#include "StdAfx.h"
#include "CurveEditorDefault.h"
#include "SigmaDoc.h"
#include "SigmaView.h"
#include "ActionModifiedItem.h"
#include "ActionBackupItem.h"
#include "DrawOperator/TypeDefine.h"
#include "ActionCurveEdit.h"
#include "ActionCurveEditAddPoint.h"
#include "ActionCurveEditDeletePoint.h"
#include "HandleDrawer.h"
#include "SegmentSnappingEngine.h"
#include "Util.h"

void CurveEditorDefault::OnDraw(CXyDC* pDC)
{
	POSITION pos = GetPos();
	if (pos == 0)
		return;

	// 调用子类实现的扩展点
	CCurveEx* pCurve = (CCurveEx*)GetDoc()->GetDraw()->GetAtValue(GetPos());
}

void CurveEditorDefault::DrawAssistant(CDC* pDC, int mouseX, int mouseY)
{
	CCurveEx* pCurve = GetControlCurve();
	if (pCurve == nullptr) return;
	
	m_handleDrawer->Init(pCurve);
	m_handleDrawer->DrawAll(pDC);
}

void CurveEditorDefault::OnLButtonDown(CDC* pDC, UINT nFlags, CPoint point, int vk)
{
	SetScreenDC(pDC);

	m_nDragSegmentIndex = -1; // 重置线段拖动索引

	// 检查：如果没有选中节点，检查是否可以拖动线段
	if (this->GetHandleIndex() < 0)
	{
		// 检查是否处于线段拖动模式
		if (GetDoc()->GetEditLineStatus() == CURVE_STATE_DRAG_SEGMENT)
		{
			int segIndex = HitTestSegment(point);
			if (segIndex >= 0)
			{
				// 进入线段拖动模式
				m_nDragSegmentIndex = segIndex;
				m_nLButtonDownPoint = point;

				c_down = GetDC()->GetReal(point);
				c_last = c_down;

				DrawMoveSegment(pDC); // 绘制初始状态
				return;
			}
		}

		if (!IsCanAddHandle(point))
			return;
	}

	// 清空上次的临时点列表
	if (NewPointList.GetCount() > 0)
		NewPointList.RemoveAll();

	// 记录鼠标按下位置（屏幕坐标和世界坐标）
	m_nLButtonDownPoint = point;
	c_down = GetDC()->GetReal(point);
	c_last = c_down;

	// 调用扩展点：绘制预览
	OnDrawDragPreview();
}

int CurveEditorDefault::OnMouseMove(CDC* dc, UINT nFlags, CPoint point)
{
	SetScreenDC(dc);

	POSITION pos = GetPos();
	if (pos == 0)
		return 1;

	CXyDC* pDC = GetDC();

	if (IsDragging(nFlags)) // 鼠标左键按下
	{
		HandleMouseDrag(pDC, point);
	}
	else
	{
		HandleMouseHover(dc, point);
	}

	m_handleDrawer->DrawFocusHandle(dc, GetHandleIndex());

	return 1;
}

void CurveEditorDefault::OnLButtonUp(CDC* pDC, UINT nFlags, CPoint point, int vk)
{
	SetScreenDC(pDC);

	if (m_bLButtonDownWhenMouseMove == false)
		return;

	m_bLButtonDownWhenMouseMove = false;

	// 处理线段拖动结束
	if (m_nDragSegmentIndex >= 0)
	{
		// 1. [擦除] 使用上一次的 c_last 擦除屏幕上的虚影
		DrawMoveSegment(pDC);

		NBase::CPoint2D rawMouse = GetDC()->GetReal(point);
		c_last = CalculateSnappedMousePos(rawMouse, m_nDragSegmentIndex);

		CCurveEx* pValue = GetControlCurve();
		int i = m_nDragSegmentIndex;
		// 安全检查
		if (i < 0 || i >= pValue->num - 1)
		{
			m_nDragSegmentIndex = -1;
			ReleaseCapture();
			return;
		}

		// 3. [Undo/Redo 准备]
		CActionCurveEdit* pAction = new CActionCurveEdit(GetDoc(), 0, GetPos());
		// 备份移动前的节点位置
		pAction->BackupUndoNode(i, pValue->x[i], pValue->y[i]);
		pAction->BackupUndoNode(i + 1, pValue->x[i + 1], pValue->y[i + 1]);

		if (m_lastSnapResult.snapType == Geometry::SnapType::PARALLEL_LINE)
		{
			// 策略 A：平行吸附 -> 强制共线 (Projection)
			const Geometry::Segment& targetSeg = m_lastSnapResult.targetSegment;

