////////////////////////////////////////////////////////////////////////////////
   // checkstyle: Checks Java source code for adherence to a set of rules.
   // Copyright (C) 2001-2019 the original author or authors.
   //
   // This library is free software; you can redistribute it and/or
   // modify it under the terms of the GNU Lesser General Public
   // License as published by the Free Software Foundation; either
   // version 2.1 of the License, or (at your option) any later version.
   //
  // This library is distributed in the hope that it will be useful,
  // but WITHOUT ANY WARRANTY; without even the implied warranty of
  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  // Lesser General Public License for more details.
  //
  // You should have received a copy of the GNU Lesser General Public
  // License along with this library; if not, write to the Free Software
  // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  ////////////////////////////////////////////////////////////////////////////////
  
  package com.puppycrawl.tools.checkstyle.checks.javadoc;
  
  import java.util.Arrays;
  import java.util.Collections;
  import java.util.Map;
  import java.util.stream.Collectors;
  
  import com.puppycrawl.tools.checkstyle.api.DetailAST;
  import com.puppycrawl.tools.checkstyle.api.Scope;
  import com.puppycrawl.tools.checkstyle.api.TokenTypes;
  import com.puppycrawl.tools.checkstyle.utils.ScopeUtil;
  
  /**
   * This enum defines the various Javadoc tags and there properties.
   *
   * <p>
   * This class was modeled after documentation located at
   * <a href="https://docs.oracle.com/javase/8/docs/technotes/tools/windows/javadoc.html">
   * javadoc</a>
   *
   * and
   *
   * <a href="https://www.oracle.com/technetwork/java/javase/documentation/index-137868.html">
   * how to write</a>.
   * </p>
   *
   * <p>
   * Some of this documentation was a little incomplete (ex: valid placement of
   * code, value, and literal tags).
   * </p>
   *
   * <p>
   * Whenever an inconsistency was found the author's judgment was used.
   * </p>
   *
   * <p>
   * For now, the number of required/optional tag arguments are not included
   * because some Javadoc tags have very complex rules for determining this
   * (ex: {@code {@value}} tag).
   * </p>
   *
   * <p>
   * Also, the {@link #isValidOn(DetailAST) isValidOn} method does not consider
   * classes defined in a local code block (method, init block, etc.).
   * </p>
   *
   */
  public enum JavadocTagInfo {
  
      /**
       * {@code @author}.
       */
      AUTHOR("@author", "author", Type.BLOCK) {
  
          @Override
          public boolean isValidOn(final DetailAST ast) {
              final int astType = ast.getType();
              return astType == TokenTypes.PACKAGE_DEF
                  || astType == TokenTypes.CLASS_DEF
                  || astType == TokenTypes.INTERFACE_DEF
                  || astType == TokenTypes.ENUM_DEF
                  || astType == TokenTypes.ANNOTATION_DEF;
          }
  
      },
  
      /**
       * {@code {@code}}.
       */
      CODE("{@code}", "code", Type.INLINE) {
  
          @Override
          public boolean isValidOn(final DetailAST ast) {
              final int astType = ast.getType();
              return Arrays.binarySearch(DEF_TOKEN_TYPES, astType) >= 0
                  && !ScopeUtil.isLocalVariableDef(ast);
          }
  
      },
  
     /**
      * {@code {@docRoot}}.
      */
     DOC_ROOT("{@docRoot}", "docRoot", Type.INLINE) {
 
         @Override
         public boolean isValidOn(final DetailAST ast) {
             final int astType = ast.getType();
             return Arrays.binarySearch(DEF_TOKEN_TYPES, astType) >= 0
                 && !ScopeUtil.isLocalVariableDef(ast);
         }
 
     },
 
     /**
      * {@code @deprecated}.
      */
     DEPRECATED("@deprecated", "deprecated", Type.BLOCK) {
 
         @Override
         public boolean isValidOn(final DetailAST ast) {
             final int astType = ast.getType();
             return Arrays.binarySearch(DEF_TOKEN_TYPES_DEPRECATED, astType) >= 0
                 && !ScopeUtil.isLocalVariableDef(ast);
         }
 
