#include "UEBlueprintMCPEditor.h"

#include "HttpModule.h"
#include "Interfaces/IHttpResponse.h"
#include "Misc/CoreDelegates.h"
#include "Framework/Notifications/NotificationManager.h"
#include "Widgets/Notifications/SNotificationList.h"
#include "BlueprintEditor.h"
#include "BlueprintEditorContext.h"
#include "EdGraph/EdGraph.h"
#include "EdGraph/EdGraphNode.h"
#include "EdGraphNode_Comment.h"
#include "Framework/Application/IInputProcessor.h"
#include "Framework/Application/SlateApplication.h"
#include "Framework/Commands/UIAction.h"
#include "Kismet2/BlueprintEditorUtils.h"
#include "ScopedTransaction.h"
#include "SGraphPanel.h"
#include "ToolMenu.h"
#include "ToolMenuEntry.h"
#include "ToolMenuSection.h"
#include "ToolMenus.h"

#define LOCTEXT_NAMESPACE "UEBlueprintMCPEditor"

namespace
{
const TCHAR* MCPZoneCommentText = TEXT("MCP Zone");
const TCHAR* LegacyMCPZoneCommentText = TEXT("MCP Draft Zone");

bool IsMCPZoneComment(const UEdGraphNode* Node)
{
    const UEdGraphNode_Comment* CommentNode = Cast<UEdGraphNode_Comment>(Node);
    return CommentNode
        && (CommentNode->NodeComment.Equals(MCPZoneCommentText, ESearchCase::IgnoreCase)
            || CommentNode->NodeComment.Equals(LegacyMCPZoneCommentText, ESearchCase::IgnoreCase));
}
}

class FMCPZoneInputProcessor : public IInputProcessor
{
public:
    explicit FMCPZoneInputProcessor(FUEBlueprintMCPEditorModule& InOwner)
        : Owner(InOwner)
    {
    }

    virtual void Tick(const float DeltaTime, FSlateApplication& SlateApp, TSharedRef<ICursor> Cursor) override
    {
    }

    virtual bool HandleMouseButtonDownEvent(FSlateApplication& SlateApp, const FPointerEvent& MouseEvent) override
    {
        if (!Owner.bMCPZoneModeActive || MouseEvent.GetEffectingButton() != EKeys::LeftMouseButton)
        {
            return false;
        }

        TSharedPtr<FBlueprintEditor> Editor = Owner.ActiveMCPZoneEditor.Pin();
        if (!Editor.IsValid() || !Editor->GetFocusedGraph())
        {
            return false;
        }

        TSharedPtr<SGraphEditor> GraphEditor = Editor->OpenGraphAndBringToFront(Editor->GetFocusedGraph(), false);
        SGraphPanel* GraphPanel = GraphEditor.IsValid() ? GraphEditor->GetGraphPanel() : nullptr;
        if (!GraphPanel)
        {
            return false;
        }

        const FGeometry& Geometry = GraphPanel->GetTickSpaceGeometry();
        const FVector2f ScreenPosition = UE::Slate::CastToVector2f(MouseEvent.GetScreenSpacePosition());
        if (!Geometry.IsUnderLocation(ScreenPosition))
        {
            return false;
        }

        bDragging = true;
        StartScreenPosition = ScreenPosition;
        return true;
    }

    virtual bool HandleMouseMoveEvent(FSlateApplication& SlateApp, const FPointerEvent& MouseEvent) override
    {
        return bDragging && Owner.bMCPZoneModeActive;
    }

    virtual bool HandleMouseButtonUpEvent(FSlateApplication& SlateApp, const FPointerEvent& MouseEvent) override
    {
        if (!bDragging || MouseEvent.GetEffectingButton() != EKeys::LeftMouseButton)
        {
            return false;
        }

        bDragging = false;
        const FVector2f EndScreenPosition = UE::Slate::CastToVector2f(MouseEvent.GetScreenSpacePosition());
        Owner.TryCreateMCPZoneFromScreenDrag(StartScreenPosition, EndScreenPosition);
        return true;
    }

    virtual const TCHAR* GetDebugName() const override
    {
        return TEXT("MCPZoneInputProcessor");
    }

private:
    FUEBlueprintMCPEditorModule& Owner;
    bool bDragging = false;
    FVector2f StartScreenPosition = FVector2f::ZeroVector;
};

IMPLEMENT_MODULE(FUEBlueprintMCPEditorModule, UEBlueprintMCPEditor)

void FUEBlueprintMCPEditorModule::StartupModule()
{
    UToolMenus::RegisterStartupCallback(
        FSimpleMulticastDelegate::FDelegate::CreateRaw(this, &FUEBlueprintMCPEditorModule::RegisterMenus));

