/*
    * 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
    *
   *   https://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.unpack200.bytecode;
  
  import java.io.DataOutputStream;
  import java.io.IOException;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.List;
  
  import org.apache.commons.compress.harmony.pack200.Pack200Exception;
  
  /**
   * Local variable table
   */
  public class LocalVariableTableAttribute extends BCIRenumberedAttribute {
  
      private static CPUTF8 attributeName;
  
      public static void setAttributeName(final CPUTF8 cpUTF8Value) {
          attributeName = cpUTF8Value;
      }
  
      private final int localVariableTableLength;
      private final int[] startPcs;
      private final int[] lengths;
      private int[] nameIndexes;
      private int[] descriptorIndexes;
      private final int[] indexes;
      private final CPUTF8[] names;
      private final CPUTF8[] descriptors;
  
      private int codeLength;
  
      public LocalVariableTableAttribute(final int localVariableTableLength, final int[] startPcs, final int[] lengths, final CPUTF8[] names,
              final CPUTF8[] descriptors, final int[] indexes) {
          super(attributeName);
          this.localVariableTableLength = localVariableTableLength;
          this.startPcs = startPcs;
          this.lengths = lengths;
          this.names = names;
          this.descriptors = descriptors;
          this.indexes = indexes;
      }
  
      @Override
      protected int getLength() {
          return 2 + 10 * localVariableTableLength;
      }
  
      @Override
      protected ClassFileEntry[] getNestedClassFileEntries() {
          final List<CPUTF8> nestedEntries = new ArrayList<>();
          nestedEntries.add(getAttributeName());
          for (int i = 0; i < localVariableTableLength; i++) {
              nestedEntries.add(names[i]);
              nestedEntries.add(descriptors[i]);
          }
          return nestedEntries.toArray(NONE);
      }
  
      @Override
      protected int[] getStartPCs() {
          return startPcs;
      }
  
      /*
       * (non-Javadoc)
       *
       * @see org.apache.commons.compress.harmony.unpack200.bytecode.BCIRenumberedAttribute#renumber(java.util.List)
       */
      @Override
      public void renumber(final List<Integer> byteCodeOffsets) throws Pack200Exception {
          // Remember the unrenumbered startPcs, since that's used later
          // to calculate end position.
          final int[] unrenumberedStartPcs = Arrays.copyOf(startPcs, startPcs.length);
  
          // Next renumber startPcs in place
          super.renumber(byteCodeOffsets);
  
          // lengths are BRANCH5 encoded, not BCI-encoded.
          // In other words:
          // startPc is BCI5 startPc
         // endPc is byteCodeOffset[(index of startPc in byteCodeOffset) +
         // (encoded length)]
         // real length = endPc - startPc
         // special case if endPc is beyond end of bytecode array
 
         final int maxSize = codeLength;
 
         // Iterate through the lengths and update each in turn.
         // This is done in place in the lengths array.
         for (int index = 0; index < lengths.length; index++) {
             final int startPc = startPcs[index];
             int revisedLength = -1;
             final int encodedLength = lengths[index];
 
             // First get the index of the startPc in the byteCodeOffsets
             final int indexOfStartPC = unrenumberedStartPcs[index];
             // Given the index of the startPc, we can now add
             // the encodedLength to it to get the stop index.
             final int stopIndex = indexOfStartPC + encodedLength;
             if (stopIndex < 0) {
                 throw new Pack200Exception("Error renumbering bytecode indexes");
             }
             // Length can either be an index into the byte code offsets, or one
             // beyond the
             // end of the byte code offsets. Need to determine which this is.
             if (stopIndex == byteCodeOffsets.size()) {
                 // Pointing to one past the end of the byte code array
                 revisedLength = maxSize - startPc;
             } else {
                 // We're indexed into the byte code array
                 final int stopValue = byteCodeOffsets.get(stopIndex).intValue();
                 revisedLength = stopValue - startPc;
             }
             lengths[index] = revisedLength;
         }
     }
 
     @Override
     protected void resolve(final ClassConstantPool pool) {
         super.resolve(pool);
         nameIndexes = new int[localVariableTableLength];
         descriptorIndexes = new int[localVariableTableLength];
         for (int i = 0; i < localVariableTableLength; i++) {
             names[i].resolve(pool);
             descriptors[i].resolve(pool);
             nameIndexes[i] = pool.indexOf(names[i]);
             descriptorIndexes[i] = pool.indexOf(descriptors[i]);
         }
     }
 
     public void setCodeLength(final int length) {
         codeLength = length;
     }
 
     @Override
     public String toString() {
         return "LocalVariableTable: " + +localVariableTableLength + " variables";
     }
 
     @Override
     protected void writeBody(final DataOutputStream dos) throws IOException {
         dos.writeShort(localVariableTableLength);
         for (int i = 0; i < localVariableTableLength; i++) {
             dos.writeShort(startPcs[i]);
             dos.writeShort(lengths[i]);
             dos.writeShort(nameIndexes[i]);
             dos.writeShort(descriptorIndexes[i]);
             dos.writeShort(indexes[i]);
         }
     }
 }