/*
    * 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;
  
  import org.apache.commons.compress.harmony.pack200.Codec;
  import org.apache.commons.compress.harmony.pack200.Pack200Exception;
  import org.apache.commons.compress.harmony.unpack200.bytecode.ClassFileEntry;
  import org.apache.commons.lang3.StringUtils;
  
  /**
   * Defines a layout that describes how an attribute will be transmitted.
   */
  public class AttributeLayout implements IMatcher {
  
      /**
       * {@value}
       */
      public static final String ACC_ABSTRACT = "ACC_ABSTRACT"; //$NON-NLS-1$
  
      /**
       * {@value}
       */
      public static final String ACC_ANNOTATION = "ACC_ANNOTATION"; //$NON-NLS-1$
  
      /**
       * {@value}
       */
      public static final String ACC_ENUM = "ACC_ENUM"; //$NON-NLS-1$
  
      /**
       * {@value}
       */
      public static final String ACC_FINAL = "ACC_FINAL"; //$NON-NLS-1$
  
      /**
       * {@value}
       */
      public static final String ACC_INTERFACE = "ACC_INTERFACE"; //$NON-NLS-1$
  
      /**
       * {@value}
       */
      public static final String ACC_NATIVE = "ACC_NATIVE"; //$NON-NLS-1$
  
      /**
       * {@value}
       */
      public static final String ACC_PRIVATE = "ACC_PRIVATE"; //$NON-NLS-1$
  
      /**
       * {@value}
       */
      public static final String ACC_PROTECTED = "ACC_PROTECTED"; //$NON-NLS-1$
  
      /**
       * {@value}
       */
      public static final String ACC_PUBLIC = "ACC_PUBLIC"; //$NON-NLS-1$
  
      /**
       * {@value}
       */
      public static final String ACC_STATIC = "ACC_STATIC"; //$NON-NLS-1$
  
      /**
       * {@value}
       */
      public static final String ACC_STRICT = "ACC_STRICT"; //$NON-NLS-1$
  
      /**
       * {@value}
       */
      public static final String ACC_SYNCHRONIZED = "ACC_SYNCHRONIZED"; //$NON-NLS-1$
  
      /**
       * {@value}
       */
      public static final String ACC_SYNTHETIC = "ACC_SYNTHETIC"; //$NON-NLS-1$
  
      /**
       * {@value}
       */
      public static final String ACC_TRANSIENT = "ACC_TRANSIENT"; //$NON-NLS-1$
 
     /**
      * {@value}
      */
     public static final String ACC_VOLATILE = "ACC_VOLATILE"; //$NON-NLS-1$
 
     /**
      * {@value}
      */
     public static final String ATTRIBUTE_ANNOTATION_DEFAULT = "AnnotationDefault"; //$NON-NLS-1$
 
     /**
      * {@value}
      */
     public static final String ATTRIBUTE_CLASS_FILE_VERSION = "class-file version"; //$NON-NLS-1$
 
     /**
      * {@value}
      */
     public static final String ATTRIBUTE_CODE = "Code"; //$NON-NLS-1$
 
     /**
      * {@value}
      */
     public static final String ATTRIBUTE_CONSTANT_VALUE = "ConstantValue"; //$NON-NLS-1$
 
     /**
      * {@value}
      */
     public static final String ATTRIBUTE_DEPRECATED = "Deprecated"; //$NON-NLS-1$
 
     /**
      * {@value}
      */
     public static final String ATTRIBUTE_ENCLOSING_METHOD = "EnclosingMethod"; //$NON-NLS-1$
 
     /**
      * {@value}
      */
     public static final String ATTRIBUTE_EXCEPTIONS = "Exceptions"; //$NON-NLS-1$
 
     /**
      * {@value}
      */
     public static final String ATTRIBUTE_INNER_CLASSES = "InnerClasses"; //$NON-NLS-1$
 
     /**
      * {@value}
      */
     public static final String ATTRIBUTE_LINE_NUMBER_TABLE = "LineNumberTable"; //$NON-NLS-1$
 
     /**
      * {@value}
      */
     public static final String ATTRIBUTE_LOCAL_VARIABLE_TABLE = "LocalVariableTable"; //$NON-NLS-1$
 
     /**
      * {@value}
      */
     public static final String ATTRIBUTE_LOCAL_VARIABLE_TYPE_TABLE = "LocalVariableTypeTable"; //$NON-NLS-1$
 
     /**
      * {@value}
      */
     public static final String ATTRIBUTE_RUNTIME_INVISIBLE_ANNOTATIONS = "RuntimeInvisibleAnnotations"; //$NON-NLS-1$
 
