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

#pragma once

#include "CoreMinimal.h"
#include "Logging/LogVerbosity.h"
#include "Misc/ScopeLock.h"
#include "SlateFwd.h"
#include "Templates/UniquePtr.h"
#include "Widgets/DeclarativeSyntaxSupport.h"
#include "Widgets/Input/SSearchBox.h"
#include "Widgets/SCompoundWidget.h"
#include "Widgets/Views/SListView.h"

// Insights
#include "Insights/Common/Stopwatch.h"
#include "Insights/ViewModels/LogFilter.h"
#include "Insights/ViewModels/LogMessage.h"

class FMenuBuilder;

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

namespace LogViewColumns
{
static const FName IdColumnName(TEXT("Id"));
static const FName TimeColumnName(TEXT("Time"));
static const FName VerbosityColumnName(TEXT("Verbosity"));
static const FName CategoryColumnName(TEXT("Category"));
static const FName MessageColumnName(TEXT("Message"));
static const FName FileColumnName(TEXT("File"));
static const FName LineColumnName(TEXT("Line"));
}  // namespace LogViewColumns

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

/**
 * Trace log window.
 */
class SLogView: public SCompoundWidget
{
public:
    /** Default constructor. */
    SLogView();

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

    void Reset();

    SLATE_BEGIN_ARGS(SLogView) {}
    SLATE_END_ARGS()

    /**
     * Construct this widget.
     * @param InArgs - The declaration data for this widget
     */
    void Construct(const FArguments& InArgs);

    /**
     * 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;

    FLogMessageCache& GetCache() { return Cache; }

    TSharedPtr<FLogMessage> GetSelectedLogMessage() const;
    void SelectedLogMessageByLogIndex(int32 LogIndex);

    FText GetFilterText() const { return FilterTextBox->GetText(); }

    bool IsFilteringAsyncTaskCancelRequested() const { return bIsFilteringAsyncTaskCancelRequested; }

protected:
    /** Generate a new list view row. */
    TSharedRef<ITableRow> OnGenerateRow(TSharedPtr<FLogMessage> InLogMessage, const TSharedRef<STableViewBase>& OwnerTable);

    void SelectLogMessage(TSharedPtr<FLogMessage> LogMessage);
    void OnMouseButtonClick(TSharedPtr<FLogMessage> LogMessage);
    void OnSelectionChanged(TSharedPtr<FLogMessage> LogMessage, ESelectInfo::Type SelectInfo);

    void FilterTextBox_OnTextChanged(const FText& InFilterText);
    void OnFilterChanged();

    void UpdateStatsText();
    FText GetStatsText() const;
    FSlateColor GetStatsTextColor() const;

    TSharedPtr<SWidget> ListView_GetContextMenu();
    TSharedRef<SWidget> MakeVerbosityThresholdMenu();
    void CreateVerbosityThresholdMenuSection(FMenuBuilder& MenuBuilder);
    TSharedRef<SWidget> MakeCategoryFilterMenu();
    void CreateCategoriesFilterMenuSection(FMenuBuilder& MenuBuilder);

    bool VerbosityThreshold_IsChecked(ELogVerbosity::Type Verbosity) const;
    void VerbosityThreshold_Execute(ELogVerbosity::Type Verbosity);
    FText VerbosityThreshold_GetSuffixGlyph(ELogVerbosity::Type Verbosity) const;
    FSlateColor VerbosityThreshold_GetSuffixColor(ELogVerbosity::Type Verbosity) const;

    bool ShowHideAllCategories_IsChecked() const;
    void ShowHideAllCategories_Execute();

    void ShowAllCategories_Execute();

    void ShowOnlyCategory_Execute(FName InName);

    bool ToggleCategory_IsChecked(FName InName) const;
    void ToggleCategory_Execute(FName InName);

protected:
    /** The list view widget. */
    TSharedPtr<SListView<TSharedPtr<FLogMessage>>> ListView;

    /** External scrollbar used to synchronize tree view position. */
    TSharedPtr<SScrollBar> ExternalScrollbar;

    /** The search box widget used to filter logs by message text. */
    TSharedPtr<SSearchBox> FilterTextBox;

    FLogFilter Filter;
    uint64 FilterChangeNumber;

    int32 FilteringStartIndex;                                          // Start index (of the range of log messages to filter) currenly used by the async task
    int32 FilteringEndIndex;                                            // End index (of the range of log messages to filter) currenly used by the async task
    uint64 FilteringChangeNumber;                                       // Change number of the filter currenly used by the async task
    TUniquePtr<FAsyncTask<FLogFilteringAsyncTask>> FilteringAsyncTask;  // The async task to filter log messages on a worker thread
    mutable volatile bool bIsFilteringAsyncTaskCancelRequested;         // true if we want the async task to finish asap

    /** Stopwatch used to measure how long it takes to filter the message list. */
    mutable FStopwatch FilteringStopwatch;

    int32 TotalNumCategories;

    /** Total number of log messages processed, from the source Trace session. Used to detect when new log messages are added in the source Trace session. */
    int32 TotalNumMessages;

    /** true if the list of messages is not yet updated (the filter has changed and/or the source trace messages have changed) */
    bool bIsDirty;

    /** Stopwatch used to measure the time since the list of messages has become dirty. */
    mutable FStopwatch DirtyStopwatch;

    /** Stats */
    FText StatsText;

    /** Cached log messages. */
    FLogMessageCache Cache;

    /** List of trace log messages to show in list view (i.e. filtered). */
    TArray<TSharedPtr<FLogMessage>> Messages;  // TODO: this needs virtualisation (an a new SListView)
};

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