpacings()
	 */
	@Override
	public void updateSpacings() {
		if (getModel() instanceof YSpacingable) {
			((SpacingHandler) getWidget()).setSpacing(((YSpacingable) getModel()).isSpacing());
		}
		if (getModel() instanceof YMarginable) {
			((MarginHandler) getWidget()).setMargin(((YMarginable) getModel()).isMargin());
		}
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.osbp.runtime.web.ecview.presentation.vaadin.common.
	 * AbstractVaadinWidgetPresenter#internalDispose()
	 */
	@Override
	protected void internalDispose() {
		try {
			if (children != null) {
				children.clear();
				children = null;
			}
		} finally {
			super.internalDispose();
		}
	}
}