/*
    * Licensed to the Apache Software Foundation (ASF) under one or more
    * contributor license agreements. See the NOTICE file distributed with this
    * work for additional information regarding copyright ownership. The ASF
    * licenses this file to You 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.apache.commons.compress.harmony.pack200;
  
  import java.io.ByteArrayOutputStream;
  import java.io.IOException;
  import java.io.OutputStream;
  import java.util.ArrayList;
  import java.util.List;
  
  import org.apache.commons.compress.harmony.pack200.Archive.PackingFile;
  import org.apache.commons.compress.harmony.pack200.Archive.SegmentUnit;
  import org.objectweb.asm.AnnotationVisitor;
  import org.objectweb.asm.Attribute;
  import org.objectweb.asm.ClassReader;
  import org.objectweb.asm.ClassVisitor;
  import org.objectweb.asm.FieldVisitor;
  import org.objectweb.asm.Label;
  import org.objectweb.asm.MethodVisitor;
  import org.objectweb.asm.Opcodes;
  import org.objectweb.asm.Type;
  
  /**
   * A Pack200 archive consists of one or more Segments.
   */
  public class Segment extends ClassVisitor {
  
      public class ArrayVisitor extends AnnotationVisitor {
  
          private final int indexInCaseArrayN;
          private final List<Integer> caseArrayN;
          private final List<Object> values;
          private final List<String> nameRU;
          private final List<String> tags;
  
          public ArrayVisitor(final List<Integer> caseArrayN, final List<String> tags, final List<String> nameRU, final List<Object> values) {
              super(ASM_API);
  
              this.caseArrayN = caseArrayN;
              this.tags = tags;
              this.nameRU = nameRU;
              this.values = values;
              this.indexInCaseArrayN = caseArrayN.size() - 1;
          }
  
          @Override
          public void visit(String name, final Object value) {
              final Integer numCases = caseArrayN.remove(indexInCaseArrayN);
              caseArrayN.add(indexInCaseArrayN, Integer.valueOf(numCases.intValue() + 1));
              if (name == null) {
                  name = "";
              }
              addValueAndTag(value, tags, values);
          }
  
          @Override
          public AnnotationVisitor visitAnnotation(final String arg0, final String arg1) {
              throw new UnsupportedOperationException("Not yet supported");
          }
  
          @Override
          public AnnotationVisitor visitArray(String name) {
              tags.add("[");
              if (name == null) {
                  name = "";
              }
              nameRU.add(name);
              caseArrayN.add(Integer.valueOf(0));
              return new ArrayVisitor(caseArrayN, tags, nameRU, values);
          }
  
          @Override
          public void visitEnd() {
          }
  
          @Override
          public void visitEnum(final String name, final String desc, final String value) {
              final Integer numCases = caseArrayN.remove(caseArrayN.size() - 1);
              caseArrayN.add(Integer.valueOf(numCases.intValue() + 1));
              tags.add("e");
              values.add(desc);
              values.add(value);
          }
      }
  
     /**
      * Exception indicating that the class currently being visited contains an unknown attribute, which means that by default the class file needs to be passed
      * through as-is in the file_bands rather than being packed with pack200.
      */
     public static class PassException extends RuntimeException {
 
         private static final long serialVersionUID = 1L;
 
     }
 
     /**
      * SegmentAnnotationVisitor implements {@code AnnotationVisitor} to visit Annotations found in a class file.
      */
     public class SegmentAnnotationVisitor extends AnnotationVisitor {
 
         private int context = -1;
         private int parameter = -1;
         private String desc;
         private boolean visible;
 
         private final List<String> nameRU = new ArrayList<>();
         private final List<String> tags = new ArrayList<>(); // tags
         private final List<Object> values = new ArrayList<>();
         private final List<Integer> caseArrayN = new ArrayList<>();
         private final List<String> nestTypeRS = new ArrayList<>();
         private final List<String> nestNameRU = new ArrayList<>();
         private final List<Integer> nestPairN = new ArrayList<>();
 
         public SegmentAnnotationVisitor(final int context) {
             super(ASM_API);
             this.context = context;
         }
 
         public SegmentAnnotationVisitor(final int context, final int parameter, final String desc, final boolean visible) {
             super(ASM_API);
             this.context = context;
             this.parameter = parameter;
             this.desc = desc;
             this.visible = visible;
         }
 
         public SegmentAnnotationVisitor(final int context, final String desc, final boolean visible) {
             super(ASM_API);
             this.context = context;
             this.desc = desc;
             this.visible = visible;
         }
 
