/* ImageLoaderDocuImage -- Image class implementation using JDK 1.4 ImageLoader

 Digital Image Library servlet components

 Copyright (C) 2002, 2003 Robert Casties (robcast@mail.berlios.de)

 This program is free software; you can redistribute  it and/or modify it
 under  the terms of  the GNU General  Public License as published by the
 Free Software Foundation;  either version 2 of the  License, or (at your
 option) any later version.
 
 Please read license.txt for the full details. A copy of the GPL
 may be found at http://www.gnu.org/copyleft/lgpl.html

 You should have received a copy of the GNU General Public License
 along with this program; if not, write to the Free Software
 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package digilib.image;

import java.awt.Rectangle;
import java.awt.RenderingHints;
import java.awt.geom.AffineTransform;
import java.awt.geom.Rectangle2D;
import java.awt.image.AffineTransformOp;
import java.awt.image.BufferedImage;
import java.awt.image.ConvolveOp;
import java.awt.image.Kernel;
import java.awt.image.RescaleOp;
import java.io.File;
import java.io.IOException;
import java.io.OutputStream;
import java.io.RandomAccessFile;
import java.util.Iterator;

import javax.imageio.IIOImage;
import javax.imageio.ImageIO;
import javax.imageio.ImageReadParam;
import javax.imageio.ImageReader;
import javax.imageio.ImageWriteParam;
import javax.imageio.ImageWriter;
import javax.imageio.stream.FileImageInputStream;
import javax.imageio.stream.ImageInputStream;
import javax.imageio.stream.ImageOutputStream;

import digilib.io.FileOpException;
import digilib.io.ImageFile;

/** Implementation of DocuImage using the ImageLoader API of Java 1.4 and Java2D. */
public class ImageLoaderDocuImage extends DocuImageImpl {

	/** image object */
	protected BufferedImage img;

	/** interpolation type */
	protected RenderingHints renderHint;

	/** ImageIO image reader */
	protected ImageReader reader;

	/** File that was read */
	protected File imgFile;

	/* loadSubimage is supported. */
	public boolean isSubimageSupported() {
		return true;
	}

	public void setQuality(int qual) {
		quality = qual;
		renderHint = new RenderingHints(null);
		// hint.put(RenderingHints.KEY_ANTIALIASING,
		// RenderingHints.VALUE_ANTIALIAS_OFF);
		// setup interpolation quality
		if (qual > 0) {
			logger.debug("quality q1");
			renderHint.put(RenderingHints.KEY_INTERPOLATION,
					RenderingHints.VALUE_INTERPOLATION_BICUBIC);
		} else {
			logger.debug("quality q0");
			renderHint.put(RenderingHints.KEY_INTERPOLATION,
					RenderingHints.VALUE_INTERPOLATION_NEAREST_NEIGHBOR);
		}
	}

	public int getHeight() {
		int h = 0;
		try {
			if (img == null) {
				h = reader.getHeight(0);
			} else {
				h = img.getHeight();
			}
		} catch (IOException e) {
			logger.debug("error in getHeight", e);
		}
		return h;
	}

	public int getWidth() {
		int w = 0;
		try {
			if (img == null) {
				w = reader.getWidth(0);
			} else {
				w = img.getWidth();
			}
		} catch (IOException e) {
			logger.debug("error in getHeight", e);
		}
		return w;
	}

	/* load image file */
	public void loadImage(ImageFile f) throws FileOpException {
		logger.debug("loadImage " + f.getFile());
		// System.gc();
		try {
			img = ImageIO.read(f.getFile());
			if (img == null) {
				throw new FileOpException("Unable to load File!");
			}
		} catch (IOException e) {
			throw new FileOpException("Error reading image.");
		}
	}

