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 * reserved.
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 * modification, are permitted provided that the following conditions
 * are met:
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#ifndef THIRD_PARTY_BLINK_RENDERER_CORE_EDITING_FRAME_SELECTION_H_
#define THIRD_PARTY_BLINK_RENDERER_CORE_EDITING_FRAME_SELECTION_H_

#include <unicode/ubidi.h>

#include <memory>
#include <optional>

#include "base/check_op.h"
#include "base/dcheck_is_on.h"
#include "third_party/blink/renderer/core/core_export.h"
#include "third_party/blink/renderer/core/editing/ephemeral_range.h"
#include "third_party/blink/renderer/core/editing/forward.h"
#include "third_party/blink/renderer/core/editing/set_selection_options.h"
#include "third_party/blink/renderer/core/editing/visible_units.h"
#include "third_party/blink/renderer/core/layout/inline/caret_rect.h"
#include "third_party/blink/renderer/core/scroll/scroll_alignment.h"
#include "third_party/blink/renderer/platform/geometry/physical_offset.h"
#include "third_party/blink/renderer/platform/heap/garbage_collected.h"
#include "ui/gfx/geometry/rect.h"

namespace blink {

class CharacterData;
class Document;
class EffectPaintPropertyNode;
class Element;
class FrameCaret;
class GranularityStrategy;
class GraphicsContext;
class InlineCursor;
class InlineCursorPosition;
class LayoutBlock;
class LayoutSelection;
class LayoutText;
class LocalFrame;
class NodeWithIndex;
class PhysicalBoxFragment;
class Range;
class SelectionEditor;
class Text;
class TextIteratorBehavior;
enum class SelectionModifyAlteration;
enum class SelectionModifyDirection;
enum class SelectionState;
struct PaintInvalidatorContext;
struct PhysicalRect;

enum RevealExtentOption { kRevealExtent, kDoNotRevealExtent };

enum class CaretVisibility;

enum class HandleVisibility { kNotVisible, kVisible };
enum class ContextMenuVisibility { kNotVisible, kVisible };
enum class SelectSoftLineBreak { kNotSelected, kSelected };

// This is return type of ComputeLayoutSelectionStatus(cursor).
// This structure represents how the fragment is selected.
// |start|, |end| : Selection start/end offset. This offset is based on
//   the text of InlineNode of a parent block thus
//   |fragemnt.StartOffset <= start <= end <= fragment.EndOffset|.
// |start| == |end| means this fragment is not selected.
// |line_break| : This value represents If this fragment is selected and
// selection wraps soft line break.
struct LayoutSelectionStatus {
  DISALLOW_NEW();

 public:
  LayoutSelectionStatus(wtf_size_t passed_start,
                        wtf_size_t passed_end,
                        SelectSoftLineBreak passed_line_break)
      : start(passed_start), end(passed_end), line_break(passed_line_break) {
    DCHECK_LE(start, end);
  }

  bool HasValidRange() const { return start < end; }

  bool operator==(const LayoutSelectionStatus& other) const {
    return start == other.start && end == other.end &&
           line_break == other.line_break;
  }

  wtf_size_t start;
  wtf_size_t end;
  SelectSoftLineBreak line_break;
};

enum class SelectionIncludeEnd { kInclude, kNotInclude };

struct LayoutTextSelectionStatus {
  STACK_ALLOCATED();

 public:
  LayoutTextSelectionStatus(wtf_size_t passed_start,
                            wtf_size_t passed_end,
                            SelectionIncludeEnd passed_include_end)
      : start(passed_start), end(passed_end), include_end(passed_include_end) {
    DCHECK_LE(start, end);
  }
  bool operator==(const LayoutTextSelectionStatus& other) const {
    return start == other.start && end == other.end &&
           include_end == other.include_end;
  }
  bool IsEmpty() const { return start == 0 && end == 0; }

  wtf_size_t start;
  wtf_size_t end;
  SelectionIncludeEnd include_end;
};

class CORE_EXPORT FrameSelection final
    : public GarbageCollected<FrameSelection> {
 public:
  explicit FrameSelection(LocalFrame&);
  FrameSelection(const FrameSelection&) = delete;
  FrameSelection& operator=(const FrameSelection&) = delete;
  ~FrameSelection();

  bool IsAvailable() const;
  // You should not call |document()| when |!isAvailable()|.
  Document& GetDocument() const;
  LocalFrame* GetFrame() const { return frame_.Get(); }
  // Note that RootEditableElementOrDocumentElement can return null if the
  // documentElement is null.
  Element* RootEditableElementOrDocumentElement() const;
  wtf_size_t CharacterIndexForPoint(const gfx::Point&) const;