         @Override
         public void visit(String name, final Object value) {
             if (name == null) {
                 name = "";
             }
             nameRU.add(name);
             addValueAndTag(value, tags, values);
         }
 
         @Override
         public AnnotationVisitor visitAnnotation(String name, final String desc) {
             tags.add("@");
             if (name == null) {
                 name = "";
             }
             nameRU.add(name);
             nestTypeRS.add(desc);
             nestPairN.add(Integer.valueOf(0));
             return new AnnotationVisitor(context, av) {
                 @Override
                 public void visit(final String name, final Object value) {
                     final Integer numPairs = nestPairN.remove(nestPairN.size() - 1);
                     nestPairN.add(Integer.valueOf(numPairs.intValue() + 1));
                     nestNameRU.add(name);
                     addValueAndTag(value, tags, values);
                 }
 
                 @Override
                 public AnnotationVisitor visitAnnotation(final String arg0, final String arg1) {
                     throw new UnsupportedOperationException("Not yet supported");
 //                    return null;
                 }
 
                 @Override
                 public AnnotationVisitor visitArray(final String arg0) {
                     throw new UnsupportedOperationException("Not yet supported");
 //                    return null;
                 }
 
                 @Override
                 public void visitEnd() {
                 }
 
                 @Override
                 public void visitEnum(final String name, final String desc, final String value) {
                     final Integer numPairs = nestPairN.remove(nestPairN.size() - 1);
                     nestPairN.add(Integer.valueOf(numPairs.intValue() + 1));
                     tags.add("e");
                     nestNameRU.add(name);
                     values.add(desc);
                     values.add(value);
                 }
             };
         }
 
         @Override
         public AnnotationVisitor visitArray(String name) {
             tags.add("[");
             if (name == null) {
                 name = "";
             }
             nameRU.add(name);
             caseArrayN.add(Integer.valueOf(0));
             return new ArrayVisitor(caseArrayN, tags, nameRU, values);
         }
 
         @Override
         public void visitEnd() {
             if (desc == null) {
                 Segment.this.classBands.addAnnotationDefault(nameRU, tags, values, caseArrayN, nestTypeRS, nestNameRU, nestPairN);
             } else if (parameter != -1) {
                 Segment.this.classBands.addParameterAnnotation(parameter, desc, visible, nameRU, tags, values, caseArrayN, nestTypeRS, nestNameRU, nestPairN);
             } else {
                 Segment.this.classBands.addAnnotation(context, desc, visible, nameRU, tags, values, caseArrayN, nestTypeRS, nestNameRU, nestPairN);
             }
         }
 
         @Override
         public void visitEnum(String name, final String desc, final String value) {
             tags.add("e");
             if (name == null) {
                 name = "";
             }
             nameRU.add(name);
             values.add(desc);
             values.add(value);
         }
     }
 
     /**
      * SegmentFieldVisitor implements {@code FieldVisitor} to visit the metadata relating to fields in a class file.
      */
     public class SegmentFieldVisitor extends FieldVisitor {
 
         public SegmentFieldVisitor() {
             super(ASM_API);
         }
 
         @Override
         public AnnotationVisitor visitAnnotation(final String desc, final boolean visible) {
             return new SegmentAnnotationVisitor(MetadataBandGroup.CONTEXT_FIELD, desc, visible);
         }
 
