/*
    * MIT License
    * Copyright (c) 2006-2025 JMockit developers
    * See LICENSE file for full license text.
    */
   package mockit.asm.types;
   
   import static mockit.asm.jvmConstants.Opcodes.ACONST_NULL;
   import static mockit.asm.jvmConstants.Opcodes.ALOAD;
  
  import edu.umd.cs.findbugs.annotations.NonNull;
  
  import org.checkerframework.checker.index.qual.NonNegative;
  
  public abstract class ReferenceType extends JavaType {
      /**
       * The internal name of this Java reference type.
       */
      @NonNull
      final char[] typeDescChars;
  
      /**
       * The offset of the internal name of this Java type in {@link #typeDescChars}.
       */
      @NonNegative
      final int off;
  
      ReferenceType(@NonNull char[] typeDesc) {
          super(typeDesc.length);
          typeDescChars = typeDesc;
          off = 0;
      }
  
      ReferenceType(@NonNull char[] typeDesc, @NonNegative int off, @NonNegative int len) {
          super(len);
          typeDescChars = typeDesc;
          this.off = off;
      }
  
      /**
       * Returns the Java type corresponding to the given type descriptor.
       *
       * @param typeDesc
       *            a type descriptor.
       */
      @NonNull
      public static ReferenceType createFromTypeDescriptor(@NonNull String typeDesc) {
          return getReferenceType(typeDesc.toCharArray(), 0);
      }
  
      /**
       * Returns the Java type corresponding to the given type descriptor. For method descriptors, <code>buf</code> is
       * supposed to contain nothing more than the descriptor itself.
       *
       * @param buf
       *            a buffer containing a type descriptor.
       * @param off
       *            the offset of this descriptor in the previous buffer.
       */
      @NonNull
      static ReferenceType getReferenceType(@NonNull char[] buf, @NonNegative int off) {
          switch (buf[off]) {
              case '[':
                  return ArrayType.create(buf, off);
              case 'L':
                  return ObjectType.create(buf, off);
              case '(':
                  return new MethodType(buf, off, buf.length - off);
              default:
                  throw new IllegalArgumentException("Invalid type descriptor: " + new String(buf));
          }
      }
  
      /**
       * Returns the object or array type corresponding to the given internal name.
       */
      @NonNull
      public static ReferenceType createFromInternalName(@NonNull String internalName) {
          char[] buf = internalName.toCharArray();
          return buf[0] == '[' ? new ArrayType(buf) : new ObjectType(buf);
      }
  
      static int findTypeNameLength(@NonNull char[] buf, @NonNegative int off, @NonNegative int len) {
          len++;
  
          while (buf[off + len] != ';') {
              len++;
          }
  
          return len;
      }
  
      static void getDescriptor(@NonNull StringBuilder buf, @NonNull Class<?> aClass) {
          buf.append('L');
  
          String name = aClass.getName();
          int len = name.length();
  
          for (int i = 0; i < len; i++) {
             char c = name.charAt(i);
             buf.append(c == '.' ? '/' : c);
         }
 
         buf.append(';');
     }
 
     @Override
     void getDescriptor(@NonNull StringBuilder typeDesc) {
         typeDesc.append(typeDescChars, off, len);
     }
 
     /**
      * Returns the internal name of the class corresponding to this object or array type. The internal name of a class
      * is its fully qualified name (as returned by Class.getName(), where '.' are replaced by '/'. For an array type, it
      * starts with "[" and ends with the type descriptor of the array element type.
      *
      * @return the internal name of the class corresponding to this object or array type.
      */
     @NonNull
     public final String getInternalName() {
         return new String(typeDescChars, off, len);
     }
 
     @Override
     public int getSize() {
         return 1;
     }
 
     @Override
     public int getOpcode(int opcode) {
         return opcode + 4;
     }
 
     @Override
     public final int getLoadOpcode() {
         return ALOAD;
     }
 
     @Override
     public final int getConstOpcode() {
         return ACONST_NULL;
     }
 
     @Override
     public final boolean equals(Object o) {
         if (this == o) {
             return true;
         }
 
         if (!(o instanceof ReferenceType)) {
             return false;
         }
 
         ReferenceType t = (ReferenceType) o;
 
         if (getClass() != t.getClass() || len != t.len) {
             return false;
         }
 
         for (int i = off, j = t.off, end = i + len; i < end; i++, j++) {
             if (typeDescChars[i] != t.typeDescChars[j]) {
                 return false;
             }
         }
 
         return true;
     }
 
     @Override
     public final int hashCode() {
         int hc = 13;
 
         for (int i = off, end = i + len; i < end; i++) {
             // noinspection CharUsedInArithmeticContext
             hc = 17 * (hc + typeDescChars[i]);
         }
 
         return hc;
     }
 }