  // An implementation of |WebFrame::moveCaretSelection()|
  void MoveCaretSelection(const gfx::Point&);

  VisibleSelection ComputeVisibleSelectionInDomTree() const;
  VisibleSelectionInFlatTree ComputeVisibleSelectionInFlatTree() const;

  // TODO(editing-dev): We should replace
  // |ComputeVisibleSelectionInDomTreeDeprecated()| with update layout and
  // |ComputeVisibleSelectionInDomTree()| to increase places hoisting update
  // layout.
  VisibleSelection ComputeVisibleSelectionInDomTreeDeprecated() const;

  void SetSelection(const SelectionInDomTree&, const SetSelectionOptions&);
  void SetSelectionAndEndTyping(const SelectionInDomTree&);
  void SelectAll(SetSelectionBy, bool canonicalize_selection = false);
  void SelectAll();
  void SelectSubString(const Element&, int offset, int count);
  void Clear();
  bool IsHidden() const;

  // TODO(tkent): These two functions were added to fix crbug.com/695211 without
  // changing focus behavior. Once we fix crbug.com/690272, we can remove these
  // functions.
  // setSelectionDeprecated() returns true if didSetSelectionDeprecated() should
  // be called.
  bool SetSelectionDeprecated(const SelectionInDomTree&,
                              const SetSelectionOptions&);
  void DidSetSelectionDeprecated(const SelectionInDomTree&,
                                 const SetSelectionOptions&);
  void SetSelectionForAccessibility(const SelectionInDomTree&,
                                    const SetSelectionOptions&);

  // Call this after doing user-triggered selections to make it easy to delete
  // the frame you entirely selected.
  void SelectFrameElementInParentIfFullySelected();

  bool Contains(const PhysicalOffset&);

  bool Modify(SelectionModifyAlteration,
              SelectionModifyDirection,
              TextGranularity,
              SetSelectionBy);

  // Moves the selection extent based on the selection granularity strategy.
  // This function does not allow the selection to collapse. If the new
  // extent is resolved to the same position as the current base, this
  // function will do nothing.
  void MoveRangeSelectionExtent(const gfx::Point&);
  void MoveRangeSelection(const gfx::Point& base_point,
                          const gfx::Point& extent_point,
                          TextGranularity);

  TextGranularity Granularity() const { return granularity_; }

  // Returns true if specified layout block should paint caret. This function is
  // called during painting only.
  bool ShouldPaintCaret(const LayoutBlock&) const;
  bool ShouldPaintCaret(const PhysicalBoxFragment&) const;

  // Bounds of (possibly transformed) caret in absolute coords
  gfx::Rect AbsoluteCaretBounds() const;

  // Returns the type of caret shape.
  CaretShape GetCaretShape() const;

  // Returns anchor and focus bounds in absolute coords.
  // If the selection range is empty, returns the caret bounds.
  // Note: this updates styles and layout, use cautiously.
  bool ComputeAbsoluteBounds(gfx::Rect& anchor, gfx::Rect& focus) const;

  // Computes the rect we should use when scrolling/zooming a selection into
  // view.
  gfx::Rect ComputeRectToScroll(RevealExtentOption);

  void DidChangeFocus();

  // Restores |element|'s text-overflow ellipsis as it loses or
  // gains focus while the selection focus stays inside it. The caller guards on
  // the feature flag (see SelectionEditor::SetContainsSelectionFocusFlag()).
  void UpdateTextOverflowOfSelectionFocus(const Element& element, bool focused);

  const SelectionInDomTree& GetSelectionInDomTree() const;
  bool IsDirectional() const;

  void DidAttachDocument(Document*);

  void DidLayout();
  void CommitAppearanceIfNeeded();
  void SetCaretEnabled(bool caret_is_visible);
  void ScheduleVisualUpdate() const;
  void ScheduleVisualUpdateForVisualOverflowIfNeeded() const;

