/*
 * Copyright (c) Contributors to the Open 3D Engine Project.
 * For complete copyright and license terms please see the LICENSE at the root of this distribution.
 *
 * SPDX-License-Identifier: Apache-2.0 OR MIT
 *
 */

#include "Asset/EditorWhiteBoxMeshAsset.h"
#include "Asset/WhiteBoxMeshAssetHandler.h"
#include "EditorWhiteBoxComponent.h"
#include "EditorWhiteBoxComponentMode.h"
#include "EditorWhiteBoxComponentModeBus.h"
#include "Rendering/WhiteBoxNullRenderMesh.h"
#include "Rendering/WhiteBoxRenderMeshInterface.h"
#include "Util/WhiteBoxEditorUtil.h"
#include "WhiteBoxComponent.h"

#include <AzCore/Component/TransformBus.h>
#include <AzCore/Console/Console.h>
#include <AzCore/Math/IntersectSegment.h>
#include <AzCore/Memory/Memory.h>
#include <AzCore/Serialization/EditContext.h>
#include <AzCore/Serialization/SerializeContext.h>
#include <AzCore/std/numeric.h>
#include <AzFramework/StringFunc/StringFunc.h>
#include <AzQtComponents/Components/Widgets/FileDialog.h>
#include <AzToolsFramework/API/ComponentEntitySelectionBus.h>
#include <AzToolsFramework/API/EditorAssetSystemAPI.h>
#include <AzToolsFramework/API/EditorPythonRunnerRequestsBus.h>
#include <AzToolsFramework/Entity/EditorEntityHelpers.h>
#include <AzToolsFramework/Entity/EditorEntityInfoBus.h>
#include <AzToolsFramework/Maths/TransformUtils.h>
#include <AzToolsFramework/UI/UICore/WidgetHelpers.h>
#include <QMessageBox>
#include <WhiteBox/EditorWhiteBoxColliderBus.h>
#include <WhiteBox/WhiteBoxBus.h>

// developer debug properties for the White Box mesh to globally enable/disable
AZ_CVAR(bool, cl_whiteBoxDebugVertexHandles, false, nullptr, AZ::ConsoleFunctorFlags::Null, "Display vertex handles");
AZ_CVAR(bool, cl_whiteBoxDebugNormals, false, nullptr, AZ::ConsoleFunctorFlags::Null, "Display normals");
AZ_CVAR(
    bool, cl_whiteBoxDebugHalfedgeHandles, false, nullptr, AZ::ConsoleFunctorFlags::Null, "Display halfedge handles");
AZ_CVAR(bool, cl_whiteBoxDebugEdgeHandles, false, nullptr, AZ::ConsoleFunctorFlags::Null, "Display edge handles");
AZ_CVAR(bool, cl_whiteBoxDebugFaceHandles, false, nullptr, AZ::ConsoleFunctorFlags::Null, "Display face handles");
AZ_CVAR(bool, cl_whiteBoxDebugAabb, false, nullptr, AZ::ConsoleFunctorFlags::Null, "Display Aabb for the White Box");

namespace WhiteBox
{
    static const char* const AssetSavedUndoRedoDesc = "White Box Mesh asset saved";
    static const char* const ObjExtension = "obj";

    static void RefreshProperties()
    {
        AzToolsFramework::PropertyEditorGUIMessages::Bus::Broadcast(
            &AzToolsFramework::PropertyEditorGUIMessages::RequestRefresh,
            AzToolsFramework::PropertyModificationRefreshLevel::Refresh_AttributesAndValues);
    }

    // build intermediate data to be passed to WhiteBoxRenderMeshInterface
    // to be used to generate concrete render mesh
    static WhiteBoxRenderData CreateWhiteBoxRenderData(const WhiteBoxMesh& whiteBox, const WhiteBoxMaterial& material)
    {
        AZ_PROFILE_FUNCTION(AzToolsFramework);

        WhiteBoxRenderData renderData;
        WhiteBoxFaces& faceData = renderData.m_faces;

        const size_t faceCount = Api::MeshFaceCount(whiteBox);
        faceData.reserve(faceCount);

        const auto createWhiteBoxFaceFromHandle = [&whiteBox](const Api::FaceHandle& faceHandle) -> WhiteBoxFace
        {
            const auto copyVertex = [&whiteBox](const Api::HalfedgeHandle& in, WhiteBoxVertex& out)
            {
                const auto vh = Api::HalfedgeVertexHandleAtTip(whiteBox, in);
                out.m_position = Api::VertexPosition(whiteBox, vh);
                out.m_uv = Api::HalfedgeUV(whiteBox, in);
            };

            WhiteBoxFace face;
            face.m_normal = Api::FaceNormal(whiteBox, faceHandle);
            const auto faceHalfedgeHandles = Api::FaceHalfedgeHandles(whiteBox, faceHandle);

            copyVertex(faceHalfedgeHandles[0], face.m_v1);
            copyVertex(faceHalfedgeHandles[1], face.m_v2);
            copyVertex(faceHalfedgeHandles[2], face.m_v3);

            return face;
        };

        const auto faceHandles = Api::MeshFaceHandles(whiteBox);
        for (const auto faceHandle : faceHandles)
        {
            faceData.push_back(createWhiteBoxFaceFromHandle(faceHandle));
        }

        renderData.m_material = material;

        return renderData;
    }

    static bool IsWhiteBoxNullRenderMesh(const AZStd::optional<AZStd::unique_ptr<RenderMeshInterface>>& m_renderMesh)
    {
        return azrtti_cast<WhiteBoxNullRenderMesh*>((*m_renderMesh).get()) != nullptr;
    }

    static bool DisplayingAsset(const DefaultShapeType defaultShapeType)
    {
        // checks if the default shape is set to a custom asset
        return defaultShapeType == DefaultShapeType::Asset;
    }