	/**
	 * Get an ImageReader for the image file.
	 * 
	 * @return
	 */
	public ImageReader getReader(ImageFile f) throws IOException {
		logger.debug("preloadImage " + f.getFile());
		if (reader != null) {
			logger.debug("Reader was not null!");
			// clean up old reader
			dispose();
		}
		// System.gc();
		RandomAccessFile rf = new RandomAccessFile(f.getFile(), "r");
		ImageInputStream istream = new FileImageInputStream(rf);
		// Iterator readers = ImageIO.getImageReaders(istream);
		String mt = f.getMimetype();
		logger.debug("File type:" + mt);
		Iterator readers = ImageIO.getImageReadersByMIMEType(mt);
		if (!readers.hasNext()) {
			throw new FileOpException("Unable to load File!");
		}
		reader = (ImageReader) readers.next();
		/* are there more readers? */
		logger.debug("ImageIO: this reader: " + reader.getClass());
		while (readers.hasNext()) {
			logger.debug("ImageIO: next reader: " + readers.next().getClass());
		}
		// */
		reader.setInput(istream);
		imgFile = f.getFile();
		return reader;
	}

	/* Load an image file into the Object. */
	public void loadSubimage(ImageFile f, Rectangle region, int prescale)
			throws FileOpException {
		logger.debug("loadSubimage");
		// System.gc();
		try {
			if ((reader == null) || (imgFile != f.getFile())) {
				getReader(f);
			}
			// set up reader parameters
			ImageReadParam readParam = reader.getDefaultReadParam();
			readParam.setSourceRegion(region);
			if (prescale > 1) {
				readParam.setSourceSubsampling(prescale, prescale, 0, 0);
			}
			// read image
			logger.debug("loading..");
			img = reader.read(0, readParam);
			logger.debug("loaded");
		} catch (IOException e) {
			throw new FileOpException("Unable to load File!");
		}
		if (img == null) {
			throw new FileOpException("Unable to load File!");
		}
	}

	/* write image of type mt to Stream */
	public void writeImage(String mt, OutputStream ostream)
			throws FileOpException {
		logger.debug("writeImage");
		// setup output
		ImageWriter writer = null;
		ImageOutputStream imgout = null;
		try {
			imgout = ImageIO.createImageOutputStream(ostream);
			if (mt == "image/jpeg") {
				/*
				 * JPEG doesn't do transparency so we have to convert any RGBA
				 * image to RGB :-( *Java2D BUG*
				 */
				if (img.getColorModel().hasAlpha()) {
					logger.debug("BARF: JPEG with transparency!!");
					int w = img.getWidth();
					int h = img.getHeight();
					// BufferedImage.TYPE_INT_RGB seems to be fastest (JDK1.4.1,
					// OSX)
					int destType = BufferedImage.TYPE_INT_RGB;
					BufferedImage img2 = new BufferedImage(w, h, destType);
					img2.createGraphics().drawImage(img, null, 0, 0);
					img = img2;
				}
				writer = (ImageWriter) ImageIO.getImageWritersByFormatName(
						"jpeg").next();
				if (writer == null) {
					throw new FileOpException("Unable to get JPEG writer");
				}
				ImageWriteParam param = writer.getDefaultWriteParam();
				if (quality > 1) {
					// change JPEG compression quality
					param.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);
					logger.debug("JPEG qual before: "
							+ Float.toString(param.getCompressionQuality()));
					param.setCompressionQuality(0.9f);
					logger.debug("JPEG qual now: "
							+ Float.toString(param.getCompressionQuality()));
				}
				writer.setOutput(imgout);
				// render output
				logger.debug("writing");
				writer.write(null, new IIOImage(img, null, null), param);
			} else if (mt == "image/png") {
				// render output
				writer = (ImageWriter) ImageIO.getImageWritersByFormatName(
						"png").next();
				if (writer == null) {
					throw new FileOpException("Unable to get PNG writer");
				}
				writer.setOutput(imgout);
				logger.debug("writing");
				writer.write(img);
			} else {
				// unknown mime type
				throw new FileOpException("Unknown mime type: " + mt);
			}

