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 * reserved comment block
 * DO NOT REMOVE OR ALTER!
 */
/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
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package com.sun.org.apache.bcel.internal.generic;


import com.sun.org.apache.bcel.internal.Constants;
import com.sun.org.apache.bcel.internal.classfile.*;
import java.util.ArrayList;

/**
 * Abstract super class for all possible java types, namely basic types
 * such as int, object types like String and array types, e.g. int[]
 *
 * @author  <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
 */
public abstract class Type implements java.io.Serializable {
  protected byte   type;
  protected String signature; // signature for the type

  /** Predefined constants
   */
  public static final BasicType     VOID         = new BasicType(Constants.T_VOID);
  public static final BasicType     BOOLEAN      = new BasicType(Constants.T_BOOLEAN);
  public static final BasicType     INT          = new BasicType(Constants.T_INT);
  public static final BasicType     SHORT        = new BasicType(Constants.T_SHORT);
  public static final BasicType     BYTE         = new BasicType(Constants.T_BYTE);
  public static final BasicType     LONG         = new BasicType(Constants.T_LONG);
  public static final BasicType     DOUBLE       = new BasicType(Constants.T_DOUBLE);
  public static final BasicType     FLOAT        = new BasicType(Constants.T_FLOAT);
  public static final BasicType     CHAR         = new BasicType(Constants.T_CHAR);
  public static final ObjectType    OBJECT       = new ObjectType("java.lang.Object");
  public static final ObjectType    STRING       = new ObjectType("java.lang.String");
  public static final ObjectType    STRINGBUFFER = new ObjectType("java.lang.StringBuffer");
  public static final ObjectType    THROWABLE    = new ObjectType("java.lang.Throwable");
  public static final Type[]        NO_ARGS      = new Type[0];
  public static final ReferenceType NULL         = new ReferenceType(){};
  public static final Type          UNKNOWN      = new Type(Constants.T_UNKNOWN,
                                                            "<unknown object>"){};

  protected Type(byte t, String s) {
    type      = t;
    signature = s;
  }

  /**
   * @return signature for given type.
   */
  public String getSignature() { return signature; }

  /**
   * @return type as defined in Constants
   */
  public byte getType() { return type; }

  /**
   * @return stack size of this type (2 for long and double, 0 for void, 1 otherwise)
   */
  public int getSize() {
    switch(type) {
    case Constants.T_DOUBLE:
    case Constants.T_LONG: return 2;
    case Constants.T_VOID: return 0;
    default:     return 1;
    }
  }

  /**
   * @return Type string, e.g. `int[]'
   */
  public String toString() {
    return ((this.equals(Type.NULL) || (type >= Constants.T_UNKNOWN)))? signature :
      Utility.signatureToString(signature, false);
  }

  /**
   * Convert type to Java method signature, e.g. int[] f(java.lang.String x)
   * becomes (Ljava/lang/String;)[I
   *
   * @param return_type what the method returns
   * @param arg_types what are the argument types
   * @return method signature for given type(s).
   */
  public static String getMethodSignature(Type return_type, Type[] arg_types) {
    StringBuffer buf = new StringBuffer("(");
    int length = (arg_types == null)? 0 : arg_types.length;

    for(int i=0; i < length; i++)
      buf.append(arg_types[i].getSignature());

    buf.append(')');
    buf.append(return_type.getSignature());

    return buf.toString();
  }

  private static int consumed_chars=0; // Remember position in string, see getArgumentTypes

  /**
   * Convert signature to a Type object.
   * @param signature signature string such as Ljava/lang/String;
   * @return type object
   */
  public static final Type getType(String signature)
    throws StringIndexOutOfBoundsException
  {
    byte type = Utility.typeOfSignature(signature);

    if(type <= Constants.T_VOID) {
      consumed_chars = 1;
      return BasicType.getType(type);
    } else if(type == Constants.T_ARRAY) {
      int dim=0;
      do { // Count dimensions
        dim++;
      } while(signature.charAt(dim) == '[');

      // Recurse, but just once, if the signature is ok
      Type t = getType(signature.substring(dim));

      consumed_chars += dim; // update counter

      return new ArrayType(t, dim);
    } else { // type == T_REFERENCE
      int index = signature.indexOf(';'); // Look for closing `;'

      if(index < 0)
        throw new ClassFormatException("Invalid signature: " + signature);

      consumed_chars = index + 1; // "Lblabla;" `L' and `;' are removed

      return new ObjectType(signature.substring(1, index).replace('/', '.'));
    }
  }

  /**
   * Convert return value of a method (signature) to a Type object.
   *
   * @param signature signature string such as (Ljava/lang/String;)V
   * @return return type
   */
  public static Type getReturnType(String signature) {
    try {
      // Read return type after `)'
      int index = signature.lastIndexOf(')') + 1;
      return getType(signature.substring(index));
    } catch(StringIndexOutOfBoundsException e) { // Should never occur
      throw new ClassFormatException("Invalid method signature: " + signature);
    }
  }

  /**
   * Convert arguments of a method (signature) to an array of Type objects.
   * @param signature signature string such as (Ljava/lang/String;)V
   * @return array of argument types
   */
  public static Type[] getArgumentTypes(String signature) {
    ArrayList vec = new ArrayList();
    int       index;
    Type[]     types;

    try { // Read all declarations between for `(' and `)'
      if(signature.charAt(0) != '(')
        throw new ClassFormatException("Invalid method signature: " + signature);

      index = 1; // current string position

      while(signature.charAt(index) != ')') {
        vec.add(getType(signature.substring(index)));
        index += consumed_chars; // update position
      }
    } catch(StringIndexOutOfBoundsException e) { // Should never occur
      throw new ClassFormatException("Invalid method signature: " + signature);
    }

    types = new Type[vec.size()];
    vec.toArray(types);
    return types;
  }

  /** Convert runtime java.lang.Class to BCEL Type object.
   * @param cl Java class
   * @return corresponding Type object
   */
  public static Type getType(java.lang.Class cl) {
    if(cl == null) {
      throw new IllegalArgumentException("Class must not be null");
    }

    /* That's an amzingly easy case, because getName() returns
     * the signature. That's what we would have liked anyway.
     */
    if(cl.isArray()) {
      return getType(cl.getName());
    } else if(cl.isPrimitive()) {
      if(cl == Integer.TYPE) {
        return INT;
      } else if(cl == Void.TYPE) {
        return VOID;
      } else if(cl == Double.TYPE) {
        return DOUBLE;
      } else if(cl == Float.TYPE) {
        return FLOAT;
      } else if(cl == Boolean.TYPE) {
        return BOOLEAN;
      } else if(cl == Byte.TYPE) {
        return BYTE;
      } else if(cl == Short.TYPE) {
        return SHORT;
      } else if(cl == Byte.TYPE) {
        return BYTE;
      } else if(cl == Long.TYPE) {
        return LONG;
      } else if(cl == Character.TYPE) {
        return CHAR;
      } else {
        throw new IllegalStateException("Ooops, what primitive type is " + cl);
      }
    } else { // "Real" class
      return new ObjectType(cl.getName());
    }
  }

  public static String getSignature(java.lang.reflect.Method meth) {
    StringBuffer sb = new StringBuffer("(");
    Class[] params = meth.getParameterTypes(); // avoid clone

    for(int j = 0; j < params.length; j++) {
      sb.append(getType(params[j]).getSignature());
    }

    sb.append(")");
    sb.append(getType(meth.getReturnType()).getSignature());
    return sb.toString();
  }
}