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.AnnotationVisitor;
  import act.asm.ClassWriter;
  import act.asm.Type;
  import act.plugin.Extends;
  import org.osgl.$;
  import org.osgl.exception.NotAppliedException;
  import org.osgl.logging.L;
  import org.osgl.logging.Logger;
  import org.osgl.util.C;
  import org.osgl.util.E;
  import org.osgl.util.S;
  
  import java.lang.annotation.Annotation;
  import java.util.ArrayList;
  import java.util.List;
  
  public abstract class ClassDetector extends ByteCodeVisitor {
  
      protected static final Logger logger = L.get(ClassDetector.class);
  
      private String className;
  
      public abstract boolean found();
  
      public String className() {
          return className;
      }
  
      @Override
      public void visit(int version, int access, String name, String signature, String superName, String[] interfaces) {
          className = Type.getObjectType(name).getClassName();
          super.visit(version, access, name, signature, superName, interfaces);
      }
  
      private static class FilteredClassDetector extends ClassDetector {
          private final ClassFilter filter;
          private boolean found = false;
          private boolean skip = false;
  
          FilteredClassDetector(ClassFilter filter) {
              E.NPE(filter);
              this.filter = filter;
          }
  
          @Override
          public int hashCode() {
              return $.hc(filter, FilteredClassDetector.class);
          }
  
          @Override
          public boolean equals(Object obj) {
              if (obj == this) {
                  return true;
              }
              if (obj instanceof FilteredClassDetector) {
                  FilteredClassDetector that = (FilteredClassDetector)obj;
                  return $.eq(that.filter, this.filter);
              }
              return false;
          }
  
          @Override
          public boolean found() {
              return found;
          }
  
          @Override
          public void visit(int version, int access, String name, String signature, String superName, String[] interfaces) {
              super.visit(version, access, name, signature, superName, interfaces);
              if (filter.noAbstract() && ((access & ACC_ABSTRACT) != 0 || (access & ACC_INTERFACE) != 0)) {
                  skip = true;
                  return;
              }
              if (filter.publicOnly() && (access & ACC_PUBLIC) != 1) {
                  skip = true;
                  return;
              }
              Class<?> superType = filter.superType();
              if (null == superType) {
                  return; // we will check annotation type anyway
              }
              final String expected = superType.getName();
              if (checkName(expected, superName)) {
                  found = true;
                  return;
              }
              int len = interfaces.length;
              for (int i = 0; i < len; ++i) {
                  String s = interfaces[i];
                  if (checkName(expected, s)) {
                      found = true;
                      return;
                  }
              }
          }
  
          @Override
          public AnnotationVisitor visitAnnotation(String desc, boolean visible) {
              AnnotationVisitor av = super.visitAnnotation(desc, visible);
              if (found || skip) {
                  return av;
              }
              if (isExtendsAnnotation(desc)) {
                  Class<?> superType = filter.superType();
                  if (null != superType) {
                      return new ExtendedAnnotationVisitor(av, superType.getName());
                  } else {
                      return av;
                  }
              }
              Class<? extends Annotation> annoType = filter.annotationType();
              if (null == annoType) {
                  return av;
              }
              if (isAnnotation(annoType, desc)) {
                  found = true;
              }
              return av;
          }
  
          private boolean checkName(String expected, String found) {
              Type type = Type.getObjectType(found);
              return type.getClassName().equals(expected);
          }
  
          private final class ExtendedAnnotationVisitor extends AnnotationVisitor {
  
              private String expected;
  
              public ExtendedAnnotationVisitor(AnnotationVisitor av, String expected) {
                  super(ASM5, av);
                  this.expected = expected;
              }
  
              @Override
              public void visit(String name, Object value) {
                  found = found || "value".equals(name) && (value instanceof Type) && ((Type) value).getClassName().equals(expected);
                  super.visit(name, value);
              }
          }
      }
  
      private static boolean isExtendsAnnotation(String desc) {
          return isAnnotation(Extends.class, desc);
      }
  
      private static boolean isAnnotation(Class<? extends Annotation> annoType, String desc) {
          return S.eq(annoType.getName(), Type.getType(desc).getClassName());
      }
  
      public static ClassDetector chain(ClassWriter cw, ClassFilter... filters) {
          return (ClassDetector) chain(cw, of(filters));
      }
  
      public static ClassDetector of(final ClassFilter... filters) {
          E.illegalArgumentIf(filters.length == 0);
          if (filters.length == 1) {
              return new FilteredClassDetector(filters[0]);
          }
          return new ClassDetector() {
              C.List<ClassDetector> detectors = C.listOf(filters).map(new $.F1<ClassFilter, ClassDetector>() {
                  @Override
                  public ClassDetector apply(ClassFilter classFilter) throws NotAppliedException, $.Break {
                      return new FilteredClassDetector(classFilter);
                  }
              });
              private List<ClassDetector> matches = new ArrayList<>();
  
              @Override
              public int hashCode() {
                  return $.hc(detectors);
              }
  
              @Override
              public boolean equals(Object obj) {
                  return obj == this;
              }
  
              @Override
              public void visit(int version, int access, String name, String signature, String superName, String[] interfaces) {
                  super.visit(version, access, name, signature, superName, interfaces);
                  for (ClassDetector detector : detectors) {
                      detector.visit(version, access, name, signature, superName, interfaces);
                      if (detector.found()) {
                          matches.add(detector);
                      }
                  }
              }
  
              @Override
              public AnnotationVisitor visitAnnotation(final String desc, final boolean visible) {
                  AnnotationVisitor av = super.visitAnnotation(desc, visible);
                  if (matches.size() == detectors.size() || !isExtendsAnnotation(desc)) {
                      return av;
                  }
                  final C.List<ClassDetector> unmatched = detectors.without(matches);
                  return new AnnotationVisitor(ASM5, av) {
                      @Override
                      public void visit(String name, Object value) {
                          for (ClassDetector detector : unmatched) {
                              AnnotationVisitor av0 = detector.visitAnnotation(desc, visible);
                              av0.visit(name, value);
                              if (detector.found()) {
                                  matches.add(detector);
                              }
                          }
                          super.visit(name, value);
                      }
                  };
              }
  
              @Override
              public boolean found() {
                  return !matches.isEmpty();
              }
          };
      }
  
  }
  