/*

  * Entagged Audio Tag library

  * Copyright (c) 2004-2005 Christian Laireiter <liree@web.de>

  * 

  * This library is free software; you can redistribute it and/or

  * modify it under the terms of the GNU Lesser General Public

  * License as published by the Free Software Foundation; either

  * version 2.1 of the License, or (at your option) any later version.

  *  

  * This library 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

  * Lesser General Public License for more details.

  * 

  * You should have received a copy of the GNU Lesser General Public

  * License along with this library; if not, write to the Free Software

  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

  */

 package org.jaudiotagger.audio.asf.data;

 import org.jaudiotagger.audio.asf.util.Utils;

 import java.io.ByteArrayOutputStream;

 import java.io.IOException;

 import java.io.OutputStream;

 import java.util.Arrays;

 /**

  * This class is a wrapper for properties within a

  * {@link org.jaudiotagger.audio.asf.data.ExtendedContentDescription}.<br>

  *

  * Each descriptor consists of the folloowing:

  *

  * Descriptor Name Length  16 bits

  * Descriptor Name UTF16LE format

  * Descriptor Value Data Type 16 bits

  * Descriptor Value Length 16 bits

  * Descriptor Value varies

  *

  * @author Christian Laireiter

  */

 public final class ContentDescriptor implements Comparable<ContentDescriptor>

 {

     /**

      * Constant for the content descriptor-type for binary data.

      */

     public final static int TYPE_BINARY = 1;

     /**

      * Constant for the content descriptor-type for booleans.

      */

     public final static int TYPE_BOOLEAN = 2;

     /**

      * Constant for the content descriptor-type for integers (32-bit). <br>

      */

     public final static int TYPE_DWORD = 3;

     /**

      * Constant for the content descriptor-type for integers (64-bit). <br>

      */

     public final static int TYPE_QWORD = 4;

     /**

      * Constant for the content descriptor-type for Strings.

      */

     public final static int TYPE_STRING = 0;

     /**

      * Constant for the content descriptor-type for integers (16-bit). <br>

      */

     public final static int TYPE_WORD = 5;

     /**

      * The name of the content descriptor.

      */

     private final String name;

     /**

          * This field shows the type of the content descriptor. <br>

          *

          * @see #TYPE_BINARY

          * @see #TYPE_BOOLEAN

          * @see #TYPE_DWORD

          * @see #TYPE_QWORD

          * @see #TYPE_STRING

          * @see #TYPE_WORD

          */

     private int descriptorType;

      /**

      * The binary representation of the value.

      */

     protected byte[] content = new byte[0];

     /**

      * Creates an Instance.

      *

      * @param propName Name of the ContentDescriptor.

      * @param propType Type of the content descriptor. See {@link #descriptorType}

      */

     public ContentDescriptor(String propName, int propType)

     {

         if (propName == null)

         {

             throw new IllegalArgumentException("Arguments must not be null.");

         }

         Utils.checkStringLengthNullSafe(propName);

         this.name = propName;

         this.descriptorType = propType;

     }

     /**

      * (overridden)

      *

      * @see java.lang.Object#clone()

      */

     public Object clone() throws CloneNotSupportedException

     {

         return createCopy();

     }

     /**

      * {@inheritDoc}

      */

     public int compareTo(ContentDescriptor o)

     {

         int result = getName().compareTo(o.getName());

         return result;

     }

     /**

      * This method creates a copy of the current object. <br>

      * All data will be copied, too. <br>

      *

      * @return A new content descriptor containing the same values as the current

      *         one.

      */

     public ContentDescriptor createCopy()

     {

         ContentDescriptor result = new ContentDescriptor(getName(), getType());

         result.content = getRawData();

         return result;

     }

     /**

      * (overridden)

      *

      * @see java.lang.Object#equals(java.lang.Object)

      */

     public boolean equals(Object obj)

     {

         boolean result = false;

         if (obj instanceof ContentDescriptor)

         {

             if (obj == this)

             {

                 result = true;

             }

             else

             {

                 ContentDescriptor other = (ContentDescriptor) obj;

                 result = other.getName().equals(getName()) && other.descriptorType == this.descriptorType && Arrays.equals(this.content, other.content);

             }

         }

         return result;

     }

     /**

      * Returns the value of the ContentDescriptor as a Boolean. <br>

      * If no Conversion is Possible false is returned. <br>

      * <code>true</code> if first byte of {@link #content}is not zero.

      *

      * @return boolean representation of the current value.

