/*

 * reserved comment block

 * DO NOT REMOVE OR ALTER!

 */

package com.sun.org.apache.bcel.internal.classfile;

/* ====================================================================

 * The Apache Software License, Version 1.1

 *

 * Copyright (c) 2001 The Apache Software Foundation.  All rights

 * reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 *

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in

 *    the documentation and/or other materials provided with the

 *    distribution.

 *

 * 3. The end-user documentation included with the redistribution,

 *    if any, must include the following acknowledgment:

 *       "This product includes software developed by the

 *        Apache Software Foundation (http://www.apache.org/)."

 *    Alternately, this acknowledgment may appear in the software itself,

 *    if and wherever such third-party acknowledgments normally appear.

 *

 * 4. The names "Apache" and "Apache Software Foundation" and

 *    "Apache BCEL" must not be used to endorse or promote products

 *    derived from this software without prior written permission. For

 *    written permission, please contact apache@apache.org.

 *

 * 5. Products derived from this software may not be called "Apache",

 *    "Apache BCEL", nor may "Apache" appear in their name, without

 *    prior written permission of the Apache Software Foundation.

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 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

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 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,

 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT

 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

 * SUCH DAMAGE.

 * ====================================================================

 *

 * This software consists of voluntary contributions made by many

 * individuals on behalf of the Apache Software Foundation.  For more

 * information on the Apache Software Foundation, please see

 * <http://www.apache.org/>.

 */

import  com.sun.org.apache.bcel.internal.Constants;

import  java.io.*;

/**

 * This class is derived from <em>Attribute</em> and represents a reference

 * to a <href="http://wwwipd.ira.uka.de/~pizza/gj/">GJ</a> attribute.

 *

 * @author  <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>

 * @see     Attribute

 */

public final class Signature extends Attribute {

  private int signature_index;

  /**

   * Initialize from another object. Note that both objects use the same

   * references (shallow copy). Use clone() for a physical copy.

   */

  public Signature(Signature c) {

    this(c.getNameIndex(), c.getLength(), c.getSignatureIndex(), c.getConstantPool());

  }

  /**

   * Construct object from file stream.

   * @param name_index Index in constant pool to CONSTANT_Utf8

   * @param length Content length in bytes

   * @param file Input stream

   * @param constant_pool Array of constants

   * @throws IOException

   */

  Signature(int name_index, int length, DataInputStream file,

           ConstantPool constant_pool) throws IOException

  {

    this(name_index, length, file.readUnsignedShort(), constant_pool);

  }

  /**

   * @param name_index Index in constant pool to CONSTANT_Utf8

   * @param length Content length in bytes

   * @param constant_pool Array of constants

   * @param Signature_index Index in constant pool to CONSTANT_Utf8

   */

  public Signature(int name_index, int length, int signature_index,

                  ConstantPool constant_pool)

  {

    super(Constants.ATTR_SIGNATURE, name_index, length, constant_pool);

    this.signature_index = signature_index;

  }

  /**

   * Called by objects that are traversing the nodes of the tree implicitely

   * defined by the contents of a Java class. I.e., the hierarchy of methods,

   * fields, attributes, etc. spawns a tree of objects.

   *

   * @param v Visitor object

   */

   public void accept(Visitor v) {

     System.err.println("Visiting non-standard Signature object");

     v.visitSignature(this);

   }

  /**

   * Dump source file attribute to file stream in binary format.

   *

   * @param file Output file stream

   * @throws IOException

   */

  public final void dump(DataOutputStream file) throws IOException

  {

    super.dump(file);

    file.writeShort(signature_index);

  }

  /**

   * @return Index in constant pool of source file name.

   */

  public final int getSignatureIndex() { return signature_index; }

  /**

   * @param Signature_index.

   */

  public final void setSignatureIndex(int signature_index) {

    this.signature_index = signature_index;

  }

  /**

   * @return GJ signature.

