package org.apache.poi.hssf.usermodel;

import org.apache.poi.util.POILogFactory;
import org.apache.poi.util.POILogger;
import org.apache.poi.hssf.util.HSSFColor;

import java.awt.*;
import java.awt.image.ImageObserver;
import java.text.AttributedCharacterIterator;

/**
 * Translates Graphics calls into escher calls.  The translation is lossy so
 * many features are not supported and some just aren't implemented yet.  If
 * in doubt test the specific calls you wish to make. Graphics calls are
 * always performed into an EscherGroup so one will need to be created.
 * <p>
 * <b>Important:</b>
 * <blockquote>
 * One important concept worth considering is that of font size.  One of the
 * difficulties in converting Graphics calls into escher drawing calls is that
 * Excel does not have the concept of absolute pixel positions.  It measures
 * it's cell widths in 'characters' and the cell heights in points.
 * Unfortunately it's not defined exactly what a type of character it's
 * measuring.  Presumably this is due to the fact that the Excel will be
 * using different fonts on different platforms or even within the same
 * platform.
 * <p>
 * Because of this constraint we've had to calculate the
 * verticalPointsPerPixel.  This the amount the font should be scaled by when
 * you issue commands such as drawString().  A good way to calculate this
 * is to use the follow formula:
 * <p>
 * <pre>
 *      multipler = groupHeightInPoints / heightOfGroup
 * </pre>
 * <p>
 * The height of the group is calculated fairly simply by calculating the
 * difference between the y coordinates of the bounding box of the shape.  The
 * height of the group can be calculated by using a convenience called
 * <code>HSSFClientAnchor.getAnchorHeightInPoints()</code>.
 * </blockquote>
 *
 * @author Glen Stampoultzis (glens at apache.org)
 */
public class EscherGraphics
        extends Graphics
{
    private HSSFShapeGroup escherGroup;
    private HSSFWorkbook workbook;
    private float verticalPointsPerPixel = 1.0f;
    private float verticalPixelsPerPoint;
    private Color foreground;
    private Color background = Color.white;
    private Font font;
    private static POILogger logger = POILogFactory.getLogger(EscherGraphics.class);

    /**
     * Construct an escher graphics object.
     *
     * @param escherGroup           The escher group to write the graphics calls into.
     * @param workbook              The workbook we are using.
     * @param forecolor             The foreground color to use as default.
     * @param verticalPointsPerPixel    The font multiplier.  (See class description for information on how this works.).
     */
    public EscherGraphics(HSSFShapeGroup escherGroup, HSSFWorkbook workbook, Color forecolor, float verticalPointsPerPixel )
    {
        this.escherGroup = escherGroup;
        this.workbook = workbook;
        this.verticalPointsPerPixel = verticalPointsPerPixel;
        this.verticalPixelsPerPoint = 1 / verticalPointsPerPixel;
        this.font = new Font("Arial", 0, 10);
        this.foreground = forecolor;
//        background = backcolor;
    }

    /**
     * Constructs an escher graphics object.
     *
     * @param escherGroup           The escher group to write the graphics calls into.
     * @param workbook              The workbook we are using.
     * @param foreground            The foreground color to use as default.
     * @param verticalPointsPerPixel    The font multiplier.  (See class description for information on how this works.).
     * @param font                  The font to use.
     */
    EscherGraphics( HSSFShapeGroup escherGroup, HSSFWorkbook workbook, Color foreground, Font font, float verticalPointsPerPixel )
    {
        this.escherGroup = escherGroup;
        this.workbook = workbook;
        this.foreground = foreground;
//        this.background = background;
        this.font = font;
        this.verticalPointsPerPixel = verticalPointsPerPixel;
        this.verticalPixelsPerPoint = 1 / verticalPointsPerPixel;
    }

