/*
 * Copyright (c) 1999, 2017, Oracle and/or its affiliates. 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.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package com.sun.jndi.ldap;

import javax.naming.*;
import javax.naming.ldap.Control;

import java.util.Hashtable;
import java.util.Vector;

This exception is raised when a referral to an alternative context
is encountered.
 An LdapReferralException object contains one or more referrals. Each referral is an alternative location for the same target entry. For example, a referral may be an LDAP URL. The referrals are attempted in sequence until one is successful or all have failed. In the case of the latter then the exception generated by the final referral is recorded and presented later. 

A referral may be skipped or may be retried. For example, in the case
of an authentication error, a referral may be retried with different
environment properties.
 An LdapReferralException object may also contain a reference to a chain of unprocessed LdapReferralException objects. Once the current set of referrals have been exhausted and unprocessed LdapReferralException objects remain, then the LdapReferralException object referenced by the current object is thrown and the cycle continues. 
 If new LdapReferralException objects are generated while following an existing referral then these new objects are appended to the end of the chain of unprocessed LdapReferralException objects. 
 If an exception was recorded while processing a chain of LdapReferralException objects then it is throw once processing has completed. 
Author:
Vincent Ryan/**
  * This exception is raised when a referral to an alternative context
  * is encountered.
  * <p>
  * An {@code LdapReferralException} object contains one or more referrals.
  * Each referral is an alternative location for the same target entry.
  * For example, a referral may be an LDAP URL.
  * The referrals are attempted in sequence until one is successful or
  * all have failed. In the case of the latter then the exception generated
  * by the final referral is recorded and presented later.
  * <p>
  * A referral may be skipped or may be retried. For example, in the case
  * of an authentication error, a referral may be retried with different
  * environment properties.
  * <p>
  * An {@code LdapReferralException} object may also contain a reference
  * to a chain of unprocessed {@code LdapReferralException} objects.
  * Once the current set of referrals have been exhausted and unprocessed
  * {@code LdapReferralException} objects remain, then the
  * {@code LdapReferralException} object referenced by the current
  * object is thrown and the cycle continues.
  * <p>
  * If new {@code LdapReferralException} objects are generated while
  * following an existing referral then these new objects are appended
  * to the end of the chain of unprocessed {@code LdapReferralException}
  * objects.
  * <p>
  * If an exception was recorded while processing a chain of
  * {@code LdapReferralException} objects then it is throw once
  * processing has completed.
  *
  * @author Vincent Ryan
  */
final public class LdapReferralException extends
    javax.naming.ldap.LdapReferralException {
    private static final long serialVersionUID = 627059076356906399L;

        // ----------- fields initialized in constructor ---------------
    private int handleReferrals;
    private Hashtable<?,?> envprops;
    private String nextName;
    private Control[] reqCtls;

        // ----------- fields that have defaults -----------------------
    private Vector<?> referrals = null; // alternatives,set by setReferralInfo()
    private int referralIndex = 0;      // index into referrals
    private int referralCount = 0;      // count of referrals
    private boolean foundEntry = false; // will stop when entry is found
    private boolean skipThisReferral = false;
    private int hopCount = 1;
    private NamingException errorEx = null;
    private String newRdn = null;
    private boolean debug = false;
            LdapReferralException nextReferralEx = null; // referral ex. chain

    
Constructs a new instance of LdapReferralException.
Params:
resolvedName –    The part of the name that has been successfully
                         resolved.
resolvedObj –     The object to which resolution was successful.
remainingName –   The remaining unresolved portion of the name.
explanation –     Additional detail about this exception./**
     * Constructs a new instance of LdapReferralException.
     * @param   resolvedName    The part of the name that has been successfully
     *                          resolved.
     * @param   resolvedObj     The object to which resolution was successful.
     * @param   remainingName   The remaining unresolved portion of the name.
     * @param   explanation     Additional detail about this exception.
     */
    LdapReferralException(Name resolvedName,
        Object resolvedObj,
        Name remainingName,
        String explanation,
        Hashtable<?,?> envprops,
        String nextName,
        int handleReferrals,
        Control[] reqCtls) {

        super(explanation);

        if (debug)
            System.out.println("LdapReferralException constructor");

        setResolvedName(resolvedName);
        setResolvedObj(resolvedObj);
        setRemainingName(remainingName);
        this.envprops = envprops;
        this.nextName = nextName;
        this.handleReferrals = handleReferrals;

