/**
 *                                                                            
 * Copyright (c) 2011, 2016 - 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 <florian.pirchner@gmail.com> - Initial implementation
 */
package org.eclipse.osbp.vaadin.addons.absolutelayout.client;

import com.google.gwt.dom.client.Element;
import com.google.gwt.dom.client.Style.Unit;
import com.google.gwt.user.client.Timer;
import com.google.gwt.user.client.ui.Widget;
import com.vaadin.client.ui.VOverlay;

// TODO: Auto-generated Javadoc
/**
 * The Class OAlignmentOverlay.
 */
public class OAlignmentOverlay extends VOverlay {

	/** The Constant THICKNESS. */
	private static final int THICKNESS = 1;

	/** The Constant CLASSNAME. */
	private static final String CLASSNAME = "o-alignmentLine";

	/** The alignment location. */
	private final AlignmentsLocation alignmentLocation;
	
	/** The drag element. */
	private final Element dragElement;

	/** The snap timer. */
	private Timer snapTimer;

	/**
	 * Shows alignment lines for drag and resize operations.
	 *
	 * @param owner the owner
	 * @param dragElement the drag element
	 * @param location the location
	 * @param snap the snap
	 * @param resize the resize
	 * @param autoSnap the auto snap
	 */
	public OAlignmentOverlay(Widget owner, final Element dragElement, AlignmentsLocation location,
			final OAlignmentSnapInfo snap, final boolean resize, boolean autoSnap) {
		super(false, false);

		super.setOwner(owner);
		this.dragElement = dragElement;
		this.alignmentLocation = location;

		setStyleName(CLASSNAME);

		setZIndex(VOverlay.Z_INDEX + 1);

		if (autoSnap && (snap.getX() != 0 || snap.getY() != 0)) {
			snapTimer = new Timer() {
				@Override
				public void run() {
					if (resize) {
						snapResizeImagePosition(dragElement, snap);
					} else {
						snapDragImagePosition(dragElement, snap);
					}
				}
			};
		}
	}

	/* (non-Javadoc)
	 * @see com.vaadin.client.ui.VOverlay#show()
	 */
	@Override
	public void show() {
		int left = 0;
		int top = 0;
		int width = 0;
		int height = 0;

		if (alignmentLocation == null) {
			return;
		}

		switch (alignmentLocation) {
		case TOP_EDGE_TOLEFT:
			width = getAlignmentLineX();
			left = getOwner().getOffsetWidth() - width;
			height = THICKNESS;
			break;
		case TOP_EDGE_TORIGHT:
			width = getAlignmentLineX();
			left = 0;
			height = THICKNESS;
			break;
		case BOTTOM_EDGE_TOLEFT:
			top = getOwner().getOffsetHeight();
			width = getAlignmentLineX();
			left = getOwner().getOffsetWidth() - width;
			height = THICKNESS;
			break;
		case BOTTOM_EDGE_TORIGHT:
			width = getAlignmentLineX();
			left = 0;
			top = getOwner().getOffsetHeight();
			height = THICKNESS;
			break;
		case LEFT_EDGE_TOBOTTOM:
			top = 0;
			width = THICKNESS;
			height = getAlignmentLineY();
			break;
		case LEFT_EDGE_TOTOP:
			top = getOwner().getOffsetHeight() - getAlignmentLineY();
			width = THICKNESS;
			height = getAlignmentLineY();
			break;
		case RIGHT_EDGE_TOBOTTOM:
			top = 0;
			left = getOwner().getOffsetWidth();
			width = THICKNESS;
			height = getAlignmentLineY();
			break;
		case RIGHT_EDGE_TOTOP:
			top = getOwner().getOffsetHeight() - getAlignmentLineY();
			left = getOwner().getOffsetWidth();
			width = THICKNESS;
			height = getAlignmentLineY();
			break;
		}

		// set adjustment size
		Element element = getContainerElement();
		element.getStyle().setWidth(width, Unit.PX);
		element.getStyle().setHeight(height, Unit.PX);
		String bg = element.getStyle().getBackgroundColor();
		if (bg == null || bg.equals("")) {
			element.getStyle().setBackgroundColor("red");
		}

		// set the popup position
		int absoluteLeft = getOwner().getAbsoluteLeft() + left;
		int absoluteTop = getOwner().getAbsoluteTop() + top;
		setPopupPosition(absoluteLeft, absoluteTop);

		super.show();

		if (snapTimer != null) {
			snapTimer.schedule(300);
		}
	}

	/**
	 * Calculates the horizontal alignment line.
	 *
	 * @return the alignment line x
	 */
	private int getAlignmentLineX() {
		if (isOwnerLeftOfImage()) {
			return dragElement.getAbsoluteLeft() - getOwner().getAbsoluteLeft() + +dragElement.getOffsetWidth();
		} else {
			return getOwner().getAbsoluteLeft() - dragElement.getAbsoluteLeft() + getOwner().getOffsetWidth();
		}
	}