   */

  public final String getSignature() {

    ConstantUtf8 c = (ConstantUtf8)constant_pool.getConstant(signature_index,

                                                             Constants.CONSTANT_Utf8);

    return c.getBytes();

  }

  /**

   * Extends ByteArrayInputStream to make 'unreading' chars possible.

   */

  private static final class MyByteArrayInputStream extends ByteArrayInputStream {

    MyByteArrayInputStream(String data) { super(data.getBytes()); }

    final int  mark()                   { return pos; }

    final String getData()              { return new String(buf); }

    final void reset(int p)             { pos = p; }

    final void unread()                 { if(pos > 0) pos--; }

  }

  private static boolean identStart(int ch) {

    return ch == 'T' || ch == 'L';

  }

  private static boolean identPart(int ch) {

    return ch == '/' || ch == ';';

  }

  private static final void matchIdent(MyByteArrayInputStream in, StringBuffer buf) {

    int ch;

    if((ch = in.read()) == -1)

      throw new RuntimeException("Illegal signature: " + in.getData() +

                                 " no ident, reaching EOF");

    //System.out.println("return from ident:" + (char)ch);

    if(!identStart(ch)) {

      StringBuffer buf2 = new StringBuffer();

      int count = 1;

      while(Character.isJavaIdentifierPart((char)ch)) {

        buf2.append((char)ch);

        count++;

        ch = in.read();

      }

      if(ch == ':') { // Ok, formal parameter

        in.skip("Ljava/lang/Object".length());

        buf.append(buf2);

        ch = in.read();

        in.unread();

        //System.out.println("so far:" + buf2 + ":next:" +(char)ch);

      } else {

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

          in.unread();

      }

      return;

    }

    StringBuffer buf2 = new StringBuffer();

    ch = in.read();

    do {

      buf2.append((char)ch);

      ch = in.read();

      //System.out.println("within ident:"+ (char)ch);

    } while((ch != -1) && (Character.isJavaIdentifierPart((char)ch) || (ch == '/')));

    buf.append(buf2.toString().replace('/', '.'));

    //System.out.println("regular return ident:"+ (char)ch + ":" + buf2);

    if(ch != -1)

      in.unread();

  }

  private static final void matchGJIdent(MyByteArrayInputStream in,

                                         StringBuffer buf)

  {

    int ch;

    matchIdent(in, buf);

    ch = in.read();

    if((ch == '<') || ch == '(') { // Parameterized or method

      //System.out.println("Enter <");

      buf.append((char)ch);

      matchGJIdent(in, buf);

      while(((ch = in.read()) != '>') && (ch != ')')) { // List of parameters

        if(ch == -1)

          throw new RuntimeException("Illegal signature: " + in.getData() +

                                     " reaching EOF");

        //System.out.println("Still no >");

        buf.append(", ");

        in.unread();

        matchGJIdent(in, buf); // Recursive call

      }

      //System.out.println("Exit >");

      buf.append((char)ch);

    } else

      in.unread();

    ch = in.read();

    if(identStart(ch)) {

      in.unread();

      matchGJIdent(in, buf);

    } else if(ch == ')') {

      in.unread();

      return;

    } else if(ch != ';')

      throw new RuntimeException("Illegal signature: " + in.getData() + " read " +

                                 (char)ch);

  }

  public static String translate(String s) {

    //System.out.println("Sig:" + s);

    StringBuffer buf = new StringBuffer();

    matchGJIdent(new MyByteArrayInputStream(s), buf);

    return buf.toString();

  }

  public static final boolean isFormalParameterList(String s) {

    return s.startsWith("<") && (s.indexOf(':') > 0);

  }

  public static final boolean isActualParameterList(String s) {

    return s.startsWith("L") && s.endsWith(">;");

  }

  /**

   * @return String representation

   */

  public final String toString() {

    String s = getSignature();

    return "Signature(" + s + ")";

  }

  /**

   * @return deep copy of this attribute

   */

  public Attribute copy(ConstantPool constant_pool) {

    return (Signature)clone();

  }

}