/*
 * Copyright 2007-2017 Ping Identity Corporation
 * All Rights Reserved.
 */
/*
 * Copyright (C) 2015-2017 Ping Identity Corporation
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License (GPLv2 only)
 * or the terms of the GNU Lesser General Public License (LGPLv2.1 only)
 * 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, see <http://www.gnu.org/licenses>.
 */
package com.unboundid.ldap.sdk.unboundidds.controls;



import java.util.ArrayList;

import com.unboundid.asn1.ASN1Element;
import com.unboundid.asn1.ASN1Enumerated;
import com.unboundid.asn1.ASN1Exception;
import com.unboundid.asn1.ASN1Integer;
import com.unboundid.asn1.ASN1OctetString;
import com.unboundid.asn1.ASN1Sequence;
import com.unboundid.ldap.sdk.Control;
import com.unboundid.ldap.sdk.DecodeableControl;
import com.unboundid.ldap.sdk.LDAPException;
import com.unboundid.ldap.sdk.LDAPResult;
import com.unboundid.ldap.sdk.ResultCode;
import com.unboundid.util.NotMutable;
import com.unboundid.util.ThreadSafety;
import com.unboundid.util.ThreadSafetyLevel;

import static com.unboundid.ldap.sdk.unboundidds.controls.ControlMessages.*;
import static com.unboundid.util.Debug.*;
import static com.unboundid.util.StaticUtils.*;



/**
 * This class provides an implementation of the password policy response control
 * as described in draft-behera-ldap-password-policy.  It may be used to provide
 * information related to a user's password policy.  It may include at most one
 * warning from the set of {@link PasswordPolicyWarningType} values and at most
 * one error from the set of {@link PasswordPolicyErrorType} values.  See the
 * documentation for those classes for more information on the information that
 * may be included.  See the {@link PasswordPolicyRequestControl} documentation
 * for an example that demonstrates the use of the password policy request and
 * response controls.
 * <BR>
 * <BLOCKQUOTE>
 *   <B>NOTE:</B>  This class, and other classes within the
 *   {@code com.unboundid.ldap.sdk.unboundidds} package structure, are only
 *   supported for use against Ping Identity, UnboundID, and Alcatel-Lucent 8661
 *   server products.  These classes provide support for proprietary
 *   functionality or for external specifications that are not considered stable
 *   or mature enough to be guaranteed to work in an interoperable way with
 *   other types of LDAP servers.
 * </BLOCKQUOTE>
 */
@NotMutable()
@ThreadSafety(level=ThreadSafetyLevel.COMPLETELY_THREADSAFE)
public final class PasswordPolicyResponseControl
       extends Control
       implements DecodeableControl
{
  /**
   * The OID (1.3.6.1.4.1.42.2.27.8.5.1) for the password policy response
   * control.
   */
  public static final String PASSWORD_POLICY_RESPONSE_OID =
       "1.3.6.1.4.1.42.2.27.8.5.1";



  /**
   * The BER type for the password policy warning element.
   */
  private static final byte TYPE_WARNING = (byte) 0xA0;



  /**
   * The BER type for the password policy error element.
   */
  private static final byte TYPE_ERROR = (byte) 0x81;



  /**
   * The BER type for the "time before expiration" warning element.
   */
  private static final byte TYPE_TIME_BEFORE_EXPIRATION = (byte) 0x80;



  /**
   * The BER type for the "grace logins remaining" warning element.
   */
  private static final byte TYPE_GRACE_LOGINS_REMAINING = (byte) 0x81;



  /**
   * The serial version UID for this serializable class.
   */
  private static final long serialVersionUID = 1835830253434331833L;



  // The password policy warning value, if applicable.
  private final int warningValue;

  // The password policy error type, if applicable.
  private final PasswordPolicyErrorType errorType;

  // The password policy warning type, if applicable.
  private final PasswordPolicyWarningType warningType;



  /**
   * Creates a new empty control instance that is intended to be used only for
   * decoding controls via the {@code DecodeableControl} interface.
   */
  PasswordPolicyResponseControl()
  {
    warningType  = null;
    errorType    = null;
    warningValue = -1;
  }



  /**
   * Creates a new password policy response control with the provided
   * information.  It will not be critical.
   *
   * @param  warningType   The password policy warning type for this response
   *                       control, or {@code null} if there should be no
   *                       warning type.
   * @param  warningValue  The value for the password policy warning type, or -1
   *                       if there is no warning type.
   * @param  errorType     The password policy error type for this response
   *                       control, or {@code null} if there should be no error
   *                       type.
   */
  public PasswordPolicyResponseControl(
              final PasswordPolicyWarningType warningType,
              final int warningValue, final PasswordPolicyErrorType errorType)
  {
    this(warningType, warningValue, errorType, false);
  }



