/*
    * Copyright 2013 The Netty Project
    *
    * The Netty Project 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 io.netty.util.internal;
  
  import java.util.HashMap;
  import java.util.Map;
  
  public abstract class TypeParameterMatcher {
  
      private static final TypeParameterMatcher NOOP = new TypeParameterMatcher() {
          @Override
          public boolean match(Object msg) {
              return true;
          }
      };
  
      public static TypeParameterMatcher get(final Class<?> parameterType) {
          final Map<Class<?>, TypeParameterMatcher> getCache =
                  InternalThreadLocalMap.get().typeParameterMatcherGetCache();
  
          TypeParameterMatcher matcher = getCache.get(parameterType);
          if (matcher == null) {
              if (parameterType == Object.class) {
                  matcher = NOOP;
              } else {
                  matcher = new ReflectiveMatcher(parameterType);
              }
              getCache.put(parameterType, matcher);
          }
  
          return matcher;
      }
  
      public static TypeParameterMatcher find(
              final Object object, final Class<?> parametrizedSuperclass, final String typeParamName) {
  
          final Map<Class<?>, Map<String, TypeParameterMatcher>> findCache =
                  InternalThreadLocalMap.get().typeParameterMatcherFindCache();
          final Class<?> thisClass = object.getClass();
  
          Map<String, TypeParameterMatcher> map = findCache.get(thisClass);
          if (map == null) {
              map = new HashMap<String, TypeParameterMatcher>();
              findCache.put(thisClass, map);
          }
  
          TypeParameterMatcher matcher = map.get(typeParamName);
          if (matcher == null) {
              matcher = get(ReflectionUtil.resolveTypeParameter(object, parametrizedSuperclass, typeParamName));
              map.put(typeParamName, matcher);
          }
  
          return matcher;
      }
  
      public abstract boolean match(Object msg);
  
      private static final class ReflectiveMatcher extends TypeParameterMatcher {
          private final Class<?> type;
  
          ReflectiveMatcher(Class<?> type) {
              this.type = type;
          }
  
          @Override
          public boolean match(Object msg) {
              return type.isInstance(msg);
          }
      }
  
      TypeParameterMatcher() { }
  }