/*
 * volumetric-ui.cpp - Volumetric UI with Z-Depth
 *
 * Production-ready example demonstrating:
 * - Volumetric rendering for UI elements
 * - Z-depth parallax for XR environments
 * - Holographic inventory previews
 * - Eye-tracking focus indicators
 * - Spatial computing patterns
 *
 * © 2026 - Agent Guardrails Template
 */

#include "CoreMinimal.h"
#include "Spatial/VolumetricRenderer.h"
#include "CommonUI/CommonUserWidget.h"
#include "DDA/DDAManager.h"
#include "Accessibility/AccessibilityPreferences.h"

namespace AgentGuardrails::UnrealUI
{

/**
 * Volumetric UI System for UE5
 * Z-depth parallax rendering for XR environments
 */
class UVolumetricUISystem : public UObject
{
    GENERATED_BODY()

private:
    VolumetricRenderer* volumetricRenderer;
    DDAManager* ddaManager;
    AccessibilityPreferences* accessibilityPrefs;

    TArray<UCommonUserWidget*> volumetricWidgets;
    float zDepthFactor = 0.5f;

public:
    void Initialize()
    {
        volumetricRenderer = VolumetricRenderer::GetInstance();
        ddaManager = DDAManager::GetInstance();
        accessibilityPrefs = AccessibilityPreferences::GetInstance();

        // Set default Z-depth factor for parallax
        zDepthFactor = 0.3f;
    }

    /**
     * Creates volumetric widget with Z-depth
     * Holographic preview for inventory items
     */
    UCommonUserWidget* CreateVolumetricWidget(const FString& widgetName, float depth)
    {
        auto* widget = NewObject<UCommonUserWidget>();
        widget->SetName(widgetName);

        // Set Z-depth for volumetric rendering
        widget->SetDepth(depth);

        // Enable holographic rendering
        widget->EnableHolographic(true);

        // Set parallax factor for spatial computing
        widget->SetParallaxFactor(zDepthFactor);

        volumetricWidgets.Add(widget);

        return widget;
    }

    /**
     * Creates holographic inventory preview
     * Z-depth parallax for item cards
     */
    UCommonUserWidget* CreateHolographicInventory()
    {
        auto* inventoryPanel = NewObject<UCommonUserWidget>();
        inventoryPanel->SetName("HolographicInventory");

        // Volumetric depth for item cards
        inventoryPanel->SetDepth(0.5f);
        inventoryPanel->EnableHolographic(true);

        // GPU instancing for batch rendering
        inventoryPanel->EnableGPUInstancing(true);

        // Add item cards with Z-depth
        auto* lootTable = LootTableManager::GetCurrentTable();
        for (auto* item : lootTable->GetItems())
        {
            auto* itemCard = CreateVolumetricItemCard(item, 0.5f);
            inventoryPanel->AddChild(itemCard);
        }

        return inventoryPanel;
    }

    /**
     * Creates volumetric item card
     * Z-depth parallax for XR environments
     */
    UCommonUserWidget* CreateVolumetricItemCard(F LootItem* item, float depth)
    {
        auto* itemCard = NewObject<UCommonUserWidget>();
        itemCard->SetName(item->GetName());

        // Set Z-depth
        itemCard->SetDepth(depth);

        // Holographic glow for legendary items
        if (item->GetRarity() == ERarity::Legendary)
        {
            itemCard->EnableHolographic(true);
            itemCard->SetGlowIntensity(1.0f);
        }

        // Parallax scrolling
        itemCard->SetParallaxFactor(zDepthFactor);

        // Eye-tracking focus ring
        itemCard->EnableEyeTrackingFocus(true);
        itemCard->SetDwellThreshold(150.0f); // 150ms

        return itemCard;
    }

    /**
     * Creates parallax scrolling UI layer
     * Multiple Z-depth layers for XR
     */
    UCommonUserWidget* CreateParallaxLayer(const FString& layerName, float depth)
    {
        auto* layer = NewObject<UCommonUserWidget>();
        layer->SetName(layerName);

        // Set Z-depth for parallax
        layer->SetDepth(depth);
        layer->SetParallaxFactor(zDepthFactor);

