/*
    * Logback: the reliable, generic, fast and flexible logging framework.
    * Copyright (C) 1999-2026, QOS.ch. All rights reserved.
    *
    * This program and the accompanying materials are dual-licensed under
    * either the terms of the Eclipse Public License v2.0 as published by
    * the Eclipse Foundation
    *
    *   or (per the licensee's choosing)
   *
   * under the terms of the GNU Lesser General Public License version 2.1
   * as published by the Free Software Foundation.
   */
  
  package ch.qos.logback.core.joran.util.beans;
  
  import java.lang.reflect.Method;
  
  /**
   * Encapsulates utility methods associated with standard java beans.
   * 
   * @author urechm
   */
  public class BeanUtil {
  
      // public static final BeanUtil SINGLETON = new BeanUtil();
  
      public static final String PREFIX_GETTER_IS = "is";
      public static final String PREFIX_GETTER_GET = "get";
      public static final String PREFIX_SETTER = "set";
      public static final String PREFIX_ADDER = "add";
  
      /**
       *
       * @param method to check if it is an 'adder' method.
       * @return true if the given method is an 'adder' method.
       */
      static public boolean isAdder(Method method) {
          int parameterCount = getParameterCount(method);
          if (parameterCount != 1) {
              return false;
          }
          Class<?> returnType = method.getReturnType();
          if (returnType != void.class) {
              return false;
          }
          String methodName = method.getName();
          return methodName.startsWith(PREFIX_ADDER);
      }
  
      /**
       *
       * @param method to check if it is a standard java beans getter.
       * @return true if the given method is a standard java beans getter.
       */
      static public boolean isGetter(Method method) {
          int parameterCount = getParameterCount(method);
          if (parameterCount > 0) {
              return false;
          }
          Class<?> returnType = method.getReturnType();
          if (returnType == void.class) {
              return false;
          }
          String methodName = method.getName();
          if (!methodName.startsWith(PREFIX_GETTER_GET) && !methodName.startsWith(PREFIX_GETTER_IS)) {
              return false;
          }
          if (methodName.startsWith(PREFIX_GETTER_IS)) {
              if (!returnType.equals(boolean.class) && !returnType.equals(Boolean.class)) {
                  return false;
              }
          }
          return true;
      }
  
      static private int getParameterCount(Method method) {
          return method.getParameterTypes().length;
      }
  
      /**
       *
       * @param method to check if it is a standard java beans setter.
       * @return true if the given method is a standard java beans setter.
       */
      static public boolean isSetter(Method method) {
          int parameterCount = getParameterCount(method);
          if (parameterCount != 1) {
              return false;
          }
          Class<?> returnType = method.getReturnType();
          if (returnType != void.class) {
              return false;
          }
          String methodName = method.getName();
          if (!methodName.startsWith(PREFIX_SETTER)) {
              return false;
          }
          return true;
     }
 
     /**
      * @param method to get the associated property name for.
      * @return The property name of the associated property if the given method
      *         matches a standard java beans getter or setter.
      */
     static public String getPropertyName(Method method) {
         String methodName = method.getName();
         String rawPropertyName = getSubstringIfPrefixMatches(methodName, PREFIX_GETTER_GET);
         if (rawPropertyName == null) {
             rawPropertyName = getSubstringIfPrefixMatches(methodName, PREFIX_SETTER);
         }
         if (rawPropertyName == null) {
             rawPropertyName = getSubstringIfPrefixMatches(methodName, PREFIX_GETTER_IS);
         }
         if (rawPropertyName == null) {
             rawPropertyName = getSubstringIfPrefixMatches(methodName, PREFIX_ADDER);
         }
         return toLowerCamelCase(rawPropertyName);
     }
 
     /**
      * Converts the given String into lower camel case form.
      * 
      * @param string to decapitalize.
      * @return null if the given String is null. Empty string if the given string is
      *         empty. The given string if the first two consecutive letters are in
      *         upper case. The given string with the first letter in lower case
      *         otherwise, which might be the given string.
      */
     static public String toLowerCamelCase(String string) {
         if (string == null) {
             return null;
         }
         if (string.isEmpty()) {
             return string;
         }
         if (string.length() > 1 && Character.isUpperCase(string.charAt(1)) && Character.isUpperCase(string.charAt(0))) {
             return string;
         }
         char chars[] = string.toCharArray();
         chars[0] = Character.toLowerCase(chars[0]);
         return new String(chars);
     }
 
     static private String getSubstringIfPrefixMatches(String wholeString, String prefix) {
         if (wholeString.startsWith(prefix)) {
             return wholeString.substring(prefix.length());
         }
         return null;
     }
 
 }