// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

part of dart._collection.dev;

/**
 * Mixin that throws on the length changing operations of [List].
 *
 * Intended to mix-in on top of [ListMixin] for fixed-length lists.
 */
abstract class FixedLengthListMixin<E> {
  /** This operation is not supported by a fixed length list. */
  void set length(int newLength) {
    throw new UnsupportedError(
        "Cannot change the length of a fixed-length list");
  }

  /** This operation is not supported by a fixed length list. */
  void add(E value) {
    throw new UnsupportedError(
        "Cannot add to a fixed-length list");
  }

  /** This operation is not supported by a fixed length list. */
  void insert(int index, E value) {
    throw new UnsupportedError(
        "Cannot add to a fixed-length list");
  }

  /** This operation is not supported by a fixed length list. */
  void insertAll(int at, Iterable<E> iterable) {
    throw new UnsupportedError(
        "Cannot add to a fixed-length list");
  }

  /** This operation is not supported by a fixed length list. */
  void addAll(Iterable<E> iterable) {
    throw new UnsupportedError(
        "Cannot add to a fixed-length list");
  }

  /** This operation is not supported by a fixed length list. */
  bool remove(Object element) {
    throw new UnsupportedError(
        "Cannot remove from a fixed-length list");
  }

  /** This operation is not supported by a fixed length list. */
  void removeWhere(bool test(E element)) {
    throw new UnsupportedError(
        "Cannot remove from a fixed-length list");
  }

  /** This operation is not supported by a fixed length list. */
  void retainWhere(bool test(E element)) {
    throw new UnsupportedError(
        "Cannot remove from a fixed-length list");
  }

  /** This operation is not supported by a fixed length list. */
  void clear() {
    throw new UnsupportedError(
        "Cannot clear a fixed-length list");
  }

  /** This operation is not supported by a fixed length list. */
  E removeAt(int index) {
    throw new UnsupportedError(
        "Cannot remove from a fixed-length list");
  }

  /** This operation is not supported by a fixed length list. */
  E removeLast() {
    throw new UnsupportedError(
        "Cannot remove from a fixed-length list");
  }

  /** This operation is not supported by a fixed length list. */
  void removeRange(int start, int end) {
    throw new UnsupportedError(
        "Cannot remove from a fixed-length list");
  }

  /** This operation is not supported by a fixed length list. */
  void replaceRange(int start, int end, Iterable<E> iterable) {
    throw new UnsupportedError(
        "Cannot remove from a fixed-length list");
  }
}

/**
 * Mixin for an unmodifiable [List] class.
 *
 * This overrides all mutating methods with methods that throw.
 * This mixin is intended to be mixed in on top of [ListMixin] on
 * unmodifiable lists.
 */
abstract class UnmodifiableListMixin<E> implements List<E> {

  /** This operation is not supported by an unmodifiable list. */
  void operator []=(int index, E value) {
    throw new UnsupportedError(
        "Cannot modify an unmodifiable list");
  }

  /** This operation is not supported by an unmodifiable list. */
  void set length(int newLength) {
    throw new UnsupportedError(
        "Cannot change the length of an unmodifiable list");
  }

  /** This operation is not supported by an unmodifiable list. */
  void setAll(int at, Iterable<E> iterable) {
    throw new UnsupportedError(
        "Cannot modify an unmodifiable list");
  }

  /** This operation is not supported by an unmodifiable list. */
  void add(E value) {
    throw new UnsupportedError(
      "Cannot add to an unmodifiable list");
  }

  /** This operation is not supported by an unmodifiable list. */
  E insert(int index, E value) {
    throw new UnsupportedError(
        "Cannot add to an unmodifiable list");
  }

  /** This operation is not supported by an unmodifiable list. */
  void insertAll(int at, Iterable<E> iterable) {
    throw new UnsupportedError(
        "Cannot add to an unmodifiable list");
  }

  /** This operation is not supported by an unmodifiable list. */
  void addAll(Iterable<E> iterable) {
    throw new UnsupportedError(
        "Cannot add to an unmodifiable list");
  }

  /** This operation is not supported by an unmodifiable list. */
  bool remove(Object element) {
    throw new UnsupportedError(
        "Cannot remove from an unmodifiable list");
  }

  /** This operation is not supported by an unmodifiable list. */
  void removeWhere(bool test(E element)) {
    throw new UnsupportedError(
        "Cannot remove from an unmodifiable list");
  }

  /** This operation is not supported by an unmodifiable list. */
  void retainWhere(bool test(E element)) {
    throw new UnsupportedError(
        "Cannot remove from an unmodifiable list");
  }

