// 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_PINNED_TAB_CONTAINER_VIEW_H_
#define CHROME_BROWSER_UI_VIEWS_TABS_COMMON_PINNED_TAB_CONTAINER_VIEW_H_

#include "base/callback_list.h"
#include "chrome/browser/ui/views/frame/browser_root_view.h"
#include "chrome/browser/ui/views/tabs/common/dragged_tabs_container.h"
#include "chrome/browser/ui/views/tabs/common/tab_collection_animating_layout_manager.h"
#include "ui/base/metadata/metadata_header_macros.h"
#include "ui/views/layout/delegating_layout_manager.h"
#include "ui/views/view.h"

class TabCollectionNode;

// The view class that represents the pinned tab region for the
// tab strip. It manages the layout of all the pinned tabs and serves
// as the drag target for pinned tabs.
class PinnedTabContainerView
    : public views::View,
      public views::LayoutDelegate,
      public DraggedTabsContainer,
      public TabCollectionAnimatingLayoutManager::Delegate {
  METADATA_HEADER(PinnedTabContainerView, views::View)

 public:
  explicit PinnedTabContainerView(TabCollectionNode* collection_node);
  PinnedTabContainerView(const PinnedTabContainerView&) = delete;
  PinnedTabContainerView& operator=(const PinnedTabContainerView&) = delete;
  ~PinnedTabContainerView() override;

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

  // views::View:
  gfx::Size GetMinimumSize() const override;

  // TabCollectionAnimatingLayoutManager::Delegate:
  bool IsDragging() const override;
  bool IsViewDragging(const views::View& child_view) const override;
  bool ShouldAnimateOpacityForAddAndRemove(
      const views::View& child_view) const override;
  bool ShouldSnapToTarget(const views::View& child_view) const override;

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

 private:
  // DraggedTabsContainer:
  views::ScrollView* GetScrollViewForContainer() const override;
  void UpdateTargetLayoutForDrag(
      const std::vector<const views::View*>& views_to_snap) override;
  const views::ProposedLayout& GetLayoutForDrag() const override;
  const TabCollectionNode* GetCollectionNodeFromView(
      const views::View& view) const override;

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

  // While in horizontal orientation, the x-coordinate of the single row is
  // used to determine the drop index.
  std::optional<BrowserRootView::DropIndex> GetLinkDropIndexForHorizontal(
      const gfx::Point& loc_in_container);
  // While collapsed, only the y-coordinate is used to determine the drop
  // index, similar to the unpinned container.
  std::optional<BrowserRootView::DropIndex> GetLinkDropIndexForCollapsed(
      const gfx::Point& loc_in_container);
  // While expanded, the x-coordinate is used to determine which row the drag
  // lands on, and the y-coordinate is used to determine where within the row
  // the drop index should be.
  std::optional<BrowserRootView::DropIndex> GetLinkDropIndexForExpanded(
      const gfx::Point& loc_in_container);

  void ResetCollectionNode();
  void OnCollapseStateChanged(tabs::VerticalTabStripCollapseState state);

  raw_ptr<TabCollectionNode> collection_node_;
  const raw_ref<TabCollectionAnimatingLayoutManager> layout_manager_;

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

#endif  // CHROME_BROWSER_UI_VIEWS_TABS_COMMON_PINNED_TAB_CONTAINER_VIEW_H_