    // callback for when the default shape field is changed
    void EditorWhiteBoxComponent::OnDefaultShapeChange()
    {
        const AZStd::string entityIdStr = AZStd::string::format("%llu", static_cast<AZ::u64>(GetEntityId()));
        const AZStd::string componentIdStr = AZStd::string::format("%llu", GetId());
        const AZStd::string shapeTypeStr = AZStd::string::format("%d", aznumeric_cast<int>(m_defaultShape));
        const AZStd::vector<AZStd::string_view> scriptArgs{entityIdStr, componentIdStr, shapeTypeStr};

        // if the shape type has just changed and it is no longer an asset type, check if a mesh asset
        // is in use and clear it if so (switch back to using the component serialized White Box mesh)
        if (!DisplayingAsset(m_defaultShape) && m_editorMeshAsset->InUse())
        {
            m_editorMeshAsset->Reset();
        }

        AzToolsFramework::EditorPythonRunnerRequestBus::Broadcast(
            &AzToolsFramework::EditorPythonRunnerRequestBus::Events::ExecuteByFilenameWithArgs,
            "@devroot@/Gems/WhiteBox/Editor/Scripts/default_shapes.py", scriptArgs);

        EditorWhiteBoxComponentNotificationBus::Event(
            AZ::EntityComponentIdPair(GetEntityId(), GetId()),
            &EditorWhiteBoxComponentNotificationBus::Events::OnDefaultShapeTypeChanged, m_defaultShape);
    }

    bool EditorWhiteBoxVersionConverter(
        AZ::SerializeContext& context, AZ::SerializeContext::DataElementNode& classElement)
    {
        if (classElement.GetVersion() <= 1)
        {
            // find the old WhiteBoxMeshAsset stored directly on the component
            AZ::Data::Asset<Pipeline::WhiteBoxMeshAsset> meshAsset;
            const int meshAssetIndex = classElement.FindElement(AZ_CRC_CE("MeshAsset"));
            if (meshAssetIndex != -1)
            {
                classElement.GetSubElement(meshAssetIndex).GetData(meshAsset);
                classElement.RemoveElement(meshAssetIndex);
            }
            else
            {
                return false;
            }

            // add the new EditorWhiteBoxMeshAsset which will contain the previous WhiteBoxMeshAsset
            const int editorMeshAssetIndex =
                classElement.AddElement<EditorWhiteBoxMeshAsset>(context, "EditorMeshAsset");

            if (editorMeshAssetIndex != -1)
            {
                // insert the existing WhiteBoxMeshAsset into the new EditorWhiteBoxMeshAsset
                classElement.GetSubElement(editorMeshAssetIndex)
                    .AddElementWithData<AZ::Data::Asset<Pipeline::WhiteBoxMeshAsset>>(context, "MeshAsset", meshAsset);
            }
            else
            {
                return false;
            }
        }

        return true;
    }

    void EditorWhiteBoxComponent::Reflect(AZ::ReflectContext* context)
    {
        EditorWhiteBoxMeshAsset::Reflect(context);

        if (auto serializeContext = azrtti_cast<AZ::SerializeContext*>(context))
        {
            serializeContext->Class<EditorWhiteBoxComponent, EditorComponentBase>()
                ->Version(2, &EditorWhiteBoxVersionConverter)
                ->Field("WhiteBoxData", &EditorWhiteBoxComponent::m_whiteBoxData)
                ->Field("DefaultShape", &EditorWhiteBoxComponent::m_defaultShape)
                ->Field("EditorMeshAsset", &EditorWhiteBoxComponent::m_editorMeshAsset)
                ->Field("Material", &EditorWhiteBoxComponent::m_material)
                ->Field("RenderData", &EditorWhiteBoxComponent::m_renderData)
                ->Field("ComponentMode", &EditorWhiteBoxComponent::m_componentModeDelegate);

