/*
    * 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
    *
    *      http://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.logging.log4j.core.config.plugins.visitors;
  
  import java.lang.annotation.Annotation;
  import java.lang.reflect.Member;
  import java.util.Map;
  
  import org.apache.logging.log4j.Logger;
  import org.apache.logging.log4j.core.config.plugins.convert.TypeConverters;
  import org.apache.logging.log4j.core.lookup.StrSubstitutor;
  import org.apache.logging.log4j.core.util.Assert;
  import org.apache.logging.log4j.status.StatusLogger;
  import org.apache.logging.log4j.util.Strings;
  
  /**
   * Base class for PluginVisitor implementations. Provides convenience methods as well as all method implementations
   * other than the {@code visit} method.
   *
   * @param <A> the Plugin annotation type.
   */
  public abstract class AbstractPluginVisitor<A extends Annotation> implements PluginVisitor<A> {
  
      protected static final Logger LOGGER = StatusLogger.getLogger();
  
      protected final Class<A> clazz;
      protected A annotation;
      protected String[] aliases;
      protected Class<?> conversionType;
      protected StrSubstitutor substitutor;
      protected Member member;
  
      /**
       * This constructor must be overridden by implementation classes as a no-arg constructor.
       *
       * @param clazz the annotation class this PluginVisitor is for.
       */
      protected AbstractPluginVisitor(final Class<A> clazz) {
          this.clazz = clazz;
      }
  
      @SuppressWarnings("unchecked")
      @Override
      public PluginVisitor<A> setAnnotation(final Annotation annotation) {
          final Annotation a = Assert.requireNonNull(annotation, "No annotation was provided");
          if (this.clazz.isInstance(a)) {
              this.annotation = (A) a;
          }
          return this;
      }
  
      @Override
      public PluginVisitor<A> setAliases(final String... aliases) {
          this.aliases = aliases;
          return this;
      }
  
      @Override
      public PluginVisitor<A> setConversionType(final Class<?> conversionType) {
          this.conversionType = Assert.requireNonNull(conversionType, "No conversion type class was provided");
          return this;
      }
  
      @Override
      public PluginVisitor<A> setStrSubstitutor(final StrSubstitutor substitutor) {
          this.substitutor = Assert.requireNonNull(substitutor, "No StrSubstitutor was provided");
          return this;
      }
  
      @Override
      public PluginVisitor<A> setMember(final Member member) {
          this.member = member;
          return this;
      }
  
      /**
       * Removes an Entry from a given Map using a key name and aliases for that key. Keys are case-insensitive.
       *
       * @param attributes the Map to remove an Entry from.
       * @param name       the key name to look up.
       * @param aliases    optional aliases of the key name to look up.
       * @return the value corresponding to the given key or {@code null} if nonexistent.
       */
      protected static String removeAttributeValue(final Map<String, String> attributes,
                                                  final String name,
                                                  final String... aliases) {
         for (final Map.Entry<String, String> entry : attributes.entrySet()) {
             final String key = entry.getKey();
             final String value = entry.getValue();
             if (key.equalsIgnoreCase(name)) {
                 attributes.remove(key);
                 return value;
             }
             if (aliases != null) {
                 for (final String alias : aliases) {
                     if (key.equalsIgnoreCase(alias)) {
                         attributes.remove(key);
                         return value;
                     }
                 }
             }
         }
         return null;
     }
 
     /**
      * Converts the given value into the configured type falling back to the provided default value.
      *
      * @param value        the value to convert.
      * @param defaultValue the fallback value to use in case of no value or an error.
      * @return the converted value whether that be based on the given value or the default value.
      */
     protected Object convert(final String value, final Object defaultValue) {
         if (defaultValue instanceof String) {
             return TypeConverters.convert(value, this.conversionType, Strings.trimToNull((String) defaultValue));
         }
         return TypeConverters.convert(value, this.conversionType, defaultValue);
     }
 }