         @Override
         public void visitAttribute(final Attribute attribute) {
             if (attribute.isUnknown()) {
                 final String action = options.getUnknownAttributeAction();
                 if (action.equals(PackingOptions.PASS)) {
                     passCurrentClass();
                 } else if (action.equals(PackingOptions.ERROR)) {
                     throw new Error("Unknown attribute encountered");
                 } // else skip
             } else if (attribute instanceof NewAttribute) {
                 final NewAttribute newAttribute = (NewAttribute) attribute;
                 if (newAttribute.isUnknown(AttributeDefinitionBands.CONTEXT_FIELD)) {
                     final String action = options.getUnknownFieldAttributeAction(newAttribute.type);
                     if (action.equals(PackingOptions.PASS)) {
                         passCurrentClass();
                     } else if (action.equals(PackingOptions.ERROR)) {
                         throw new Error("Unknown attribute encountered");
                     } // else skip
                 }
                 classBands.addFieldAttribute(newAttribute);
             } else {
                 throw new IllegalArgumentException("Unexpected attribute encountered: " + attribute.type);
             }
         }
 
         @Override
         public void visitEnd() {
         }
     }
 
     /**
      * This class implements MethodVisitor to visit the contents and metadata related to methods in a class file.
      *
      * It delegates to BcBands for bytecode related visits and to ClassBands for everything else.
      */
     public class SegmentMethodVisitor extends MethodVisitor {
 
         public SegmentMethodVisitor() {
             super(ASM_API);
         }
 
         @Override
         public AnnotationVisitor visitAnnotation(final String desc, final boolean visible) {
             return new SegmentAnnotationVisitor(MetadataBandGroup.CONTEXT_METHOD, desc, visible);
         }
 
         @Override
         public AnnotationVisitor visitAnnotationDefault() {
             return new SegmentAnnotationVisitor(MetadataBandGroup.CONTEXT_METHOD);
         }
 
         @Override
         public void visitAttribute(final Attribute attribute) {
             if (attribute.isUnknown()) {
                 final String action = options.getUnknownAttributeAction();
                 if (action.equals(PackingOptions.PASS)) {
                     passCurrentClass();
                 } else if (action.equals(PackingOptions.ERROR)) {
                     throw new Error("Unknown attribute encountered");
                 } // else skip
             } else if (attribute instanceof NewAttribute) {
                 final NewAttribute newAttribute = (NewAttribute) attribute;
                 if (attribute.isCodeAttribute()) {
                     if (newAttribute.isUnknown(AttributeDefinitionBands.CONTEXT_CODE)) {
                         final String action = options.getUnknownCodeAttributeAction(newAttribute.type);
                         if (action.equals(PackingOptions.PASS)) {
                             passCurrentClass();
                         } else if (action.equals(PackingOptions.ERROR)) {
                             throw new Error("Unknown attribute encountered");
                         } // else skip
                     }
                     classBands.addCodeAttribute(newAttribute);
                 } else {
                     if (newAttribute.isUnknown(AttributeDefinitionBands.CONTEXT_METHOD)) {
                         final String action = options.getUnknownMethodAttributeAction(newAttribute.type);
                         if (action.equals(PackingOptions.PASS)) {
                             passCurrentClass();
                         } else if (action.equals(PackingOptions.ERROR)) {
                             throw new Error("Unknown attribute encountered");
                         } // else skip
                     }
                     classBands.addMethodAttribute(newAttribute);
                 }
             } else {
                 throw new IllegalArgumentException("Unexpected attribute encountered: " + attribute.type);
             }
         }
 
         @Override
         public void visitCode() {
             classBands.addCode();
         }
 
         @Override
         public void visitEnd() {
             classBands.endOfMethod();
             bcBands.visitEnd();
         }
 
         @Override
         public void visitFieldInsn(final int opcode, final String owner, final String name, final String desc) {
             bcBands.visitFieldInsn(opcode, owner, name, desc);
         }
 
         @Override
         public void visitFrame(final int arg0, final int arg1, final Object[] arg2, final int arg3, final Object[] arg4) {
             // TODO: Java 6 - implement support for this
 
         }
 
         @Override
         public void visitIincInsn(final int var, final int increment) {
             bcBands.visitIincInsn(var, increment);
         }
 
         @Override
         public void visitInsn(final int opcode) {
             bcBands.visitInsn(opcode);
         }
 
         @Override
         public void visitIntInsn(final int opcode, final int operand) {
             bcBands.visitIntInsn(opcode, operand);
         }
 
         @Override
         public void visitJumpInsn(final int opcode, final Label label) {
             bcBands.visitJumpInsn(opcode, label);
         }
 
