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Java Simplified. Extensions and Useful Constructs for the Java Platform. Codeprimate Elements (a.k.a. cp-elements) is a Java library and micro-framework used to simplify the development of software applications written in Java. Elements packages several APIs into one library in order to address various application concerns and aspects of software design and development collectively and conveniently. Elements is a highly simple, yet robust and proven library built on solid OO principles, software design patterns and best practices to effectively solve common and reoccurring problems in software development.

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/*
 * Copyright 2016 Author or Authors.
 *
 * 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 org.cp.elements.util;

import java.util.HashMap;
import java.util.Map;
import java.util.SortedMap;
import java.util.TreeMap;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;

import org.cp.elements.lang.Assert;

/**
 * The {@link MapBuilder} class is an implementation of the Builder Software Design Pattern and is used to build
 * a {@link Map} implementation with a mapping of keys and values.
 *
 * @author John Blum
 * @param  {@link Class type} of the {@link Map} key.
 * @param  {@link Class type} of the {@link Map} value.
 * @see java.util.HashMap
 * @see java.util.Map
 * @see java.util.SortedMap
 * @see java.util.concurrent.ConcurrentMap
 * @since 1.0.0
 */
@SuppressWarnings("all")
public class MapBuilder {

  private final Map map;

  /**
   * Factory method used to construct a new instance of {@link MapBuilder} initialized with
   * a {@link ConcurrentMap} implementation.
   *
   * @param  {@link Class type} of the {@link Map} key.
   * @param  {@link Class type} of the {@link Map} value.
   * @return a new instance of {@link MapBuilder} initialized with a {@link ConcurrentMap}.
   * @see java.util.concurrent.ConcurrentMap
   * @see #MapBuilder(Map)
   */
  public static  MapBuilder newConcurrentMap() {
    return new MapBuilder<>(new ConcurrentHashMap<>());
  }

  /**
   * Factory method used to construct a new instance of {@link MapBuilder} initialized with
   * a {@link HashMap} implementation.
   *
   * @param  {@link Class type} of the {@link Map} key.
   * @param  {@link Class type} of the {@link Map} value.
   * @return a new instance of {@link MapBuilder} initialized with a {@link HashMap}.
   * @see java.util.HashMap
   * @see #MapBuilder(Map)
   */
  public static  MapBuilder newHashMap() {
    return new MapBuilder<>(new HashMap<>());
  }

  /**
   * Factory method used to construct a new instance of {@link MapBuilder} initialized with
   * a {@link SortedMap} implementation.
   *
   * @param  {@link Class type} of the {@link Map} key.
   * @param  {@link Class type} of the {@link Map} value.
   * @return a new instance of {@link MapBuilder} initialized with a {@link SortedMap}.
   * @see java.util.SortedMap
   * @see #MapBuilder(Map)
   */
  public static  MapBuilder newSortedMap() {
    return new MapBuilder<>(new TreeMap<>());
  }

  /**
   * Constructs a new instance of {@link MapBuilder} initialized with the given {@link Map}.
   *
   * @param map {@link Map} to build (populate with {@link Map#put(Object, Object) put} operations;
   * must not be {@literal null}.
   * @throws IllegalArgumentException if {@link Map} is {@literal null}.
   * @see java.util.Map
   */
  protected MapBuilder(Map map) {
    Assert.notNull(map, "Map is required");
    this.map = map;
  }

  /**
   * Returns a reference to the {@link Map} being built.
   *
   * @return a reference to the {@link Map} being built.
   * @see java.util.Map
   */
  protected Map getMap() {
    return this.map;
  }

  /**
   * Puts the given {@link KEY key} and {@link VALUE value} into the {@link Map} being built
   * by this {@link MapBuilder builder}.
   *
   * @param key {@link KEY key} to put.
   * @param value {@link VALUE value} to put mapped to the given {@link KEY key}.
   * @return this {@link MapBuilder}.
   * @see java.util.Map#put(Object, Object)
   */
  public MapBuilder put(KEY key, VALUE value) {
    getMap().put(key, value);
    return this;
  }

  /**
   * Puts all the {@link KEY keys} and {@link VALUE values} from the given {@link Map} into the {@link Map} being built
   * by this {@link MapBuilder builder}.
   *
   * @param map {@link Map} containing the {@link KEY keys} and {@link VALUE values} to put into this {@link Map}.
   * @return this {@link MapBuilder}.
   * @see java.util.Map#putAll(Map)
   */
  public MapBuilder putAll(Map map) {
    getMap().putAll(map);
    return this;
  }

  /**
   * Puts the given {@link KEY key} mapped to the given {@link VALUE value} into the {@link Map} being built
   * by this {@link MapBuilder} iff the {@link KEY key} is not already mapped to a value.
   *
   * @param key {@link KEY key} to put.
   * @param value {@link VALUE value} to put mapped to the given {@link KEY key}.
   * @return this {@link MapBuilder}.
   * @see java.util.Map#putIfAbsent(Object, Object)
   */
  public MapBuilder putIfAbsent(KEY key, VALUE value) {
    getMap().putIfAbsent(key, value);
    return this;
  }

  /**
   * Builds the {@link Map}.
   *
   * @param  {@link Class sub-type} of the built {@link Map}.
   * @return the built {@link Map}.
   * @see java.util.Map
   * @see #getMap()
   */
  @SuppressWarnings("unchecked")
  public > T build() {
    return (T) getMap();
  }
}