/*
    * 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.maven.di;
  
  import java.util.function.Supplier;
  
  import org.apache.maven.api.annotations.Experimental;
  import org.apache.maven.api.annotations.Nonnull;
  
  /**
   * Defines how object instances are managed within a specific scope.
   * <p>
   * A Scope controls the lifecycle and visibility of objects created by the injector.
   * It determines when new instances are created and when existing instances can be
   * reused. This allows for different caching strategies depending on the desired
   * lifecycle of the objects.
   * <p>
   * Example implementation for a simple caching scope:
   * <pre>
   * public class CachingScope implements Scope {
   *     private final Map&lt;Key&lt;?&gt;, Object&gt; cache = new ConcurrentHashMap&lt;&gt;();
   *
   *     {@literal @}Override
   *     public &lt;T&gt; Supplier&lt;T&gt; scope(Key&lt;T&gt; key, Supplier&lt;T&gt; unscoped) {
   *         return () -&gt; {
   *             return (T) cache.computeIfAbsent(key, k -&gt; unscoped.get());
   *         };
   *     }
   * }
   * </pre>
   *
   * @see org.apache.maven.api.di.Scope
   * @since 4.0.0
   */
  @Experimental
  public interface Scope {
  
      /**
       * Scopes a supplier of instances.
       * <p>
       * This method wraps an unscoped instance supplier with scope-specific logic
       * that controls when new instances are created versus when existing instances
       * are reused.
       *
       * @param <T> the type of instance being scoped
       * @param key the key identifying the instance type
       * @param unscoped the original unscoped instance supplier
       * @return a scoped supplier that implements the scope's caching strategy
       * @throws NullPointerException if key or unscoped is null
       */
      @Nonnull
      <T> Supplier<T> scope(@Nonnull Key<T> key, @Nonnull Supplier<T> unscoped);
  }