////////////////////////////////////////////////////////////////////////////////
   // 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.whitespace;
  
  import java.util.Locale;
  
  import com.puppycrawl.tools.checkstyle.StatelessCheck;
  import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
  import com.puppycrawl.tools.checkstyle.api.DetailAST;
  import com.puppycrawl.tools.checkstyle.api.TokenTypes;
  import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
  
  /**
   * <p>
   * Checks the padding between the identifier of a method definition,
   * constructor definition, method call, or constructor invocation;
   * and the left parenthesis of the parameter list.
   * That is, if the identifier and left parenthesis are on the same line,
   * checks whether a space is required immediately after the identifier or
   * such a space is forbidden.
   * If they are not on the same line, reports an error, unless configured to
   * allow line breaks.
   * </p>
   * <p> By default the check will check the following tokens:
   *  {@link TokenTypes#CTOR_DEF CTOR_DEF},
   *  {@link TokenTypes#LITERAL_NEW LITERAL_NEW},
   *  {@link TokenTypes#METHOD_CALL METHOD_CALL},
   *  {@link TokenTypes#METHOD_DEF METHOD_DEF},
   *  {@link TokenTypes#SUPER_CTOR_CALL SUPER_CTOR_CALL}.
   * </p>
   * <p>
   * An example of how to configure the check is:
   * </p>
   * <pre>
   * &lt;module name="MethodParamPad"/&gt;
   * </pre>
   * <p> An example of how to configure the check to require a space
   * after the identifier of a method definition, except if the left
   * parenthesis occurs on a new line, is:
   * </p>
   * <pre>
   * &lt;module name="MethodParamPad"&gt;
   *     &lt;property name="tokens" value="METHOD_DEF"/&gt;
   *     &lt;property name="option" value="space"/&gt;
   *     &lt;property name="allowLineBreaks" value="true"/&gt;
   * &lt;/module&gt;
   * </pre>
   */
  
  @StatelessCheck
  public class MethodParamPadCheck
      extends AbstractCheck {
  
      /**
       * A key is pointing to the warning message text in "messages.properties"
       * file.
       */
      public static final String MSG_LINE_PREVIOUS = "line.previous";
  
      /**
       * A key is pointing to the warning message text in "messages.properties"
       * file.
       */
      public static final String MSG_WS_PRECEDED = "ws.preceded";
  
      /**
       * A key is pointing to the warning message text in "messages.properties"
       * file.
       */
      public static final String MSG_WS_NOT_PRECEDED = "ws.notPreceded";
  
      /**
       * Whether whitespace is allowed if the method identifier is at a
       * linebreak.
       */
      private boolean allowLineBreaks;
  
      /** The policy to enforce. */
      private PadOption option = PadOption.NOSPACE;
  
      @Override
      public int[] getDefaultTokens() {
         return getAcceptableTokens();
     }
 
     @Override
     public int[] getAcceptableTokens() {
         return new int[] {
             TokenTypes.CTOR_DEF,
             TokenTypes.LITERAL_NEW,
             TokenTypes.METHOD_CALL,
             TokenTypes.METHOD_DEF,
             TokenTypes.SUPER_CTOR_CALL,
             TokenTypes.ENUM_CONSTANT_DEF,
         };
     }
 
     @Override
     public int[] getRequiredTokens() {
         return CommonUtil.EMPTY_INT_ARRAY;
     }
 
     @Override
     public void visitToken(DetailAST ast) {
         final DetailAST parenAST;
         if (ast.getType() == TokenTypes.METHOD_CALL) {
             parenAST = ast;
         }
         else {
             parenAST = ast.findFirstToken(TokenTypes.LPAREN);
             // array construction => parenAST == null
         }
 
         if (parenAST != null) {
             final String line = getLines()[parenAST.getLineNo() - 1];
             if (CommonUtil.hasWhitespaceBefore(parenAST.getColumnNo(), line)) {
                 if (!allowLineBreaks) {
                     log(parenAST, MSG_LINE_PREVIOUS, parenAST.getText());
                 }
             }
             else {
                 final int before = parenAST.getColumnNo() - 1;
                 if (option == PadOption.NOSPACE
                     && Character.isWhitespace(line.charAt(before))) {
                     log(parenAST, MSG_WS_PRECEDED, parenAST.getText());
                 }
                 else if (option == PadOption.SPACE
                          && !Character.isWhitespace(line.charAt(before))) {
                     log(parenAST, MSG_WS_NOT_PRECEDED, parenAST.getText());
                 }
             }
         }
     }
 
     /**
      * Control whether whitespace is flagged at line breaks.
      * @param allowLineBreaks whether whitespace should be
      *     flagged at line breaks.
      */
     public void setAllowLineBreaks(boolean allowLineBreaks) {
         this.allowLineBreaks = allowLineBreaks;
     }
 
     /**
      * Set the option to enforce.
      * @param optionStr string to decode option from
      * @throws IllegalArgumentException if unable to decode
      */
     public void setOption(String optionStr) {
         option = PadOption.valueOf(optionStr.trim().toUpperCase(Locale.ENGLISH));
     }
 
 }