     /**
      * {@value}
      */
     public static final String ATTRIBUTE_RUNTIME_INVISIBLE_PARAMETER_ANNOTATIONS = "RuntimeInvisibleParameterAnnotations"; //$NON-NLS-1$
 
     /**
      * {@value}
      */
     public static final String ATTRIBUTE_RUNTIME_VISIBLE_ANNOTATIONS = "RuntimeVisibleAnnotations"; //$NON-NLS-1$
 
     /**
      * {@value}
      */
     public static final String ATTRIBUTE_RUNTIME_VISIBLE_PARAMETER_ANNOTATIONS = "RuntimeVisibleParameterAnnotations"; //$NON-NLS-1$
 
     /**
      * {@value}
      */
     public static final String ATTRIBUTE_SIGNATURE = "Signature"; //$NON-NLS-1$
 
     /**
      * {@value}
      */
     public static final String ATTRIBUTE_SOURCE_FILE = "SourceFile"; //$NON-NLS-1$
 
     /**
      * {@value}
      */
     public static final int CONTEXT_CLASS = 0;
 
     /**
      * {@value}
      */
     public static final int CONTEXT_CODE = 3;
 
     /**
      * {@value}
      */
     public static final int CONTEXT_FIELD = 1;
 
     /**
      * {@value}
      */
     public static final int CONTEXT_METHOD = 2;
 
     /**
      * Context names.
      */
     public static final String[] contextNames = { "Class", "Field", "Method", //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
             "Code", }; //$NON-NLS-1$
 
     private static ClassFileEntry getValue(final String layout, long longIndex, final SegmentConstantPool pool) throws Pack200Exception {
         if (layout.startsWith("R")) { //$NON-NLS-1$
             // references
             if (layout.indexOf('N') != -1) {
                 longIndex--;
             }
             if (layout.startsWith("RU")) { //$NON-NLS-1$
                 return pool.getValue(SegmentConstantPool.UTF_8, longIndex);
             }
             if (layout.startsWith("RS")) { //$NON-NLS-1$
                 return pool.getValue(SegmentConstantPool.SIGNATURE, longIndex);
             }
         } else if (layout.startsWith("K")) { //$NON-NLS-1$
             final char type = layout.charAt(1);
             switch (type) {
             case 'S': // String
                 return pool.getValue(SegmentConstantPool.CP_STRING, longIndex);
             case 'I': // Int (or byte or short)
             case 'C': // Char
                 return pool.getValue(SegmentConstantPool.CP_INT, longIndex);
             case 'F': // Float
                 return pool.getValue(SegmentConstantPool.CP_FLOAT, longIndex);
             case 'J': // Long
                 return pool.getValue(SegmentConstantPool.CP_LONG, longIndex);
             case 'D': // Double
                 return pool.getValue(SegmentConstantPool.CP_DOUBLE, longIndex);
             }
         }
         throw new Pack200Exception("Unknown layout encoding: " + layout);
     }
 
     private final int context;
 
     private final int index;
 
     private final String layout;
 
     private long mask;
 
     private final String name;
     private final boolean isDefault;
     private int backwardsCallCount;
 
     /**
      * Constructs a default AttributeLayout (equivalent to {@code new AttributeLayout(name, context, layout, index, true);})
      *
      * @param name    The layout name.
      * @param context One of {@link #CONTEXT_CLASS}, {@link #CONTEXT_CODE}, {@link #CONTEXT_FIELD}, {@link #CONTEXT_METHOD}.
      * @param layout  The layout.
      * @param index   The index, currently used as part of computing the hash code.
      * @throws Pack200Exception Attribute context out of range.
      * @throws Pack200Exception Cannot have a null layout.
      * @throws Pack200Exception Cannot have an unnamed layout.
      */
     public AttributeLayout(final String name, final int context, final String layout, final int index) throws Pack200Exception {
         this(name, context, layout, index, true);
     }
 
