content: package act.app.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.Act;
  import act.asm.AnnotationVisitor;
  import act.exception.EnvNotMatchException;
  import act.sys.Env;
  import act.util.ByteCodeVisitor;
  import org.osgl.util.E;
  import org.rythmengine.utils.S;
  
  import java.util.ArrayList;
  import java.util.List;
  
  /**
   * Detect if a class has `Env` annotations and check if
   * the class's `Env` annotation matches current running environment
   */
  public class EnvMatcher extends ByteCodeVisitor {
  
      public EnvMatcher() {
      }
  
      @Override
      public AnnotationVisitor visitAnnotation(String desc, boolean visible) {
          AnnotationVisitor av = super.visitAnnotation(desc, visible);
          if (desc.startsWith("Lact/sys/Env$")) {
              return new EnvAnnotationVisitor(av, desc);
          }
          return av;
      }
  
      private static class EnvAnnotationVisitor extends AnnotationVisitor {
  
          enum Type {
              Profile() {
                  @Override
                  boolean matches(EnvAnnotationVisitor visitor) {
                      return Env.profileMatches(visitor.arrayValue.toArray(new String[visitor.arrayValue.size()]), visitor.except);
                  }
              }, Group() {
                  @Override
                  boolean matches(EnvAnnotationVisitor visitor) {
                      return Env.groupMatches(visitor.arrayValue.toArray(new String[visitor.arrayValue.size()]), visitor.except);
                  }
              }, Mode() {
                  @Override
                  boolean matches(EnvAnnotationVisitor visitor) {
                      return Env.modeMatches(Act.Mode.valueOf(visitor.value), visitor.except);
                  }
              };
  
              abstract boolean matches(EnvAnnotationVisitor visitor);
          }
  
          private Type type;
          private List<String> arrayValue = new ArrayList<>();
          private String value;
          private boolean except;
  
          public EnvAnnotationVisitor(AnnotationVisitor av, String desc) {
              super(ASM5, av);
              initType(desc);
          }
  
          @Override
          public void visit(String name, Object value) {
              if ("value".equals(name)) {
                  this.value = value.toString();
              } else if ("except".equals(name)) {
                  this.except = Boolean.parseBoolean(value.toString());
              }
              super.visit(name, value);
          }
  
          @Override
          public AnnotationVisitor visitArray(String name) {
              AnnotationVisitor av = super.visitArray(name);
              if ("value".equals(name)) {
                  return new AnnotationVisitor(ASM5, av) {
                      @Override
                      public void visit(String name, Object value) {
                          arrayValue.add(S.string(value));
                          super.visit(name, value);
                      }
                  };
              }
              return av;
          }
  
          @Override
          public void visitEnum(String name, String desc, String value) {
              if ("value".equals(name)) {
                  this.value = value;
              }
              super.visitEnum(name, desc, value);
          }
  
          private void initType(String desc) {
              if (desc.contains("Profile")) {
                  type = Type.Profile;
              } else if (desc.contains("Mode")) {
                  type = Type.Mode;
              } else if (desc.contains("Group")) {
                  type = Type.Group;
              } else {
                  throw E.unexpected("Unknown Env annotation: %s", desc);
              }
          }
  
          @Override
          public void visitEnd() {
              if (!matches()) {
                  throw new EnvNotMatchException();
              }
              super.visitEnd();
          }
  
          private boolean matches() {
              return type.matches(this);
          }
      }
  }
  