            if (AZ::EditContext* editContext = serializeContext->GetEditContext())
            {
                editContext->Class<EditorWhiteBoxComponent>("White Box", "White Box level editing")
                    ->ClassElement(AZ::Edit::ClassElements::EditorData, "")
                    ->Attribute(AZ::Edit::Attributes::Category, "Shape")
                    ->Attribute(AZ::Edit::Attributes::Icon, "Editor/Icons/Components/WhiteBox.svg")
                    ->Attribute(AZ::Edit::Attributes::ViewportIcon, "Editor/Icons/Components/Viewport/WhiteBox.svg")
                    ->Attribute(AZ::Edit::Attributes::AppearsInAddComponentMenu, AZ_CRC("Game", 0x232b318c))
                    ->Attribute(
                        AZ::Edit::Attributes::HelpPageURL, "https://o3de.org/docs/user-guide/components/reference/shape/white-box/")
                    ->Attribute(AZ::Edit::Attributes::AutoExpand, true)
                    ->DataElement(
                        AZ::Edit::UIHandlers::ComboBox, &EditorWhiteBoxComponent::m_defaultShape, "Default Shape",
                        "Default shape of the white box mesh.")
                    ->EnumAttribute(DefaultShapeType::Cube, "Cube")
                    ->EnumAttribute(DefaultShapeType::Tetrahedron, "Tetrahedron")
                    ->EnumAttribute(DefaultShapeType::Icosahedron, "Icosahedron")
                    ->EnumAttribute(DefaultShapeType::Cylinder, "Cylinder")
                    ->EnumAttribute(DefaultShapeType::Sphere, "Sphere")
                    ->EnumAttribute(DefaultShapeType::Asset, "Mesh Asset")
                    ->Attribute(AZ::Edit::Attributes::ChangeNotify, &EditorWhiteBoxComponent::OnDefaultShapeChange)
                    ->Attribute(AZ::Edit::Attributes::ChangeNotify, AZ_CRC("RefreshEntireTree", 0xefbc823c))
                    ->DataElement(
                        AZ::Edit::UIHandlers::Default, &EditorWhiteBoxComponent::m_editorMeshAsset, "Editor Mesh Asset",
                        "Editor Mesh Asset")
                    ->Attribute(AZ::Edit::Attributes::Visibility, &EditorWhiteBoxComponent::AssetVisibility)
                    ->UIElement(AZ::Edit::UIHandlers::Button, "Save as asset", "Save as asset")
                    ->Attribute(AZ::Edit::Attributes::ChangeNotify, &EditorWhiteBoxComponent::SaveAsAsset)
                    ->Attribute(AZ::Edit::Attributes::ChangeNotify, AZ_CRC("RefreshEntireTree", 0xefbc823c))
                    ->Attribute(AZ::Edit::Attributes::ButtonText, "Save As ...")
                    ->DataElement(
                        AZ::Edit::UIHandlers::Default, &EditorWhiteBoxComponent::m_material, "White Box Material",
                        "The properties of the White Box material.")
                    ->Attribute(AZ::Edit::Attributes::ChangeNotify, &EditorWhiteBoxComponent::OnMaterialChange)
                    ->Attribute(AZ::Edit::Attributes::Visibility, AZ::Edit::PropertyVisibility::ShowChildrenOnly)
                    ->DataElement(
                        AZ::Edit::UIHandlers::Default, &EditorWhiteBoxComponent::m_componentModeDelegate,
                        "Component Mode", "White Box Tool Component Mode")
                    ->Attribute(AZ::Edit::Attributes::Visibility, AZ::Edit::PropertyVisibility::ShowChildrenOnly)
                    ->UIElement(AZ::Edit::UIHandlers::Button, "", "Export to obj")
                    ->Attribute(AZ::Edit::Attributes::ChangeNotify, &EditorWhiteBoxComponent::ExportToFile)
                    ->Attribute(AZ::Edit::Attributes::ButtonText, "Export");
            }
        }
    }

    void EditorWhiteBoxComponent::OnMaterialChange()
    {
        if (m_renderMesh.has_value())
        {
            (*m_renderMesh)->UpdateMaterial(m_material);
        }

        RebuildRenderMesh();
    }

    AZ::Crc32 EditorWhiteBoxComponent::AssetVisibility() const
    {
        return DisplayingAsset(m_defaultShape) ? AZ::Edit::PropertyVisibility::ShowChildrenOnly
                                               : AZ::Edit::PropertyVisibility::Hide;
    }

    void EditorWhiteBoxComponent::GetRequiredServices(AZ::ComponentDescriptor::DependencyArrayType& required)
    {
        required.push_back(AZ_CRC_CE("TransformService"));
    }

    void EditorWhiteBoxComponent::GetProvidedServices(AZ::ComponentDescriptor::DependencyArrayType& provided)
    {
        provided.push_back(AZ_CRC_CE("WhiteBoxService"));
    }

    void EditorWhiteBoxComponent::GetIncompatibleServices(AZ::ComponentDescriptor::DependencyArrayType& incompatible)
    {
        incompatible.push_back(AZ_CRC_CE("NonUniformScaleService"));
        incompatible.push_back(AZ_CRC_CE("MeshService"));
    }

    EditorWhiteBoxComponent::EditorWhiteBoxComponent() = default;

    EditorWhiteBoxComponent::~EditorWhiteBoxComponent()
    {
        // note: m_editorMeshAsset is (usually) serialized so it is created by the reflection system
        // in Reflect (no explicit `new`) - we must still clean-up the resource on destruction though
        // to not leak resources.
        delete m_editorMeshAsset;
    }

    void EditorWhiteBoxComponent::Init()
    {
        if (m_editorMeshAsset)
        {
            return;
        }

        // if the m_editorMeshAsset has not been created by the serialization system
        // create a new EditorWhiteBoxMeshAsset here
        m_editorMeshAsset = aznew EditorWhiteBoxMeshAsset();
    }

    void EditorWhiteBoxComponent::Activate()
    {
        const AZ::EntityId entityId = GetEntityId();
        const AZ::EntityComponentIdPair entityComponentIdPair{entityId, GetId()};