    /**
     * Constructs an escher graphics object.
     *
     * @param escherGroup           The escher group to write the graphics calls into.
     * @param workbook              The workbook we are using.
     * @param forecolor             The default foreground color.
     */
//    public EscherGraphics( HSSFShapeGroup escherGroup, HSSFWorkbook workbook, Color forecolor)
//    {
//        this(escherGroup, workbook, forecolor, 1.0f);
//    }


    public void clearRect(int x, int y, int width, int height)
    {
        Color color = foreground;
        setColor(background);
        fillRect(x,y,width,height);
        setColor(color);
    }

    public void clipRect(int x, int y, int width, int height)
    {
        logger.log(POILogger.WARN,"clipRect not supported");
    }

    public void copyArea(int x, int y, int width, int height, int dx, int dy)
    {
        logger.log(POILogger.WARN,"copyArea not supported");
    }

    public Graphics create()
    {
        EscherGraphics g = new EscherGraphics(escherGroup, workbook,
                foreground, font, verticalPointsPerPixel );
        return g;
    }

    public void dispose()
    {
    }

    public void drawArc(int x, int y, int width, int height,
				 int startAngle, int arcAngle)
    {
        logger.log(POILogger.WARN,"drawArc not supported");
    }

    public boolean drawImage(Image img,
				      int dx1, int dy1, int dx2, int dy2,
				      int sx1, int sy1, int sx2, int sy2,
				      Color bgcolor,
				      ImageObserver observer)
    {
        logger.log(POILogger.WARN,"drawImage not supported");

        return true;
    }

    public boolean drawImage(Image img,
				      int dx1, int dy1, int dx2, int dy2,
				      int sx1, int sy1, int sx2, int sy2,
				      ImageObserver observer)
    {
        logger.log(POILogger.WARN,"drawImage not supported");
        return true;
    }

    public boolean drawImage(Image image, int i, int j, int k, int l, Color color, ImageObserver imageobserver)
    {
        return drawImage(image, i, j, i + k, j + l, 0, 0, image.getWidth(imageobserver), image.getHeight(imageobserver), color, imageobserver);
    }

    public boolean drawImage(Image image, int i, int j, int k, int l, ImageObserver imageobserver)
    {
        return drawImage(image, i, j, i + k, j + l, 0, 0, image.getWidth(imageobserver), image.getHeight(imageobserver), imageobserver);
    }

    public boolean drawImage(Image image, int i, int j, Color color, ImageObserver imageobserver)
    {
        return drawImage(image, i, j, image.getWidth(imageobserver), image.getHeight(imageobserver), color, imageobserver);
    }

    public boolean drawImage(Image image, int i, int j, ImageObserver imageobserver)
    {
        return drawImage(image, i, j, image.getWidth(imageobserver), image.getHeight(imageobserver), imageobserver);
    }

    public void drawLine(int x1, int y1, int x2, int y2)
    {
        HSSFSimpleShape shape = escherGroup.createShape(new HSSFChildAnchor(x1, y1, x2, y2) );
        shape.setShapeType(HSSFSimpleShape.OBJECT_TYPE_LINE);
        shape.setLineWidth(0);
        shape.setLineStyleColor(foreground.getRed(), foreground.getGreen(), foreground.getBlue());
    }

    public void drawOval(int x, int y, int width, int height)
    {
        HSSFSimpleShape shape = escherGroup.createShape(new HSSFChildAnchor(x,y,x+width,y+height) );
        shape.setShapeType(HSSFSimpleShape.OBJECT_TYPE_OVAL);
        shape.setLineWidth(0);
        shape.setLineStyleColor(foreground.getRed(), foreground.getGreen(), foreground.getBlue());
        shape.setNoFill(true);
    }

    public void drawPolygon(int xPoints[], int yPoints[],
				     int nPoints)
    {
        int right  = findBiggest(xPoints);
        int bottom = findBiggest(yPoints);
        int left   = findSmallest(xPoints);
        int top    = findSmallest(yPoints);
        HSSFPolygon shape = escherGroup.createPolygon(new HSSFChildAnchor(left,top,right,bottom) );
        shape.setPolygonDrawArea(right - left, bottom - top);
        shape.setPoints(addToAll(xPoints, -left), addToAll(yPoints, -top));
        shape.setLineStyleColor(foreground.getRed(), foreground.getGreen(), foreground.getBlue());
        shape.setLineWidth(0);
        shape.setNoFill(true);
    }