  /**
   * Creates a new password policy response control with the provided
   * information.
   *
   * @param  warningType   The password policy warning type for this response
   *                       control, or {@code null} if there should be no
   *                       warning type.
   * @param  warningValue  The value for the password policy warning type, or -1
   *                       if there is no warning type.
   * @param  errorType     The password policy error type for this response
   *                       control, or {@code null} if there should be no error
   *                       type.
   * @param  isCritical    Indicates whether this control should be marked
   *                       critical.  Response controls should generally not be
   *                       critical.
   */
  public PasswordPolicyResponseControl(
              final PasswordPolicyWarningType warningType,
              final int warningValue, final PasswordPolicyErrorType errorType,
              final boolean isCritical)
  {
    super(PASSWORD_POLICY_RESPONSE_OID, isCritical,
          encodeValue(warningType, warningValue, errorType));

    this.warningType = warningType;
    this.errorType   = errorType;

    if (warningType == null)
    {
      this.warningValue = -1;
    }
    else
    {
      this.warningValue = warningValue;
    }
  }



  /**
   * Creates a new password policy response control with the provided
   * information.
   *
   * @param  oid         The OID for the control.
   * @param  isCritical  Indicates whether the control should be marked
   *                     critical.
   * @param  value       The encoded value for the control.  This may be
   *                     {@code null} if no value was provided.
   *
   * @throws  LDAPException  If the provided control cannot be decoded as a
   *                         password policy response control.
   */
  public PasswordPolicyResponseControl(final String oid,
                                       final boolean isCritical,
                                       final ASN1OctetString value)
         throws LDAPException
  {
    super(oid, isCritical, value);

    if (value == null)
    {
      throw new LDAPException(ResultCode.DECODING_ERROR,
                              ERR_PWP_RESPONSE_NO_VALUE.get());
    }

    final ASN1Sequence valueSequence;
    try
    {
      final ASN1Element valueElement = ASN1Element.decode(value.getValue());
      valueSequence = ASN1Sequence.decodeAsSequence(valueElement);
    }
    catch (final ASN1Exception ae)
    {
      debugException(ae);
      throw new LDAPException(ResultCode.DECODING_ERROR,
                              ERR_PWP_RESPONSE_VALUE_NOT_SEQUENCE.get(ae), ae);
    }

    final ASN1Element[] valueElements = valueSequence.elements();
    if (valueElements.length > 2)
    {
      throw new LDAPException(ResultCode.DECODING_ERROR,
                              ERR_PWP_RESPONSE_INVALID_ELEMENT_COUNT.get(
                                   valueElements.length));
    }

    int                       wv = -1;
    PasswordPolicyErrorType   et = null;
    PasswordPolicyWarningType wt = null;
    for (final ASN1Element e : valueElements)
    {
      switch (e.getType())
      {
        case TYPE_WARNING:
          if (wt == null)
          {
            try
            {
              final ASN1Element warningElement =
                   ASN1Element.decode(e.getValue());
              wv = ASN1Integer.decodeAsInteger(warningElement).intValue();
              switch (warningElement.getType())
              {
                case TYPE_TIME_BEFORE_EXPIRATION:
                  wt = PasswordPolicyWarningType.TIME_BEFORE_EXPIRATION;
                  break;

                case TYPE_GRACE_LOGINS_REMAINING:
                  wt = PasswordPolicyWarningType.GRACE_LOGINS_REMAINING;
                  break;

                default:
                  throw new LDAPException(ResultCode.DECODING_ERROR,
                                 ERR_PWP_RESPONSE_INVALID_WARNING_TYPE.get(
                                      toHex(warningElement.getType())));
              }
            }
            catch (final ASN1Exception ae)
            {
              debugException(ae);
              throw new LDAPException(ResultCode.DECODING_ERROR,
                             ERR_PWP_RESPONSE_CANNOT_DECODE_WARNING.get(ae),
                             ae);
            }
          }
          else
          {
            throw new LDAPException(ResultCode.DECODING_ERROR,
                                    ERR_PWP_RESPONSE_MULTIPLE_WARNING.get());
          }
          break;

        case TYPE_ERROR:
          if (et == null)
          {
            try
            {
              final ASN1Enumerated errorElement =
                   ASN1Enumerated.decodeAsEnumerated(e);
              et = PasswordPolicyErrorType.valueOf(errorElement.intValue());
              if (et == null)
              {
                  throw new LDAPException(ResultCode.DECODING_ERROR,
                                 ERR_PWP_RESPONSE_INVALID_ERROR_TYPE.get(
                                      errorElement.intValue()));
              }
            }
            catch (final ASN1Exception ae)
            {
              debugException(ae);
              throw new LDAPException(ResultCode.DECODING_ERROR,
                             ERR_PWP_RESPONSE_CANNOT_DECODE_ERROR.get(ae), ae);
            }
          }
          else
          {
            throw new LDAPException(ResultCode.DECODING_ERROR,
                                    ERR_PWP_RESPONSE_MULTIPLE_ERROR.get());
          }
          break;

        default:
          throw new LDAPException(ResultCode.DECODING_ERROR,
                                  ERR_PWP_RESPONSE_INVALID_TYPE.get(
                                       toHex(e.getType())));
      }
    }

    warningType  = wt;
    warningValue = wv;
    errorType    = et;
  }



  /**
   * {@inheritDoc}
   */
  @Override()
  public PasswordPolicyResponseControl
              decodeControl(final String oid, final boolean isCritical,
                            final ASN1OctetString value)
         throws LDAPException
  {
    return new PasswordPolicyResponseControl(oid, isCritical, value);
  }



