// Copyright (c) 2012, 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 $LIBRARYNAME;

/**
 * Lazy implementation of the child nodes of an element that does not request
 * the actual child nodes of an element until strictly necessary greatly
 * improving performance for the typical cases where it is not required.
 */
class _ChildNodeListLazy implements List {
  final Node _this;

  _ChildNodeListLazy(this._this);


$if DART2JS
  Node get first {
    Node result = JS('Node', '#.firstChild', _this);
    if (result == null) throw new StateError("No elements");
    return result;
  }
  Node get last {
    Node result = JS('Node', '#.lastChild', _this);
    if (result == null) throw new StateError("No elements");
    return result;
  }
  Node get single {
    int l = this.length;
    if (l == 0) throw new StateError("No elements");
    if (l > 1) throw new StateError("More than one element");
    return JS('Node', '#.firstChild', _this);
  }
$else
  Node get first {
    Node result = _this.$dom_firstChild;
    if (result == null) throw new StateError("No elements");
    return result;
  }
  Node get last {
    Node result = _this.$dom_lastChild;
    if (result == null) throw new StateError("No elements");
    return result;
  }
  Node get single {
    int l = this.length;
    if (l == 0) throw new StateError("No elements");
    if (l > 1) throw new StateError("More than one element");
    return _this.$dom_firstChild;
  }
$endif

  Node min([int compare(Node a, Node b)]) {
    return IterableMixinWorkaround.min(this, compare);
  }

  Node max([int compare(Node a, Node b)]) {
    return IterableMixinWorkaround.max(this, compare);
  }

  void add(Node value) {
    _this.$dom_appendChild(value);
  }

  void addLast(Node value) {
    _this.$dom_appendChild(value);
  }


  void addAll(Iterable<Node> iterable) {
    if (iterable is _ChildNodeListLazy) {
      if (iterable._this != _this) {
        // Optimized route for copying between nodes.
        for (var i = 0, len = iterable.length; i < len; ++i) {
          _this.$dom_appendChild(iterable[0]);
        }
      }
      return;
    }
    for (Node node in iterable) {
      _this.$dom_appendChild(node);
    }
  }

  Node removeLast() {
    final result = last;
    if (result != null) {
      _this.$dom_removeChild(result);
    }
    return result;
  }

  Node removeAt(int index) {
    var result = this[index];
    if (result != null) {
      _this.$dom_removeChild(result);
    }
    return result;
  }

  void remove(Object object) {
    if (object is! Node) return;
    Node node = object;
    if (!identical(_this, node.parentNode)) return;
    _this.$dom_removeChild(node);
  }

  void removeAll(Iterable elements) {
    IterableMixinWorkaround.removeAll(this, elements);
  }

  void retainAll(Iterable elements) {
    IterableMixinWorkaround.retainAll(this, elements);
  }

  void removeMatching(bool test(Node node)) {
    IterableMixinWorkaround.removeMatching(this, test);
  }

  void retainMatching(bool test(Node node)) {
    IterableMixinWorkaround.retainMatching(this, test);
  }

  void clear() {
    _this.text = '';
  }

  void operator []=(int index, Node value) {
    _this.$dom_replaceChild(value, this[index]);
  }

  Iterator<Node> get iterator => _this.$dom_childNodes.iterator;

  // TODO(jacobr): We can implement these methods much more efficiently by
  // looking up the nodeList only once instead of once per iteration.
  bool contains(Node element) => IterableMixinWorkaround.contains(this, element);

  void forEach(void f(Node element)) => IterableMixinWorkaround.forEach(this, f);

  dynamic reduce(dynamic initialValue,
      dynamic combine(dynamic previousValue, Node element)) {
    return IterableMixinWorkaround.reduce(this, initialValue, combine);
  }

  String join([String separator]) {
    return IterableMixinWorkaround.joinList(this, separator);
  }

  Iterable map(f(Node element)) {
    return IterableMixinWorkaround.mapList(this, f);
  }

  Iterable<Node> where(bool f(Node element)) {
    return IterableMixinWorkaround.where(this, f);
  }