		} catch (IOException e) {
			throw new FileOpException("Error writing image.");
		} finally {
			// clean up
			if (writer != null) {
				writer.dispose();
			}
		}
	}

	public void scale(double scale, double scaleY) throws ImageOpException {
		logger.debug("scale");
		/* for downscaling in high quality the image is blurred first */
		if ((scale <= 0.5) && (quality > 1)) {
			int bl = (int) Math.floor(1 / scale);
			blur(bl);
		}
		/* then scaled */
		AffineTransformOp scaleOp = new AffineTransformOp(AffineTransform
				.getScaleInstance(scale, scale), renderHint);
		BufferedImage scaledImg = null;
		// enforce destination image type (*Java2D BUG*)
		int type = img.getType();
		// FIXME: which type would be best?
		if ((quality > 0) && (type != 0)) {
			logger.debug("creating destination image");
			Rectangle2D dstBounds = scaleOp.getBounds2D(img);
			scaledImg = new BufferedImage((int) dstBounds.getWidth(),
					(int) dstBounds.getHeight(), type);
		}
		logger.debug("scaling...");
		scaledImg = scaleOp.filter(img, scaledImg);
		logger.debug("destination image type " + scaledImg.getType());
		if (scaledImg == null) {
			throw new ImageOpException("Unable to scale");
		}
		// DEBUG
		logger.debug("SCALE: " + scale + " ->" + scaledImg.getWidth() + "x"
				+ scaledImg.getHeight());
		img = scaledImg;
		scaledImg = null;
	}

	public void blur(int radius) throws ImageOpException {
		// DEBUG
		logger.debug("blur: " + radius);
		// minimum radius is 2
		int klen = Math.max(radius, 2);
		// FIXME: use constant kernels for most common sizes
		int ksize = klen * klen;
		// kernel is constant 1/k
		float f = 1f / ksize;
		float[] kern = new float[ksize];
		for (int i = 0; i < ksize; i++) {
			kern[i] = f;
		}
		Kernel blur = new Kernel(klen, klen, kern);
		// blur with convolve operation
		ConvolveOp blurOp = new ConvolveOp(blur, ConvolveOp.EDGE_NO_OP,
				renderHint);
		// blur needs explicit destination image type for color *Java2D BUG*
		BufferedImage blurredImg = null;
		if (img.getType() == BufferedImage.TYPE_3BYTE_BGR) {
			blurredImg = new BufferedImage(img.getWidth(), img.getHeight(), img
					.getType());
		}
		blurredImg = blurOp.filter(img, blurredImg);
		if (blurredImg == null) {
			throw new ImageOpException("Unable to scale");
		}
		img = blurredImg;
	}

	public void crop(int x_off, int y_off, int width, int height)
			throws ImageOpException {
		// setup Crop
		BufferedImage croppedImg = img.getSubimage(x_off, y_off, width, height);
		logger.debug("CROP:" + croppedImg.getWidth() + "x"
				+ croppedImg.getHeight());
		// DEBUG
		// util.dprintln(2, " time
		// "+(System.currentTimeMillis()-startTime)+"ms");
		if (croppedImg == null) {
			throw new ImageOpException("Unable to crop");
		}
		img = croppedImg;
	}

	public void enhance(float mult, float add) throws ImageOpException {
		/*
		 * Only one constant should work regardless of the number of bands
		 * according to the JDK spec. Doesn't work on JDK 1.4 for OSX and Linux
		 * (at least). RescaleOp scaleOp = new RescaleOp( (float)mult,
		 * (float)add, null); scaleOp.filter(img, img);
		 */

		/* The number of constants must match the number of bands in the image. */
		int ncol = img.getColorModel().getNumComponents();
		float[] dm = new float[ncol];
		float[] da = new float[ncol];
		for (int i = 0; i < ncol; i++) {
			dm[i] = (float) mult;
			da[i] = (float) add;
		}
		RescaleOp scaleOp = new RescaleOp(dm, da, null);
		scaleOp.filter(img, img);
	}

	public void enhanceRGB(float[] rgbm, float[] rgba) throws ImageOpException {

		/*
		 * The number of constants must match the number of bands in the image.
		 * We do only 3 (RGB) bands.
		 */

		int ncol = img.getColorModel().getNumColorComponents();
		if ((ncol != 3) || (rgbm.length != 3) || (rgba.length != 3)) {
			logger
					.debug("ERROR(enhance): unknown number of color bands or coefficients ("
							+ ncol + ")");
			return;
		}
		RescaleOp scaleOp = new RescaleOp(rgbOrdered(rgbm), rgbOrdered(rgba),
				null);
		scaleOp.filter(img, img);
	}