  // Paint invalidation methods delegating to FrameCaret.
  void LayoutBlockWillBeDestroyed(const LayoutBlock&);
  void UpdateStyleAndLayoutIfNeeded();
  void InvalidatePaint(const LayoutBlock&, const PaintInvalidatorContext&);
  void EnsureInvalidationOfPreviousLayoutBlock();

  void PaintCaret(GraphicsContext&, const PhysicalOffset&);
  const LayoutBlock* GetCaretLayoutBlock() const;

  // Used to suspend caret blinking while the mouse is down.
  void SetCaretBlinkingSuspended(bool);
  bool IsCaretBlinkingSuspended() const;

  // Focus
  bool SelectionHasFocus() const;
  void SetFrameIsFocused(bool);
  bool FrameIsFocused() const { return focused_; }
  bool FrameIsFocusedAndActive() const;
  void PageActivationChanged();

  bool IsHandleVisible() const { return is_handle_visible_; }

  // Bidi embedding level of the caret's current fragment. Used by FrameCaret
  // for correct caret rendering at bidi boundaries.
  std::optional<UBiDiLevel> CaretBidiLevel() const { return caret_bidi_level_; }
  void SetHandleVisibleForTesting() { is_handle_visible_ = true; }
  bool ShouldShrinkNextTap() const { return should_shrink_next_tap_; }

  // Returns true if a word is selected.
  bool SelectWordAroundCaret();

  // Returns whether a selection was successfully executed. Currently supports
  // word and sentence granularities. Also sets the visibility of the handle and
  // context menu based on parameters passed.
  bool SelectAroundCaret(TextGranularity text_granularity,
                         HandleVisibility handle_visibility,
                         ContextMenuVisibility context_menu_visibility);

  // Returns the range corresponding to a word selection around the caret.
  // Returns a null range if the selection failed, either because the current
  // selection was not a caret or if a word selection could not be made.
  EphemeralRange GetWordSelectionRangeAroundCaret() const;

  // Returns the range corresponding to a |text_granularity| selection around
  // the caret. Returns a null range if the selection failed, either because
  // the current selection was not a caret or if a |text_granularity| selection
  // could not be made.
  EphemeralRange GetSelectionRangeAroundCaretForTesting(
      TextGranularity text_granularity) const;

#if DCHECK_IS_ON()
  void ShowTreeForThis() const;
#endif

  void SetFocusedNodeIfNeeded();
  void NotifyTextControlOfSelectionChange(SetSelectionBy);

  String SelectedHtmlForClipboard() const;
  String SelectedText(const TextIteratorBehavior&) const;
  String SelectedText() const;
  String SelectedTextForClipboard() const;
  // Returns true if the current selection corresponds to a non-empty visible
  // text range within this frame.
  bool HasVisibleText() const;

  // This returns last layouted selection bounds of LayoutSelection rather than
  // SelectionEditor keeps.
  PhysicalRect AbsoluteUnclippedBounds() const;

  // TODO(tkent): This function has a bug that scrolling doesn't work well in
  // a case of RangeSelection. crbug.com/443061
  void RevealSelection(
      const mojom::blink::ScrollAlignment& = ScrollAlignment::CenterIfNeeded(),
      RevealExtentOption = kDoNotRevealExtent);
  void SetSelectionFromNone();

  void UpdateAppearance();

  void CacheRangeOfDocument(Range*);
  Range* DocumentCachedRange() const;
  void ClearDocumentCachedRange();

  // Invalidates the cached visual selection information, like
  // |VisibleSelection| and selection bounds.
  void MarkCacheDirty();

  const EffectPaintPropertyNode& CaretEffectNode() const;

  FrameCaret& FrameCaretForTesting() const { return *frame_caret_; }

  LayoutTextSelectionStatus ComputeLayoutSelectionStatus(
      const LayoutText& text) const;
  LayoutSelectionStatus ComputeLayoutSelectionStatus(
      const InlineCursor& cursor) const;
  SelectionState ComputePaintingSelectionStateForCursor(
      const InlineCursorPosition& position) const;