     /**
      * Constructs a default AttributeLayout (equivalent to {@code new AttributeLayout(name, context, layout, index, true);})
      *
      * @param name    The layout name.
      * @param context One of {@link #CONTEXT_CLASS}, {@link #CONTEXT_CODE}, {@link #CONTEXT_FIELD}, {@link #CONTEXT_METHOD}.
      * @param layout  The layout.
      * @param index   The index, currently used as part of computing the hash code.
      * @param isDefault Whether this is the default layout.
      * @throws Pack200Exception Attribute context out of range.
      * @throws Pack200Exception Cannot have a null layout.
      * @throws Pack200Exception Cannot have an unnamed layout.
      */
     public AttributeLayout(final String name, final int context, final String layout, final int index, final boolean isDefault) throws Pack200Exception {
         this.index = index;
         this.context = context;
         if (index >= 0) {
             this.mask = 1L << index;
         } else {
             this.mask = 0;
         }
         if (context != CONTEXT_CLASS && context != CONTEXT_CODE && context != CONTEXT_FIELD && context != CONTEXT_METHOD) {
             throw new Pack200Exception("Attribute context out of range: " + context);
         }
         if (layout == null) {
             throw new Pack200Exception("Cannot have a null layout");
         }
         if (StringUtils.isEmpty(name)) {
             throw new Pack200Exception("Cannot have an unnamed layout");
         }
         this.name = name;
         this.layout = layout;
         this.isDefault = isDefault;
     }
 
     /**
      * Gets the Codec based on the layout.
      *
      * @return the Codec.
      */
     public Codec getCodec() {
         if (layout.indexOf('O') >= 0) {
             return Codec.BRANCH5;
         }
         if (layout.indexOf('P') >= 0) {
             return Codec.BCI5;
         }
         if (layout.indexOf('S') >= 0 && !layout.contains("KS") //$NON-NLS-1$
                 && !layout.contains("RS")) { //$NON-NLS-1$
             return Codec.SIGNED5;
         }
         if (layout.indexOf('B') >= 0) {
             return Codec.BYTE1;
         }
         return Codec.UNSIGNED5;
     }
 
     /**
      * Gets the context.
      *
      * @return the context.
      */
     public int getContext() {
         return context;
     }
 
     /**
      * Gets the index.
      *
      * @return the index.
      */
     public int getIndex() {
         return index;
     }
 
     /**
      * Gets the layout.
      *
      * @return the layout.
      */
     public String getLayout() {
         return layout;
     }
 
     /**
      * Gets the name.
      *
      * @return the name.
      */
     public String getName() {
         return name;
     }
 
     /**
      * Gets the ClassFileEntry for the given input.
      *
      * @param longIndex An index into the segment constant pool.
      * @param pool the segment constant pool.
      * @return the matching ClassFileEntry.
      * @throws Pack200Exception if the input is invalid.
      */
     public ClassFileEntry getValue(final long longIndex, final SegmentConstantPool pool) throws Pack200Exception {
         return getValue(layout, longIndex, pool);
     }
 
     /**
      * Gets the ClassFileEntry for the given input.
      *
      * @param longIndex An index into the segment constant pool.
      * @param type the Java type signature.
      * @param pool the segment constant pool.
      * @return the matching ClassFileEntry.
      * @throws Pack200Exception if the input is invalid.
      */
     public ClassFileEntry getValue(final long longIndex, final String type, final SegmentConstantPool pool) throws Pack200Exception {
         // TODO This really needs to be better tested, esp. the different types
         // TODO This should have the ability to deal with RUN stuff too, and
         // unions
         if (!layout.startsWith("KQ")) {
             return getValue(layout, longIndex, pool);
         }
         if (type.equals("Ljava/lang/String;")) { //$NON-NLS-1$
             return getValue("KS", longIndex, pool);
         }
         return getValue("K" + type + layout.substring(2), longIndex, //$NON-NLS-1$
                 pool);
     }
 
     @Override
     public int hashCode() {
         final int prime = 31;
         int r = 1;
         if (name != null) {
             r = r * prime + name.hashCode();
         }
         if (layout != null) {
             r = r * prime + layout.hashCode();
         }
         r = r * prime + index;
         r = r * prime + context;
         return r;
     }
 
     /**
      * Tests whether this is the default layout.
      *
      * @return whether this is the default layout.
      */
     public boolean isDefaultLayout() {
         return isDefault;
     }
 
     /*
      * (non-Javadoc)
      *
      * @see org.apache.commons.compress.harmony.unpack200.IMatches#matches(long)
      */
     @Override
     public boolean matches(final long value) {
         return (value & mask) != 0;
     }
 
     /**
      * Gets the backward call count.
      *
      * @return the backward call count.
      */
     public int numBackwardsCallables() {
         if ("*".equals(layout)) {
             return 1;
         }
         return backwardsCallCount;
     }
 
     /**
      * Sets the backward call count.
      *
      * @param backwardsCallCount the backward call count.
      */
     public void setBackwardsCallCount(final int backwardsCallCount) {
         this.backwardsCallCount = backwardsCallCount;
     }
 
     @Override
     public String toString() {
         return contextNames[context] + ": " + name;
     }
 
 }