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

#pragma once

#include "CoreMinimal.h"
#include "Fonts/SlateFontInfo.h"

// Insights
#include "Insights/ViewModels/BaseTimingTrack.h"
#include "Insights/ViewModels/GraphSeries.h"

class FMenuBuilder;
struct FSlateBrush;

class FTimingTrackViewport;

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

// Various available options for display
enum class EGraphOptions
{
    None                   = 0,

    ShowDebugInfo          = (1 << 0),
    ShowPoints             = (1 << 1),
    ShowPointsWithBorder   = (1 << 2),
    ShowLines              = (1 << 3),
    ShowPolygon            = (1 << 4),
    UseEventDuration       = (1 << 5),
    ShowBars               = (1 << 6),
    ShowBaseline           = (1 << 7),
    ShowVerticalAxisGrid   = (1 << 8),
    ShowHeader             = (1 << 9),

    FirstCustomOption      = (1 << 10),

    DefaultEnabledOptions  = None,
    DefaultVisibleOptions  = ShowPoints | ShowPointsWithBorder | ShowLines | ShowPolygon | UseEventDuration | ShowBars,
    DefaultEditableOptions = ShowPoints | ShowPointsWithBorder | ShowLines | ShowPolygon | UseEventDuration | ShowBars,
};

ENUM_CLASS_FLAGS(EGraphOptions);

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

class TRACEINSIGHTS_API FGraphTrack: public FBaseTimingTrack
{
    friend class FGraphTrackBuilder;

    INSIGHTS_DECLARE_RTTI(FGraphTrack, FBaseTimingTrack)

private:
    // Visual size of points (in pixels).
    static constexpr float PointVisualSize = 5.0f;

    // Size of points (in pixels) used in reduction algorithm.
    static constexpr double PointSizeX = 3.0f;
    static constexpr float PointSizeY  = 3.0f;

public:
    explicit FGraphTrack();
    explicit FGraphTrack(const FString& InName);
    virtual ~FGraphTrack();

    //////////////////////////////////////////////////
    // Options

    EGraphOptions GetEnabledOptions() const { return EnabledOptions; }
    void SetEnabledOptions(EGraphOptions Options) { EnabledOptions = Options; }

    bool AreAllOptionsEnabled(EGraphOptions Options) const { return EnumHasAllFlags(EnabledOptions, Options); }
    bool IsAnyOptionEnabled(EGraphOptions Options) const { return EnumHasAnyFlags(EnabledOptions, Options); }
    void EnableOptions(EGraphOptions Options) { EnabledOptions |= Options; }
    void DisableOptions(EGraphOptions Options) { EnabledOptions &= ~Options; }
    void ToggleOptions(EGraphOptions Options) { EnabledOptions ^= Options; }

    EGraphOptions GetVisibleOptions() const { return VisibleOptions; }
    void SetVisibleOptions(EGraphOptions Options) { VisibleOptions = Options; }

    EGraphOptions GetEditableOptions() const { return EditableOptions; }
    void SetEditableOptions(EGraphOptions Options) { EditableOptions = Options; }

    //////////////////////////////////////////////////
    // FBaseTimingTrack

    virtual void Reset() override;

    virtual void PostUpdate(const ITimingTrackUpdateContext& Context) override;

    virtual void PreDraw(const ITimingTrackDrawContext& Context) const override;
    virtual void Draw(const ITimingTrackDrawContext& Context) const override;
    virtual void DrawEvent(const ITimingTrackDrawContext& Context, const ITimingEvent& InTimingEvent, EDrawEventMode InDrawMode) const override;

    virtual void InitTooltip(FTooltipDrawState& InOutTooltip, const ITimingEvent& InTooltipEvent) const override;

    virtual const TSharedPtr<const ITimingEvent> GetEvent(float InPosX, float InPosY, const FTimingTrackViewport& Viewport) const override;

    virtual void BuildContextMenu(FMenuBuilder& MenuBuilder) override;

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

    TArray<TSharedPtr<FGraphSeries>>& GetSeries() { return AllSeries; }

    FGraphValueViewport& GetSharedValueViewport() { return SharedValueViewport; }
    const FGraphValueViewport& GetSharedValueViewport() const { return SharedValueViewport; }

    // TODO: virtual int GetDebugStringLineCount() const override;
    // TODO: virtual void BuildDebugString(FString& OutStr) const override;

    int32 GetNumAddedEvents() const { return NumAddedEvents; }
    int32 GetNumDrawPoints() const { return NumDrawPoints; }
    int32 GetNumDrawLines() const { return NumDrawLines; }
    int32 GetNumDrawBoxes() const { return NumDrawBoxes; }

protected:
    void UpdateStats();

    void DrawSeries(const FGraphSeries& Series, FDrawContext& DrawContext, const FTimingTrackViewport& Viewport) const;

    virtual void DrawVerticalAxisGrid(const ITimingTrackDrawContext& Context) const;
    virtual void DrawHeader(const ITimingTrackDrawContext& Context) const;

    // Get the Y value that is used to provide a clipping border between adjacent graph tracks.
    virtual float GetBorderY() const { return 0.0f; }

private:
    bool ContextMenu_ToggleOption_CanExecute(EGraphOptions Option);
    void ContextMenu_ToggleOption_Execute(EGraphOptions Option);
    bool ContextMenu_ToggleOption_IsChecked(EGraphOptions Option);
    bool ContextMenu_ShowPointsWithBorder_CanExecute();
    bool ContextMenu_UseEventDuration_CanExecute();

protected:
    TArray<TSharedPtr<FGraphSeries>> AllSeries;

    // Slate resources
    const FSlateBrush* WhiteBrush;
    const FSlateBrush* PointBrush;
    const FSlateBrush* BorderBrush;
    const FSlateFontInfo Font;

    // Flags controlling various Graph options
    EGraphOptions EnabledOptions;   // currently enabled options
    EGraphOptions VisibleOptions;   // if the option is visible in the context menu
    EGraphOptions EditableOptions;  // if the option is editable from the context menu (if false, the option can be readonly)

    FGraphValueViewport SharedValueViewport;

    // Stats
    int32 NumAddedEvents;  // total event count
    int32 NumDrawPoints;
    int32 NumDrawLines;
    int32 NumDrawBoxes;
};

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

class TRACEINSIGHTS_API FRandomGraphTrack: public FGraphTrack
{
    INSIGHTS_DECLARE_RTTI(FRandomGraphTrack, FGraphTrack)

public:
    FRandomGraphTrack();
    virtual ~FRandomGraphTrack();

    virtual void Update(const ITimingTrackUpdateContext& Context) override;

    void AddDefaultSeries();

protected:
    void GenerateSeries(FGraphSeries& Series, const FTimingTrackViewport& Viewport, const int32 EventCount, int32 Seed);
};

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