  // Returns the fragment-local character offset of the character covered by
  // the block caret within |cursor|'s current text fragment, or std::nullopt
  // if the block caret does not overlap this fragment.
  std::optional<wtf_size_t> ComputeBlockCaretCharacterOffset(
      const InlineCursor& cursor) const;

  // Notifications from the Document.
  void ContextDestroyed();
  void DidChangeChildren(const ContainerNode::ChildrenChange& change);
  void DidMergeTextNodes(const Text& merged_node,
                         const NodeWithIndex& node_to_be_removed_with_index,
                         wtf_size_t old_length);
  void DidSplitTextNode(const Text&);
  void DidUpdateCharacterData(CharacterData*,
                              wtf_size_t offset,
                              wtf_size_t old_length,
                              wtf_size_t new_length);
  void NodeChildrenWillBeRemoved(ContainerNode&);
  void NodeWillBeRemoved(Node&);

  void Trace(Visitor*) const;

 private:
  friend class CaretDisplayItemClientTest;
  friend class FrameSelectionTest;
  friend class PaintControllerPaintTestBase;
  friend class SelectionControllerTest;

  void NotifyAccessibilityForSelectionChange();
  void NotifyCompositorForSelectionChange();
  void NotifyEventHandlerForSelectionChange();
  void NotifyDisplayLockForSelectionChange(
      Document& document,
      const SelectionInDomTree& old_selection,
      const SelectionInDomTree& new_selection);

  void FocusedOrActiveStateChanged();
  void MaybeNotifyEventHandlerForSelectionChange(const SetSelectionOptions&);

  GranularityStrategy* GetGranularityStrategy();

  void MoveRangeSelectionInternal(const SelectionInDomTree&, TextGranularity);

  // Returns the range corresponding to a |text_granularity| selection around
  // the caret. Returns a null range if the selection failed, either because
  // the current selection was not a caret or if a |text_granularity| selection
  // could not be made.
  EphemeralRange GetSelectionRangeAroundCaret(
      TextGranularity text_granularity) const;
  EphemeralRange GetSelectionRangeAroundPosition(
      TextGranularity text_granularity,
      Position position,
      WordSide word_side) const;

  Member<LocalFrame> frame_;
  WeakMember<Document> document_;
  const Member<LayoutSelection> layout_selection_;
  const Member<SelectionEditor> selection_editor_;

  TextGranularity granularity_ = TextGranularity::kCharacter;
  LayoutUnit x_pos_for_vertical_arrow_navigation_;

  // Bidi embedding level of the caret's current fragment. Persisted across
  // consecutive keyboard-driven caret movements to disambiguate which side
  // of a bidi boundary the caret belongs to. Reset to nullopt on mouse
  // clicks and programmatic selection changes.
  std::optional<UBiDiLevel> caret_bidi_level_;

  // Whether the previous visual caret movement placed the caret at a bidi
  // boundary entry point. When true, the next boundary crossing is an EXIT
  // and should skip the shared-x entry point to produce visible movement.
  // Persisted alongside caret_bidi_level_ across keystrokes.
  bool entered_bidi_run_ = false;

  bool focused_ : 1;

  // The selection is currently being modified via the "Modify" method.
  bool is_being_modified_ = false;

  bool is_handle_visible_ = false;
  // TODO(editing-dev): We should change is_directional_ type to enum.
  // as directional can have three values forward, backward or directionless.
  bool is_directional_;
  bool should_shrink_next_tap_ = false;

  // Controls text granularity used to adjust the selection's extent in
  // moveRangeSelectionExtent.
  std::unique_ptr<GranularityStrategy> granularity_strategy_;

  const Member<FrameCaret> frame_caret_;
};

}  // namespace blink

#if DCHECK_IS_ON()
// Outside the blink namespace for ease of invocation from gdb.
void ShowTree(const blink::FrameSelection&);
void ShowTree(const blink::FrameSelection*);
#endif

#endif  // THIRD_PARTY_BLINK_RENDERER_CORE_EDITING_FRAME_SELECTION_H_