/*
 * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
 *           (C) 1999 Antti Koivisto (koivisto@kde.org)
 *           (C) 2001 Dirk Mueller (mueller@kde.org)
 *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
 * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012 Apple Inc. All
 * rights reserved.
 * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved.
 * (http://www.torchmobile.com/)
 * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
 * Copyright (C) 2011 Google Inc. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 *
 */

#ifndef THIRD_PARTY_BLINK_RENDERER_CORE_CSS_STYLE_SHEET_COLLECTION_H_
#define THIRD_PARTY_BLINK_RENDERER_CORE_CSS_STYLE_SHEET_COLLECTION_H_

#include "third_party/blink/renderer/core/core_export.h"
#include "third_party/blink/renderer/core/css/active_style_sheets.h"
#include "third_party/blink/renderer/core/css/mixin_map.h"
#include "third_party/blink/renderer/core/dom/tree_ordered_list.h"
#include "third_party/blink/renderer/platform/bindings/name_client.h"
#include "third_party/blink/renderer/platform/heap/collection_support/heap_vector.h"
#include "third_party/blink/renderer/platform/heap/garbage_collected.h"
#include "third_party/blink/renderer/platform/wtf/allocator/allocator.h"
#include "third_party/blink/renderer/platform/wtf/vector.h"

namespace blink {

class MediaQueryEvaluator;
class Node;
class StyleSheet;

// StyleSheetCollection is responsible for keeping track of which style sheets
// are relevant for a given tree scope. Style sheets may be relevant for either
// or both of:
//
//  - DOM visibility purposes (the “style sheet list”; the CSSOM spec calls this
//    “document or shadow root CSS style sheets”), or
//  - Style calculation (“active style sheets”; not quite what the CSSOM spec
//    calls “the final CSS style sheets” because we remove disabled sheets)
//
// The style sheets are collected from places like <link> nodes, <style> nodes,
// adopted style sheets, inspector-added style sheets and so on. (You tell the
// collection about relevant DOM nodes by calling AddStyleSheetCandidateNode()
// and RemoveStyleSheetCandidateNode().)
//
// The precise logic for which sheets are in which list (e.g., do we include
// injected author style sheets or not?) will depend on whether the tree scope
// is a document or a shadow tree. However, it is broadly similar between
// the two.
//
// Note, however, that even for a shadow tree, StyleSheetCollection only
// considers the list of stylesheets for _one_ tree scope, not any parent tree
// scopes. Thus, ScopedStyleResolver also needs to consider
// StyleSheetCollections for parent tree scopes (for nodes in Shadow DOM), since
// style sheets there may be relevant for ::host, ::part() and similar.
class CORE_EXPORT StyleSheetCollection
    : public GarbageCollected<StyleSheetCollection>,
      public NameClient {
 public:
  explicit StyleSheetCollection(TreeScope&);
  StyleSheetCollection(const StyleSheetCollection&) = delete;
  StyleSheetCollection& operator=(const StyleSheetCollection&) = delete;
  ~StyleSheetCollection() override = default;

  const ActiveStyleSheetVector& ActiveStyleSheets() const {
    return active_style_sheets_;
  }
  const HeapVector<Member<StyleSheet>>& StyleSheetsForStyleSheetList() const {
    return style_sheets_for_style_sheet_list_;
  }

  void MarkSheetListDirty() { sheet_list_dirty_ = true; }

  virtual void Trace(Visitor*) const;
  const char* GetHumanReadableName() const override {
    return "StyleSheetCollection";
  }

  void AddStyleSheetCandidateNode(Node&);
  void RemoveStyleSheetCandidateNode(Node& node) {
    style_sheet_candidate_nodes_.Remove(&node);
  }
  bool HasStyleSheetCandidateNodes() const {
    return !style_sheet_candidate_nodes_.IsEmpty();
  }

  bool IsShadowTreeStyleSheetCollection() const { return is_shadow_tree_; }
  void UpdateStyleSheetList();

  const MixinMap& Mixins() const { return mixins_; }

  // Updates mixins_ but not active_style_sheets_.
  void PrepareUpdateActiveStyleSheets(const MediaQueryEvaluator&);

  // Must be called once, after all PrepareUpdateActiveStyleSheets().
  void FinishUpdateActiveStyleSheets(const MixinMap& effective_mixins);

 private:
  friend class StyleCascadeTest;
  void AddPendingActiveStyleSheetForTest(CSSStyleSheet* sheet) {
    pending_active_style_sheets_.push_back(std::pair(sheet, nullptr));
  }

  Document& GetDocument() const { return tree_scope_->GetDocument(); }

  Member<TreeScope> tree_scope_;
  HeapVector<Member<StyleSheet>> style_sheets_for_style_sheet_list_;
  TreeOrderedList<Node> style_sheet_candidate_nodes_;
  ActiveStyleSheetVector active_style_sheets_;
  ActiveStyleSheetVector pending_active_style_sheets_;
  MixinMap mixins_;

  bool sheet_list_dirty_ = true;
  const bool is_shadow_tree_;
};

}  // namespace blink

#endif  // THIRD_PARTY_BLINK_RENDERER_CORE_CSS_STYLE_SHEET_COLLECTION_H_