// Copyright Epic Games, Inc. All Rights Reserved.

#pragma once

#include "CoreMinimal.h"
#include "Input/CursorReply.h"
#include "Input/Reply.h"
#include "Layout/Geometry.h"
#include "Rendering/RenderingCommon.h"
#include "Styling/SlateTypes.h"
#include "TraceServices/Model/NetProfiler.h"
#include "Widgets/DeclarativeSyntaxSupport.h"
#include "Widgets/SCompoundWidget.h"

// Insights
#include "Insights/Common/FixedCircularBuffer.h"
#include "Insights/NetworkingProfiler/ViewModels/PacketContentViewDrawHelper.h"
#include "Insights/NetworkingProfiler/ViewModels/PacketContentViewport.h"
#include "Insights/ViewModels/TooltipDrawState.h"

class SScrollBar;
class SNetworkingProfilerWindow;

////////////////////////////////////////////////////////////////////////////////////////////////////

struct FNetworkPacketEventRef
{
    FNetworkPacketEvent Event;
    bool bIsValid;

    FNetworkPacketEventRef()
        : Event(), bIsValid(false)
    {
    }

    FNetworkPacketEventRef(const FNetworkPacketEvent& InEvent)
        : Event(InEvent), bIsValid(true)
    {
    }

    FNetworkPacketEventRef(const FNetworkPacketEventRef& Other)
        : Event(Other.Event), bIsValid(Other.bIsValid)
    {
    }

    FNetworkPacketEventRef& operator=(const FNetworkPacketEventRef& Other)
    {
        Event    = Other.Event;
        bIsValid = Other.bIsValid;
        return *this;
    }

    void Set(const FNetworkPacketEvent& InEvent)
    {
        Event    = InEvent;
        bIsValid = true;
    }

    void Reset()
    {
        bIsValid = false;
    }

    bool IsValid() const
    {
        return bIsValid;
    }

    bool Equals(const FNetworkPacketEventRef& Other) const
    {
        return bIsValid == Other.bIsValid && Event.Equals(Other.Event);
    }

    static bool AreEquals(const FNetworkPacketEventRef& A, const FNetworkPacketEventRef& B)
    {
        return A.Equals(B);
    }
};

////////////////////////////////////////////////////////////////////////////////////////////////////
/**
 * Widget used to present content of a network packet.
 */
class SPacketContentView: public SCompoundWidget
{
public:
    /** Number of pixels. */
    static constexpr float MOUSE_SNAP_DISTANCE = 2.0f;

    enum class ECursorType
    {
        Default,
        Arrow,
        Hand,
    };

public:
    /** Default constructor. */
    SPacketContentView();

    /** Virtual destructor. */
    virtual ~SPacketContentView();

    /** Resets internal widget's data to the default one. */
    void Reset();

    SLATE_BEGIN_ARGS(SPacketContentView) {}
    SLATE_END_ARGS()

    void Construct(const FArguments& InArgs, TSharedPtr<SNetworkingProfilerWindow> InProfilerWindow);

    /**
     * Ticks this widget. Override in derived classes, but always call the parent implementation.
     * @param  AllottedGeometry The space allotted for this widget
     * @param  InCurrentTime  Current absolute real time
     * @param  InDeltaTime  Real time passed since last tick
     */
    virtual void Tick(const FGeometry& AllottedGeometry, const double InCurrentTime, const float InDeltaTime) override;

    virtual int32 OnPaint(const FPaintArgs& Args, const FGeometry& AllottedGeometry, const FSlateRect& MyCullingRect, FSlateWindowElementList& OutDrawElements, int32 LayerId, const FWidgetStyle& InWidgetStyle, bool bParentEnabled) const override;

    virtual FReply OnMouseButtonDown(const FGeometry& MyGeometry, const FPointerEvent& MouseEvent) override;
    virtual FReply OnMouseButtonUp(const FGeometry& MyGeometry, const FPointerEvent& MouseEvent) override;
    virtual FReply OnMouseMove(const FGeometry& MyGeometry, const FPointerEvent& MouseEvent) override;
    virtual void OnMouseEnter(const FGeometry& MyGeometry, const FPointerEvent& MouseEvent) override;
    virtual void OnMouseLeave(const FPointerEvent& MouseEvent) override;
    virtual FReply OnMouseWheel(const FGeometry& MyGeometry, const FPointerEvent& MouseEvent) override;
    virtual FReply OnMouseButtonDoubleClick(const FGeometry& MyGeometry, const FPointerEvent& MouseEvent) override;

    virtual FCursorReply OnCursorQuery(const FGeometry& MyGeometry, const FPointerEvent& CursorEvent) const override;

    virtual bool SupportsKeyboardFocus() const override { return true; }
    virtual FReply OnKeyDown(const FGeometry& MyGeometry, const FKeyEvent& InKeyEvent) override;
    // virtual FReply OnKeyUp(const FGeometry& MyGeometry, const FKeyEvent& InKeyEvent) override;

    void ResetPacket();
    void SetPacket(uint32 InGameInstanceIndex, uint32 InConnectionIndex, Trace::ENetProfilerConnectionMode InConnectionMode, uint32 InPacketIndex, int64 InPacketBitSize);

    bool IsFilterByNetIdEnabled() const { return bFilterByNetId; }
    uint32 GetFilterNetId() const { return FilterNetId; }
    void SetFilterNetId(const uint32 InNetId);

    bool IsFilterByEventTypeEnabled() const { return bFilterByEventType; }
    uint32 GetFilterEventTypeIndex() const { return FilterEventTypeIndex; }
    const FText& GetFilterEventName() const { return FilterEventName; }
    void SetFilterEventType(const uint32 InEventTypeIndex, const FText& InEventName);
    void EnableFilterEventType(const uint32 InEventTypeIndex);
    void DisableFilterEventType();

