/*******************************************************************************
 * Copyright (c) 2012 Original authors and others.
 * 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:
 *     Original authors and others - initial API and implementation
 ******************************************************************************/
package org.eclipse.nebula.widgets.nattable.style;

import java.util.ArrayList;
import java.util.List;

import org.eclipse.nebula.widgets.nattable.config.CellConfigAttributes;
import org.eclipse.nebula.widgets.nattable.config.IConfigRegistry;
import org.eclipse.nebula.widgets.nattable.layer.cell.ILayerCell;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.Rectangle;

public class CellStyleUtil {

    public static IStyle getCellStyle(ILayerCell cell,
            IConfigRegistry configRegistry) {
        return new CellStyleProxy(configRegistry, cell.getDisplayMode(), cell
                .getConfigLabels().getLabels());
    }

    public static int getHorizontalAlignmentPadding(IStyle cellStyle,
            Rectangle rectangle, int contentWidth) {
        HorizontalAlignmentEnum horizontalAlignment = cellStyle
                .getAttributeValue(CellStyleAttributes.HORIZONTAL_ALIGNMENT);
        return getHorizontalAlignmentPadding(horizontalAlignment, rectangle,
                contentWidth);
    }

    /**
     * Calculate padding needed at the left to align horizontally. Defaults to
     * CENTER horizontal alignment.
     */
    public static int getHorizontalAlignmentPadding(
            HorizontalAlignmentEnum horizontalAlignment, Rectangle rectangle,
            int contentWidth) {
        if (horizontalAlignment == null) {
            horizontalAlignment = HorizontalAlignmentEnum.CENTER;
        }

        int padding = 0;

        switch (horizontalAlignment) {
            case CENTER:
                padding = (rectangle.width - contentWidth) / 2;
                break;
            case RIGHT:
                padding = rectangle.width - contentWidth;
                break;
        }

        if (padding < 0) {
            padding = 0;
        }

        return padding;
    }

    public static int getVerticalAlignmentPadding(IStyle cellStyle,
            Rectangle rectangle, int contentHeight) {
        VerticalAlignmentEnum verticalAlignment = cellStyle
                .getAttributeValue(CellStyleAttributes.VERTICAL_ALIGNMENT);
        return getVerticalAlignmentPadding(verticalAlignment, rectangle,
                contentHeight);
    }

    /**
     * Calculate padding needed at the top to align vertically. Defaults to
     * MIDDLE vertical alignment.
     */
    public static int getVerticalAlignmentPadding(
            VerticalAlignmentEnum verticalAlignment, Rectangle rectangle,
            int contentHeight) {
        if (verticalAlignment == null) {
            verticalAlignment = VerticalAlignmentEnum.MIDDLE;
        }

        int padding = 0;

        switch (verticalAlignment) {
            case MIDDLE:
                padding = (rectangle.height - contentHeight) / 2;
                break;
            case BOTTOM:
                padding = rectangle.height - contentHeight;
                break;
        }

        if (padding < 0) {
            padding = 0;
        }

        return padding;
    }

    public static List<Color> getAllBackgroundColors(ILayerCell cell,
            IConfigRegistry configRegistry, String displayMode) {

        final List<Color> colors = new ArrayList<Color>();

        for (String configLabel : cell.getConfigLabels().getLabels()) {
            IStyle cellStyle = configRegistry.getSpecificConfigAttribute(
                    CellConfigAttributes.CELL_STYLE, displayMode, configLabel);
            if (cellStyle != null) {
                Color color = cellStyle
                        .getAttributeValue(CellStyleAttributes.BACKGROUND_COLOR);

                if (color != null) {
                    colors.add(color);
                }
            }
        }

        return colors;
    }

}