/**

  * copy-image-resizer

  * Copyright © 2014 František Kučera (frantovo.cz)

  *

  * 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 3 of the License, or

  * (at your option) any later version.

  *

  * This program is distributed in the hope that it will be useful,

  * but WITHOUT ANY WARRANTY; without even the implied warranty of

  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

  * GNU General Public License for more details.

  *

  * You should have received a copy of the GNU General Public License

  * along with this program. If not, see <http://www.gnu.org/licenses/>.

  */

 package cz.frantovo.copyImageResizer;

 import cz.frantovo.copyImageResizer.SingleImageResizer.ImageFormat;

 import java.awt.image.BufferedImage;

 import java.io.File;

 import java.io.FileInputStream;

 import java.io.FileNotFoundException;

 import java.io.FileOutputStream;

 import java.io.IOException;

 import java.io.InputStream;

 import java.nio.channels.Channels;

 import java.nio.channels.FileChannel;

 import java.nio.channels.ReadableByteChannel;

 import java.nio.channels.WritableByteChannel;

 import java.util.logging.Level;

 import java.util.logging.Logger;

 import javax.imageio.ImageIO;

 /**

  *

  * @author Ing. František Kučera (frantovo.cz)

  */

 public class RecursiveImageResizer {

 	private static final Logger log = Logger.getLogger(RecursiveImageResizer.class.getName());

 	private final SingleImageResizer resizer = new SingleImageResizer();

 	public void resize(RecursiveOptions options) throws RecursiveException, ResizeException {

 		resizeDirectory(options.getInput(), options);

 	}

 	private void resizeFile(File inputFile, RecursiveOptions options) throws ResizeException {

 		File inputFileRelative = relativize(options.getInput(), inputFile);

 		log.log(Level.FINE, "Resizing file: {0}", inputFileRelative);

 		ImageFormat format = ImageFormat.getMatching(inputFile.getName());

 		if (format == null) {

 			log.log(Level.FINE, "Skipping file: {0} (no image format matched this extension)", inputFileRelative);

 		} else {

 			try {

 				for (SizeSpecification size : options.getSizes()) {

 					File sizeRoot = new File(options.getOutput(), size.getDirectory());

 					File outputFile = new File(sizeRoot, inputFileRelative.getPath());

 					try (FileInputStream input = new FileInputStream(inputFile)) {

 						BufferedImage image = readImage(input);

 						if (shouldResize(image, size)) {

 							try (FileOutputStream output = new FileOutputStream(outputFile)) {

 								resizer.resize(image, output, size, format);

 							}

 						} else {

 							log.log(Level.INFO, "File: {0} has already required size → just copy", inputFileRelative);

 							justCopy(inputFile, outputFile);

 						}

 					}

 				}

 			} catch (FileNotFoundException e) {

 				throw new ResizeException("Error while opening stream", e);

 			} catch (IOException e) {

 				throw new ResizeException("Error while closing stream", e);

 			}

 		}

 	}

 	private static boolean shouldResize(BufferedImage input, SizeSpecification requested) {

 		if (requested.isResizeSmaller()) {

 			return input.getHeight() != requested.getHeight() || input.getWidth() != requested.getWidth();

 		} else {

 			return input.getHeight() > requested.getHeight() || input.getWidth() > requested.getWidth();

 		}

 	}

 	private static BufferedImage readImage(InputStream input) throws ResizeException {

 		try {

 			return ImageIO.read(input);

 		} catch (IOException e) {

 			throw new ResizeException("Unable to read image from stream", e);

 		}

 	}

 	private static void justCopy(File inputFile, File outputFile) throws ResizeException {

 		try {

 			if (!outputFile.exists()) {

 				outputFile.createNewFile();

 			}

 			try (FileChannel input = new FileInputStream(inputFile).getChannel()) {

 				try (FileChannel output = new FileOutputStream(outputFile).getChannel()) {

 					output.transferFrom(input, 0, input.size());

 				}

 			}

 		} catch (IOException e) {

 			throw new ResizeException("Unable copy stream/channel", e);

 		}

 	}

 	private void resizeDirectory(File directory, RecursiveOptions options) throws ResizeException {

 		log.log(Level.FINE, "Resizing directory: {0}", directory);

 		for (SizeSpecification size : options.getSizes()) {

 			File relative = relativize(options.getInput(), directory);

 			File sizeRoot = new File(options.getOutput(), size.getDirectory());

 			File dir = new File(sizeRoot, relative.getPath());

 			dir.mkdirs();

 		}

 		for (File entry : directory.listFiles()) {

 			if (entry.isDirectory()) {

 				resizeDirectory(entry, options);

 			} else {

 				resizeFile(entry, options);

 			}

 		}

 	}

 	private static File relativize(File root, File child) {

 		return root.toPath().relativize(child.toPath()).toFile();

 	}

 }