/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at
 * trunk/opends/resource/legal-notices/OpenDS.LICENSE
 * or https://OpenDS.dev.java.net/OpenDS.LICENSE.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at
 * trunk/opends/resource/legal-notices/OpenDS.LICENSE.  If applicable,
 * add the following below this CDDL HEADER, with the fields enclosed
 * by brackets "[]" replaced with your own identifying information:
 *      Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 *
 *
 *      Copyright 2010 Sun Microsystems, Inc.
 */
package org.opends.sdk.controls;



import static com.sun.opends.sdk.messages.Messages.ERR_PSEARCH_BAD_CHANGE_TYPES;
import static com.sun.opends.sdk.messages.Messages.ERR_PSEARCH_CANNOT_DECODE_VALUE;
import static com.sun.opends.sdk.messages.Messages.ERR_PSEARCH_CONTROL_BAD_OID;
import static com.sun.opends.sdk.messages.Messages.ERR_PSEARCH_NO_CONTROL_VALUE;
import static com.sun.opends.sdk.util.StaticUtils.getExceptionMessage;

import java.io.IOException;
import java.util.*;

import org.opends.sdk.*;
import org.opends.sdk.asn1.ASN1;
import org.opends.sdk.asn1.ASN1Reader;
import org.opends.sdk.asn1.ASN1Writer;

import com.sun.opends.sdk.util.StaticUtils;
import com.sun.opends.sdk.util.Validator;



/**
 * The persistent search request control as defined in
 * draft-ietf-ldapext-psearch. This control allows a client to receive
 * notification of changes that occur in an LDAP server.
 *
 * @see EntryChangeNotificationResponseControl
 * @see PersistentSearchChangeType
 * @see <a
 *      href="http://tools.ietf.org/html/draft-ietf-ldapext-psearch">draft-ietf-ldapext-psearch
 *      - Persistent Search: A Simple LDAP Change Notification Mechanism </a>
 */
public final class PersistentSearchRequestControl implements Control
{
  /**
   * The OID for the persistent search request control.
   */
  public static final String OID = "2.16.840.1.113730.3.4.3";

  /**
   * A decoder which can be used for decoding the persistent search request
   * control.
   */
  public static final ControlDecoder<PersistentSearchRequestControl> DECODER =
    new ControlDecoder<PersistentSearchRequestControl>()
  {

    public PersistentSearchRequestControl decodeControl(final Control control,
        final DecodeOptions options) throws DecodeException
    {
      Validator.ensureNotNull(control);

      if (control instanceof PersistentSearchRequestControl)
      {
        return (PersistentSearchRequestControl) control;
      }

      if (!control.getOID().equals(OID))
      {
        final LocalizableMessage message = ERR_PSEARCH_CONTROL_BAD_OID.get(
            control.getOID(), OID);
        throw DecodeException.error(message);
      }

      if (!control.hasValue())
      {
        // The control must always have a value.
        final LocalizableMessage message = ERR_PSEARCH_NO_CONTROL_VALUE.get();
        throw DecodeException.error(message);
      }

      final ASN1Reader reader = ASN1.getReader(control.getValue());
      boolean changesOnly;
      boolean returnECs;
      int changeTypes;

      try
      {
        reader.readStartSequence();

        changeTypes = (int) reader.readInteger();
        changesOnly = reader.readBoolean();
        returnECs = reader.readBoolean();

        reader.readEndSequence();
      }
      catch (final IOException e)
      {
        StaticUtils.DEBUG_LOG.throwing("PersistentSearchControl.Decoder",
            "decode", e);

        final LocalizableMessage message = ERR_PSEARCH_CANNOT_DECODE_VALUE
            .get(getExceptionMessage(e));
        throw DecodeException.error(message, e);
      }

      final Set<PersistentSearchChangeType> changeTypeSet = EnumSet
          .noneOf(PersistentSearchChangeType.class);

      if ((changeTypes & 15) != 0)
      {
        final LocalizableMessage message = ERR_PSEARCH_BAD_CHANGE_TYPES
            .get(changeTypes);
        throw DecodeException.error(message);
      }

      if ((changeTypes & 1) != 0)
      {
        changeTypeSet.add(PersistentSearchChangeType.ADD);
      }

      if ((changeTypes & 2) != 0)
      {
        changeTypeSet.add(PersistentSearchChangeType.DELETE);
      }

      if ((changeTypes & 4) != 0)
      {
        changeTypeSet.add(PersistentSearchChangeType.MODIFY);
      }

      if ((changeTypes & 8) != 0)
      {
        changeTypeSet.add(PersistentSearchChangeType.MODIFY_DN);
      }

      return new PersistentSearchRequestControl(control.isCritical(),
          changesOnly, returnECs, Collections.unmodifiableSet(changeTypeSet));
    }



    public String getOID()
    {
      return OID;
    }
  };



  /**
   * Creates a new persistent search request control.
   *
   * @param isCritical
   *          {@code true} if it is unacceptable to perform the operation
   *          without applying the semantics of this control, or {@code false}
   *          if it can be ignored
   * @param changesOnly
   *          Indicates whether or not only updated entries should be returned
   *          (added, modified, deleted, or subject to a modifyDN operation). If
   *          this parameter is {@code false} then the search will initially
   *          return all the existing entries which match the filter.
   * @param returnECs
   *          Indicates whether or not the entry change notification control
   *          should be included in updated entries that match the associated
   *          search criteria.
   * @param changeTypes
   *          The types of update operation for which change notifications
   *          should be returned.
   * @return The new control.
   * @throws NullPointerException
   *           If {@code changeTypes} was {@code null}.
   */
  public static PersistentSearchRequestControl newControl(
      final boolean isCritical, final boolean changesOnly,
      final boolean returnECs,
      final Collection<PersistentSearchChangeType> changeTypes)
      throws NullPointerException
  {
    Validator.ensureNotNull(changeTypes);

    final Set<PersistentSearchChangeType> copyOfChangeTypes = EnumSet
        .noneOf(PersistentSearchChangeType.class);
    copyOfChangeTypes.addAll(changeTypes);
    return new PersistentSearchRequestControl(isCritical, changesOnly,
        returnECs, Collections.unmodifiableSet(copyOfChangeTypes));
  }