      */

     public boolean getBoolean()

     {

         return content.length > 0 && content[0] != 0;

     }

     /**

      * This method will return a byte array, which can directly be written into

      * an "Extended Content Description"-chunk. <br>

      *

      * @return byte[] with the data, that occurs in asf files.

      */

     public byte[] getBytes()

     {

         ByteArrayOutputStream result = new ByteArrayOutputStream();

         try

         {

             byte[] nameBytes = Utils.getBytes(getName(), AsfHeader.ASF_CHARSET);

             // Write the number of bytes the name needs. +2 because of the

             // Zero term character.

             result.write(Utils.getBytes(nameBytes.length + 2, 2));

             // Write the name itself

             result.write(nameBytes);

             // Write zero term character

             result.write(Utils.getBytes(0, 2));

             // Write the type of the current descriptor

             result.write(Utils.getBytes(getType(), 2));

             /*

              * Now the content.

              */

             if (this.getType() == TYPE_STRING)

             {

                 // String length +2 for zero termination

                 result.write(Utils.getBytes(content.length + 2, 2));

                 // Value

                 result.write(content);

                 // Zero term

                 result.write(Utils.getBytes(0, 2));

             }

             else

             {

                 result.write(Utils.getBytes(content.length, 2));

                 result.write(content);

             }

         } catch (Exception e)

         {

             e.printStackTrace();

         }

         return result.toByteArray();

     }

     /**

      * Returns the size (in bytes) this descriptor will take when written to 

      * an ASF file.<br>

      * 

      * @return size of the descriptor in an ASF file.

      */

     public int getCurrentAsfSize()

     {

         /*

          * 2 bytes name length, 2 bytes name zero term, 2 bytes type, 2 bytes

          * content length

          */

         int result = 8;

         result += getName().length() * 2;

         result += this.content.length;

         if (TYPE_STRING == this.getType())

         {

             result += 2; // zero term of content string.

         }

         return result;

     }

     /**

      * This method returns the name of the content descriptor.

      *

      * @return Name.

      */

     public String getName()

     {

         return this.name;

     }

     /**

      * This method returns the value of the content descriptor as an integer.

      * <br>

      * Converts the needed amount of byte out of {@link #content}to a number.

      * <br>

      * Only possible if {@link #getType()}equals on of the following: <br>

      * <li>

      *

      * @return integer value.

      * @see #TYPE_BOOLEAN </li>

      *      <li>

      * @see #TYPE_DWORD </li>

      *      <li>

      * @see #TYPE_QWORD </li>

      *      <li>

      * @see #TYPE_WORD </li>

      */

     public long getNumber()

     {

         long result = 0;

         int bytesNeeded = -1;

         switch (getType())

         {

             case TYPE_BOOLEAN:

                 bytesNeeded = 1;

                 break;

             case TYPE_DWORD:

                 bytesNeeded = 4;

                 break;

             case TYPE_QWORD:

                 bytesNeeded = 8;

                 break;

             case TYPE_WORD:

                 bytesNeeded = 2;

                 break;

             default:

                 throw new UnsupportedOperationException("The current type doesn't allow an interpretation as a number.");

         }

         if (bytesNeeded > content.length)

         {

             throw new IllegalStateException("The stored data cannot represent the type of current object.");

         }

         for (int i = 0; i < bytesNeeded; i++)

         {

             result |= (content[i] << (i * 8));

         }

         return result;

     }

     /**

      * This method returns a copy of the content of the descriptor. <br>

      *

      * @return The content in binary representation, as it would be written to

      *         asf file. <br>

      */

     public byte[] getRawData()

     {

         byte[] copy = new byte[this.content.length];

         System.arraycopy(this.content, 0, copy, 0, this.content.length);

         return copy;

     }

     /**

      * Returns the value of the ContentDescriptor as a String. <br>

      *

      * @return String - Representation Value

      */

     public String getString()

     {

         String result = "";

         switch (getType())

         {

             case TYPE_BINARY:

                 result = "binary data";

                 break;

             case TYPE_BOOLEAN:

                 result = String.valueOf(getBoolean());

                 break;

             case TYPE_QWORD:

             case TYPE_DWORD:

             case TYPE_WORD:

                 result = String.valueOf(getNumber());

                 break;

             case TYPE_STRING:

                 try

                 {

                     result = new String(content, "UTF-16LE");

                 } catch (Exception e)

                 {

                     e.printStackTrace();

                 }

                 break;

             default:

                 throw new IllegalStateException("Current type is not known.");

         }

         return result;

     }

     /**

      * Returns the type of the content descriptor. <br>

      *

      * @return the value of {@link #descriptorType}

      * @see #TYPE_BINARY

      * @see #TYPE_BOOLEAN

      * @see #TYPE_DWORD

      * @see #TYPE_QWORD

      * @see #TYPE_STRING

      * @see #TYPE_WORD

      */

     public int getType()

     {

         return this.descriptorType;

     }

     /**

      * This method checks if the binary data is empty. <br>

      * Disregarding the type of the descriptor its content is stored as a byte

      * array.