			// 构造当前点 (转换类型)
			Geometry::Point pStart = { pValue->x[i], pValue->y[i] };
			Geometry::Point pEnd = { pValue->x[i + 1], pValue->y[i + 1] };

			// 计算投影因子 t (相对于目标线段)
			double t1 = Geometry::GeometryUtils::getProjectionFactor(pStart, targetSeg);
			double t2 = Geometry::GeometryUtils::getProjectionFactor(pEnd, targetSeg);

			Geometry::Point dir = targetSeg.direction();

			// 计算投影后的新坐标 (Start + t * Dir)
			Geometry::Point newStart = targetSeg.start + (dir * t1);
			Geometry::Point newEnd = targetSeg.start + (dir * t2);

			// 直接赋值新坐标，修正微小的角度偏差
			pValue->x[i] = newStart.x;
			pValue->y[i] = newStart.y;
			pValue->x[i + 1] = newEnd.x;
			pValue->y[i + 1] = newEnd.y;
		}
		else
		{
			// 策略 B：普通移动 -> 刚体平移 (Rigid Translation)
			dfPoint pt1, pt2;
			GetXY(pValue, i, pt1);
			GetXY(pValue, i + 1, pt2);

			double mouseDx = c_last.x0 - c_down.x0;
			double mouseDy = c_last.y0 - c_down.y0;

			// 计算沿法线的偏移量
			NBase::CPoint2D offset = CalculateNormalOffset(pt1, pt2, mouseDx, mouseDy);

			pValue->x[i] += offset.x0;
			pValue->y[i] += offset.y0;
			pValue->x[i + 1] += offset.x0;
			pValue->y[i + 1] += offset.y0;
		}

		if (pValue->bAutoLocation)
			pValue->GetLocation();

		// 6. [Redo 记录]
		pAction->BackupRedoNode(i, pValue->x[i], pValue->y[i]);
		pAction->BackupRedoNode(i + 1, pValue->x[i + 1], pValue->y[i + 1]);
		GetDoc()->SetActionItem(pAction);

		// 7. [收尾工作]
		SetModifiedFlag(TRUE);
		GetDoc()->Modified();
		
		m_nDragSegmentIndex = -1;
		ReleaseCapture();

		// 刷新显示
		Invalidate();
		return;
	}

	if (this->GetHandleIndex() < 0)
	{
		CPoint2D pt = GetDC()->GetReal(point);
		POSITION pos = GetDoc()->GetSelectedItem(pt);
		if (pos == GetPos()) return;

		EndEdit();
		return;
	}

	c_last = GetDC()->GetReal(point);
	
	// 擦除预览线
	OnDrawDragPreview();

	if (c_last == c_down)
		return;

	// 应用修改
	OnCalculateDragEffect(nullptr);

	SetModifiedFlag(TRUE);
	GetDoc()->Modified();
	SetHandleIndex(-1);
	ReleaseCapture();
}

void CurveEditorDefault::OnLButtonDblClk(UINT nFlags, CPoint point)
{
	POSITION pos = GetPos();
	if (pos == nullptr) return;

	COne* pOne = GetDoc()->GetDraw()->GetAt(pos);
	if (pOne == nullptr) return;

	std::unique_ptr<CActionModifiedItem> pAction = std::make_unique<CActionModifiedItem>(GetDoc(), 0);
	pAction->BackupOldItem(pos, pOne);

	if (GetHandleIndex() >= 0)
	{
		if (IsCaptureState()) ReleaseCapture();
		int index = GetHandleIndex();
		CCurveEx* pcurve = GetControlCurve();
		CRect8 range(1e300, -1e300, -1e300, 1e300);
		for (int i = index - 1; i <= index + 1; i++)
		{
			if (i < 0 || i > pcurve->num - 1) continue;
			range.CombinRect(pcurve->x[i], pcurve->y[i], pcurve->x[i], pcurve->y[i]);
		}
		DeleteHandle(GetHandleIndex());
		SetHandleIndex(-1);
		CRect rt = GetDC()->GetScreen(range);
		CSize8 sz = GetDoc()->GetSelectSize();
		CSize size((int)sz.cx + 1, (int)sz.cy + 1);
		rt.InflateRect(size);
	}
	else if (IsCanAddHandle(point))
	{
		int ret = AddHandle(point);
		if (ret < 0) return;
	}

	pAction->BackupNewItem();
	GetDoc()->SetActionItem(pAction.release());
	GetDoc()->Modified();

	if (GetDoc()->GetItem()->GetType() == ITEM_CURVE_EDIT)
	{
		EndEdit();
	}
}

BOOL CurveEditorDefault::OnSetCursor(CWnd* pWnd, UINT nHitTest, UINT message)
{
	return TRUE;
}