        AzToolsFramework::Components::EditorComponentBase::Activate();
        EditorWhiteBoxComponentRequestBus::Handler::BusConnect(entityComponentIdPair);
        EditorWhiteBoxComponentNotificationBus::Handler::BusConnect(entityComponentIdPair);
        AZ::TransformNotificationBus::Handler::BusConnect(entityId);
        AzFramework::BoundsRequestBus::Handler::BusConnect(entityId);
        AzFramework::EntityDebugDisplayEventBus::Handler::BusConnect(entityId);
        AzToolsFramework::EditorComponentSelectionRequestsBus::Handler::BusConnect(entityId);
        AzToolsFramework::EditorVisibilityNotificationBus::Handler::BusConnect(entityId);

        m_componentModeDelegate.ConnectWithSingleComponentMode<EditorWhiteBoxComponent, EditorWhiteBoxComponentMode>(
            entityComponentIdPair, this);

        AZ::Transform worldFromLocal = AZ::Transform::CreateIdentity();
        AZ::TransformBus::EventResult(worldFromLocal, entityId, &AZ::TransformBus::Events::GetWorldTM);
        m_worldFromLocal = AzToolsFramework::TransformUniformScale(worldFromLocal);

        m_editorMeshAsset->Associate(entityComponentIdPair);

        // deserialize the white box data into a mesh object or load the serialized asset ref
        DeserializeWhiteBox();

        if (AzToolsFramework::IsEntityVisible(entityId))
        {
            ShowRenderMesh();
        }
    }

    void EditorWhiteBoxComponent::Deactivate()
    {
        AzToolsFramework::EditorVisibilityNotificationBus::Handler::BusDisconnect();
        AzToolsFramework::EditorComponentSelectionRequestsBus::Handler::BusDisconnect();
        AzFramework::EntityDebugDisplayEventBus::Handler::BusDisconnect();
        AzFramework::BoundsRequestBus::Handler::BusDisconnect();
        AZ::TransformNotificationBus::Handler::BusDisconnect();
        EditorWhiteBoxComponentRequestBus::Handler::BusDisconnect();
        EditorWhiteBoxComponentNotificationBus::Handler::BusDisconnect();
        AzToolsFramework::Components::EditorComponentBase::Deactivate();

        m_componentModeDelegate.Disconnect();
        m_editorMeshAsset->Release();
        m_renderMesh.reset();
        m_whiteBox.reset();
    }

    void EditorWhiteBoxComponent::DeserializeWhiteBox()
    {
        // create WhiteBoxMesh object from internal data
        m_whiteBox = Api::CreateWhiteBoxMesh();

        if (m_editorMeshAsset->InUse())
        {
            m_editorMeshAsset->Load();
        }
        else
        {
            // attempt to load the mesh
            const auto result = Api::ReadMesh(*m_whiteBox, m_whiteBoxData);
            AZ_Error("EditorWhiteBoxComponent", result != WhiteBox::Api::ReadResult::Error, "Error deserializing white box mesh stream");

            // if the read was successful but the byte stream is empty
            // (there was nothing to load), create a default mesh
            if (result == Api::ReadResult::Empty)
            {
                Api::InitializeAsUnitCube(*m_whiteBox);
            }
        }
    }

    void EditorWhiteBoxComponent::RebuildWhiteBox()
    {
        RebuildRenderMesh();
        RebuildPhysicsMesh();
    }

    void EditorWhiteBoxComponent::BuildGameEntity(AZ::Entity* gameEntity)
    {
        if (auto* whiteBoxComponent = gameEntity->CreateComponent<WhiteBoxComponent>())
        {
            // note: it is important no edit time only functions are called here as BuildGameEntity
            // will be called by the Asset Processor when creating dynamic slices
            whiteBoxComponent->GenerateWhiteBoxMesh(m_renderData);
        }
    }

    WhiteBoxMesh* EditorWhiteBoxComponent::GetWhiteBoxMesh()
    {
        if (WhiteBoxMesh* whiteBox = m_editorMeshAsset->GetWhiteBoxMesh())
        {
            return whiteBox;
        }

        return m_whiteBox.get();
    }

    void EditorWhiteBoxComponent::OnWhiteBoxMeshModified()
    {
        // if using an asset, notify other editor mesh assets using the same id that
        // the asset has been modified, this will in turn cause all components to update
        // their render and physics meshes
        if (m_editorMeshAsset->InUse())
        {
            WhiteBoxMeshAssetNotificationBus::Event(
                m_editorMeshAsset->GetWhiteBoxMeshAssetId(),
                &WhiteBoxMeshAssetNotificationBus::Events::OnWhiteBoxMeshAssetModified,
                m_editorMeshAsset->GetWhiteBoxMeshAsset());
        }
        // otherwise, update the render and physics mesh immediately
        else
        {
            RebuildWhiteBox();
        }
    }

    void EditorWhiteBoxComponent::RebuildRenderMesh()
    {
        AZ_PROFILE_FUNCTION(AzToolsFramework);

        // reset caches when the mesh changes
        m_worldAabb.reset();
        m_localAabb.reset();
        m_faces.reset();