  /** This operation is not supported by an unmodifiable list. */
  void sort([Comparator<E> compare]) {
    throw new UnsupportedError(
        "Cannot modify an unmodifiable list");
  }

  /** This operation is not supported by an unmodifiable list. */
  void shuffle([Random random]) {
    throw new UnsupportedError(
        "Cannot modify an unmodifiable list");
  }

  /** This operation is not supported by an unmodifiable list. */
  void clear() {
    throw new UnsupportedError(
        "Cannot clear an unmodifiable list");
  }

  /** This operation is not supported by an unmodifiable list. */
  E removeAt(int index) {
    throw new UnsupportedError(
        "Cannot remove from an unmodifiable list");
  }

  /** This operation is not supported by an unmodifiable list. */
  E removeLast() {
    throw new UnsupportedError(
        "Cannot remove from an unmodifiable list");
  }

  /** This operation is not supported by an unmodifiable list. */
  void setRange(int start, int end, Iterable<E> iterable, [int skipCount = 0]) {
    throw new UnsupportedError(
        "Cannot modify an unmodifiable list");
  }

  /** This operation is not supported by an unmodifiable list. */
  void removeRange(int start, int end) {
    throw new UnsupportedError(
        "Cannot remove from an unmodifiable list");
  }

  /** This operation is not supported by an unmodifiable list. */
  void replaceRange(int start, int end, Iterable<E> iterable) {
    throw new UnsupportedError(
        "Cannot remove from an unmodifiable list");
  }

  /** This operation is not supported by an unmodifiable list. */
  void fillRange(int start, int end, [E fillValue]) {
    throw new UnsupportedError(
        "Cannot modify an unmodifiable list");
  }
}

/**
 * Abstract implementation of a fixed-length list.
 *
 * All operations are defined in terms of `length`, `operator[]` and
 * `operator[]=`, which need to be implemented.
 */
abstract class FixedLengthListBase<E> =
    ListBase<E> with FixedLengthListMixin<E>;

/**
 * Abstract implementation of an unmodifiable list.
 *
 * All operations are defined in terms of `length` and `operator[]`,
 * which need to be implemented.
 */
abstract class UnmodifiableListBase<E> =
    ListBase<E> with UnmodifiableListMixin<E>;

class _ListIndicesIterable extends ListIterable<int> {
  List _backedList;

  _ListIndicesIterable(this._backedList);

  int get length => _backedList.length;
  int elementAt(int index) {
    if (index < 0 || index >= length) {
      throw new RangeError.range(index, 0, length);
    }
    return index;
  }
}

class ListMapView<E> implements Map<int, E> {
  List<E> _values;

  ListMapView(this._values);

  E operator[] (int key) => containsKey(key) ? _values[key] : null;
  int get length => _values.length;

  Iterable<E> get values => new SubListIterable<E>(_values, 0, null);
  Iterable<int> get keys => new _ListIndicesIterable(_values);

  bool get isEmpty => _values.isEmpty;
  bool get isNotEmpty => _values.isNotEmpty;
  bool containsValue(Object value) => _values.contains(value);
  bool containsKey(int key) => key is int && key >= 0 && key < length;

  void forEach(void f(int key, E value)) {
    int length = _values.length;
    for (int i = 0; i < length; i++) {
      f(i, _values[i]);
      if (length != _values.length) {
        throw new ConcurrentModificationError(_values);
      }
    }
  }

  /** This operation is not supported by an unmodifiable map. */
  void operator[]= (int key, E value) {
    throw new UnsupportedError("Cannot modify an unmodifiable map");
  }

  /** This operation is not supported by an unmodifiable map. */
  E putIfAbsent(int key, E ifAbsent()) {
    throw new UnsupportedError("Cannot modify an unmodifiable map");
  }

  /** This operation is not supported by an unmodifiable map. */
  E remove(int key) {
    throw new UnsupportedError("Cannot modify an unmodifiable map");
  }

  /** This operation is not supported by an unmodifiable map. */
  void clear() {
    throw new UnsupportedError("Cannot modify an unmodifiable map");
  }

  /** This operation is not supported by an unmodifiable map. */
  void addAll(Map<int, E> other) {
    throw new UnsupportedError("Cannot modify an unmodifiable map");
  }
}

class ReversedListIterable<E> extends ListIterable<E> {
  Iterable<E> _source;
  ReversedListIterable(this._source);

  int get length => _source.length;

  E elementAt(int index) => _source.elementAt(_source.length - 1 - index);
}