        // Enable volumetric rendering
        layer->EnableVolumetric(true);

        return layer;
    }

    /**
     * Updates volumetric widgets based on DDA tier
     * Reduces Z-depth complexity for stressed players
     */
    void UpdateForDDATier(DDAManager::EDifficultyTier tier)
    {
        switch (tier)
        {
            case DDAManager::EDifficultyTier::Difficult:
                // Stressed players: reduce Z-depth complexity
                zDepthFactor = 0.1f;
                SetVolumetricIntensity(0.5f);
                break;

            case DDAManager::EDifficultyTier::Normal:
                // Standard Z-depth
                zDepthFactor = 0.3f;
                SetVolumetricIntensity(1.0f);
                break;

            case DDAManager::EDifficultyTier::Relaxed:
                // Engaged players: enhanced Z-depth
                zDepthFactor = 0.5f;
                SetVolumetricIntensity(1.2f);
                break;
        }
    }

    /**
     * Sets volumetric rendering intensity
     * Scales with DDA 3.0 tier
     */
    void SetVolumetricIntensity(float intensity)
    {
        for (auto* widget : volumetricWidgets)
        {
            widget->SetVolumetricIntensity(intensity);
        }
    }

    /**
     * Eye-tracking focus indicator
     * Pupil dilation detection for stress
     */
    void UpdateEyeTrackingFocus()
    {
        for (auto* widget : volumetricWidgets)
        {
            widget->EnableEyeTrackingFocus(true);
            widget->SetDwellThreshold(150.0f);
        }
    }

    /**
     * Creates Z-depth health bar
     | Volumetric health indicator with parallax
     */
    UCommonUserWidget* CreateVolumetricHealthBar(const FString& healthBarName)
    {
        auto* healthBar = NewObject<UCommonUserWidget>();
        healthBar->SetName(healthBarName);

        // Z-depth for volumetric rendering
        healthBar->SetDepth(0.3f);
        healthBar->SetParallaxFactor(zDepthFactor);

        // Shape + color redundancy for colorblindness
        healthBar->SetShapeIndicator(true);
        healthBar->SetHighContrast(accessibilityPrefs->IsHighContrastEnabled());

        // DDA opacity adaptation
        healthBar->SetOpacity(ddaManager->GetUIOpacityFactor());

        return healthBar;
    }

    /**
     * Creates volumetric skill tree
     * Z-depth nodes for spatial computing
     */
    UCommonUserWidget* CreateVolumetricSkillTree()
    {
        auto* skillTree = NewObject<UCommonUserWidget>();
        skillTree->SetName("VolumetricSkillTree");

        // Z-depth for skill nodes
        skillTree->SetDepth(0.5f);
        skillTree->EnableHolographic(true);

        // GPU instancing for node rendering
        skillTree->EnableGPUInstancing(true);

        // Parallax factor for XR
        skillTree->SetParallaxFactor(zDepthFactor);

        return skillTree;
    }
};

/**
 * Volumetric UI Component
 * Stores Z-depth and holographic state
 */
USTRUCT()
struct FVolumetricUIComponent
{
    GENERATED_BODY()

    float Depth;              // Z-depth value (0.0-1.0)
    bool IsHolographic;       // Holographic rendering enabled
    float ParallaxFactor;     // Parallax scrolling factor
    float VolumetricIntensity; // Intensity multiplier
    bool EyeTrackingEnabled;  // Eye-tracking support
    float DwellThreshold;     // Dwell threshold in ms
};

/**
 * Volumetric rendering utilities
 */
namespace VolumetricUIUtils
{
    /**
     * Calculates parallax offset based on Z-depth
     */
    FVector2D CalculateParallaxOffset(float depth, FVector2D viewportSize)
    {
        return FVector2D(
            viewportSize.X * depth * 0.1f,
            viewportSize.Y * depth * 0.1f
        );
    }

    /**
     * Creates holographic glow effect
     */
    void ApplyHolographicGlow(UCommonUserWidget* widget, float intensity)
    {
        widget->SetGlowIntensity(intensity);
        widget->EnableHolographic(true);
    }

    /**
     * Enables eye-tracking focus ring
     */
    void EnableEyeTrackingFocus(UCommonUserWidget* widget, float dwellThreshold)
    {
        widget->EnableEyeTrackingFocus(true);
        widget->SetDwellThreshold(dwellThreshold);
    }
}

// Enumeration definitions
UENUM()
enum class ERarity
{
    Common,
    Rare,
    Epic,
    Legendary
};

} // namespace AgentGuardrails::UnrealUI