         @Override
         public void visitLabel(final Label label) {
             bcBands.visitLabel(label);
         }
 
         @Override
         public void visitLdcInsn(final Object cst) {
             bcBands.visitLdcInsn(cst);
         }
 
         @Override
         public void visitLineNumber(final int line, final Label start) {
             if (!stripDebug) {
                 classBands.addLineNumber(line, start);
             }
         }
 
         @Override
         public void visitLocalVariable(final String name, final String desc, final String signature, final Label start, final Label end, final int index) {
             if (!stripDebug) {
                 classBands.addLocalVariable(name, desc, signature, start, end, index);
             }
         }
 
         @Override
         public void visitLookupSwitchInsn(final Label dflt, final int[] keys, final Label[] labels) {
             bcBands.visitLookupSwitchInsn(dflt, keys, labels);
         }
 
         @Override
         public void visitMaxs(final int maxStack, final int maxLocals) {
             classBands.addMaxStack(maxStack, maxLocals);
         }
 
         @Override
         public void visitMethodInsn(final int opcode, final String owner, final String name, final String desc) {
             bcBands.visitMethodInsn(opcode, owner, name, desc);
         }
 
         @Override
         public void visitMultiANewArrayInsn(final String desc, final int dimensions) {
             bcBands.visitMultiANewArrayInsn(desc, dimensions);
         }
 
         @Override
         public AnnotationVisitor visitParameterAnnotation(final int parameter, final String desc, final boolean visible) {
             return new SegmentAnnotationVisitor(MetadataBandGroup.CONTEXT_METHOD, parameter, desc, visible);
         }
 
         @Override
         public void visitTableSwitchInsn(final int min, final int max, final Label dflt, final Label... labels) {
             bcBands.visitTableSwitchInsn(min, max, dflt, labels);
         }
 
         @Override
         public void visitTryCatchBlock(final Label start, final Label end, final Label handler, final String type) {
             classBands.addHandler(start, end, handler, type);
         }
 
         @Override
         public void visitTypeInsn(final int opcode, final String type) {
             bcBands.visitTypeInsn(opcode, type);
         }
 
         @Override
         public void visitVarInsn(final int opcode, final int var) {
             bcBands.visitVarInsn(opcode, var);
         }
 
     }
 
     /** See https://asm.ow2.io/Javadoc/org/objectweb/asm/Opcodes.html#ASM4 */
     public static int ASM_API = Opcodes.ASM4;
     private SegmentHeader segmentHeader;
     private CpBands cpBands;
     private AttributeDefinitionBands attributeDefinitionBands;
 
     private IcBands icBands;
     private ClassBands classBands;
     private BcBands bcBands;
     private FileBands fileBands;
     private final SegmentFieldVisitor fieldVisitor = new SegmentFieldVisitor();
     private final SegmentMethodVisitor methodVisitor = new SegmentMethodVisitor();
 
     private Pack200ClassReader currentClassReader;
 
     private PackingOptions options;
 
     private boolean stripDebug;
 
     private Attribute[] nonStandardAttributePrototypes;
 
     public Segment() {
         super(ASM_API);
     }
 
     // helper method for annotation visitors
     private void addValueAndTag(final Object value, final List<String> tags, final List<Object> values) {
         if (value instanceof Integer) {
             tags.add("I");
             values.add(value);
         } else if (value instanceof Double) {
             tags.add("D");
             values.add(value);
         } else if (value instanceof Float) {
             tags.add("F");
             values.add(value);
         } else if (value instanceof Long) {
             tags.add("J");
             values.add(value);
         } else if (value instanceof Byte) {
             tags.add("B");
             values.add(Integer.valueOf(((Byte) value).intValue()));
         } else if (value instanceof Character) {
             tags.add("C");
             values.add(Integer.valueOf(((Character) value).charValue()));
         } else if (value instanceof Short) {
             tags.add("S");
             values.add(Integer.valueOf(((Short) value).intValue()));
         } else if (value instanceof Boolean) {
             tags.add("Z");
             values.add(Integer.valueOf(((Boolean) value).booleanValue() ? 1 : 0));
         } else if (value instanceof String) {
             tags.add("s");
             values.add(value);
         } else if (value instanceof Type) {
             tags.add("c");
             values.add(((Type) value).toString());
         }
     }
 