    private int[] addToAll( int[] values, int amount )
    {
        int[] result = new int[values.length];
        for ( int i = 0; i < values.length; i++ )
            result[i] = values[i] + amount;
        return result;
    }

    public void drawPolyline(int xPoints[], int yPoints[],
				      int nPoints)
    {
        logger.log(POILogger.WARN,"drawPolyline not supported");
    }

    public void drawRect(int x, int y, int width, int height)
    {
        logger.log(POILogger.WARN,"drawRect not supported");
    }

    public void drawRoundRect(int x, int y, int width, int height,
				       int arcWidth, int arcHeight)
    {
        logger.log(POILogger.WARN,"drawRoundRect not supported");
    }

    public void drawString(String str, int x, int y)
    {
        if (str == null || str.equals(""))
            return;

        Font excelFont = font;
        if ( font.getName().equals( "SansSerif" ) )
        {
            excelFont = new Font( "Arial", font.getStyle(), (int) ( font.getSize() / verticalPixelsPerPoint ) );
        }
        else
        {
            excelFont = new Font( font.getName(), font.getStyle(), (int) ( font.getSize() / verticalPixelsPerPoint ));
        }
        FontDetails d = StaticFontMetrics.getFontDetails( excelFont );
        int width = (int) ( (d.getStringWidth( str ) * 8)  + 12 );
        int height = (int) ( ( font.getSize() / verticalPixelsPerPoint ) + 6 ) * 2;
        y -= ( font.getSize() / verticalPixelsPerPoint ) + 2 * verticalPixelsPerPoint;    // we want to draw the shape from the top-left
        HSSFTextbox textbox = escherGroup.createTextbox( new HSSFChildAnchor( x, y, x + width, y + height ) );
        textbox.setNoFill( true );
        textbox.setLineStyle( HSSFShape.LINESTYLE_NONE );
        HSSFRichTextString s = new HSSFRichTextString( str );
        HSSFFont hssfFont = matchFont( excelFont );
        s.applyFont( hssfFont );
        textbox.setString( s );
    }

    private HSSFFont matchFont( Font font )
    {
        HSSFColor hssfColor = workbook.getCustomPalette()
                .findColor((byte)foreground.getRed(), (byte)foreground.getGreen(), (byte)foreground.getBlue());
        if (hssfColor == null)
            hssfColor = workbook.getCustomPalette().findSimilarColor((byte)foreground.getRed(), (byte)foreground.getGreen(), (byte)foreground.getBlue());
        boolean bold = (font.getStyle() & Font.BOLD) != 0;
        boolean italic = (font.getStyle() & Font.ITALIC) != 0;
        HSSFFont hssfFont = workbook.findFont(bold ? HSSFFont.BOLDWEIGHT_BOLD : 0,
                    hssfColor.getIndex(),
                    (short)(font.getSize() * 20),
                    font.getName(),
                    italic,
                    false,
                    (short)0,
                    (byte)0);
        if (hssfFont == null)
        {
            hssfFont = workbook.createFont();
            hssfFont.setBoldweight(bold ? HSSFFont.BOLDWEIGHT_BOLD : 0);
            hssfFont.setColor(hssfColor.getIndex());
            hssfFont.setFontHeight((short)(font.getSize() * 20));
            hssfFont.setFontName(font.getName());
            hssfFont.setItalic(italic);
            hssfFont.setStrikeout(false);
            hssfFont.setTypeOffset((short) 0);
            hssfFont.setUnderline((byte) 0);
        }

        return hssfFont;
    }


    public void drawString(AttributedCharacterIterator iterator,
                                    int x, int y)
    {
        logger.log(POILogger.WARN,"drawString not supported");
    }