     },
 
     /**
      * {@code @exception}.
      */
     EXCEPTION("@exception", "exception", Type.BLOCK) {
 
         @Override
         public boolean isValidOn(final DetailAST ast) {
             final int astType = ast.getType();
             return astType == TokenTypes.METHOD_DEF || astType == TokenTypes.CTOR_DEF;
         }
 
     },
 
     /**
      * {@code {@inheritDoc}}.
      */
     INHERIT_DOC("{@inheritDoc}", "inheritDoc", Type.INLINE) {
 
         @Override
         public boolean isValidOn(final DetailAST ast) {
             final int astType = ast.getType();
 
             return astType == TokenTypes.METHOD_DEF
                 && ast.findFirstToken(TokenTypes.MODIFIERS)
                     .findFirstToken(TokenTypes.LITERAL_STATIC) == null
                 && ScopeUtil.getScopeFromMods(ast
                     .findFirstToken(TokenTypes.MODIFIERS)) != Scope.PRIVATE;
         }
 
     },
 
     /**
      * {@code {@link}}.
      */
     LINK("{@link}", "link", Type.INLINE) {
 
         @Override
         public boolean isValidOn(final DetailAST ast) {
             final int astType = ast.getType();
             return Arrays.binarySearch(DEF_TOKEN_TYPES, astType) >= 0
                 && !ScopeUtil.isLocalVariableDef(ast);
         }
 
     },
 
     /**
      * {@code {@linkplain}}.
      */
     LINKPLAIN("{@linkplain}", "linkplain", Type.INLINE) {
 
         @Override
         public boolean isValidOn(final DetailAST ast) {
             final int astType = ast.getType();
             return Arrays.binarySearch(DEF_TOKEN_TYPES, astType) >= 0
                 && !ScopeUtil.isLocalVariableDef(ast);
         }
 
     },
 
     /**
      * {@code {@literal}}.
      */
     LITERAL("{@literal}", "literal", Type.INLINE) {
 
         @Override
         public boolean isValidOn(final DetailAST ast) {
             final int astType = ast.getType();
             return Arrays.binarySearch(DEF_TOKEN_TYPES, astType) >= 0
                 && !ScopeUtil.isLocalVariableDef(ast);
         }
 
     },
 
     /**
      * {@code @param}.
      */
     PARAM("@param", "param", Type.BLOCK) {
 
         @Override
         public boolean isValidOn(final DetailAST ast) {
             final int astType = ast.getType();
             return astType == TokenTypes.CLASS_DEF
                 || astType == TokenTypes.INTERFACE_DEF
                 || astType == TokenTypes.METHOD_DEF
                 || astType == TokenTypes.CTOR_DEF;
         }
 
     },
 
     /**
      * {@code @return}.
      */
     RETURN("@return", "return", Type.BLOCK) {
 
         @Override
         public boolean isValidOn(final DetailAST ast) {
             final int astType = ast.getType();
             final DetailAST returnType = ast.findFirstToken(TokenTypes.TYPE);
 
             return astType == TokenTypes.METHOD_DEF
                 && returnType.getFirstChild().getType() != TokenTypes.LITERAL_VOID;
         }
 
     },
 
     /**
      * {@code @see}.
      */
     SEE("@see", "see", Type.BLOCK) {
 
         @Override
         public boolean isValidOn(final DetailAST ast) {
             final int astType = ast.getType();
             return Arrays.binarySearch(DEF_TOKEN_TYPES, astType) >= 0
                 && !ScopeUtil.isLocalVariableDef(ast);
         }
 
     },
 
     /**
      * {@code @serial}.
      */
     SERIAL("@serial", "serial", Type.BLOCK) {
 
         @Override
         public boolean isValidOn(final DetailAST ast) {
             final int astType = ast.getType();
 
             return astType == TokenTypes.VARIABLE_DEF
                 && !ScopeUtil.isLocalVariableDef(ast);
         }
 
     },
 
     /**
      * {@code @serialData}.
      */
     SERIAL_DATA("@serialData", "serialData", Type.BLOCK) {
 