    FCoreDelegates::OnPostEngineInit.AddRaw(this, &FUEBlueprintMCPEditorModule::NotifyBridgeStatus);
}

void FUEBlueprintMCPEditorModule::NotifyBridgeStatus()
{
    const FString Url = TEXT("http://127.0.0.1:30010/remote/info");
    TSharedRef<IHttpRequest> Request = FHttpModule::Get().CreateRequest();
    Request->SetVerb(TEXT("GET"));
    Request->SetURL(Url);
    Request->SetTimeout(3.0f);
    Request->OnProcessRequestComplete().BindLambda(
        [](FHttpRequestPtr Req, FHttpResponsePtr Resp, bool bSucceeded)
        {
            const bool bOk = bSucceeded && Resp.IsValid() && Resp->GetResponseCode() == 200;
            FNotificationInfo Info(bOk
                ? LOCTEXT("MCPBridgeUp", "UE Blueprint MCP bridge ready (Remote Control :30010)")
                : LOCTEXT("MCPBridgeDown", "UE Blueprint MCP bridge NOT reachable on :30010 — check Remote Control plugin"));
            Info.ExpireDuration = bOk ? 4.0f : 8.0f;
            Info.bUseSuccessFailIcons = true;
            Info.bFireAndForget = true;
            TSharedPtr<SNotificationItem> Item = FSlateNotificationManager::Get().AddNotification(Info);
            if (Item.IsValid())
            {
                Item->SetCompletionState(bOk ? SNotificationItem::CS_Success : SNotificationItem::CS_Fail);
            }
        });
    Request->ProcessRequest();
}

void FUEBlueprintMCPEditorModule::ShutdownModule()
{
    FCoreDelegates::OnPostEngineInit.RemoveAll(this);

    if (MCPZoneInputProcessor.IsValid() && FSlateApplication::IsInitialized())
    {
        FSlateApplication::Get().UnregisterInputPreProcessor(MCPZoneInputProcessor);
        MCPZoneInputProcessor.Reset();
    }

    if (UToolMenus::IsToolMenuUIEnabled())
    {
        UToolMenus::UnRegisterStartupCallback(this);
        UToolMenus::UnregisterOwner(this);
    }
}

void FUEBlueprintMCPEditorModule::RegisterMenus()
{
    FToolMenuOwnerScoped OwnerScoped(this);
    UToolMenu* Toolbar = UToolMenus::Get()->ExtendMenu("AssetEditor.BlueprintEditor.ToolBar");
    FToolMenuSection& Section = Toolbar->FindOrAddSection("Settings");

    Section.AddDynamicEntry("MCPDraftZoneCommands", FNewToolMenuSectionDelegate::CreateLambda([this](FToolMenuSection& InSection)
    {
        UBlueprintEditorToolMenuContext* Context = InSection.FindContext<UBlueprintEditorToolMenuContext>();
        if (!Context || !Context->BlueprintEditor.IsValid() || !Context->GetBlueprintObj())
        {
            return;
        }

        TWeakPtr<FBlueprintEditor> WeakEditor = Context->BlueprintEditor;
        FUIAction Action(
            FExecuteAction::CreateLambda([this, WeakEditor]()
            {
                ToggleMCPZoneMode(WeakEditor);
            }),
            FCanExecuteAction::CreateLambda([WeakEditor]()
            {
                return WeakEditor.IsValid() && WeakEditor.Pin()->GetFocusedGraph() != nullptr;
            }),
            FIsActionChecked::CreateLambda([this, WeakEditor]()
            {
                return IsMCPZoneModeActive(WeakEditor);
            }));

        FToolMenuEntry Entry = FToolMenuEntry::InitToolBarButton(
            FName(TEXT("MCPDraftZone")),
            FToolUIActionChoice(Action),
            LOCTEXT("MCPDraftZone_Label", "MCP Zone"),
            LOCTEXT("MCPDraftZone_Tooltip", "Toggle MCP Zone mode. While active, left-mouse drag in the graph to create a generation zone. Toggle off to remove MCP Zone comments while keeping generated nodes."),
            FSlateIcon(),
            EUserInterfaceActionType::ToggleButton);
        InSection.AddEntry(Entry);
    }));
}

void FUEBlueprintMCPEditorModule::ToggleMCPZoneMode(TWeakPtr<FBlueprintEditor> BlueprintEditor)
{
    TSharedPtr<FBlueprintEditor> Editor = BlueprintEditor.Pin();
    if (!Editor.IsValid())
    {
        return;
    }

    if (bMCPZoneModeActive && ActiveMCPZoneEditor.Pin() == Editor)
    {
        RemoveMCPZones(Editor->GetBlueprintObj());
        bMCPZoneModeActive = false;
        ActiveMCPZoneEditor.Reset();
        if (MCPZoneInputProcessor.IsValid() && FSlateApplication::IsInitialized())
        {
            FSlateApplication::Get().UnregisterInputPreProcessor(MCPZoneInputProcessor);
            MCPZoneInputProcessor.Reset();
        }
        return;
    }

    if (bMCPZoneModeActive)
    {
        if (TSharedPtr<FBlueprintEditor> PreviousEditor = ActiveMCPZoneEditor.Pin())
        {
            RemoveMCPZones(PreviousEditor->GetBlueprintObj());
        }
    }

