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

#include "Utils.h"
#include "EditorViewportClient.h"

#if PLATFORM_WINDOWS
#include "Windows/WindowsHWrapper.h"
// Needed for showing balloon messages
#include "Windows/AllowWindowsPlatformTypes.h"
#include <ShellAPI.h>
#include "Windows/HideWindowsPlatformTypes.h"
#endif

DEFINE_LOG_CATEGORY(LogUtils);

IMPLEMENT_HIT_PROXY(HWidgetUtilProxy, HHitProxy);

float UnrealEd_WidgetSize = 0.15f;  // Proportion of the viewport the widget should fill

/** Utility for calculating drag direction when you click on this widget. */
void HWidgetUtilProxy::CalcVectors(FSceneView* SceneView, const FViewportClick& Click, FVector& LocalManDir, FVector& WorldManDir, float& DragDirX, float& DragDirY)
{
    if (Axis == EAxisList::X)
    {
        WorldManDir = WidgetMatrix.GetScaledAxis(EAxis::X);
        LocalManDir = FVector(1, 0, 0);
    }
    else if (Axis == EAxisList::Y)
    {
        WorldManDir = WidgetMatrix.GetScaledAxis(EAxis::Y);
        LocalManDir = FVector(0, 1, 0);
    }
    else
    {
        WorldManDir = WidgetMatrix.GetScaledAxis(EAxis::Z);
        LocalManDir = FVector(0, 0, 1);
    }

    FVector WorldDragDir = WorldManDir;

    if (Mode == WMM_Rotate)
    {
        if (FMath::Abs(Click.GetDirection() | WorldManDir) > KINDA_SMALL_NUMBER)  // If click direction and circle plane are parallel.. can't resolve.
        {
            // First, find actual position we clicking on the circle in world space.
            const FVector ClickPosition = FMath::LinePlaneIntersection(Click.GetOrigin(),
                                                                       Click.GetOrigin() + Click.GetDirection(),
                                                                       WidgetMatrix.GetOrigin(),
                                                                       WorldManDir);

            // Then find Radial direction vector (from center to widget to clicked position).
            FVector RadialDir = (ClickPosition - WidgetMatrix.GetOrigin());
            RadialDir.Normalize();

            // Then tangent in plane is just the cross product. Should always be unit length again because RadialDir and WorlManDir should be orthogonal.
            WorldDragDir = RadialDir ^ WorldManDir;
        }
    }

    // Transform world-space drag dir to screen space.
    FVector ScreenDir = SceneView->ViewMatrices.GetViewMatrix().TransformVector(WorldDragDir);
    ScreenDir.Z       = 0.0f;

    if (ScreenDir.IsZero())
    {
        DragDirX = 0.0f;
        DragDirY = 0.0f;
    }
    else
    {
        ScreenDir.Normalize();
        DragDirX = ScreenDir.X;
        DragDirY = ScreenDir.Y;
    }
}

/**
 *	Utility function for drawing manipulation widget in a 3D viewport.
 *	If we are hit-testing will create HWidgetUtilProxys for each axis, filling in InInfo1 and InInfo2 as passed in by user.
 */
void FUnrealEdUtils::DrawWidget(const FSceneView* View, FPrimitiveDrawInterface* PDI, const FMatrix& WidgetMatrix, int32 InInfo1, int32 InInfo2, EAxisList::Type HighlightAxis, EWidgetMovementMode bInMode)
{
    DrawWidget(View, PDI, WidgetMatrix, InInfo1, InInfo2, HighlightAxis, bInMode, PDI->IsHitTesting());
}

void FUnrealEdUtils::DrawWidget(const FSceneView* View, FPrimitiveDrawInterface* PDI, const FMatrix& WidgetMatrix, int32 InInfo1, int32 InInfo2, EAxisList::Type HighlightAxis, EWidgetMovementMode bInMode, bool bHitTesting)
{
    const FVector WidgetOrigin = WidgetMatrix.GetOrigin();

    // Calculate size to draw widget so it takes up the same screen space.
    const float ZoomFactor   = FMath::Min<float>(View->ViewMatrices.GetProjectionMatrix().M[0][0], View->ViewMatrices.GetProjectionMatrix().M[1][1]);
    const float WidgetRadius = View->Project(WidgetOrigin).W * (UnrealEd_WidgetSize / ZoomFactor);