     public AttributeDefinitionBands getAttrBands() {
         return attributeDefinitionBands;
     }
 
     public ClassBands getClassBands() {
         return classBands;
     }
 
     public CpBands getCpBands() {
         return cpBands;
     }
 
     public Pack200ClassReader getCurrentClassReader() {
         return currentClassReader;
     }
 
     public IcBands getIcBands() {
         return icBands;
     }
 
     public SegmentHeader getSegmentHeader() {
         return segmentHeader;
     }
 
     public boolean lastConstantHadWideIndex() {
         return currentClassReader.lastConstantHadWideIndex();
     }
 
     /**
      * The main method on Segment. Reads in all the class files, packs them and then writes the packed segment out to the given OutputStream.
      *
      * @param segmentUnit TODO
      * @param out         the OutputStream to write the packed Segment to
      * @param options     packing options
      * @throws IOException      If an I/O error occurs.
      * @throws Pack200Exception TODO
      */
     public void pack(final SegmentUnit segmentUnit, final OutputStream out, final PackingOptions options) throws IOException, Pack200Exception {
         this.options = options;
         this.stripDebug = options.isStripDebug();
         final int effort = options.getEffort();
         nonStandardAttributePrototypes = options.getUnknownAttributePrototypes();
 
         PackingUtils.log("Start to pack a new segment with " + segmentUnit.fileListSize() + " files including " + segmentUnit.classListSize() + " classes");
 
         PackingUtils.log("Initialize a header for the segment");
         segmentHeader = new SegmentHeader();
         segmentHeader.setFile_count(segmentUnit.fileListSize());
         segmentHeader.setHave_all_code_flags(!stripDebug);
         if (!options.isKeepDeflateHint()) {
             segmentHeader.setDeflate_hint(Boolean.parseBoolean(options.getDeflateHint()));
         }
 
         PackingUtils.log("Setup constant pool bands for the segment");
         cpBands = new CpBands(this, effort);
 
         PackingUtils.log("Setup attribute definition bands for the segment");
         attributeDefinitionBands = new AttributeDefinitionBands(this, effort, nonStandardAttributePrototypes);
 
         PackingUtils.log("Setup internal class bands for the segment");
         icBands = new IcBands(segmentHeader, cpBands, effort);
 
         PackingUtils.log("Setup class bands for the segment");
         classBands = new ClassBands(this, segmentUnit.classListSize(), effort, stripDebug);
 
         PackingUtils.log("Setup byte code bands for the segment");
         bcBands = new BcBands(cpBands, this, effort);
 
         PackingUtils.log("Setup file bands for the segment");
         fileBands = new FileBands(cpBands, segmentHeader, options, segmentUnit, effort);
 
         processClasses(segmentUnit, nonStandardAttributePrototypes);
 
         cpBands.finaliseBands();
         attributeDefinitionBands.finaliseBands();
         icBands.finaliseBands();
         classBands.finaliseBands();
         bcBands.finaliseBands();
         fileBands.finaliseBands();
 
         // Using a temporary stream because we have to pack the other bands
         // before segmentHeader because the band_headers band is only created
         // when the other bands are packed, but comes before them in the packed
         // file.
         final ByteArrayOutputStream bandsOutputStream = new ByteArrayOutputStream();
 
         PackingUtils.log("Packing...");
         final int finalNumberOfClasses = classBands.numClassesProcessed();
         segmentHeader.setClass_count(finalNumberOfClasses);
         cpBands.pack(bandsOutputStream);
         if (finalNumberOfClasses > 0) {
             attributeDefinitionBands.pack(bandsOutputStream);
             icBands.pack(bandsOutputStream);
             classBands.pack(bandsOutputStream);
             bcBands.pack(bandsOutputStream);
         }
         fileBands.pack(bandsOutputStream);
 
         final ByteArrayOutputStream headerOutputStream = new ByteArrayOutputStream();
         segmentHeader.pack(headerOutputStream);
 
         headerOutputStream.writeTo(out);
         bandsOutputStream.writeTo(out);
 
         segmentUnit.addPackedByteAmount(headerOutputStream.size());
         segmentUnit.addPackedByteAmount(bandsOutputStream.size());
 
