BookUtil.java

/*
 * Copyright (C) 2007-2013 Geometer Plus <contact@geometerplus.com>
 *
 * 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.
 *
 * 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, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 */

package org.geometerplus.fbreader.book;

import java.io.IOException;
import java.io.InputStream;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Formatter;
import java.util.Locale;

import org.geometerplus.fbreader.bookmodel.BookReadingException;
import org.geometerplus.zlibrary.core.filesystem.ZLArchiveEntryFile;
import org.geometerplus.zlibrary.core.filesystem.ZLFile;
import org.geometerplus.zlibrary.core.filesystem.ZLResourceFile;
import org.geometerplus.zlibrary.core.image.ZLImage;

public abstract class BookUtil {
	public static ZLImage getCover(Book book) {
		return book != null ? book.getCover() : null;
	}

	public static String getAnnotation(Book book) {
		try {
			return book.getPlugin().readAnnotation(book.File);
		} catch (BookReadingException e) {
			return null;
		}
	}

	public static ZLResourceFile getHelpFile() {
		final Locale locale = Locale.getDefault();

		ZLResourceFile file = ZLResourceFile.createResourceFile(
			"data/help/MiniHelp." + locale.getLanguage() + "_" + locale.getCountry() + ".fb2"
		);
		if (file.exists()) {
			return file;
		}

		file = ZLResourceFile.createResourceFile(
			"data/help/MiniHelp." + locale.getLanguage() + ".fb2"
		);
		if (file.exists()) {
			return file;
		}

		return ZLResourceFile.createResourceFile("data/help/MiniHelp.en.fb2");
	}

	public static boolean canRemoveBookFile(Book book) {
		ZLFile file = book.File;
		if (file.getPhysicalFile() == null) {
			return false;
		}
		while (file instanceof ZLArchiveEntryFile) {
			file = file.getParent();
			if (file.children().size() != 1) {
				return false;
			}
		}
		return true;
	}

	public static UID createSHA256Uid(ZLFile file) {
		InputStream stream = null;

		try {
			final MessageDigest hash = MessageDigest.getInstance("SHA-256");
			stream = file.getInputStream();

			final byte[] buffer = new byte[2048];
			while (true) {
				final int nread = stream.read(buffer);
				if (nread == -1) {
					break;
				}
				hash.update(buffer, 0, nread);
			}

			final Formatter f = new Formatter();
			for (byte b : hash.digest()) {
				f.format("%02X", b & 0xFF);
			}
			return new UID("SHA-256", f.toString());
		} catch (IOException e) {
			return null;
		} catch (NoSuchAlgorithmException e) {
			return null;
		} finally {
			if (stream != null) {
				try {
					stream.close();
				} catch (IOException e) {
				}
			}
		}
	}

}