         @Override
         public boolean isValidOn(final DetailAST ast) {
             final int astType = ast.getType();
             final DetailAST methodNameAst = ast.findFirstToken(TokenTypes.IDENT);
             final String methodName = methodNameAst.getText();
 
             return astType == TokenTypes.METHOD_DEF
                 && ("writeObject".equals(methodName)
                     || "readObject".equals(methodName)
                     || "writeExternal".equals(methodName)
                     || "readExternal".equals(methodName)
                     || "writeReplace".equals(methodName)
                     || "readResolve".equals(methodName));
         }
 
     },
 
     /**
      * {@code @serialField}.
      */
     SERIAL_FIELD("@serialField", "serialField", Type.BLOCK) {
 
         @Override
         public boolean isValidOn(final DetailAST ast) {
             final int astType = ast.getType();
             final DetailAST varType = ast.findFirstToken(TokenTypes.TYPE);
 
             return astType == TokenTypes.VARIABLE_DEF
                 && varType.getFirstChild().getType() == TokenTypes.ARRAY_DECLARATOR
                 && "ObjectStreamField".equals(varType.getFirstChild().getText());
         }
 
     },
 
     /**
      * {@code @since}.
      */
     SINCE("@since", "since", Type.BLOCK) {
 
         @Override
         public boolean isValidOn(final DetailAST ast) {
             final int astType = ast.getType();
             return Arrays.binarySearch(DEF_TOKEN_TYPES, astType) >= 0
                 && !ScopeUtil.isLocalVariableDef(ast);
         }
 
     },
 
     /**
      * {@code @throws}.
      */
     THROWS("@throws", "throws", Type.BLOCK) {
 
         @Override
         public boolean isValidOn(final DetailAST ast) {
             final int astType = ast.getType();
             return astType == TokenTypes.METHOD_DEF
                 || astType == TokenTypes.CTOR_DEF;
         }
 
     },
 
     /**
      * {@code {@value}}.
      */
     VALUE("{@value}", "value", Type.INLINE) {
 
         @Override
         public boolean isValidOn(final DetailAST ast) {
             final int astType = ast.getType();
             return Arrays.binarySearch(DEF_TOKEN_TYPES, astType) >= 0
                 && !ScopeUtil.isLocalVariableDef(ast);
         }
 
     },
 
     /**
      * {@code @version}.
      */
     VERSION("@version", "version", Type.BLOCK) {
 
         @Override
         public boolean isValidOn(final DetailAST ast) {
             final int astType = ast.getType();
             return astType == TokenTypes.PACKAGE_DEF
                 || astType == TokenTypes.CLASS_DEF
                 || astType == TokenTypes.INTERFACE_DEF
                 || astType == TokenTypes.ENUM_DEF
                 || astType == TokenTypes.ANNOTATION_DEF;
         }
 
     };
 
     /** Default token types for DEPRECATED Javadoc tag.*/
     private static final int[] DEF_TOKEN_TYPES_DEPRECATED = {
         TokenTypes.CTOR_DEF,
         TokenTypes.METHOD_DEF,
         TokenTypes.VARIABLE_DEF,
         TokenTypes.CLASS_DEF,
         TokenTypes.INTERFACE_DEF,
         TokenTypes.ENUM_DEF,
         TokenTypes.ENUM_CONSTANT_DEF,
         TokenTypes.ANNOTATION_DEF,
         TokenTypes.ANNOTATION_FIELD_DEF,
     };
 
     /** Default token types.*/
     private static final int[] DEF_TOKEN_TYPES = {
         TokenTypes.CTOR_DEF,
         TokenTypes.METHOD_DEF,
         TokenTypes.VARIABLE_DEF,
         TokenTypes.CLASS_DEF,
         TokenTypes.INTERFACE_DEF,
         TokenTypes.PACKAGE_DEF,
         TokenTypes.ENUM_DEF,
         TokenTypes.ANNOTATION_DEF,
     };
 
