// Copyright 2025 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CHROME_BROWSER_UI_VIEWS_TABS_COMMON_SPLIT_TAB_VIEW_H_
#define CHROME_BROWSER_UI_VIEWS_TABS_COMMON_SPLIT_TAB_VIEW_H_

#include "base/callback_list.h"
#include "base/memory/raw_ptr.h"
#include "chrome/browser/ui/views/frame/browser_root_view.h"
#include "ui/base/metadata/metadata_header_macros.h"
#include "ui/views/layout/delegating_layout_manager.h"
#include "ui/views/view.h"

class TabCollectionNode;
class GlowHoverController;

namespace tabs {
enum class VerticalTabStripCollapseState;
}  // namespace tabs

// The view class for vertical split tab container. It manages layout
// of the tabs within the split. It also ensures hover states are synchronized
// with tab views within the split.
class SplitTabView : public views::View, public views::LayoutDelegate {
  METADATA_HEADER(SplitTabView, views::View)

 public:
  // This represents the gap between the two tabs in a Split View. This might be
  // vertical or horizontal.
  static constexpr int kSplitViewGap = 2;

  explicit SplitTabView(TabCollectionNode* collection_node);
  SplitTabView(const SplitTabView&) = delete;
  SplitTabView& operator=(const SplitTabView&) = delete;
  ~SplitTabView() override;

  // views::View
  void OnThemeChanged() override;
  void AddedToWidget() override;
  void RemovedFromWidget() override;
  void OnMouseEntered(const ui::MouseEvent& event) override;
  void OnMouseExited(const ui::MouseEvent& event) override;
  void OnMouseMoved(const ui::MouseEvent& event) override;
  void OnPaint(gfx::Canvas* canvas) override;

  // LayoutDelegate:
  views::ProposedLayout CalculateProposedLayout(
      const views::SizeBounds& size_bounds) const override;
  gfx::Size GetMinimumSize() const override;

  std::optional<BrowserRootView::DropIndex> GetLinkDropIndex(
      const gfx::Point& loc_in_view);

  // Used by children to sync their animation values with the parent.
  double GetHoverAnimationValue() const;
  GlowHoverController* hover_controller() const {
    return hover_controller_.get();
  }

  const TabCollectionNode* collection_node() const { return collection_node_; }

 private:
  void ResetCollectionNode();
  void OnDataChanged();
  void UpdateBorder();
  void UpdateHovered(bool hovered);

  views::ProposedLayout CalculateHorizontalLayout(
      const views::SizeBounds& size_bounds) const;
  views::ProposedLayout CalculateVerticalLayout(
      const views::SizeBounds& size_bounds) const;

  void OnCollapseStateChanged(tabs::VerticalTabStripCollapseState state);

  // Handles removing a `child_view` from `this` for reparenting to other
  // TabCollectionNode views. Records relevant metadata used for animating move
  // operations.
  std::unique_ptr<views::View> RemoveChildViewForReparenting(
      views::View* child_view);

  raw_ptr<TabCollectionNode> collection_node_ = nullptr;
  bool hovered_ = false;
  bool pinned_ = false;
  bool collapsed_ = false;
  std::unique_ptr<GlowHoverController> hover_controller_;

  base::CallbackListSubscription node_destroyed_subscription_;
  base::CallbackListSubscription paint_as_active_subscription_;
  base::CallbackListSubscription collapsed_state_changed_subscription_;
};

#endif  // CHROME_BROWSER_UI_VIEWS_TABS_COMMON_SPLIT_TAB_VIEW_H_