        // If following referral, request controls are passed to referral ctx
        this.reqCtls =
            (handleReferrals == LdapClient.LDAP_REF_FOLLOW ||
                    handleReferrals == LdapClient.LDAP_REF_FOLLOW_SCHEME ? reqCtls : null);
    }

    
Gets a context at which to continue processing.
The current environment properties are re-used.
/**
     * Gets a context at which to continue processing.
     * The current environment properties are re-used.
     */
    public Context getReferralContext() throws NamingException {
        return getReferralContext(envprops, null);
    }

    
Gets a context at which to continue processing.
The supplied environment properties are used.
/**
     * Gets a context at which to continue processing.
     * The supplied environment properties are used.
     */
    public Context getReferralContext(Hashtable<?,?> newProps) throws
        NamingException {
        return getReferralContext(newProps, null);
    }

    
Gets a context at which to continue processing.
The supplied environment properties and connection controls are used.
/**
     * Gets a context at which to continue processing.
     * The supplied environment properties and connection controls are used.
     */
    public Context getReferralContext(Hashtable<?,?> newProps, Control[] connCtls)
        throws NamingException {

        if (debug)
            System.out.println("LdapReferralException.getReferralContext");

        LdapReferralContext refCtx = new LdapReferralContext(
            this, newProps, connCtls, reqCtls,
            nextName, skipThisReferral, handleReferrals);

        refCtx.setHopCount(hopCount + 1);

        if (skipThisReferral) {
            skipThisReferral = false; // reset
        }
        return (Context)refCtx;
    }

    
Gets referral information.
/**
      * Gets referral information.
      */
    public Object getReferralInfo() {
        if (debug) {
            System.out.println("LdapReferralException.getReferralInfo");
            System.out.println("  referralIndex=" + referralIndex);
        }

        if (hasMoreReferrals()) {
            return referrals.elementAt(referralIndex);
        } else {
            return null;
        }
    }

    
Marks the current referral as one to be retried.
/**
     * Marks the current referral as one to be retried.
     */
    public void retryReferral() {
        if (debug)
            System.out.println("LdapReferralException.retryReferral");

        if (referralIndex > 0)
            referralIndex--; // decrement index
    }

    
Marks the current referral as one to be ignored.
Returns false when there are no referrals remaining to be processed.
/**
     * Marks the current referral as one to be ignored.
     * Returns false when there are no referrals remaining to be processed.
     */
    public boolean skipReferral() {
        if (debug)
            System.out.println("LdapReferralException.skipReferral");

        skipThisReferral = true;

        // advance to next referral
        try {
            getNextReferral();
        } catch (ReferralException e) {
            // mask the referral exception
        }

        return (hasMoreReferrals() || hasMoreReferralExceptions());
    }


    
Sets referral information.
/**
     * Sets referral information.
     */
    void setReferralInfo(Vector<?> referrals, boolean continuationRef) {
        // %%% continuationRef is currently ignored

        if (debug)
            System.out.println("LdapReferralException.setReferralInfo");

        this.referrals = referrals;
        referralCount = (referrals == null) ? 0 : referrals.size();

        if (debug) {
            if (referrals != null) {
                for (int i = 0; i < referralCount; i++) {
                    System.out.println("  [" + i + "] " + referrals.elementAt(i));
                }
            } else {
                System.out.println("setReferralInfo : referrals == null");
            }
        }
    }

    
Gets the next referral. When the current set of referrals have
been exhausted then the next referral exception is thrown, if available.
/**
     * Gets the next referral. When the current set of referrals have
     * been exhausted then the next referral exception is thrown, if available.
     */
    String getNextReferral() throws ReferralException {

        if (debug)
            System.out.println("LdapReferralException.getNextReferral");

        if (hasMoreReferrals()) {
            return (String)referrals.elementAt(referralIndex++);
        } else if (hasMoreReferralExceptions()) {
            throw nextReferralEx;
        } else {
            return null;
        }
    }

    
Appends the supplied (chain of) referral exception onto the end of
the current (chain of) referral exception. Spent referral exceptions
are trimmed off.
/**
     * Appends the supplied (chain of) referral exception onto the end of
     * the current (chain of) referral exception. Spent referral exceptions
     * are trimmed off.
     */
    LdapReferralException
        appendUnprocessedReferrals(LdapReferralException back) {

        if (debug) {
            System.out.println(
                "LdapReferralException.appendUnprocessedReferrals");
            dump();
            if (back != null) {
                back.dump();
            }
        }

        LdapReferralException front = this;

        if (! front.hasMoreReferrals()) {
            front = nextReferralEx; // trim

            if ((errorEx != null) && (front != null)) {
                front.setNamingException(errorEx); //advance the saved exception
            }
        }