	/**
	 * Checks if is owner left of image.
	 *
	 * @return true, if is owner left of image
	 */
	private boolean isOwnerLeftOfImage() {
		return getOwner().getAbsoluteLeft() < dragElement.getAbsoluteLeft();
	}

	/**
	 * Calculates the vertical alignment line.
	 *
	 * @return the alignment line y
	 */
	private int getAlignmentLineY() {
		if (isOwnerTopOfImage()) {
			return dragElement.getAbsoluteTop() - getOwner().getAbsoluteTop() + dragElement.getOffsetHeight();
		} else {
			return getOwner().getAbsoluteTop() - dragElement.getAbsoluteTop() + getOwner().getOffsetHeight();
		}
	}

	/**
	 * Checks if is owner top of image.
	 *
	 * @return true, if is owner top of image
	 */
	private boolean isOwnerTopOfImage() {
		return getOwner().getAbsoluteTop() < dragElement.getAbsoluteTop();
	}

	/* (non-Javadoc)
	 * @see com.vaadin.client.ui.VOverlay#hide()
	 */
	@Override
	public void hide() {
		if (snapTimer != null) {
			snapTimer.cancel();
		}

		super.hide();
	}

	/**
	 * Snap drag image position.
	 *
	 * @param dragImage the drag image
	 * @param snap the snap
	 */
	private void snapDragImagePosition(final Element dragImage, final OAlignmentSnapInfo snap) {
		int offsetTop = 0;
		try {
			String offsetTopStr = dragImage.getStyle().getMarginTop();
			offsetTop = Integer.parseInt(offsetTopStr.substring(0, offsetTopStr.length() - 2));
		} catch (NumberFormatException e) {
			// nothing to do
		}
		dragImage.getStyle().setTop(dragImage.getAbsoluteTop() - offsetTop - snap.getY(), Unit.PX);

		int offsetLeft = 0;
		try {
			String offsetLeftStr = dragImage.getStyle().getMarginLeft();
			offsetLeft = Integer.parseInt(offsetLeftStr.substring(0, offsetLeftStr.length() - 2));
		} catch (NumberFormatException e) {
			// nothing to do
		}
		dragImage.getStyle().setLeft(dragImage.getAbsoluteLeft() - offsetLeft - snap.getX(), Unit.PX);
	}

	/**
	 * Snap resize image position.
	 *
	 * @param dragImage the drag image
	 * @param delta the delta
	 */
	private void snapResizeImagePosition(final Element dragImage, final OAlignmentSnapInfo delta) {

		OResizeLocation location = OAlignmentManager.get().getResizeLocation();
		int oldWidth = dragImage.getOffsetWidth();
		int oldHeigth = dragImage.getOffsetHeight();

		int newWidth = 0;
		int newHeight = 0;

		switch (location) {
		case TOP:
		case TOP_LEFT:
		case LEFT:
			newHeight = oldHeigth + delta.getY();
			newWidth = oldWidth + delta.getX();
			break;
		case BOTTOM:
		case BOTTOM_RIGHT:
		case RIGHT:
			newHeight = oldHeigth - delta.getY();
			newWidth = oldWidth - delta.getX();
			break;
		case TOP_RIGHT:
			newHeight = oldHeigth + delta.getY();
			newWidth = oldWidth - delta.getX();
			break;
		case BOTTOM_LEFT:
			newHeight = oldHeigth - delta.getY();
			newWidth = oldWidth + delta.getX();
			break;
		}

		dragImage.getStyle().setWidth(newWidth, Unit.PX);
		dragImage.getStyle().setHeight(newHeight, Unit.PX);
	}

	/**
	 * Indicates where the alignments should be painted.
	 */
	public enum AlignmentsLocation {
		
		/** The top edge toleft. */
		TOP_EDGE_TOLEFT, 
 /** The top edge toright. */
 TOP_EDGE_TORIGHT, 
 /** The left edge totop. */
 LEFT_EDGE_TOTOP, 
 /** The left edge tobottom. */
 LEFT_EDGE_TOBOTTOM, 
 /** The bottom edge toleft. */
 BOTTOM_EDGE_TOLEFT, 
 /** The bottom edge toright. */
 BOTTOM_EDGE_TORIGHT, 
 /** The right edge totop. */
 RIGHT_EDGE_TOTOP, 
 /** The right edge tobottom. */
 RIGHT_EDGE_TOBOTTOM
	}
}