content: package act.util;
  
  /*-
   * #%L
   * ACT Framework
   * %%
   * Copyright (C) 2014 - 2017 ActFramework
   * %%
   * Licensed 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.
   * #L%
   */
  
  import act.asm.Label;
  import act.asm.MethodVisitor;
  import act.asm.Opcodes;
  import act.asm.Type;
  import act.data.annotation.Data;
  import org.osgl.$;
  import org.osgl.util.S;
  
  import java.util.ArrayList;
  import java.util.List;
  
  /**
   * Datastructure captures a class's meta information in related to {@link DataObjectEnhancer}.
   * The following info will be captured:
   * <ul>
   *     <li>Is the class annotated with {@link Data} annotation</li>
   *     <li>A list of {@link FieldMetaInfo} of all declared fields</li>
   * </ul>
   */
  class ObjectMetaInfo implements Opcodes {
  
      /**
       * Datastructure captures a class's declared field meta info
       */
      static class FieldMetaInfo implements Opcodes {
          private String name;
          private boolean isTransient = false;
          private boolean equalForce = false;
          private boolean equalIgnore = false;
          private Type type;
          FieldMetaInfo(String name, Type type, boolean isTransient) {
              this.name = $.NPE(name);
              this.type = $.NPE(type);
              this.isTransient = isTransient;
          }
          void setEqualForce() {
              equalForce = true;
          }
          void setEqualIgnore() {
              equalIgnore = true;
          }
          void addEqualInstructions(Type host, MethodVisitor mv, Label jumpTo) {
              if (!eligible()) {
                  return;
              }
              String typeDesc = type.getDescriptor();
              // ALOAD 0: this
              // ALOAD 2: that = (Type) obj (which is 1)
              mv.visitVarInsn(ALOAD, 2);
              mv.visitFieldInsn(GETFIELD, host.getInternalName(), name, typeDesc);
              mv.visitVarInsn(ALOAD, 0);
              mv.visitFieldInsn(GETFIELD, host.getInternalName(), name, typeDesc);
              String s = typeDesc;
              if (s.length() > 1) {
                  s = OBJECT_TYPE.getDescriptor();
              }
              String op = "eq";
              if (typeDesc.startsWith("[")) {
                  // array needs deep eq
                  op = "eq2";
              }
              mv.visitMethodInsn(INVOKESTATIC, "org/osgl/Osgl", op, S.fmt("(%s%s)Z", s, s), false);
              mv.visitJumpInsn(IFEQ, jumpTo);
          }
          boolean addHashCodeInstruction(Type host, MethodVisitor mv) {
              if (!eligible()) {
                  return false;
              }
              mv.visitVarInsn(ALOAD, 0); // load this pointer
              mv.visitFieldInsn(GETFIELD, host.getInternalName(), name, type.getDescriptor());
              convertFromPrimaryType(type, mv);
              return true;
          }
          private void convertFromPrimaryType(Type fieldType, MethodVisitor mv) {
              switch (fieldType.getSort()) {
                  case Type.BOOLEAN:
                      mv.visitMethodInsn(Opcodes.INVOKESTATIC, "java/lang/Boolean", "valueOf", "(Z)Ljava/lang/Boolean;",false);
                      break;
                  case Type.BYTE:
                      mv.visitMethodInsn(Opcodes.INVOKESTATIC, "java/lang/Byte", "valueOf", "(B)Ljava/lang/Byte;",false);
                      break;
                  case Type.CHAR:
                      mv.visitMethodInsn(Opcodes.INVOKESTATIC, "java/lang/Character", "valueOf", "(C)Ljava/lang/Character;",false);
                      break;
                  case Type.SHORT:
                      mv.visitMethodInsn(Opcodes.INVOKESTATIC, "java/lang/Short", "valueOf", "(S)Ljava/lang/Short;",false);
                      break;
                  case Type.INT:
                      mv.visitMethodInsn(Opcodes.INVOKESTATIC, "java/lang/Integer", "valueOf", "(I)Ljava/lang/Integer;",false);
                      break;
                  case Type.LONG:
                      mv.visitMethodInsn(Opcodes.INVOKESTATIC, "java/lang/Long", "valueOf", "(J)Ljava/lang/Long;",false);
                      break;
                  case Type.FLOAT:
                      mv.visitMethodInsn(Opcodes.INVOKESTATIC, "java/lang/Float", "valueOf", "(F)Ljava/lang/Float;",false);
                      break;
                  case Type.DOUBLE:
                      mv.visitMethodInsn(Opcodes.INVOKESTATIC, "java/lang/Double", "valueOf", "(D)Ljava/lang/Double;",false);
                      break;
                  default:
                      // do nothing
              }
          }
          boolean eligible() {
              return !equalIgnore && (!isTransient || equalForce);
          }
      }
  
      private Type superType;
      private Type type;
      private boolean callSuper;
      private List<FieldMetaInfo> fields = new ArrayList<>();
      private boolean hasEqualMethod = false;
      private boolean hasHashCodeMethod = false;
      private boolean hasToStringMethod = false;
      private boolean hasAutoObjectAnnotation = false;
      private static Type OBJECT_TYPE = Type.getType(Object.class);
  
      ObjectMetaInfo(Type type, Type superType) {
          this.type = $.NPE(type);
          if (null != superType && !OBJECT_TYPE.equals(superType)) {
              this.superType = superType;
          }
      }
  
      Type type() {
          return type;
      }
  
      Type superType() {
          return superType;
      }
  
      List<FieldMetaInfo> fields() {
          return fields;
      }
  
      FieldMetaInfo addField(String fieldName, Type fieldType, boolean isTransient) {
          FieldMetaInfo fi = new FieldMetaInfo(fieldName, fieldType, isTransient);
          fields.add(fi);
          return fi;
      }
  
      void requireCallSuper() {
          callSuper = true;
      }
  
      boolean shouldCallSuper() {
          return callSuper && null != superType;
      }
  
      void equalMethodFound() {
          hasEqualMethod = true;
      }
  
      void hashCodeMethodFound() {
          hasHashCodeMethod = true;
      }
  
      void toStringMethodFound() {
          hasToStringMethod = true;
      }
  
      void autoObjectAnnotationFound() {
          hasAutoObjectAnnotation = true;
      }
  
      boolean hasDataAnnotation() {
          return hasAutoObjectAnnotation;
      }
  
      boolean shouldGenerateEqualsMethod() {
          return hasAutoObjectAnnotation && !hasEqualMethod;
      }
  
      boolean shouldGenerateHashCodeMethod() {
          return hasAutoObjectAnnotation && !hasHashCodeMethod;
      }
  
  }
  