    // Choose its color. Highlight manipulated axis in yellow.
    FColor XColor(FColor::Red);
    FColor YColor(FColor::Green);
    FColor ZColor(FColor::Blue);

    if (HighlightAxis == EAxisList::X)
    {
        XColor = FColor::Yellow;
    }
    else if (HighlightAxis == EAxisList::Y)
    {
        YColor = FColor::Yellow;
    }
    else if (HighlightAxis == EAxisList::Z)
    {
        ZColor = FColor::Yellow;
    }

    const FVector XAxis = WidgetMatrix.GetScaledAxis(EAxis::X);
    const FVector YAxis = WidgetMatrix.GetScaledAxis(EAxis::Y);
    const FVector ZAxis = WidgetMatrix.GetScaledAxis(EAxis::Z);

    if (bInMode == WMM_Rotate)
    {
        if (bHitTesting)
            PDI->SetHitProxy(new HWidgetUtilProxy(InInfo1, InInfo2, EAxisList::X, WidgetMatrix, bInMode));
        DrawCircle(PDI, WidgetOrigin, YAxis, ZAxis, XColor, WidgetRadius, 24, SDPG_Foreground);
        if (bHitTesting)
            PDI->SetHitProxy(NULL);

        if (bHitTesting)
            PDI->SetHitProxy(new HWidgetUtilProxy(InInfo1, InInfo2, EAxisList::Y, WidgetMatrix, bInMode));
        DrawCircle(PDI, WidgetOrigin, XAxis, ZAxis, YColor, WidgetRadius, 24, SDPG_Foreground);
        if (bHitTesting)
            PDI->SetHitProxy(NULL);

        if (bHitTesting)
            PDI->SetHitProxy(new HWidgetUtilProxy(InInfo1, InInfo2, EAxisList::Z, WidgetMatrix, bInMode));
        DrawCircle(PDI, WidgetOrigin, XAxis, YAxis, ZColor, WidgetRadius, 24, SDPG_Foreground);
        if (bHitTesting)
            PDI->SetHitProxy(NULL);
    }
    else
    {
        FMatrix WidgetTM;

        // Draw the widget arrows.
        if (bHitTesting)
            PDI->SetHitProxy(new HWidgetUtilProxy(InInfo1, InInfo2, EAxisList::X, WidgetMatrix, bInMode));
        WidgetTM = FMatrix(XAxis, YAxis, ZAxis, WidgetOrigin);
        DrawDirectionalArrow(PDI, WidgetTM, XColor, WidgetRadius, 1.f, SDPG_Foreground);
        if (bHitTesting)
            PDI->SetHitProxy(NULL);

        if (bHitTesting)
            PDI->SetHitProxy(new HWidgetUtilProxy(InInfo1, InInfo2, EAxisList::Y, WidgetMatrix, bInMode));
        WidgetTM = FMatrix(YAxis, ZAxis, XAxis, WidgetOrigin);
        DrawDirectionalArrow(PDI, WidgetTM, YColor, WidgetRadius, 1.f, SDPG_Foreground);
        if (bHitTesting)
            PDI->SetHitProxy(NULL);

        if (bHitTesting)
            PDI->SetHitProxy(new HWidgetUtilProxy(InInfo1, InInfo2, EAxisList::Z, WidgetMatrix, bInMode));
        WidgetTM = FMatrix(ZAxis, XAxis, YAxis, WidgetOrigin);
        DrawDirectionalArrow(PDI, WidgetTM, ZColor, WidgetRadius, 1.f, SDPG_Foreground);
        if (bHitTesting)
            PDI->SetHitProxy(NULL);

        if (bInMode == WMM_Scale)
        {
            FVector AlongX = WidgetOrigin + (XAxis * WidgetRadius * 0.3f);
            FVector AlongY = WidgetOrigin + (YAxis * WidgetRadius * 0.3f);
            FVector AlongZ = WidgetOrigin + (ZAxis * WidgetRadius * 0.3f);

            PDI->DrawLine(AlongX, AlongY, FColor::White, SDPG_Foreground);
            PDI->DrawLine(AlongY, AlongZ, FColor::White, SDPG_Foreground);
            PDI->DrawLine(AlongZ, AlongX, FColor::White, SDPG_Foreground);
        }
    }
}