/*

 * Copyright 2008 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 com.sun.jmx.namespace;

import static javax.management.namespace.JMXNamespaces.NAMESPACE_SEPARATOR;

import javax.management.MalformedObjectNameException;

import javax.management.ObjectInstance;

import javax.management.ObjectName;

/**

 * The ObjectNameRouter is used to rewrite routing object names.

 * <p><b>

 * This API is a Sun internal API and is subject to changes without notice.

 * </b></p>

 * @since 1.7

 */

public class ObjectNameRouter {

    private static final int NAMESPACE_SEPARATOR_LENGTH =

            NAMESPACE_SEPARATOR.length();

    final String targetPrefix;

    final String sourcePrefix;

    final int slen;

    final int tlen;

    final boolean identity;

    public ObjectNameRouter(String targetDirName) {

        this(targetDirName,null);

    }

    /** Creates a new instance of ObjectNameRouter */

    public ObjectNameRouter(final String remove, final String add) {

        this.targetPrefix = (remove==null?"":remove);

        this.sourcePrefix = (add==null?"":add);

        tlen = targetPrefix.length();

        slen = sourcePrefix.length();

        identity = targetPrefix.equals(sourcePrefix);

    }

    public final ObjectName toTargetContext(ObjectName sourceName,

            boolean removeLeadingSeparators) {

        if (sourceName == null) return null;

        if (identity) return sourceName;

        String srcDomain = sourceName.getDomain();

        // if the ObjectName starts with // and removeLeadingSeparators is

        // true, then recursively strip leading //.

        // Otherwise, do not rewrite ObjectName.

        //

        if (srcDomain.startsWith(NAMESPACE_SEPARATOR)) {

            if (!removeLeadingSeparators) return sourceName;

            else srcDomain = normalizeDomain(srcDomain,true);

        }

        if (slen != 0) {

            if (!srcDomain.startsWith(sourcePrefix) ||

                    !srcDomain.startsWith(NAMESPACE_SEPARATOR,slen))

                throw new IllegalArgumentException(

                        "ObjectName does not start with expected prefix "

                        + sourcePrefix + ": " +

                        String.valueOf(sourceName));

            srcDomain = srcDomain.substring(slen+NAMESPACE_SEPARATOR_LENGTH);

        }

        final String targetDomain =

                (tlen>0?targetPrefix+NAMESPACE_SEPARATOR+srcDomain:srcDomain);

        try {

            return sourceName.withDomain(targetDomain);

        } catch (MalformedObjectNameException x) {

            throw new IllegalArgumentException(String.valueOf(sourceName),x);

        }

    }

    public final ObjectName toSourceContext(ObjectName targetName,

            boolean removeLeadingSeparators) {

        if (targetName == null) return null;

        if (identity) return targetName;

        String targetDomain = targetName.getDomain();

        if (targetDomain.startsWith(NAMESPACE_SEPARATOR)) {

            if (!removeLeadingSeparators) return targetName;

            else targetDomain =

                    normalizeDomain(targetDomain,true);

        }

        if (tlen != 0) {

            if (!targetDomain.startsWith(targetPrefix) ||

                    !targetDomain.startsWith(NAMESPACE_SEPARATOR,tlen))

                throw new IllegalArgumentException(

                        "ObjectName does not start with expected prefix "

                        + targetPrefix + ": " +

                        String.valueOf(targetName));

            targetDomain = targetDomain.

                    substring(tlen+NAMESPACE_SEPARATOR_LENGTH);

        }

        final String sourceDomain =

                (slen>0?sourcePrefix+NAMESPACE_SEPARATOR+targetDomain:

                    targetDomain);

        try {

            return targetName.withDomain(sourceDomain);

        } catch (MalformedObjectNameException x) {

            throw new IllegalArgumentException(String.valueOf(targetName),x);

        }

    }

    public final ObjectInstance toTargetContext(ObjectInstance sourceMoi,

            boolean removeLeadingSeparators) {

        if (sourceMoi == null) return null;

        if (identity) return sourceMoi;

        return new ObjectInstance(

                toTargetContext(sourceMoi.getObjectName(),

                    removeLeadingSeparators),

                    sourceMoi.getClassName());

    }

    /**

     * Removes leading, trailing, or duplicate // in a name space path.

     **/

    public static String normalizeDomain(String domain,

                                         boolean removeLeadingSep) {

        return normalizeNamespacePath(domain,removeLeadingSep,false,true);

    }

    /**

     * Removes leading, trailing, or duplicate // in a name space path.

     **/

    public static String normalizeNamespacePath(String namespacePath,

                                            boolean removeLeadingSep,

                                            boolean removeTrailingSep,

                                            boolean endsWithDomain) {

        if (namespacePath.equals(""))

            return "";

        final String[] components = namespacePath.split(NAMESPACE_SEPARATOR);

        final StringBuilder b =

                new StringBuilder(namespacePath.length()+NAMESPACE_SEPARATOR_LENGTH);

        String sep = null;

        if (!removeLeadingSep && namespacePath.startsWith(NAMESPACE_SEPARATOR))

            b.append(NAMESPACE_SEPARATOR);

        int count = 0;

        for (int i=0; i<components.length; i++) {

            final String n=components[i];

            if (n.equals("")) continue;

            if (n.startsWith("/")||n.endsWith("/")) {

                // throw exception unless we're looking at the last domain

                // part of the ObjectName

                if (! (endsWithDomain && i==(components.length-1))) {

                    throw new IllegalArgumentException(n+

                        " is not a valid name space identifier");

                } else {

                    // There's a dirty little corner case when the domain

                    // part (last item) is exactly '/' - in that case we must

                    // not append '//'

                    //

                    removeTrailingSep = removeTrailingSep || n.equals("/");

                }

            }

            if (sep != null) b.append(sep);

            b.append(n);

            sep = NAMESPACE_SEPARATOR;

            count++;

        }

        if (!removeTrailingSep && namespacePath.endsWith(NAMESPACE_SEPARATOR)

            && count > 0)

            b.append(NAMESPACE_SEPARATOR);

        return b.toString();

    }

}