  Iterable expand(Iterable f(Node element)) {
    return IterableMixinWorkaround.expand(this, f);
  }

  bool every(bool f(Node element)) => IterableMixinWorkaround.every(this, f);

  bool any(bool f(Node element)) => IterableMixinWorkaround.any(this, f);

  List<Node> toList({ bool growable: true }) =>
      new List<Node>.from(this, growable: growable);
  Set<Node> toSet() => new Set<Node>.from(this);

  bool get isEmpty => this.length == 0;

  // From List<Node>:

  Iterable<Node> take(int n) {
    return IterableMixinWorkaround.takeList(this, n);
  }

  Iterable<Node> takeWhile(bool test(Node value)) {
    return IterableMixinWorkaround.takeWhile(this, test);
  }

  Iterable<Node> skip(int n) {
    return IterableMixinWorkaround.skipList(this, n);
  }

  Iterable<Node> skipWhile(bool test(Node value)) {
    return IterableMixinWorkaround.skipWhile(this, test);
  }

  Node firstMatching(bool test(Node value), {Node orElse()}) {
    return IterableMixinWorkaround.firstMatching(this, test, orElse);
  }

  Node lastMatching(bool test(Node value), {Node orElse()}) {
    return IterableMixinWorkaround.lastMatchingInList(this, test, orElse);
  }

  Node singleMatching(bool test(Node value)) {
    return IterableMixinWorkaround.singleMatching(this, test);
  }

  Node elementAt(int index) {
    return this[index];
  }

  Iterable<Node> get reversed {
    return IterableMixinWorkaround.reversedList(this);
  }

  // TODO(jacobr): this could be implemented for child node lists.
  // The exception we throw here is misleading.
  void sort([int compare(Node a, Node b)]) {
    throw new UnsupportedError("Cannot sort immutable List.");
  }

  int indexOf(Node element, [int start = 0]) =>
      Lists.indexOf(this, element, start, this.length);

  int lastIndexOf(Node element, [int start = 0]) =>
      Lists.lastIndexOf(this, element, start);

  // FIXME: implement these.
  void setRange(int start, int rangeLength, List<Node> from, [int startFrom]) {
    throw new UnsupportedError(
        "Cannot setRange on immutable List.");
  }
  void removeRange(int start, int rangeLength) {
    throw new UnsupportedError(
        "Cannot removeRange on immutable List.");
  }
  void insertRange(int start, int rangeLength, [Node initialValue]) {
    throw new UnsupportedError(
        "Cannot insertRange on immutable List.");
  }
  List<Node> getRange(int start, int rangeLength) =>
      Lists.getRange(this, start, rangeLength, <Node>[]);

  // -- end List<Node> mixins.

  // TODO(jacobr): benchmark whether this is more efficient or whether caching
  // a local copy of $dom_childNodes is more efficient.
  int get length => _this.$dom_childNodes.length;

  void set length(int value) {
    throw new UnsupportedError(
        "Cannot set length on immutable List.");
  }

  Node operator[](int index) => _this.$dom_childNodes[index];

  Map<int, Node> asMap() => IterableMixinWorkaround.asMapList(this);
}

$(ANNOTATIONS)class $CLASSNAME$EXTENDS$IMPLEMENTS$NATIVESPEC {
  List<Node> get nodes {
    return new _ChildNodeListLazy(this);
  }

  void set nodes(Collection<Node> value) {
    // Copy list first since we don't want liveness during iteration.
    // TODO(jacobr): there is a better way to do this.
    List copy = new List.from(value);
    text = '';
    for (Node node in copy) {
      $dom_appendChild(node);
    }
  }

  /**
   * Removes this node from the DOM.
   */
  @DomName('Node.removeChild')
  void remove() {
    // TODO(jacobr): should we throw an exception if parent is already null?
    // TODO(vsm): Use the native remove when available.
    if (this.parentNode != null) {
      final Node parent = this.parentNode;
      parentNode.$dom_removeChild(this);
    }
  }

  /**
   * Replaces this node with another node.
   */
  @DomName('Node.replaceChild')
  Node replaceWith(Node otherNode) {
    try {
      final Node parent = this.parentNode;
      parent.$dom_replaceChild(otherNode, this);
    } catch (e) {

    };
    return this;
  }

$!MEMBERS
}