/*
    * Copyright (C) 2008 the original author or authors.
    *
    * 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.
   */
  
  package org.codehaus.plexus.metadata.ann;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.util.ArrayList;
  
  import org.objectweb.asm.AnnotationVisitor;
  import org.objectweb.asm.ClassReader;
  import org.objectweb.asm.ClassVisitor;
  import org.objectweb.asm.FieldVisitor;
  import org.objectweb.asm.MethodVisitor;
  import org.objectweb.asm.Opcodes;
  
  /**
   * @author Eugene Kuleshov
   */
  public class AnnReader extends ClassVisitor {
  
      private final AnnClass annClass;
  
      private AnnReader(AnnClass annClass) {
          super(Opcodes.ASM9);
          this.annClass = annClass;
      }
  
      public static AnnClass read(InputStream is, ClassLoader cl) throws IOException {
          AnnClass annClass = new AnnClass(cl);
          AnnReader cv = new AnnReader(annClass);
          ClassReader r = new ClassReader(is);
          r.accept(cv, ClassReader.SKIP_FRAMES | ClassReader.SKIP_CODE);
          return annClass;
      }
  
      public void visit(int version, int access, String name, String signature, String superName, String[] interfaces) {
          annClass.setName(name);
          annClass.setAccess(access);
          annClass.setSuperName(superName);
          annClass.setInterfaces(interfaces);
      }
  
      public AnnotationVisitor visitAnnotation(final String desc, boolean visible) {
          Ann ann = new Ann(desc);
          annClass.addAnn(ann);
          return new AnnAnnReader(ann);
      }
  
      public FieldVisitor visitField(int access, final String name, final String desc, String signature, Object value) {
          final AnnField field = new AnnField(annClass, access, name, desc);
          annClass.addField(field);
          return new FieldVisitor(Opcodes.ASM9) {
  
              public AnnotationVisitor visitAnnotation(String desc, boolean visible) {
                  Ann ann = new Ann(desc);
                  field.addAnn(ann);
                  return new AnnAnnReader(ann);
              }
          };
      }
  
      public MethodVisitor visitMethod(
              int access, final String mname, final String mdesc, String signature, String[] exceptions) {
          final AnnMethod method = new AnnMethod(annClass, access, mname, mdesc);
          annClass.addMethod(method);
  
          return new MethodVisitor(Opcodes.ASM9) {
  
              public AnnotationVisitor visitAnnotation(String desc, boolean visible) {
                  Ann ann = new Ann(desc);
                  method.addAnn(ann);
                  return new AnnAnnReader(ann);
              }
  
              public AnnotationVisitor visitParameterAnnotation(int parameter, String desc, boolean visible) {
                  Ann ann = new Ann(desc);
                  method.addParamAnn(parameter, ann);
                  return new AnnAnnReader(ann);
              }
          };
      }
  
      static class AnnAnnReader extends AnnotationVisitor {
          private Ann ann;
  
         public AnnAnnReader(Ann ann) {
             super(Opcodes.ASM9);
             this.ann = ann;
         }
 
         public void visit(String name, Object value) {
             ann.addParam(name, value);
         }
 
         public void visitEnum(String name, String desc, String value) {
             ann.addParam(name, new AnnEnum(desc, value));
         }
 
         public AnnotationVisitor visitAnnotation(String name, String desc) {
             Ann ann = new Ann(desc);
             this.ann.addParam(name, ann);
             return new AnnAnnReader(ann);
         }
 
         public AnnotationVisitor visitArray(String name) {
             return new AnnAnnArrayReader(ann, name);
         }
     }
 
     static class AnnAnnArrayReader extends AnnotationVisitor {
 
         private Ann ann;
 
         private String name;
 
         // TODO good enough for now, but does not cover general case
         private ArrayList<String> array = new ArrayList<String>();
 
         public AnnAnnArrayReader(Ann ann, String name) {
             super(Opcodes.ASM9);
             this.ann = ann;
             this.name = name;
         }
 
         public void visit(String name, Object value) {
             if (value instanceof String) {
                 array.add((String) value);
             }
         }
 
         public void visitEnd() {
             ann.addParam(name, array.toArray(new String[array.size()]));
         }
     }
 }