/*
 * 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 com.datastax.driver.core;

import com.google.common.reflect.TypeParameter;
import com.google.common.reflect.TypeToken;
import java.util.List;
import java.util.Map;
import java.util.Set;

/** Utility methods to create {@code TypeToken} instances. */
public final class TypeTokens {
  private TypeTokens() {}

  /**
   * Create a {@link TypeToken} that represents a {@link List} whose elements are of the given type.
   *
   * @param eltType The list element type.
   * @param <T> The list element type.
   * @return A {@link TypeToken} that represents a {@link List} whose elements are of the given
   *     type.
   */
  public static <T> TypeToken<List<T>> listOf(Class<T> eltType) {
    // @formatter:off
    return new TypeToken<List<T>>() {}.where(new TypeParameter<T>() {}, eltType);
    // @formatter:on
  }

  /**
   * Create a {@link TypeToken} that represents a {@link List} whose elements are of the given type.
   *
   * @param eltType The list element type.
   * @param <T> The list element type.
   * @return A {@link TypeToken} that represents a {@link List} whose elements are of the given
   *     type.
   */
  public static <T> TypeToken<List<T>> listOf(TypeToken<T> eltType) {
    // @formatter:off
    return new TypeToken<List<T>>() {}.where(new TypeParameter<T>() {}, eltType);
    // @formatter:on
  }

  /**
   * Create a {@link TypeToken} that represents a {@link Set} whose elements are of the given type.
   *
   * @param eltType The set element type.
   * @param <T> The set element type.
   * @return A {@link TypeToken} that represents a {@link Set} whose elements are of the given type.
   */
  public static <T> TypeToken<Set<T>> setOf(Class<T> eltType) {
    // @formatter:off
    return new TypeToken<Set<T>>() {}.where(new TypeParameter<T>() {}, eltType);
    // @formatter:on
  }

  /**
   * Create a {@link TypeToken} that represents a {@link Set} whose elements are of the given type.
   *
   * @param eltType The set element type.
   * @param <T> The set element type.
   * @return A {@link TypeToken} that represents a {@link Set} whose elements are of the given type.
   */
  public static <T> TypeToken<Set<T>> setOf(TypeToken<T> eltType) {
    // @formatter:off
    return new TypeToken<Set<T>>() {}.where(new TypeParameter<T>() {}, eltType);
    // @formatter:on
  }

  /**
   * Create a {@link TypeToken} that represents a {@link Map} whose keys and values are of the given
   * key and value types.
   *
   * @param keyType The map key type.
   * @param valueType The map value type
   * @param <K> The map key type.
   * @param <V> The map value type
   * @return A {@link TypeToken} that represents a {@link Map} whose keys and values are of the
   *     given key and value types
   */
  public static <K, V> TypeToken<Map<K, V>> mapOf(Class<K> keyType, Class<V> valueType) {
    // @formatter:off
    return new TypeToken<Map<K, V>>() {}.where(new TypeParameter<K>() {}, keyType)
        .where(new TypeParameter<V>() {}, valueType);
    // @formatter:on
  }

  /**
   * Create a {@link TypeToken} that represents a {@link Map} whose keys and values are of the given
   * key and value types.
   *
   * @param keyType The map key type.
   * @param valueType The map value type
   * @param <K> The map key type.
   * @param <V> The map value type
   * @return A {@link TypeToken} that represents a {@link Map} whose keys and values are of the
   *     given key and value types
   */
  public static <K, V> TypeToken<Map<K, V>> mapOf(TypeToken<K> keyType, TypeToken<V> valueType) {
    // @formatter:off
    return new TypeToken<Map<K, V>>() {}.where(new TypeParameter<K>() {}, keyType)
        .where(new TypeParameter<V>() {}, valueType);
    // @formatter:on
  }
}