    public void fillArc(int x, int y, int width, int height,
				 int startAngle, int arcAngle)
    {
        logger.log(POILogger.WARN,"fillArc not supported");
    }

    public void fillOval(int x, int y, int width, int height)
    {
        HSSFSimpleShape shape = escherGroup.createShape(new HSSFChildAnchor( x, y, x + width, y + height ) );
        shape.setShapeType(HSSFSimpleShape.OBJECT_TYPE_OVAL);
        shape.setLineStyle(HSSFShape.LINESTYLE_NONE);
        shape.setFillColor(foreground.getRed(), foreground.getGreen(), foreground.getBlue());
        shape.setLineStyleColor(foreground.getRed(), foreground.getGreen(), foreground.getBlue());
    }

    public void fillPolygon(int xPoints[], int yPoints[],
				     int nPoints)
    {
        int right  = findBiggest(xPoints);
        int bottom = findBiggest(yPoints);
        int left   = findSmallest(xPoints);
        int top    = findSmallest(yPoints);
        HSSFPolygon shape = escherGroup.createPolygon(new HSSFChildAnchor(left,top,right,bottom) );
        shape.setPolygonDrawArea(right - left, bottom - top);
        shape.setPoints(addToAll(xPoints, -left), addToAll(yPoints, -top));
        shape.setLineStyleColor(foreground.getRed(), foreground.getGreen(), foreground.getBlue());
        shape.setFillColor(foreground.getRed(), foreground.getGreen(), foreground.getBlue());
    }

    private int findBiggest( int[] values )
    {
        int result = Integer.MIN_VALUE;
        for ( int i = 0; i < values.length; i++ )
        {
            if (values[i] > result)
                result = values[i];
        }
        return result;
    }

    private int findSmallest( int[] values )
    {
        int result = Integer.MAX_VALUE;
        for ( int i = 0; i < values.length; i++ )
        {
            if (values[i] < result)
                result = values[i];
        }
        return result;
    }

    public void fillRect(int x, int y, int width, int height)
    {
        HSSFSimpleShape shape = escherGroup.createShape(new HSSFChildAnchor( x, y, x + width, y + height ) );
        shape.setShapeType(HSSFSimpleShape.OBJECT_TYPE_RECTANGLE);
        shape.setLineStyle(HSSFShape.LINESTYLE_NONE);
        shape.setFillColor(foreground.getRed(), foreground.getGreen(), foreground.getBlue());
        shape.setLineStyleColor(foreground.getRed(), foreground.getGreen(), foreground.getBlue());
    }

    public void fillRoundRect(int x, int y, int width, int height,
				       int arcWidth, int arcHeight)
    {
        logger.log(POILogger.WARN,"fillRoundRect not supported");
    }

    public Shape getClip()
    {
        return getClipBounds();
    }

    public Rectangle getClipBounds()
    {
        return null;
    }

    public Rectangle getClipRect()
    {
        return getClipBounds();
    }

    public Color getColor()
    {
        return foreground;
    }

    public Font getFont()
    {
        return font;
    }

    public FontMetrics getFontMetrics(Font f)
    {
        return Toolkit.getDefaultToolkit().getFontMetrics(f);
    }

    public void setClip(int x, int y, int width, int height)
    {
        setClip(((Shape) (new Rectangle(x,y,width,height))));
    }

    public void setClip(Shape shape)
    {
        // ignore... not implemented
    }

    public void setColor(Color color)
    {
        foreground = color;
    }

    public void setFont(Font f)
    {
        font = f;
    }

    public void setPaintMode()
    {
        logger.log(POILogger.WARN,"setPaintMode not supported");
    }

    public void setXORMode(Color color)
    {
        logger.log(POILogger.WARN,"setXORMode not supported");
    }

    public void translate(int x, int y)
    {
        logger.log(POILogger.WARN,"translate not supported");
    }

    public Color getBackground()
    {
        return background;
    }

    public void setBackground( Color background )
    {
        this.background = background;
    }


}