         PackingUtils.log("Wrote total of " + segmentUnit.getPackedByteAmount() + " bytes");
         PackingUtils.log("Transmitted " + segmentUnit.fileListSize() + " files of " + segmentUnit.getByteAmount() + " input bytes in a segment of "
                 + segmentUnit.getPackedByteAmount() + " bytes");
     }
 
     private void passCurrentClass() {
         throw new PassException();
     }
 
     private void processClasses(final SegmentUnit segmentUnit, final Attribute[] attributes) throws Pack200Exception {
         segmentHeader.setClass_count(segmentUnit.classListSize());
         for (final Pack200ClassReader classReader : segmentUnit.getClassList()) {
             currentClassReader = classReader;
             int flags = 0;
             if (stripDebug) {
                 flags |= ClassReader.SKIP_DEBUG;
             }
             try {
                 classReader.accept(this, attributes, flags);
             } catch (final PassException pe) {
                 // Pass this class through as-is rather than packing it
                 // TODO: probably need to deal with any inner classes
                 classBands.removeCurrentClass();
                 final String name = classReader.getFileName();
                 options.addPassFile(name);
                 cpBands.addCPUtf8(name);
                 boolean found = false;
                 for (final PackingFile file : segmentUnit.getFileList()) {
                     if (file.getName().equals(name)) {
                         found = true;
                         file.setContents(classReader.b);
                         break;
                     }
                 }
                 if (!found) {
                     throw new Pack200Exception("Error passing file " + name);
                 }
             }
         }
     }
 
     @Override
     public void visit(final int version, final int access, final String name, final String signature, final String superName, final String[] interfaces) {
         bcBands.setCurrentClass(name, superName);
         segmentHeader.addMajorVersion(version);
         classBands.addClass(version, access, name, signature, superName, interfaces);
     }
 
     @Override
     public AnnotationVisitor visitAnnotation(final String desc, final boolean visible) {
         return new SegmentAnnotationVisitor(MetadataBandGroup.CONTEXT_CLASS, desc, visible);
     }
 
     @Override
     public void visitAttribute(final Attribute attribute) {
         if (attribute.isUnknown()) {
             final String action = options.getUnknownAttributeAction();
             if (action.equals(PackingOptions.PASS)) {
                 passCurrentClass();
             } else if (action.equals(PackingOptions.ERROR)) {
                 throw new Error("Unknown attribute encountered");
             } // else skip
         } else if (attribute instanceof NewAttribute) {
             final NewAttribute newAttribute = (NewAttribute) attribute;
             if (newAttribute.isUnknown(AttributeDefinitionBands.CONTEXT_CLASS)) {
                 final String action = options.getUnknownClassAttributeAction(newAttribute.type);
                 if (action.equals(PackingOptions.PASS)) {
                     passCurrentClass();
                 } else if (action.equals(PackingOptions.ERROR)) {
                     throw new Error("Unknown attribute encountered");
                 } // else skip
             }
             classBands.addClassAttribute(newAttribute);
         } else {
             throw new IllegalArgumentException("Unexpected attribute encountered: " + attribute.type);
         }
     }
 
     @Override
     public void visitEnd() {
         classBands.endOfClass();
     }
 
     @Override
     public FieldVisitor visitField(final int flags, final String name, final String desc, final String signature, final Object value) {
         classBands.addField(flags, name, desc, signature, value);
         return fieldVisitor;
     }
 
     @Override
     public void visitInnerClass(final String name, final String outerName, final String innerName, final int flags) {
         icBands.addInnerClass(name, outerName, innerName, flags);
     }
 
     @Override
     public MethodVisitor visitMethod(final int flags, final String name, final String desc, final String signature, final String[] exceptions) {
         classBands.addMethod(flags, name, desc, signature, exceptions);
         return methodVisitor;
     }
 
     @Override
     public void visitOuterClass(final String owner, final String name, final String desc) {
         classBands.addEnclosingMethod(owner, name, desc);
 
     }
 
     @Override
     public void visitSource(final String source, final String debug) {
         if (!stripDebug) {
             classBands.addSourceFile(source);
         }
     }
 }