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

#pragma once

#include "Containers/Ticker.h"
#include "CoreMinimal.h"
#include "Framework/Commands/UICommandList.h"
#include "Logging/LogMacros.h"

// Insights
#include "Insights/InsightsManager.h"
#include "Insights/IUnrealInsightsModule.h"
#include "Insights/MemoryProfiler/MemoryProfilerCommands.h"

class FMemorySharedState;
class SMemoryProfilerWindow;

DECLARE_LOG_CATEGORY_EXTERN(MemoryProfiler, Log, All);

////////////////////////////////////////////////////////////////////////////////////////////////////
/**
 * This class manages the Memory Profiler (Asset Memory Insights) state and settings.
 */
class FMemoryProfilerManager: public TSharedFromThis<FMemoryProfilerManager>
    , public IInsightsComponent
{
    friend class FMemoryProfilerActionManager;

public:
    /** Creates the Memory Profiler manager, only one instance can exist. */
    FMemoryProfilerManager(TSharedRef<FUICommandList> InCommandList);

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

    /** Creates an instance of the Memory Profiler manager. */
    static TSharedPtr<FMemoryProfilerManager> CreateInstance();

    /**
     * @return the global instance of the Memory Profiler manager.
     * This is an internal singleton and cannot be used outside TraceInsights.
     * For external use:
     *     IUnrealInsightsModule& Module = FModuleManager::Get().LoadModuleChecked<IUnrealInsightsModule>("TraceInsights");
     *     Module.GetMemoryProfilerManager();
     */
    static TSharedPtr<FMemoryProfilerManager> Get();

    //////////////////////////////////////////////////
    // IInsightsComponent

    virtual void Initialize(IUnrealInsightsModule& InsightsModule) override;
    virtual void Shutdown() override;
    virtual void RegisterMajorTabs(IUnrealInsightsModule& InsightsModule) override;
    virtual void UnregisterMajorTabs() override;

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

    /** @returns UI command list for the Memory Profiler manager. */
    const TSharedRef<FUICommandList> GetCommandList() const;

    /** @return an instance of the Memory Profiler commands. */
    static const FMemoryProfilerCommands& GetCommands();

    /** @return an instance of the Memory Profiler action manager. */
    static FMemoryProfilerActionManager& GetActionManager();

    void AssignProfilerWindow(const TSharedRef<SMemoryProfilerWindow>& InProfilerWindow)
    {
        ProfilerWindow = InProfilerWindow;
    }

    void RemoveProfilerWindow()
    {
        ProfilerWindow.Reset();
    }

    /**
     * Converts profiler window weak pointer to a shared pointer and returns it.
     * Make sure the returned pointer is valid before trying to dereference it.
     */
    TSharedPtr<class SMemoryProfilerWindow> GetProfilerWindow() const
    {
        return ProfilerWindow.Pin();
    }

    FMemorySharedState* GetSharedState();

    ////////////////////////////////////////////////////////////////////////////////////////////////////
    // Getters and setters used by Toggle Commands.

    /** @return true, if the Timing view is visible */
    const bool IsTimingViewVisible() const { return bIsTimingViewVisible; }
    void SetTimingViewVisible(const bool bIsVisible) { bIsTimingViewVisible = bIsVisible; }
    void ShowHideTimingView(const bool bIsVisible);

    /** @return true, if the Export Details tree view is visible */
    const bool IsMemTagTreeViewVisible() const { return bIsMemTagTreeViewVisible; }
    void SetMemTagTreeViewVisible(const bool bIsVisible) { bIsMemTagTreeViewVisible = bIsVisible; }
    void ShowHideMemTagTreeView(const bool bIsVisible);

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

    void OnSessionChanged();

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

    /** Called to spawn the Memory Profiler major tab. */
    TSharedRef<SDockTab> SpawnTab(const FSpawnTabArgs& Args);

    bool CanSpawnTab(const FSpawnTabArgs& Args) const;

    /** Callback called when the Memory Profiler major tab is closed. */
    void OnTabClosed(TSharedRef<SDockTab> TabBeingClosed);

    /** Updates this manager, done through FCoreTicker. */
    bool Tick(float DeltaTime);

private:
    bool bIsInitialized;
    bool bIsAvailable;
    FAvailabilityCheck AvailabilityCheck;

    /** The delegate to be invoked when this manager ticks. */
    FTickerDelegate OnTick;

    /** Handle to the registered OnTick. */
    FDelegateHandle OnTickHandle;

    /** List of UI commands for this manager. This will be filled by this and corresponding classes. */
    TSharedRef<FUICommandList> CommandList;

    /** An instance of the Memory Profiler action manager. */
    FMemoryProfilerActionManager ActionManager;

    /** A weak pointer to the Memory Profiler window. */
    TWeakPtr<class SMemoryProfilerWindow> ProfilerWindow;

    /** If the Timing view is visible or hidden. */
    bool bIsTimingViewVisible;

    /** If the Categories tree view is visible or hidden. */
    bool bIsMemTagTreeViewVisible;

    /** A shared pointer to the global instance of the Memory Profiler manager. */
    static TSharedPtr<FMemoryProfilerManager> Instance;
};