/*
 *
 *    OPEN-XCHANGE legal information
 *
 *    All intellectual property rights in the Software are protected by
 *    international copyright laws.
 *
 *
 *    In some countries OX, OX Open-Xchange, open xchange and OXtender
 *    as well as the corresponding Logos OX Open-Xchange and OX are registered
 *    trademarks of the Open-Xchange, Inc. group of companies.
 *    The use of the Logos is not covered by the GNU General Public License.
 *    Instead, you are allowed to use these Logos according to the terms and
 *    conditions of the Creative Commons License, Version 2.5, Attribution,
 *    Non-commercial, ShareAlike, and the interpretation of the term
 *    Non-commercial applicable to the aforementioned license is published
 *    on the web site http://www.open-xchange.com/EN/legal/index.html.
 *
 *    Please make sure that third-party modules and libraries are used
 *    according to their respective licenses.
 *
 *    Any modifications to this package must retain all copyright notices
 *    of the original copyright holder(s) for the original code used.
 *
 *    After any such modifications, the original and derivative code shall remain
 *    under the copyright of the copyright holder(s) and/or original author(s)per
 *    the Attribution and Assignment Agreement that can be located at
 *    http://www.open-xchange.com/EN/developer/. The contributing author shall be
 *    given Attribution for the derivative code and a license granting use.
 *
 *     Copyright (C) 2004-2011 Open-Xchange, Inc.
 *     Mail: info@open-xchange.com
 *
 *
 *     This program is free software; you can redistribute it and/or modify it
 *     under the terms of the GNU General Public License, Version 2 as published
 *     by the Free Software Foundation.
 *
 *     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., 59
 *     Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 */

package com.openexchange.tools.versit.old;

import java.io.IOException;
import java.util.ArrayList;
import com.openexchange.tools.versit.VersitException;

public class OldQuotedPrintable implements OldEncoding {

    public static final OldEncoding Default = new OldQuotedPrintable();

    private int getHexDigit(final OldScanner s) throws IOException {
        int retval;
        if (s.peek >= '0' && s.peek <= '9') {
            retval = s.read() - '0';
        } else if (s.peek >= 'A' && s.peek <= 'F') {
            retval = s.read() - 'A' + 10;
        } else if (s.peek >= 'a' && s.peek <= 'f') {
            retval = s.read() - 'a' + 10;
        } else {
            throw new VersitException(s, "Invalid character in Quoted-Printable encoding");
        }
        return retval;
    }

    public byte[] decode(final OldScanner s) throws IOException {
        final ArrayList<Byte> al = new ArrayList<Byte>();
        int len = 0;
        s.unfold = false;
        while (s.peek != -1 && s.peek != -2) {
            if (s.peek == '=') {
                len = al.size();
                s.read();
                if (s.peek >= '0' && s.peek <= '9' || s.peek >= 'A' && s.peek <= 'F' || s.peek >= 'a' && s.peek <= 'f') {
                    al.add(Byte.valueOf((byte) ((getHexDigit(s) << 4) + getHexDigit(s))));
                    len = al.size();
                } else if (s.peek == -2) {
                    s.read();
                } else {
                    al.add(Byte.valueOf((byte) '='));
                }
            } else if (s.peek >= 33 && s.peek <= 126) {
                al.add(Byte.valueOf((byte) s.read()));
                len = al.size();
            } else if (s.peek == 9 || s.peek == 32) {
                al.add(Byte.valueOf((byte) s.read()));
            } else {
                throw new VersitException(s, "Invalid character in Quoted-Printable encoding");
            }
        }
        final byte[] retval = new byte[len];
        for (int i = 0; i < len; i++) {
            retval[i] = al.get(i).byteValue();
        }
        s.unfold = true;
        return retval;
    }

    private byte hexDigit(final int value) {
        final int val = value & 15;
        return (byte) (val + (val > 9 ? 'A' - 10 : '0'));
    }

    private static final byte[] SoftBreak = { '=', '\r', '\n' };

    public void encode(final OldFoldingWriter fw, final byte[] b) throws IOException {
        int len = fw.lineLength();
        fw.rawStart();
        final byte[] Escape = { '=', 0, 0 };
        final byte[] Simple = { 0 };
        for (int i = 0; i < b.length; i++) {
            if (b[i] != '\t' && b[i] < 32 || b[i] == '=' || b[i] > 126 || i == b.length - 1 && (b[i] == '\t' || b[i] == ' ')) {
                if (len >= 73) {
                    fw.writeRaw(SoftBreak);
                    len = 0;
                }
                Escape[1] = hexDigit(b[i] >> 4);
                Escape[2] = hexDigit(b[i]);
                fw.writeRaw(Escape);
                len += 3;
            } else {
                if (len >= 75) {
                    fw.writeRaw(SoftBreak);
                    len = 0;
                }
                Simple[0] = b[i];
                fw.writeRaw(Simple);
                len++;
            }
        }
        fw.rawEnd();
    }
}
