/*
 * Copyright 2007 Google Inc.
 *
 * 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 java.util;

import static javaemul.internal.InternalPreconditions.checkNotNull;

import java.util.function.UnaryOperator;
import java.util.stream.Collectors;
import javaemul.internal.ArrayHelper;
import jsinterop.annotations.JsIgnore;
import jsinterop.annotations.JsMethod;
import jsinterop.annotations.JsNonNull;
import jsinterop.annotations.JsType;

/**
 * Represents a sequence of objects.
 * See <a href="https://docs.oracle.com/javase/8/docs/api/java/util/List.html">
 * the official Java API doc</a> for details.
 *
 * @param <E> element type
 */
@JsType
public interface List<E> extends Collection<E> {

  @JsIgnore
  static <E> List<E> of() {
    return Collections.unmodifiableList(Collections.emptyList());
  }

  @JsIgnore
  static <E> List<E> of(E e1) {
    return __ofInternal((E[]) new Object[] {e1});
  }

  @JsIgnore
  static <E> List<E> of(E e1, E e2) {
    return __ofInternal((E[]) new Object[] {e1, e2});
  }

  @JsIgnore
  static <E> List<E> of(E e1, E e2, E e3) {
    return __ofInternal((E[]) new Object[] {e1, e2, e3});
  }

  @JsIgnore
  static <E> List<E> of(E e1, E e2, E e3, E e4) {
    return __ofInternal((E[]) new Object[] {e1, e2, e3, e4});
  }

  @JsIgnore
  static <E> List<E> of(E e1, E e2, E e3, E e4, E e5) {
    return __ofInternal((E[]) new Object[] {e1, e2, e3, e4, e5});
  }

  @JsIgnore
  static <E> List<E> of(E e1, E e2, E e3, E e4, E e5, E e6) {
    return __ofInternal((E[]) new Object[] {e1, e2, e3, e4, e5, e6});
  }

  @JsIgnore
  static <E> List<E> of(E e1, E e2, E e3, E e4, E e5, E e6, E e7) {
    return __ofInternal((E[]) new Object[] {e1, e2, e3, e4, e5, e6, e7});
  }

  @JsIgnore
  static <E> List<E> of(E e1, E e2, E e3, E e4, E e5, E e6, E e7, E e8) {
    return __ofInternal((E[]) new Object[] {e1, e2, e3, e4, e5, e6, e7, e8});
  }

  @JsIgnore
  static <E> List<E> of(E e1, E e2, E e3, E e4, E e5, E e6, E e7, E e8, E e9) {
    return __ofInternal((E[]) new Object[] {e1, e2, e3, e4, e5, e6, e7, e8, e9});
  }

  @JsIgnore
  static <E> List<E> of(E e1, E e2, E e3, E e4, E e5, E e6, E e7, E e8, E e9, E e10) {
    return __ofInternal((E[]) new Object[] {e1, e2, e3, e4, e5, e6, e7, e8, e9, e10});
  }

  // CHECKSTYLE_OFF: Internal only method that cannot collide with future JRE changes
  /**
   * Internal-only helper to avoid copying the incoming array, and instead just wrap it with an
   * immutable List after checking there are no nulls.
   */
  @JsIgnore
  static <E> List<E> __ofInternal(E[] elements) {
    for (int i = 0; i < elements.length; i++) {
      checkNotNull(elements[i]);
    }
    return Collections.unmodifiableList(Arrays.asList(elements));
  }
  // CHECKSTYLE_ON

  @JsIgnore
  static <E> List<E> of(E... elements) {
    for (int i = 0; i < elements.length; i++) {
      checkNotNull(elements[i]);
    }
    return Collections.unmodifiableList(
            Arrays.asList((E[]) ArrayHelper.unsafeClone(elements, 0, elements.length))
    );
  }

  @JsMethod(name = "addAtIndex")
  void add(int index, E element);

  @JsMethod(name = "addAllAtIndex")
  boolean addAll(int index, Collection<? extends E> c);

  @JsMethod(name = "getAtIndex")
  E get(int index);

  int indexOf(Object o);

  int lastIndexOf(Object o);

  @JsIgnore
  ListIterator<E> listIterator();

  @JsIgnore
  ListIterator<E> listIterator(int from);

  @JsMethod(name = "removeAtIndex")
  E remove(int index);

  @JsIgnore
  default void replaceAll(UnaryOperator<E> operator) {
    checkNotNull(operator);
    for (int i = 0, size = size(); i < size; i++) {
      set(i, operator.apply(get(i)));
    }
  }

  @JsMethod(name = "setAtIndex")
  E set(int index, E element);

  @JsIgnore
  @SuppressWarnings("unchecked")
  default void sort(Comparator<? super E> c) {
    Object[] a = toArray();
    Arrays.sort(a, (Comparator<Object>) c);
    for (int i = 0; i < a.length; i++) {
      set(i, (E) a[i]);
    }
  }

  @JsIgnore
  @Override
  default Spliterator<E> spliterator() {
    return Spliterators.spliterator(this, Spliterator.ORDERED);
  }

  @JsNonNull List<E> subList(int fromIndex, int toIndex);

  static <E> List<E> copyOf(Collection<? extends E> coll) {
    // TODO if the given collection is immutable and has no nulls, return it
    return coll.stream().collect(Collectors.toUnmodifiableList());
  }
}