        AZ::Interface<AzFramework::IEntityBoundsUnion>::Get()->RefreshEntityLocalBoundsUnion(GetEntityId());

        // must have been created in Activate or have had the Entity made visible again
        if (m_renderMesh.has_value())
        {
            // cache the white box render data
            m_renderData = CreateWhiteBoxRenderData(*GetWhiteBoxMesh(), m_material);

            // it's possible the white box mesh data isn't yet ready (for example if it's stored
            // in an asset which hasn't finished loading yet) so don't attempt to create a render
            // mesh with no data
            if (!m_renderData.m_faces.empty())
            {
                // check if we need to instantiate a concrete render mesh implementation
                if (IsWhiteBoxNullRenderMesh(m_renderMesh))
                {
                    // create a concrete implementation of the render mesh
                    WhiteBoxRequestBus::BroadcastResult(m_renderMesh, &WhiteBoxRequests::CreateRenderMeshInterface);
                }

                // generate the mesh
                // TODO: LYN-786
                (*m_renderMesh)->BuildMesh(m_renderData, m_worldFromLocal, GetEntityId());
            }
        }

        EditorWhiteBoxComponentModeRequestBus::Event(
            AZ::EntityComponentIdPair{GetEntityId(), GetId()},
            &EditorWhiteBoxComponentModeRequests::MarkWhiteBoxIntersectionDataDirty);
    }

    void EditorWhiteBoxComponent::WriteAssetToComponent()
    {
        if (m_editorMeshAsset->Loaded())
        {
            Api::WriteMesh(*m_editorMeshAsset->GetWhiteBoxMesh(), m_whiteBoxData);
        }
    }

    void EditorWhiteBoxComponent::SerializeWhiteBox()
    {
        if (m_editorMeshAsset->Loaded())
        {
            m_editorMeshAsset->Serialize();
        }
        else
        {
            Api::WriteMesh(*m_whiteBox, m_whiteBoxData);
        }
    }

    void EditorWhiteBoxComponent::SetDefaultShape(const DefaultShapeType defaultShape)
    {
        m_defaultShape = defaultShape;
        OnDefaultShapeChange();
    }

    void EditorWhiteBoxComponent::OnTransformChanged(
        [[maybe_unused]] const AZ::Transform& local, const AZ::Transform& world)
    {
        AZ_PROFILE_FUNCTION(AzToolsFramework);

        m_worldAabb.reset();
        m_localAabb.reset();

        const AZ::Transform worldUniformScale = AzToolsFramework::TransformUniformScale(world);
        m_worldFromLocal = worldUniformScale;

        if (m_renderMesh.has_value())
        {
            (*m_renderMesh)->UpdateTransform(worldUniformScale);
        }
    }

    void EditorWhiteBoxComponent::RebuildPhysicsMesh()
    {
        AZ_PROFILE_FUNCTION(AzToolsFramework);

        EditorWhiteBoxColliderRequestBus::Event(
            GetEntityId(), &EditorWhiteBoxColliderRequests::CreatePhysics, *GetWhiteBoxMesh());
    }

    static AZStd::string WhiteBoxPathAtProjectRoot(const AZStd::string_view name, const AZStd::string_view extension)
    {
        const char* projectFolder = nullptr;
        AzToolsFramework::AssetSystemRequestBus::BroadcastResult(
            projectFolder, &AzToolsFramework::AssetSystem::AssetSystemRequest::GetAbsoluteDevGameFolderPath);

        return AZStd::string::format(
            "%s\\%.*s_whitebox.%.*s", projectFolder, aznumeric_cast<int>(name.size()), name.data(),
            aznumeric_cast<int>(extension.size()), extension.data());
    }

    void EditorWhiteBoxComponent::ExportToFile()
    {
        const AZStd::string initialAbsolutePathToExport =
            WhiteBoxPathAtProjectRoot(GetEntity()->GetName(), ObjExtension);

        const QString fileFilter = AZStd::string::format("*.%s", ObjExtension).c_str();
        const QString absoluteSaveFilePath = AzQtComponents::FileDialog::GetSaveFileName(
            nullptr, "Save As...", QString(initialAbsolutePathToExport.c_str()), fileFilter);

        const auto absoluteSaveFilePathUtf8 = absoluteSaveFilePath.toUtf8();
        const auto absoluteSaveFilePathCstr = absoluteSaveFilePathUtf8.constData();
        if (WhiteBox::Api::SaveToObj(*GetWhiteBoxMesh(), absoluteSaveFilePathCstr))
        {
            AZ_Printf("EditorWhiteBoxComponent", "Exported white box mesh to: %s", absoluteSaveFilePathCstr);
            RequestEditSourceControl(absoluteSaveFilePathCstr);
        }
        else
        {
            AZ_Warning(
                "EditorWhiteBoxComponent", false, "Failed to export white box mesh to: %s", absoluteSaveFilePathCstr);
        }
    }

    AZStd::optional<WhiteBoxSaveResult> TrySaveAs(
        const AZStd::string_view entityName,
        const AZStd::function<AZStd::string(const AZStd::string&)>& absoluteSavePathFn,
        const AZStd::function<AZStd::optional<AZStd::string>(const AZStd::string&)>& relativePathFn,
        const AZStd::function<int()>& saveDecisionFn)
    {
        const AZStd::string initialAbsolutePathToSave =
            WhiteBoxPathAtProjectRoot(entityName, Pipeline::WhiteBoxMeshAssetHandler::AssetFileExtension);

        const QString absoluteSaveFilePath = QString(absoluteSavePathFn(initialAbsolutePathToSave).c_str());