    bMCPZoneModeActive = true;
    ActiveMCPZoneEditor = Editor;
    if (!MCPZoneInputProcessor.IsValid() && FSlateApplication::IsInitialized())
    {
        MCPZoneInputProcessor = MakeShared<FMCPZoneInputProcessor>(*this);
        FSlateApplication::Get().RegisterInputPreProcessor(MCPZoneInputProcessor);
    }
}

bool FUEBlueprintMCPEditorModule::IsMCPZoneModeActive(TWeakPtr<FBlueprintEditor> BlueprintEditor) const
{
    return bMCPZoneModeActive && ActiveMCPZoneEditor.Pin() == BlueprintEditor.Pin();
}

bool FUEBlueprintMCPEditorModule::TryCreateMCPZoneFromScreenDrag(const FVector2f& StartScreenPosition, const FVector2f& EndScreenPosition)
{
    TSharedPtr<FBlueprintEditor> Editor = ActiveMCPZoneEditor.Pin();
    if (!Editor.IsValid())
    {
        return false;
    }

    UBlueprint* Blueprint = Editor->GetBlueprintObj();
    UEdGraph* Graph = Editor->GetFocusedGraph();
    if (!Blueprint || !Graph)
    {
        return false;
    }

    TSharedPtr<SGraphEditor> GraphEditor = Editor->OpenGraphAndBringToFront(Graph, false);
    SGraphPanel* GraphPanel = GraphEditor.IsValid() ? GraphEditor->GetGraphPanel() : nullptr;
    if (!GraphPanel)
    {
        return false;
    }

    const FGeometry& Geometry = GraphPanel->GetTickSpaceGeometry();
    const FVector2f LocalStart = UE::Slate::CastToVector2f(Geometry.AbsoluteToLocal(StartScreenPosition));
    const FVector2f LocalEnd = UE::Slate::CastToVector2f(Geometry.AbsoluteToLocal(EndScreenPosition));
    const FVector2f GraphStart = UE::Slate::CastToVector2f(GraphPanel->PanelCoordToGraphCoord(LocalStart));
    const FVector2f GraphEnd = UE::Slate::CastToVector2f(GraphPanel->PanelCoordToGraphCoord(LocalEnd));

    CreateMCPZone(Graph, Blueprint, GraphStart, GraphEnd);
    return true;
}

void FUEBlueprintMCPEditorModule::CreateMCPZone(UEdGraph* Graph, UBlueprint* Blueprint, const FVector2f& GraphStart, const FVector2f& GraphEnd) const
{
    if (!Blueprint || !Graph)
    {
        return;
    }

    const FScopedTransaction Transaction(LOCTEXT("CreateMCPDraftZone", "Create MCP Draft Zone"));
    Graph->Modify();
    Blueprint->Modify();

    constexpr int32 MinWidth = 240;
    constexpr int32 MinHeight = 160;
    const int32 MinX = FMath::FloorToInt(FMath::Min(GraphStart.X, GraphEnd.X));
    const int32 MinY = FMath::FloorToInt(FMath::Min(GraphStart.Y, GraphEnd.Y));
    const int32 MaxX = FMath::CeilToInt(FMath::Max(GraphStart.X, GraphEnd.X));
    const int32 MaxY = FMath::CeilToInt(FMath::Max(GraphStart.Y, GraphEnd.Y));

    UEdGraphNode_Comment* ZoneNode = NewObject<UEdGraphNode_Comment>(Graph);
    ZoneNode->CreateNewGuid();
    ZoneNode->NodeComment = MCPZoneCommentText;
    ZoneNode->bCommentBubbleVisible = false;
    ZoneNode->CommentColor = FLinearColor(0.05f, 0.32f, 0.85f, 0.35f);
    ZoneNode->NodePosX = MinX;
    ZoneNode->NodePosY = MinY;
    ZoneNode->NodeWidth = FMath::Max(MinWidth, MaxX - MinX);
    ZoneNode->NodeHeight = FMath::Max(MinHeight, MaxY - MinY);

    Graph->AddNode(ZoneNode, true, false);
    ZoneNode->PostPlacedNewNode();
    FBlueprintEditorUtils::MarkBlueprintAsModified(Blueprint);
}

void FUEBlueprintMCPEditorModule::RemoveMCPZones(UBlueprint* Blueprint) const
{
    if (!Blueprint)
    {
        return;
    }

    const FScopedTransaction Transaction(LOCTEXT("RemoveMCPDraftZones", "Remove MCP Draft Zones"));
    Blueprint->Modify();

    TArray<UEdGraph*> Graphs;
    Blueprint->GetAllGraphs(Graphs);
    for (UEdGraph* Graph : Graphs)
    {
        if (!Graph)
        {
            continue;
        }

        Graph->Modify();
        TArray<UEdGraphNode*> Nodes = Graph->Nodes;
        for (UEdGraphNode* Node : Nodes)
        {
            if (IsMCPZoneComment(Node))
            {
                Graph->RemoveNode(Node);
            }
        }
    }

    FBlueprintEditorUtils::MarkBlueprintAsModified(Blueprint);
}

#undef LOCTEXT_NAMESPACE