/*
 * 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/ds/resource/legal-notices/cddl.txt
 * or http://www.opensource.org/licenses/cddl1.php.
 * 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/ds/resource/legal-notices/cddl.txt.  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 2010-2016 UnboundID Corp.
 */
package com.unboundid.directory.sdk.broker.types;

import com.unboundid.util.Validator;

import java.util.Date;
import java.util.Set;

/**
 * Abstract class for an OAuth 2 token.
 */
public abstract class Token
{
  // The application ID that has been authorized.
  private final String applicationId;
  // The set of scope IDs for which the application has requested or authorized.
  private final Set<String> scopeIds;
  // The time that this token was generated.
  private final Date generateTimestamp;
  // The maximum length of time in seconds that this token will be
  // considered valid.
  private final long maxValiditySeconds;
  // A value of this token that will be exposed to clients.
  private volatile String value;

  /**
   * Construct a new Token instance.
   *
   * @param applicationId The application ID with which this token is
   *                      associated. Must not be null.
   * @param scopeIds The set of scopes for which the client has been authorized.
   *                 Must not be null.
   * @param generateTimestamp The time that this token was generated. Must not
   *                          be null.
   * @param maxValiditySeconds The maximum length of time in seconds that this
   *                           token will be considered valid. Must not be null.
   */
  protected Token(final String applicationId, final Set<String> scopeIds,
                  final Date generateTimestamp,
                  final long maxValiditySeconds)
  {
    Validator.ensureNotNull(applicationId, scopeIds, generateTimestamp,
        maxValiditySeconds);
    this.scopeIds = scopeIds;
    this.applicationId = applicationId;
    this.generateTimestamp = generateTimestamp;
    this.maxValiditySeconds = maxValiditySeconds;
  }

  /**
   * Retrieves the application ID with which this token is associated.
   *
   * @return The application ID with which this token is associated.
   */
  public String getApplicationId()
  {
    return applicationId;
  }

  /**
   * Retrieves the set of scope IDs for which the client has been authorized.
   *
   * @return The set of scope IDs for which the client has been authorized.
   */
  public Set<String> getScopeIds()
  {
    return scopeIds;
  }

  /**
   * Retrieves the time that this token was generated.
   *
   * @return The time that this token was generated.
   */
  public Date getGenerateTimestamp()
  {
    return generateTimestamp;
  }

  /**
   * Retrieves the maximum length of time in seconds that this code will be
   * considered valid.
   *
   * @return The maximum length of time in seconds that this code will be
   *         considered valid.
   */
  public long getMaxValiditySeconds()
  {
    return maxValiditySeconds;
  }

  /**
   * Retrieves the string value of this token that should be returned to
   * the client.
   *
   * @return The string value of this token that should be returned to
   *         the client.
   */
  public String getValue()
  {
    return value;
  }

  /**
   * Sets the string value of this token that should be returned to the
   * client.
   *
   * @param value The string value of this token that should be returned
   *              to the client.
   */
  public void setValue(final String value)
  {
    Validator.ensureNotNull(value);
    this.value = value;
  }

  /**
   * Indicates whether this token is expired.
   *
   * @return {@code true} if this token is expired, or
   *         {@code false} if not.
   */
  public boolean isExpired()
  {
    final long generateTS = generateTimestamp.getTime();
    final long expirationTime = (generateTS + (1000L * maxValiditySeconds));
    final long currentTime = System.currentTimeMillis();
    return currentTime > expirationTime;
  }

  /**
   * Retrieves a hash code for this token.
   *
   * @return A hash code for this token.
   */
  @Override
  public int hashCode()
  {
    final int prime = 31;
    int result = 1;
    result = prime * result + (applicationId != null ?
        applicationId.hashCode() : 0);
    result = prime * result + (generateTimestamp != null ?
        generateTimestamp.hashCode() : 0);
    result = prime * result + (int) (maxValiditySeconds ^
        (maxValiditySeconds >>> 32));
    return result;
  }

  /**
   * Indicates whether the provided object is equal to this token.
   *
   * @param o The object for which to make the determination.
   *
   * @return {@code true} if the provided object is equal to this authorization
   *         code, or {@code false} if not.
   */
  @Override
  public boolean equals(final Object o)
  {
    if (this == o)
    {
      return true;
    }
    if (o == null || getClass() != o.getClass())
    {
      return false;
    }

    Token that = (Token) o;

    if (maxValiditySeconds != that.maxValiditySeconds)
    {
      return false;
    }
    if (applicationId != null ?
        !applicationId.equals(that.applicationId) :
        that.applicationId != null)
    {
      return false;
    }
    if (generateTimestamp != null ?
        !generateTimestamp.equals(that.generateTimestamp) :
        that.generateTimestamp != null)
    {
      return false;
    }
    if (value != null ? !value.equals(that.value) : that.value != null)
    {
      return false;
    }

    return true;
  }

  /**
   * Retrieves a string representation of this token.
   *
   * @return A string representation of this token.
   */
  @Override()
  public String toString()
  {
    final StringBuilder buffer = new StringBuilder();
    toString(buffer);
    return buffer.toString();
  }

  /**
   * Appends a string representation of this token to the provided
   * buffer.
   *
   * @param buffer The buffer to which the string representation should be
   *               appended.
   */
  protected abstract void toString(final StringBuilder buffer);
}