        // user pressed cancel
        if (absoluteSaveFilePath.isEmpty())
        {
            return AZStd::nullopt;
        }

        const auto absoluteSaveFilePathUtf8 = absoluteSaveFilePath.toUtf8();
        const auto absoluteSaveFilePathCstr = absoluteSaveFilePathUtf8.constData();

        const AZStd::optional<AZStd::string> relativePath =
            relativePathFn(AZStd::string(absoluteSaveFilePathCstr, absoluteSaveFilePathUtf8.length()));

        if (!relativePath.has_value())
        {
            int saveDecision = saveDecisionFn();

            // save the file but do not attempt to create an asset
            if (saveDecision == QMessageBox::Save)
            {
                return WhiteBoxSaveResult{AZStd::nullopt, AZStd::string(absoluteSaveFilePathCstr)};
            }

            // the user decided not to save the asset outside the project folder after the prompt
            return AZStd::nullopt;
        }

        return WhiteBoxSaveResult{relativePath, AZStd::string(absoluteSaveFilePathCstr)};
    }

    void EditorWhiteBoxComponent::SaveAsAsset()
    {
        // let the user select final location of the saved asset
        const auto absoluteSavePathFn = [](const AZStd::string& initialAbsolutePath)
        {
            const QString fileFilter =
                AZStd::string::format("*.%s", Pipeline::WhiteBoxMeshAssetHandler::AssetFileExtension).c_str();
            const QString absolutePath = AzQtComponents::FileDialog::GetSaveFileName(
                nullptr, "Save As Asset...", QString(initialAbsolutePath.c_str()), fileFilter);

            return AZStd::string(absolutePath.toUtf8());
        };

        // ask the asset system to try and convert the absolutePath to a cache relative path
        const auto relativePathFn = [](const AZStd::string& absolutePath) -> AZStd::optional<AZStd::string>
        {
            AZStd::string relativePath;
            bool foundRelativePath = false;
            AzToolsFramework::AssetSystemRequestBus::BroadcastResult(
                foundRelativePath,
                &AzToolsFramework::AssetSystem::AssetSystemRequest::GetRelativeProductPathFromFullSourceOrProductPath,
                absolutePath, relativePath);

            if (foundRelativePath)
            {
                return relativePath;
            }

            return AZStd::nullopt;
        };

        // present the user with the option of accepting saving outside the project folder or allow them to cancel the
        // operation
        const auto saveDecisionFn = []()
        {
            return QMessageBox::warning(
                AzToolsFramework::GetActiveWindow(), "Warning",
                "Saving a White Box Mesh Asset (.wbm) outside of the project root will not create an Asset for the "
                "Component to use. The file will be saved but will not be processed. For live updates to happen the "
                "asset must be saved somewhere in the current project folder. Would you like to continue?",
                (QMessageBox::Save | QMessageBox::Cancel), QMessageBox::Cancel);
        };

        const AZStd::optional<WhiteBoxSaveResult> saveResult =
            TrySaveAs(GetEntity()->GetName(), absoluteSavePathFn, relativePathFn, saveDecisionFn);

        // user pressed cancel
        if (!saveResult.has_value())
        {
            return;
        }

        const char* const absoluteSaveFilePath = saveResult.value().m_absoluteFilePath.c_str();
        if (saveResult.value().m_relativeAssetPath.has_value())
        {
            const auto& relativeAssetPath = saveResult.value().m_relativeAssetPath.value();

            // notify undo system the entity has been changed (m_meshAsset)
            AzToolsFramework::ScopedUndoBatch undoBatch(AssetSavedUndoRedoDesc);

            // if there was a previous asset selected, it has to be cloned to a new one
            // otherwise the internal mesh can simply be moved into the new asset
            m_editorMeshAsset->TakeOwnershipOfWhiteBoxMesh(
                relativeAssetPath,
                m_editorMeshAsset->InUse() ? Api::CloneMesh(*GetWhiteBoxMesh())
                                           : AZStd::exchange(m_whiteBox, Api::CreateWhiteBoxMesh()));

            // change default shape to asset
            m_defaultShape = DefaultShapeType::Asset;

            // ensure this change gets tracked
            undoBatch.MarkEntityDirty(GetEntityId());

            RefreshProperties();

            m_editorMeshAsset->Save(absoluteSaveFilePath);
        }
        else
        {
            // save the asset to disk outside the project folder
            if (Api::SaveToWbm(*GetWhiteBoxMesh(), absoluteSaveFilePath))
            {
                RequestEditSourceControl(absoluteSaveFilePath);
            }
        }
    }

    template<typename TransformFn>
    AZ::Aabb CalculateAabb(const WhiteBoxMesh& whiteBox, TransformFn&& transformFn)
    {
        const auto vertexHandles = Api::MeshVertexHandles(whiteBox);
        return AZStd::accumulate(
            AZStd::cbegin(vertexHandles), AZStd::cend(vertexHandles), AZ::Aabb::CreateNull(), transformFn);
    }

