/*

 * Copyright 1997-2004 Sun Microsystems, Inc.  All Rights Reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Sun designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Sun in the LICENSE file that accompanied this code.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

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

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

package sun.security.x509;

import java.io.*;

import sun.security.util.*;

/**

 * Represent the GeneralSubtree ASN.1 object, whose syntax is:

 * <pre>

 * GeneralSubtree ::= SEQUENCE {

 *    base             GeneralName,

 *    minimum  [0]     BaseDistance DEFAULT 0,

 *    maximum  [1]     BaseDistance OPTIONAL

 * }

 * BaseDistance ::= INTEGER (0..MAX)

 * </pre>

 * @author Amit Kapoor

 * @author Hemma Prafullchandra

 */

public class GeneralSubtree {

    private static final byte TAG_MIN = 0;

    private static final byte TAG_MAX = 1;

    private static final int  MIN_DEFAULT = 0;

    private GeneralName name;

    private int         minimum = MIN_DEFAULT;

    private int         maximum = -1;

    private int myhash = -1;

    /**

     * The default constructor for the class.

     *

     * @params name the GeneralName

     * @params min the minimum BaseDistance

     * @params max the maximum BaseDistance

     */

    public GeneralSubtree(GeneralName name, int min, int max) {

        this.name = name;

        this.minimum = min;

        this.maximum = max;

    }

    /**

     * Create the object from its DER encoded form.

     *

     * @param val the DER encoded from of the same.

     */

    public GeneralSubtree(DerValue val) throws IOException {

        if (val.tag != DerValue.tag_Sequence) {

            throw new IOException("Invalid encoding for GeneralSubtree.");

        }

        name = new GeneralName(val.data.getDerValue(), true);

        // NB. this is always encoded with the IMPLICIT tag

        // The checks only make sense if we assume implicit tagging,

        // with explicit tagging the form is always constructed.

        while (val.data.available() != 0) {

            DerValue opt = val.data.getDerValue();

            if (opt.isContextSpecific(TAG_MIN) && !opt.isConstructed()) {

                opt.resetTag(DerValue.tag_Integer);

                minimum = opt.getInteger();

            } else if (opt.isContextSpecific(TAG_MAX) && !opt.isConstructed()) {

                opt.resetTag(DerValue.tag_Integer);

                maximum = opt.getInteger();

            } else

                throw new IOException("Invalid encoding of GeneralSubtree.");

        }

    }

    /**

     * Return the GeneralName.

     *

     * @return the GeneralName

     */

    public GeneralName getName() {

        //XXXX May want to consider cloning this

        return name;

    }

    /**

     * Return the minimum BaseDistance.

     *

     * @return the minimum BaseDistance. Default is 0 if not set.

     */

    public int getMinimum() {

        return minimum;

    }

    /**

     * Return the maximum BaseDistance.

     *

     * @return the maximum BaseDistance, or -1 if not set.

     */

    public int getMaximum() {

        return maximum;

    }

    /**

     * Return a printable string of the GeneralSubtree.

     */

    public String toString() {

        String s = "\n   GeneralSubtree: [\n" +

            "    GeneralName: " + ((name == null) ? "" : name.toString()) +

            "\n    Minimum: " + minimum;

            if (maximum == -1) {

                s += "\t    Maximum: undefined";

            } else

                s += "\t    Maximum: " + maximum;

            s += "    ]\n";

        return (s);

    }

    /**

     * Compare this GeneralSubtree with another

     *

     * @param other GeneralSubtree to compare to this

     * @returns true if match

     */

    public boolean equals(Object other) {

        if (!(other instanceof GeneralSubtree))

            return false;

        GeneralSubtree otherGS = (GeneralSubtree)other;

        if (this.name == null) {

            if (otherGS.name != null) {

                return false;

            }

        } else {

            if (!((this.name).equals(otherGS.name)))

                return false;

        }

        if (this.minimum != otherGS.minimum)

            return false;

        if (this.maximum != otherGS.maximum)

            return false;

        return true;

    }

    /**

     * Returns the hash code for this GeneralSubtree.

     *

     * @return a hash code value.

     */

    public int hashCode() {

        if (myhash == -1) {

            myhash = 17;

            if (name != null) {

                myhash = 37 * myhash + name.hashCode();

            }

            if (minimum != MIN_DEFAULT) {

                myhash = 37 * myhash + minimum;

            }

            if (maximum != -1) {

                myhash = 37 * myhash + maximum;

            }

        }

        return myhash;

    }

    /**

     * Encode the GeneralSubtree.

     *

     * @params out the DerOutputStream to encode this object to.

     */

    public void encode(DerOutputStream out) throws IOException {

        DerOutputStream seq = new DerOutputStream();

        name.encode(seq);

        if (minimum != MIN_DEFAULT) {

            DerOutputStream tmp = new DerOutputStream();

            tmp.putInteger(minimum);

            seq.writeImplicit(DerValue.createTag(DerValue.TAG_CONTEXT,

                              false, TAG_MIN), tmp);

        }

        if (maximum != -1) {

            DerOutputStream tmp = new DerOutputStream();

            tmp.putInteger(maximum);

            seq.writeImplicit(DerValue.createTag(DerValue.TAG_CONTEXT,

                              false, TAG_MAX), tmp);

        }

        out.write(DerValue.tag_Sequence, seq);

    }

}