        // don't append onto itself
        if (this == back) {
            return front;
        }

        if ((back != null) && (! back.hasMoreReferrals())) {
            back = back.nextReferralEx; // trim
        }

        if (back == null) {
            return front;
        }

        // Locate the end of the current chain
        LdapReferralException ptr = front;
        while (ptr.nextReferralEx != null) {
            ptr = ptr.nextReferralEx;
        }
        ptr.nextReferralEx = back; // append

        return front;
    }

    
Tests if there are any referrals remaining to be processed.
If name resolution has already completed then any remaining
referrals (in the current referral exception) will be ignored.
/**
     * Tests if there are any referrals remaining to be processed.
     * If name resolution has already completed then any remaining
     * referrals (in the current referral exception) will be ignored.
     */
    boolean hasMoreReferrals() {
        if (debug)
            System.out.println("LdapReferralException.hasMoreReferrals");

        return (! foundEntry) && (referralIndex < referralCount);
    }

    
Tests if there are any referral exceptions remaining to be processed.
/**
     * Tests if there are any referral exceptions remaining to be processed.
     */
    boolean hasMoreReferralExceptions() {
        if (debug)
            System.out.println(
                "LdapReferralException.hasMoreReferralExceptions");

        return (nextReferralEx != null);
    }

    
Sets the counter which records the number of hops that result
from following a sequence of referrals.
/**
     * Sets the counter which records the number of hops that result
     * from following a sequence of referrals.
     */
    void setHopCount(int hopCount) {
        if (debug)
            System.out.println("LdapReferralException.setHopCount");

        this.hopCount = hopCount;
    }

    
Sets the flag to indicate that the target name has been resolved.
/**
     * Sets the flag to indicate that the target name has been resolved.
     */
    void setNameResolved(boolean resolved) {
        if (debug)
            System.out.println("LdapReferralException.setNameResolved");

        foundEntry = resolved;
    }

    
Sets the exception generated while processing a referral.
Only the first exception is recorded.
/**
     * Sets the exception generated while processing a referral.
     * Only the first exception is recorded.
     */
    void setNamingException(NamingException e) {
        if (debug)
            System.out.println("LdapReferralException.setNamingException");

        if (errorEx == null) {
            e.setRootCause(this); //record the referral exception that caused it
            errorEx = e;
        }
    }

    
Gets the new RDN name.
/**
     * Gets the new RDN name.
     */
    String getNewRdn() {
        if (debug)
            System.out.println("LdapReferralException.getNewRdn");

        return newRdn;
    }

    
Sets the new RDN name so that the rename operation can be completed
(when a referral is being followed).
/**
     * Sets the new RDN name so that the rename operation can be completed
     * (when a referral is being followed).
     */
    void setNewRdn(String newRdn) {
        if (debug)
            System.out.println("LdapReferralException.setNewRdn");

        this.newRdn = newRdn;
    }

    
Gets the exception generated while processing a referral.
/**
     * Gets the exception generated while processing a referral.
     */
    NamingException getNamingException() {
        if (debug)
            System.out.println("LdapReferralException.getNamingException");

        return errorEx;
    }

    
Display the state of each element in a chain of LdapReferralException
objects.
/**
     * Display the state of each element in a chain of LdapReferralException
     * objects.
     */
    void dump() {

        System.out.println();
        System.out.println("LdapReferralException.dump");
        LdapReferralException ptr = this;
        while (ptr != null) {
            ptr.dumpState();
            ptr = ptr.nextReferralEx;
        }
    }

    
Display the state of this LdapReferralException object.
/**
     * Display the state of this LdapReferralException object.
     */
    private void dumpState() {
        System.out.println("LdapReferralException.dumpState");
        System.out.println("  hashCode=" + hashCode());
        System.out.println("  foundEntry=" + foundEntry);
        System.out.println("  skipThisReferral=" + skipThisReferral);
        System.out.println("  referralIndex=" + referralIndex);

        if (referrals != null) {
            System.out.println("  referrals:");
            for (int i = 0; i < referralCount; i++) {
                System.out.println("    [" + i + "] " + referrals.elementAt(i));
            }
        } else {
            System.out.println("  referrals=null");
        }

        System.out.println("  errorEx=" + errorEx);

        if (nextReferralEx == null) {
            System.out.println("  nextRefEx=null");
        } else {
            System.out.println("  nextRefEx=" + nextReferralEx.hashCode());
        }
        System.out.println();
    }
}