    AZ::Aabb EditorWhiteBoxComponent::GetEditorSelectionBoundsViewport(
        [[maybe_unused]] const AzFramework::ViewportInfo& viewportInfo)
    {
        return GetWorldBounds();
    }

    AZ::Aabb EditorWhiteBoxComponent::GetWorldBounds()
    {
        AZ_PROFILE_FUNCTION(AzToolsFramework);

        if (!m_worldAabb.has_value())
        {
            m_worldAabb = GetLocalBounds();
            m_worldAabb->ApplyTransform(m_worldFromLocal);
        }

        return m_worldAabb.value();
    }

    AZ::Aabb EditorWhiteBoxComponent::GetLocalBounds()
    {
        AZ_PROFILE_FUNCTION(AzToolsFramework);

        if (!m_localAabb.has_value())
        {
            auto& whiteBoxMesh = *GetWhiteBoxMesh();

            m_localAabb = CalculateAabb(
                whiteBoxMesh,
                [&whiteBox = whiteBoxMesh](AZ::Aabb aabb, const Api::VertexHandle vertexHandle)
                {
                    aabb.AddPoint(Api::VertexPosition(whiteBox, vertexHandle));
                    return aabb;
                });
        }

        return m_localAabb.value();
    }

    bool EditorWhiteBoxComponent::EditorSelectionIntersectRayViewport(
        [[maybe_unused]] const AzFramework::ViewportInfo& viewportInfo, const AZ::Vector3& src, const AZ::Vector3& dir,
        float& distance)
    {
        AZ_PROFILE_FUNCTION(AzToolsFramework);

        if (!m_faces.has_value())
        {
            m_faces = Api::MeshFaces(*GetWhiteBoxMesh());
        }

        // must have at least one triangle
        if (m_faces->empty())
        {
            distance = std::numeric_limits<float>::max();
            return false;
        }

        // transform ray into local space
        const AZ::Transform worldFromLocalUniform = AzToolsFramework::TransformUniformScale(m_worldFromLocal);
        const AZ::Transform localFromWorldUniform = worldFromLocalUniform.GetInverse();

        // setup beginning/end of segment
        const float rayLength = 1000.0f;
        const AZ::Vector3 localRayOrigin = localFromWorldUniform.TransformPoint(src);
        const AZ::Vector3 localRayDirection = localFromWorldUniform.TransformVector(dir);
        const AZ::Vector3 localRayEnd = localRayOrigin + localRayDirection * rayLength;

        bool intersection = false;
        distance = std::numeric_limits<float>::max();
        for (const auto& face : m_faces.value())
        {
            float t;
            AZ::Vector3 normal;
            if (AZ::Intersect::IntersectSegmentTriangle(
                    localRayOrigin, localRayEnd, face[0], face[1], face[2], normal, t))
            {
                intersection = true;

                // find closest intersection
                const float dist = t * rayLength;
                if (dist < distance)
                {
                    distance = dist;
                }
            }
        }

        return intersection;
    }

    void EditorWhiteBoxComponent::OnEntityVisibilityChanged(const bool visibility)
    {
        if (visibility)
        {
            ShowRenderMesh();
        }
        else
        {
            HideRenderMesh();
        }
    }

    void EditorWhiteBoxComponent::ShowRenderMesh()
    {
        // if we wish to display the render mesh, set a null render mesh indicating a mesh can exist
        // note: if the optional remains empty, no render mesh will be created
        m_renderMesh.emplace(AZStd::make_unique<WhiteBoxNullRenderMesh>());
        RebuildRenderMesh();
    }

    void EditorWhiteBoxComponent::HideRenderMesh()
    {
        // clear the optional
        m_renderMesh.reset();
    }

    bool EditorWhiteBoxComponent::AssetInUse() const
    {
        return m_editorMeshAsset->InUse();
    }

    bool EditorWhiteBoxComponent::HasRenderMesh() const
    {
        // if the optional has a value we know a render mesh exists
        // note: This implicitly implies that the Entity is visible
        return m_renderMesh.has_value();
    }

    void EditorWhiteBoxComponent::OverrideEditorWhiteBoxMeshAsset(EditorWhiteBoxMeshAsset* editorMeshAsset)
    {
        // ensure we do not leak resources
        delete m_editorMeshAsset;

        m_editorMeshAsset = editorMeshAsset;
    }

    static bool DebugDrawingEnabled()
    {
        return cl_whiteBoxDebugVertexHandles || cl_whiteBoxDebugNormals || cl_whiteBoxDebugHalfedgeHandles ||
            cl_whiteBoxDebugEdgeHandles || cl_whiteBoxDebugFaceHandles || cl_whiteBoxDebugAabb;
    }

    static void WhiteBoxDebugRendering(
        const WhiteBoxMesh& whiteBoxMesh, const AZ::Transform& worldFromLocal,
        AzFramework::DebugDisplayRequests& debugDisplay, const AZ::Aabb& editorBounds)
    {
        const AZ::Quaternion worldOrientationFromLocal = worldFromLocal.GetRotation();

        debugDisplay.DepthTestOn();

        for (const auto faceHandle : Api::MeshFaceHandles(whiteBoxMesh))
        {
            const auto faceHalfedgeHandles = Api::FaceHalfedgeHandles(whiteBoxMesh, faceHandle);

