content: /*
   * Copyright (C) 2020 ActiveJ LLC.
   *
   * Licensed 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 io.activej.types;
  
  import java.lang.reflect.AnnotatedParameterizedType;
  import java.lang.reflect.AnnotatedType;
  import java.lang.reflect.Type;
  
  /**
   * A type token for defining complex types (annotated, parameterized)
   * <p>
   * Usage example:
   * <p>
   * {@code Type listOfStringsType = new TypeT<List<String>>(){}.getType()}
   *
   * @param <T> actual type
   */
  public abstract class TypeT<T> {
  	private final AnnotatedType annotatedType;
  
  	/**
  	 * Creates a new type token. A type argument {@link T} <b>must</b> be specified.
  	 * A typical usage is:
  	 * <p>
  	 * {@code TypeT<List<Integer>> integerListTypeT = new TypeT<List<Integer>>(){};}
  	 *
  	 * @throws AssertionError if a {@link TypeT} is created with a raw type
  	 */
  	protected TypeT() {
  		this.annotatedType = getSuperclassTypeParameter(this.getClass());
  	}
  
  	private static AnnotatedType getSuperclassTypeParameter(Class<?> subclass) {
  		AnnotatedType superclass = subclass.getAnnotatedSuperclass();
  		if (superclass instanceof AnnotatedParameterizedType) {
  			return ((AnnotatedParameterizedType) superclass).getAnnotatedActualTypeArguments()[0];
  		}
  		throw new AssertionError();
  	}
  
  	/**
  	 * Returns an {@link AnnotatedType} of a {@link T}
  	 */
  	public final AnnotatedType getAnnotatedType() {
  		return annotatedType;
  	}
  
  	/**
  	 * Returns a {@link Type} of a {@link T}
  	 */
  	public final Type getType() {
  		return annotatedType.getType();
  	}
  
  	/**
  	 * Returns a raw type (e.g {@link Class}) of a {@link T}
  	 */
  	@SuppressWarnings("unchecked")
  	public final Class<T> getRawType() {
  		return (Class<T>) Types.getRawType(annotatedType.getType());
  	}
  
  	@Override
  	public final String toString() {
  		return annotatedType.toString();
  	}
  
  }
  