  /**
   * Extracts a password policy response control from the provided result.
   *
   * @param  result  The result from which to retrieve the password policy
   *                 response control.
   *
   * @return  The password policy response control contained in the provided
   *          result, or {@code null} if the result did not contain a password
   *          policy response control.
   *
   * @throws  LDAPException  If a problem is encountered while attempting to
   *                         decode the password policy response control
   *                         contained in the provided result.
   */
  public static PasswordPolicyResponseControl get(final LDAPResult result)
         throws LDAPException
  {
    final Control c = result.getResponseControl(PASSWORD_POLICY_RESPONSE_OID);
    if (c == null)
    {
      return null;
    }

    if (c instanceof PasswordPolicyResponseControl)
    {
      return (PasswordPolicyResponseControl) c;
    }
    else
    {
      return new PasswordPolicyResponseControl(c.getOID(), c.isCritical(),
           c.getValue());
    }
  }



  /**
   * Encodes the provided information as appropriate for use as the value of a
   * password policy response control.
   *
   * @param  warningType   The warning type to use for the warning element, or
   *                       {@code null} if there is not to be a warning element.
   * @param  warningValue  The value to use for the warning element.
   * @param  errorType     The error type to use for the error element, or
   *                       {@code null} if there is not to be an error element.
   *
   * @return  The ASN.1 octet string containing the encoded control value.
   */
  private static ASN1OctetString
          encodeValue(final PasswordPolicyWarningType warningType,
                      final int warningValue,
                      final PasswordPolicyErrorType errorType)
  {
    final ArrayList<ASN1Element> valueElements = new ArrayList<ASN1Element>(2);

    if (warningType != null)
    {
      switch (warningType)
      {
        case TIME_BEFORE_EXPIRATION:
          valueElements.add(new ASN1Element(TYPE_WARNING,
               new ASN1Integer(TYPE_TIME_BEFORE_EXPIRATION,
                               warningValue).encode()));
          break;

        case GRACE_LOGINS_REMAINING:
          valueElements.add(new ASN1Element(TYPE_WARNING,
               new ASN1Integer(TYPE_GRACE_LOGINS_REMAINING,
                               warningValue).encode()));
          break;
      }
    }

    if (errorType != null)
    {
      valueElements.add(new ASN1Enumerated(TYPE_ERROR, errorType.intValue()));
    }

    return new ASN1OctetString(new ASN1Sequence(valueElements).encode());
  }



  /**
   * Retrieves the warning type for this password policy response control, if
   * available.
   *
   * @return  The warning type for this password policy response control, or
   *          {@code null} if there is no warning type.
   */
  public PasswordPolicyWarningType getWarningType()
  {
    return warningType;
  }



  /**
   * Retrieves the warning value for this password policy response control, if
   * available.
   *
   * @return  The warning value for this password policy response control, or -1
   *          if there is no warning type.
   */
  public int getWarningValue()
  {
    return warningValue;
  }



  /**
   * Retrieves the error type for this password policy response control, if
   * available.
   *
   * @return  The error type for this password policy response control, or
   *          {@code null} if there is no error type.
   */
  public PasswordPolicyErrorType getErrorType()
  {
    return errorType;
  }



  /**
   * {@inheritDoc}
   */
  @Override()
  public String getControlName()
  {
    return INFO_CONTROL_NAME_PW_POLICY_RESPONSE.get();
  }



  /**
   * {@inheritDoc}
   */
  @Override()
  public void toString(final StringBuilder buffer)
  {
    boolean elementAdded = false;

    buffer.append("PasswordPolicyResponseControl(");

    if (warningType != null)
    {
      buffer.append("warningType='");
      buffer.append(warningType.getName());
      buffer.append("', warningValue=");
      buffer.append(warningValue);
      elementAdded = true;
    }

    if (errorType != null)
    {
      if (elementAdded)
      {
        buffer.append(", ");
      }

      buffer.append("errorType='");
      buffer.append(errorType.getName());
      buffer.append('\'');
      elementAdded = true;
    }

    if (elementAdded)
    {
      buffer.append(", ");
    }

    buffer.append("isCritical=");
    buffer.append(isCritical());
    buffer.append(')');
  }
}