     /** Holds tag text to tag enum mappings. **/
     private static final Map<String, JavadocTagInfo> TEXT_TO_TAG;
     /** Holds tag name to tag enum mappings. **/
     private static final Map<String, JavadocTagInfo> NAME_TO_TAG;
 
     static {
         TEXT_TO_TAG = Collections.unmodifiableMap(Arrays.stream(JavadocTagInfo.values())
             .collect(Collectors.toMap(JavadocTagInfo::getText, tagText -> tagText)));
         NAME_TO_TAG = Collections.unmodifiableMap(Arrays.stream(JavadocTagInfo.values())
             .collect(Collectors.toMap(JavadocTagInfo::getName, tagName -> tagName)));
 
         //Arrays sorting for binary search
         Arrays.sort(DEF_TOKEN_TYPES);
         Arrays.sort(DEF_TOKEN_TYPES_DEPRECATED);
     }
 
     /** The tag text. **/
     private final String text;
     /** The tag name. **/
     private final String name;
     /** The tag type. **/
     private final Type type;
 
     /**
      * Sets the various properties of a Javadoc tag.
      *
      * @param text the tag text
      * @param name the tag name
      * @param type the type of tag
      */
     JavadocTagInfo(final String text, final String name,
         final Type type) {
         this.text = text;
         this.name = name;
         this.type = type;
     }
 
     /**
      * Checks if a particular Javadoc tag is valid within a Javadoc block of a
      * given AST.
      *
      * <p>
      * If passing in a DetailAST representing a non-void METHOD_DEF
      * {@code true } would be returned. If passing in a DetailAST
      * representing a CLASS_DEF {@code false } would be returned because
      * CLASS_DEF's cannot return a value.
      * </p>
      *
      * @param ast the AST representing a type that can be Javadoc'd
      * @return true if tag is valid.
      */
     public abstract boolean isValidOn(DetailAST ast);
 
     /**
      * Gets the tag text.
      * @return the tag text
      */
     public String getText() {
         return text;
     }
 
     /**
      * Gets the tag name.
      * @return the tag name
      */
     public String getName() {
         return name;
     }
 
     /**
      * Gets the Tag type defined by {@link Type Type}.
      * @return the Tag type
      */
     public Type getType() {
         return type;
     }
 
     /**
      * Returns a JavadocTag from the tag text.
      * @param text String representing the tag text
      * @return Returns a JavadocTag type from a String representing the tag
      * @throws NullPointerException if the text is null
      * @throws IllegalArgumentException if the text is not a valid tag
      */
     public static JavadocTagInfo fromText(final String text) {
         if (text == null) {
             throw new IllegalArgumentException("the text is null");
         }
 
         final JavadocTagInfo tag = TEXT_TO_TAG.get(text);
 
         if (tag == null) {
             throw new IllegalArgumentException("the text [" + text
                 + "] is not a valid Javadoc tag text");
         }
 
         return tag;
     }
 
     /**
      * Returns a JavadocTag from the tag name.
      * @param name String name of the tag
      * @return Returns a JavadocTag type from a String representing the tag
      * @throws NullPointerException if the text is null
      * @throws IllegalArgumentException if the text is not a valid tag. The name
      *     can be checked using {@link JavadocTagInfo#isValidName(String)}
      */
     public static JavadocTagInfo fromName(final String name) {
         if (name == null) {
             throw new IllegalArgumentException("the name is null");
         }
 
         final JavadocTagInfo tag = NAME_TO_TAG.get(name);
 
         if (tag == null) {
             throw new IllegalArgumentException("the name [" + name
                 + "] is not a valid Javadoc tag name");
         }
 
         return tag;
     }
 
     /**
      * Returns whether the provided name is for a valid tag.
      * @param name the tag name to check.
      * @return whether the provided name is for a valid tag.
      */
     public static boolean isValidName(final String name) {
         return NAME_TO_TAG.containsKey(name);
     }
 
     @Override
     public String toString() {
         return "text [" + text + "] name [" + name
             + "] type [" + type + "]";
     }
 
     /**
      * The Javadoc Type.
      *
      * <p>For example a {@code @param} tag is a block tag while a
      * {@code {@link}} tag is a inline tag.
      *
      */
     public enum Type {
 
         /** Block type. **/
         BLOCK,
 
         /** Inline type. **/
         INLINE
 
     }
 
 }