      *

      * @return <code>true</code> if no value is set.

      */

     public boolean isEmpty()

     {

         return this.content.length == 0;

     }

     /**

      * Sets the Value of the current content descriptor. <br>

      * Using this method will change {@link #descriptorType}to

      * {@link #TYPE_BINARY}.<br>

      *

      * @param data Value to set.

      * @throws IllegalArgumentException If the byte array is greater that 65535 bytes.

      */

     public void setBinaryValue(byte[] data) throws IllegalArgumentException

     {

         if (data.length > 65535)

         {

             throw new IllegalArgumentException("Too many bytes. 65535 is maximum.");

         }

         this.content = data;

         this.descriptorType = TYPE_BINARY;

     }

     /**

      * Sets the Value of the current content descriptor. <br>

      * Using this method will change {@link #descriptorType}to

      * {@link #TYPE_BOOLEAN}.<br>

      *

      * @param value Value to set.

      */

     public void setBooleanValue(boolean value)

     {

         this.content = new byte[]{value ? (byte) 1 : 0, 0, 0, 0};

         this.descriptorType = TYPE_BOOLEAN;

     }

     /**

      * Sets the Value of the current content descriptor. <br>

      * Using this method will change {@link #descriptorType}to

      * {@link #TYPE_DWORD}.

      *

      * @param value Value to set.

      */

     public void setDWordValue(long value)

     {

         this.content = Utils.getBytes(value, 4);

         this.descriptorType = TYPE_DWORD;

     }

     /**

      * Sets the Value of the current content descriptor. <br>

      * Using this method will change {@link #descriptorType}to

      * {@link #TYPE_QWORD}

      *

      * @param value Value to set.

      */

     public void setQWordValue(long value)

     {

         this.content = Utils.getBytes(value, 8);

         this.descriptorType = TYPE_QWORD;

     }

     /**

      * Sets the Value of the current content descriptor. <br>

      * Using this method will change {@link #descriptorType}to

      * {@link #TYPE_STRING}.

      *

      * @param value Value to set.

      * @throws IllegalArgumentException If byte representation would take more than 65535 Bytes.

      */

     public void setStringValue(String value) throws IllegalArgumentException

     {

         Utils.checkStringLengthNullSafe(value);

         if (value != null)

         {

             this.content = Utils.getBytes(value, AsfHeader.ASF_CHARSET);

         }

         else

         {

             this.content = new byte[0];

         }

         this.descriptorType = TYPE_STRING;

     }

     /**

      * Sets the Value of the current content descriptor. <br>

      * Using this method will change {@link #descriptorType}to

      * {@link #TYPE_WORD}

      *

      * @param value Value to set.

      */

     public void setWordValue(int value)

     {

         this.content = Utils.getBytes(value, 2);

         this.descriptorType = TYPE_WORD;

     }

     /**

      * (overridden)

      *

      * @see java.lang.Object#toString()

      */

     public String toString()

     {

         return getName() + " : " + new String[]{"String: ", "Binary: ", "Boolean: ", "DWORD: ", "QWORD:", "WORD:"}[this.descriptorType] + getString();

     }

     /**

      * Writes this descriptor into the specified output stream.<br>

      * 

      * @param out stream to write into.

      * @return amount of bytes written.

      * @throws IOException on I/O Errors

      */

     public int writeInto(OutputStream out) throws IOException

     {

         final int size = getCurrentAsfSize();

         Utils.writeUINT16(getName().length() * 2 + 2, out);

         out.write(Utils.getBytes(getName(), AsfHeader.ASF_CHARSET));

         out.write(AsfHeader.ZERO_TERM);

         final int type = getType();

         Utils.writeUINT16(type, out);

         int contentLen = this.content.length;

         if (TYPE_STRING == type)

         {

             contentLen += 2; // Zero Term

         }

         Utils.writeUINT16(contentLen, out);

         out.write(this.content);

         if (TYPE_STRING == type)

         {

             out.write(AsfHeader.ZERO_TERM);

         }

         return size;

     }

 }