	/**
	 * Ensures that the array f is in the right order to map the images RGB
	 * components. (not shure what happens
	 */
	public float[] rgbOrdered(float[] fa) {
		/*
		 * TODO: this is UGLY, UGLY!!
		 */
		float[] fb;
		int t = img.getType();
		if (img.getColorModel().hasAlpha()) {
			fb = new float[4];
			if ((t == BufferedImage.TYPE_INT_ARGB)
					|| (t == BufferedImage.TYPE_INT_ARGB_PRE)) {
				// RGB Type
				fb[0] = fa[0];
				fb[1] = fa[1];
				fb[2] = fa[2];
				fb[3] = 1f;
			} else {
				// this isn't tested :-(
				fb[0] = 1f;
				fb[1] = fa[0];
				fb[2] = fa[1];
				fb[3] = fa[2];
			}
		} else {
			fb = new float[3];
			if (t == BufferedImage.TYPE_3BYTE_BGR) {
				// BGR Type (actually it looks like RBG...)
				fb[0] = fa[0];
				fb[1] = fa[2];
				fb[2] = fa[1];
			} else {
				fb[0] = fa[0];
				fb[1] = fa[1];
				fb[2] = fa[2];
			}
		}
		return fb;
	}

	public void rotate(double angle) throws ImageOpException {
		// setup rotation
		double rangle = Math.toRadians(angle);
		// create offset to make shure the rotated image has no negative
		// coordinates
		double w = img.getWidth();
		double h = img.getHeight();
		AffineTransform trafo = new AffineTransform();
		// center of rotation
		double x = (w / 2);
		double y = (h / 2);
		trafo.rotate(rangle, x, y);
		// try rotation to see how far we're out of bounds
		AffineTransformOp rotOp = new AffineTransformOp(trafo, renderHint);
		Rectangle2D rotbounds = rotOp.getBounds2D(img);
		double xoff = rotbounds.getX();
		double yoff = rotbounds.getY();
		// move image back in line
		trafo
				.preConcatenate(AffineTransform.getTranslateInstance(-xoff,
						-yoff));
		// transform image
		rotOp = new AffineTransformOp(trafo, renderHint);
		BufferedImage rotImg = rotOp.filter(img, null);
		// calculate new bounding box
		// Rectangle2D bounds = rotOp.getBounds2D(img);
		if (rotImg == null) {
			throw new ImageOpException("Unable to rotate");
		}
		img = rotImg;
		// crop new image (with self-made rounding)
		/*
		 * img = rotImg.getSubimage( (int) (bounds.getX()+0.5), (int)
		 * (bounds.getY()+0.5), (int) (bounds.getWidth()+0.5), (int)
		 * (bounds.getHeight()+0.5));
		 */
	}

	public void mirror(double angle) throws ImageOpException {
		// setup mirror
		double mx = 1;
		double my = 1;
		double tx = 0;
		double ty = 0;
		if (Math.abs(angle - 0) < epsilon) { // 0 degree
			mx = -1;
			tx = getWidth();
		} else if (Math.abs(angle - 90) < epsilon) { // 90 degree
			my = -1;
			ty = getHeight();
		} else if (Math.abs(angle - 180) < epsilon) { // 180 degree
			mx = -1;
			tx = getWidth();
		} else if (Math.abs(angle - 270) < epsilon) { // 270 degree
			my = -1;
			ty = getHeight();
		} else if (Math.abs(angle - 360) < epsilon) { // 360 degree
			mx = -1;
			tx = getWidth();
		}
		AffineTransformOp mirOp = new AffineTransformOp(new AffineTransform(mx,
				0, 0, my, tx, ty), renderHint);
		BufferedImage mirImg = mirOp.filter(img, null);
		if (mirImg == null) {
			throw new ImageOpException("Unable to mirror");
		}
		img = mirImg;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see java.lang.Object#finalize()
	 */
	protected void finalize() throws Throwable {
		dispose();
		super.finalize();
	}

	public void dispose() {
		// we must dispose the ImageReader because it keeps the filehandle
		// open!
		if (reader != null) {
			reader.dispose();
			reader = null;
		}
		img = null;
	}

}