    FReply FindFirstEvent();
    FReply FindPreviousEvent();
    FReply FindNextEvent();
    FReply FindLastEvent();

private:
    FReply FindPreviousPacket_OnClicked();
    FReply FindNextPacket_OnClicked();

    FText GetPacketText() const;
    void Packet_OnTextCommitted(const FText& InNewText, ETextCommit::Type InTextCommit);

    ECheckBoxState FilterByNetId_IsChecked() const;
    void FilterByNetId_OnCheckStateChanged(ECheckBoxState NewState);
    FText GetFilterNetIdText() const;
    void FilterNetId_OnTextCommitted(const FText& InNewText, ETextCommit::Type InTextCommit);

    ECheckBoxState FilterByEventType_IsChecked() const;
    void FilterByEventType_OnCheckStateChanged(ECheckBoxState NewState);
    FText GetFilterEventTypeText() const { return FilterEventName; }

    ECheckBoxState HighlightFilteredEvents_IsChecked() const;
    void HighlightFilteredEvents_OnCheckStateChanged(ECheckBoxState NewState);

    // void ShowContextMenu(const FPointerEvent& MouseEvent);

    /** Binds our UI commands to delegates. */
    void BindCommands();

    ////////////////////////////////////////////////////////////////////////////////////////////////////

    /**
     * Called when the user scrolls the horizontal scrollbar.
     * @param ScrollOffset Scroll offset as a fraction between 0 and 1.
     */
    void HorizontalScrollBar_OnUserScrolled(float ScrollOffset);
    void UpdateHorizontalScrollBar();

    void ZoomHorizontally(const float Delta, const float X);
    void BringIntoView(const float X1, const float X2);
    void BringEventIntoView(const FNetworkPacketEventRef& EventRef);

    ////////////////////////////////////////////////////////////////////////////////////////////////////

    uint32 GetPacketSequence(int32 PacketIndex) const;

    void UpdateState();

    void UpdateHoveredEvent();
    FNetworkPacketEventRef GetEventAtMousePosition(float X, float Y);

    void OnSelectedEventChanged();
    void SelectHoveredEvent();

private:
    TSharedPtr<SNetworkingProfilerWindow> ProfilerWindow;

    /** The track's viewport. Encapsulates info about position and scale. */
    FPacketContentViewport Viewport;
    bool bIsViewportDirty;

    float NetEventsOffsetY;

    uint32 GameInstanceIndex;
    uint32 ConnectionIndex;
    Trace::ENetProfilerConnectionMode ConnectionMode;
    uint32 PacketIndex;
    uint32 PacketSequence;
    int64 PacketBitSize;  // total number of bits; [bit]

    bool bFilterByEventType;
    uint32 FilterEventTypeIndex;
    FText FilterEventName;

    bool bFilterByNetId;
    uint32 FilterNetId;

    bool bHighlightFilteredEvents;

    /** Cached draw state of the packet content. */
    TSharedRef<FPacketContentViewDrawState> DrawState;
    TSharedRef<FPacketContentViewDrawState> FilteredDrawState;
    bool bIsStateDirty;

    //////////////////////////////////////////////////

    TSharedPtr<SScrollBar> HorizontalScrollBar;

    //////////////////////////////////////////////////
    // Panning and Zooming behaviors

    /** The current mouse position. */
    FVector2D MousePosition;

    /** Mouse position during the call on mouse button down. */
    FVector2D MousePositionOnButtonDown;
    float ViewportPosXOnButtonDown;

    /** Mouse position during the call on mouse button up. */
    FVector2D MousePositionOnButtonUp;

    bool bIsLMB_Pressed;
    bool bIsRMB_Pressed;

    /** True, if the user is currently interactively scrolling the view (ex.: by holding the left mouse button and dragging). */
    bool bIsScrolling;

    //////////////////////////////////////////////////
    // Selection

    FNetworkPacketEventRef HoveredEvent;
    FNetworkPacketEventRef SelectedEvent;

    FTooltipDrawState Tooltip;

    //////////////////////////////////////////////////
    // Misc

    FGeometry ThisGeometry;

    /** Cursor type. */
    ECursorType CursorType;

    // Debug stats
    TFixedCircularBuffer<uint64, 32> UpdateDurationHistory;
    mutable TFixedCircularBuffer<uint64, 32> DrawDurationHistory;
    mutable TFixedCircularBuffer<uint64, 32> OnPaintDurationHistory;
    mutable uint64 LastOnPaintTime;
};