            const AZ::Vector3 localFaceCenter =
                AZStd::accumulate(
                    faceHalfedgeHandles.cbegin(), faceHalfedgeHandles.cend(), AZ::Vector3::CreateZero(),
                    [&whiteBoxMesh](AZ::Vector3 start, const Api::HalfedgeHandle halfedgeHandle)
                    {
                        return start +
                            Api::VertexPosition(
                                   whiteBoxMesh, Api::HalfedgeVertexHandleAtTip(whiteBoxMesh, halfedgeHandle));
                    }) /
                3.0f;

            for (const auto halfedgeHandle : faceHalfedgeHandles)
            {
                const Api::VertexHandle vertexHandleAtTip =
                    Api::HalfedgeVertexHandleAtTip(whiteBoxMesh, halfedgeHandle);
                const Api::VertexHandle vertexHandleAtTail =
                    Api::HalfedgeVertexHandleAtTail(whiteBoxMesh, halfedgeHandle);

                const AZ::Vector3 localTailPoint = Api::VertexPosition(whiteBoxMesh, vertexHandleAtTail);
                const AZ::Vector3 localTipPoint = Api::VertexPosition(whiteBoxMesh, vertexHandleAtTip);
                const AZ::Vector3 localFaceNormal = Api::FaceNormal(whiteBoxMesh, faceHandle);
                const AZ::Vector3 localHalfedgeCenter = (localTailPoint + localTipPoint) * 0.5f;

                // offset halfedge slightly based on the face it is associated with
                const AZ::Vector3 localHalfedgePositionWithOffset =
                    localHalfedgeCenter + ((localFaceCenter - localHalfedgeCenter).GetNormalized() * 0.1f);

                const AZ::Vector3 worldVertexPosition = worldFromLocal.TransformPoint(localTipPoint);
                const AZ::Vector3 worldHalfedgePosition =
                    worldFromLocal.TransformPoint(localHalfedgePositionWithOffset);
                const AZ::Vector3 worldNormal =
                    (worldOrientationFromLocal.TransformVector(localFaceNormal)).GetNormalized();

                if (cl_whiteBoxDebugVertexHandles)
                {
                    debugDisplay.SetColor(AZ::Colors::Cyan);
                    const AZStd::string vertex = AZStd::string::format("%d", vertexHandleAtTip.Index());
                    debugDisplay.DrawTextLabel(worldVertexPosition, 3.0f, vertex.c_str(), true, 0, 1);
                }

                if (cl_whiteBoxDebugHalfedgeHandles)
                {
                    debugDisplay.SetColor(AZ::Colors::LawnGreen);
                    const AZStd::string halfedge = AZStd::string::format("%d", halfedgeHandle.Index());
                    debugDisplay.DrawTextLabel(worldHalfedgePosition, 2.0f, halfedge.c_str(), true);
                }

                if (cl_whiteBoxDebugNormals)
                {
                    debugDisplay.SetColor(AZ::Colors::White);
                    debugDisplay.DrawBall(worldVertexPosition, 0.025f);
                    debugDisplay.DrawLine(worldVertexPosition, worldVertexPosition + worldNormal * 0.4f);
                }
            }

            if (cl_whiteBoxDebugFaceHandles)
            {
                debugDisplay.SetColor(AZ::Colors::White);
                const AZ::Vector3 worldFacePosition = worldFromLocal.TransformPoint(localFaceCenter);
                const AZStd::string face = AZStd::string::format("%d", faceHandle.Index());
                debugDisplay.DrawTextLabel(worldFacePosition, 2.0f, face.c_str(), true);
            }
        }

        if (cl_whiteBoxDebugEdgeHandles)
        {
            for (const auto edgeHandle : Api::MeshEdgeHandles(whiteBoxMesh))
            {
                const AZ::Vector3 localEdgeMidpoint = Api::EdgeMidpoint(whiteBoxMesh, edgeHandle);
                const AZ::Vector3 worldEdgeMidpoint = worldFromLocal.TransformPoint(localEdgeMidpoint);
                debugDisplay.SetColor(AZ::Colors::CornflowerBlue);
                const AZStd::string edge = AZStd::string::format("%d", edgeHandle.Index());
                debugDisplay.DrawTextLabel(worldEdgeMidpoint, 2.0f, edge.c_str(), true);
            }
        }

        if (cl_whiteBoxDebugAabb)
        {
            debugDisplay.SetColor(AZ::Colors::Blue);
            debugDisplay.DrawWireBox(editorBounds.GetMin(), editorBounds.GetMax());
        }
    }

    void EditorWhiteBoxComponent::DisplayEntityViewport(
        [[maybe_unused]] const AzFramework::ViewportInfo& viewportInfo, AzFramework::DebugDisplayRequests& debugDisplay)
    {
        AZ_PROFILE_FUNCTION(AzToolsFramework);

        if (DebugDrawingEnabled())
        {
            WhiteBoxDebugRendering(
                *GetWhiteBoxMesh(), m_worldFromLocal, debugDisplay,
                GetEditorSelectionBoundsViewport(AzFramework::ViewportInfo{}));
        }
    }
} // namespace WhiteBox