  /**
   * Creates a new persistent search request control.
   *
   * @param isCritical
   *          {@code true} if it is unacceptable to perform the operation
   *          without applying the semantics of this control, or {@code false}
   *          if it can be ignored
   * @param changesOnly
   *          Indicates whether or not only updated entries should be returned
   *          (added, modified, deleted, or subject to a modifyDN operation). If
   *          this parameter is {@code false} then the search will initially
   *          return all the existing entries which match the filter.
   * @param returnECs
   *          Indicates whether or not the entry change notification control
   *          should be included in updated entries that match the associated
   *          search criteria.
   * @param changeTypes
   *          The types of update operation for which change notifications
   *          should be returned.
   * @return The new control.
   * @throws NullPointerException
   *           If {@code changeTypes} was {@code null}.
   */
  public static PersistentSearchRequestControl newControl(
      final boolean isCritical, final boolean changesOnly,
      final boolean returnECs, final PersistentSearchChangeType... changeTypes)
      throws NullPointerException
  {
    Validator.ensureNotNull((Object) changeTypes);

    return newControl(isCritical, changesOnly, returnECs, Arrays
        .asList(changeTypes));
  }



  // Indicates whether to only return entries that have been updated
  // since the beginning of the search.
  private final boolean changesOnly;

  // Indicates whether entries returned as a result of changes to
  // directory data should include the entry change notification control.
  private final boolean returnECs;

  // The logical OR of change types associated with this control.
  private final Set<PersistentSearchChangeType> changeTypes;

  private final boolean isCritical;



  private PersistentSearchRequestControl(final boolean isCritical,
      final boolean changesOnly, final boolean returnECs,
      final Set<PersistentSearchChangeType> changeTypes)
  {
    this.isCritical = isCritical;
    this.changesOnly = changesOnly;
    this.returnECs = returnECs;
    this.changeTypes = changeTypes;
  }



  /**
   * Returns an unmodifiable set containing the types of update operation for
   * which change notifications should be returned.
   *
   * @return An unmodifiable set containing the types of update operation for
   *         which change notifications should be returned.
   */
  public Set<PersistentSearchChangeType> getChangeTypes()
  {
    return changeTypes;
  }



  /**
   * {@inheritDoc}
   */
  public String getOID()
  {
    return OID;
  }



  /**
   * {@inheritDoc}
   */
  public ByteString getValue()
  {
    final ByteStringBuilder buffer = new ByteStringBuilder();
    final ASN1Writer writer = ASN1.getWriter(buffer);
    try
    {
      writer.writeStartSequence();

      int changeTypesInt = 0;
      for (final PersistentSearchChangeType changeType : changeTypes)
      {
        changeTypesInt |= changeType.intValue();
      }
      writer.writeInteger(changeTypesInt);

      writer.writeBoolean(changesOnly);
      writer.writeBoolean(returnECs);
      writer.writeEndSequence();
      return buffer.toByteString();
    }
    catch (final IOException ioe)
    {
      // This should never happen unless there is a bug somewhere.
      throw new RuntimeException(ioe);
    }
  }



  /**
   * {@inheritDoc}
   */
  public boolean hasValue()
  {
    return true;
  }



  /**
   * Returns {@code true} if only updated entries should be returned (added,
   * modified, deleted, or subject to a modifyDN operation), otherwise {@code
   * false} if the search will initially return all the existing entries which
   * match the filter.
   *
   * @return {@code true} if only updated entries should be returned (added,
   *         modified, deleted, or subject to a modifyDN operation), otherwise
   *         {@code false} if the search will initially return all the existing
   *         entries which match the filter.
   */
  public boolean isChangesOnly()
  {
    return changesOnly;
  }



  /**
   * {@inheritDoc}
   */
  public boolean isCritical()
  {
    return isCritical;
  }



  /**
   * Returns {@code true} if the entry change notification control should be
   * included in updated entries that match the associated search criteria.
   *
   * @return {@code true} if the entry change notification control should be
   *         included in updated entries that match the associated search
   *         criteria.
   */
  public boolean isReturnECs()
  {
    return returnECs;
  }



  /**
   * {@inheritDoc}
   */
  @Override
  public String toString()
  {
    final StringBuilder builder = new StringBuilder();
    builder.append("PersistentSearchRequestControl(oid=");
    builder.append(getOID());
    builder.append(", criticality=");
    builder.append(isCritical());
    builder.append(", changeTypes=[");

    boolean comma = false;
    for (final PersistentSearchChangeType type : changeTypes)
    {
      if (comma)
      {
        builder.append(", ");
      }
      builder.append(type);
      comma = true;
    }

    builder.append("](");
    builder.append(changeTypes);
    builder.append("), changesOnly=");
    builder.append(changesOnly);
    builder.append(", returnECs=");
    builder.append(returnECs);
    builder.append(")");
    return builder.toString();
  }
}