/*
 * The contents of this file are subject to the terms of the Common Development and
 * Distribution License (the License). You may not use this file except in compliance with the
 * License.
 *
 * You can obtain a copy of the License at legal/CDDLv1.0.txt. See the License for the
 * specific language governing permission and limitations under the License.
 *
 * When distributing Covered Software, include this CDDL Header Notice in each file and include
 * the License file at legal/CDDLv1.0.txt. If applicable, add the following below the CDDL
 * Header, with the fields enclosed by brackets [] replaced by your own identifying
 * information: "Portions Copyright [year] [name of copyright owner]".
 *
 * Copyright 2008-2009 Sun Microsystems, Inc.
 * Portions Copyright 2015-2016 ForgeRock AS.
 */

package org.opends.guitools.controlpanel.datamodel;

import java.io.File;
import java.text.ParseException;
import java.util.Objects;

import org.forgerock.opendj.ldap.Base64;

/**
 * Class used to represent Binary Values.  This is required in particular
 * when the user wants to use the value in a file.  To be able to reflect
 * this this object is used: it contains the binary itself, the base 64
 * representation and the file that has been used.
 */
public class BinaryValue
{
  private Type type;
  private String base64;
  private byte[] bytes;
  private File file;
  private int hashCode;

  /** The type of the binary value. */
  public enum Type
  {
    /** The binary value is provided as Base 64 string. */
    BASE64_STRING,
    /** The binary value is provided as a byte array. */
    BYTE_ARRAY
  }

  /** This is done to force the use of the factory methods (createBase64 and createFromFile). */
  private BinaryValue()
  {
  }

  /**
   * Creates a binary value using a base64 string.
   * @param base64 the base64 representation of the binary.
   * @return the binary value.
   * @throws ParseException if there is an error decoding the provided base64
   * string.
   */
  public static BinaryValue createBase64(String base64) throws ParseException
  {
    BinaryValue value =  new BinaryValue();
    value.type = Type.BASE64_STRING;
    value.base64 = base64;
    value.bytes = value.getBytes();
    value.hashCode = base64.hashCode();
    return value;
  }

  /**
   * Creates a binary value using an array of bytes.
   * @param bytes the byte array.
   * @return the binary value.
   */
  public static BinaryValue createBase64(byte[] bytes)
  {
    BinaryValue value =  new BinaryValue();
    value.type = Type.BASE64_STRING;
    value.bytes = bytes;
    value.base64 = value.getBase64();
    value.hashCode = value.base64.hashCode();
    return value;
  }

  /**
   * Creates a binary value using an array of bytes and a file.
   * @param bytes the bytes in the file.
   * @param file the file the bytes were read from.
   * @return the binary value.
   */
  public static BinaryValue createFromFile(byte[] bytes, File file)
  {
    BinaryValue value =  new BinaryValue();
    value.type = Type.BYTE_ARRAY;
    value.bytes = bytes;
    value.base64 = value.getBase64();
    value.hashCode = value.base64.hashCode();
    value.file = file;
    return value;
  }

  /**
   * Returns the base64 representation of the binary value.
   * @return the base64 representation of the binary value.
   */
  public String getBase64()
  {
    if (base64 == null && bytes != null)
    {
      base64 = Base64.encode(bytes);
    }
    return base64;
  }

  /**
   * Returns the byte array of the binary value.
   * @return the byte array of the binary value.
   * @throws ParseException if this object was created using a base64 string
   * and there was an error parsing it.
   */
  public byte[] getBytes() throws ParseException
  {
    if (bytes == null && base64 != null)
    {
      bytes = Base64.decode(base64).toByteArray();
    }
    return bytes;
  }

  /**
   * Return the type of the binary value.
   * @return the type of the binary value.
   */
  public Type getType()
  {
    return type;
  }

  /**
   * Return the file that was used to read the binary value.
   * @return the file that was used to read the binary value.
   */
  public File getFile()
  {
    return file;
  }

  @Override
  public boolean equals(Object o)
  {
    if (this == o)
    {
      return true;
    }
    if (o instanceof BinaryValue)
    {
      BinaryValue candidate = (BinaryValue)o;
      return candidate.getType() == getType()
          && Objects.equals(file, candidate.getFile())
          && bytesEqual(candidate);
    }
    return false;
  }

  private boolean bytesEqual(BinaryValue candidate)
  {
    if (type == Type.BASE64_STRING)
    {
      return candidate.getBase64().equals(getBase64());
    }

    try
    {
      if (candidate.getBytes().length != getBytes().length) {
        return false;
      }
      boolean equals = true;
      for (int i=0; i<getBytes().length && equals; i++)
      {
        equals = bytes[i] == candidate.getBytes()[i];
      }
      return equals;
    }
    catch (ParseException pe)
    {
      throw new RuntimeException(
          "Unexpected error getting bytes: "+pe, pe);
    }
  }

  @Override
  public int hashCode()
  {
    return hashCode;
  }
}