BOOL CurveEditorDefault::OnKeyDown(UINT nChar, UINT nRepCnt, UINT nFlags)
{
	switch (nChar)
	{
	case VK_ESCAPE:
		if (!IsCaptureState()) break;
		OnDrawDragPreview();
		DrawSelectHandle(GetHandleIndex());
		SetHandleIndex(-1);
		ReleaseCapture();
		return TRUE;
	}
	return FALSE;
}

BOOL CurveEditorDefault::OnKeyUp(UINT nChar, UINT nRepCnt, UINT nFlags)
{
	switch (nChar)
	{
	case VK_ESCAPE:
		EndEdit();
		return TRUE;
	}
	return FALSE;
}

int CurveEditorDefault::GetSubMenu()
{
	return 6;
}

void CurveEditorDefault::SetPos(POSITION pos)
{
	CItem::SetPos(pos);
	m_pBakOne.reset();  // 清除旧备份
	
	if (pos)
	{
		COne* pOne = GetDoc()->GetDraw()->GetAt(GetPos());
		m_pBakOne = std::make_unique<COne>();
		*m_pBakOne = *pOne;
		
		// 调用钩子：模式特定的初始化（样条模式会计算m_pMarkCurve）
		OnModeInitialize();
	}
}

void CurveEditorDefault::Clear(void)
{
	m_pBakOne.reset();  // 清除备份

	if (GetPos() != nullptr)
	{
		COne* pOne = GetDoc()->GetDraw()->GetAt(GetPos());
		CRect8 range(1e100, -1e100, -1e100, 1e100);
		pOne->GetRange(range);
		CRect rt = GetDC()->GetScreen(range);
		rt.NormalizeRect();
		rt.InflateRect(GetDoc()->GetHandleSize());
		rt.InflateRect(1, 1);
	}
}

void CurveEditorDefault::Draw(CDC* pDC)
{
	POSITION pos = GetPos();
	if (pos == 0) return;
	CCurveEx* pValue = GetControlCurve();
	DrawHandlesByCDC(pDC, pValue);
}

int CurveEditorDefault::GetNumberOfNode()
{
	CCurveEx* pc = GetControlCurve();
	if (pc == 0) return -1;
	return pc->num;
}

void CurveEditorDefault::EreaseHandles(CDC* pDC)
{
	m_handleDrawer->ClearAll(pDC);
}

// ========== 编辑会话管理（完全实现）==========

void CurveEditorDefault::EndEdit(void)
{
	if (GetPos() == nullptr) return;
	COne* pOne = GetDoc()->GetDraw()->GetAt(GetPos());

	CRect8 range(1e100, -1e100, -1e100, 1e100);
	pOne->GetRange(range);
	CRect rt = GetDC()->GetScreen(range);
	rt.NormalizeRect();
	rt.InflateRect(GetDoc()->GetHandleSize());
	rt.InflateRect(1, 1);

	if (((CCurveEx*)pOne->GetValue())->num < 2)
	{
		if (::AfxMessageBox(IDS_STRING_CURVE_ONLY_ONE_POINT, MB_YESNO | MB_ICONQUESTION) == IDYES)
		{
			*pOne = *m_pBakOne;
			CPositionList list;
			list.AddTail(GetPos());
			CItem::SetPos(nullptr);
			GetDoc()->InvalidateDelete(list);
			return;
		}
	}

	if (IsModified())
	{
		CActionItem* pAction = new CActionModifiedItem(GetDoc(), IDS_STRING_TOOLBAR_EDIT);
		((CActionModifiedItem*)pAction)->BackupOldItem(GetPos(), m_pBakOne.get());
		GetDoc()->SetActionItem(pAction);
	}
}

void CurveEditorDefault::CancelAll(void)
{
	if (m_pBakOne)
	{
		COne* pOne = GetDoc()->GetDraw()->GetAt(GetPos());
		*pOne = *m_pBakOne;
		GetMarkCurve();
	}
}

BOOL CurveEditorDefault::IsCanCancelAll(void)
{
	return m_pBakOne != nullptr ? TRUE : FALSE;
}

void CurveEditorDefault::GetXY(CCurveEx* pValue, int nIndex, dfPoint& point)
{
	pValue->GetPoint(nIndex, point);
}

CCurveEx* CurveEditorDefault::GetControlCurve(void)
{
	POSITION pos = GetPos();
	if (pos == nullptr) return nullptr;
	return (CCurveEx*)GetDoc()->GetDraw()->GetAtValue(pos);
}

int CurveEditorDefault::HitTestHandle(CPoint point)
{
	return HitTestHandle(GetControlCurve(), point);
}

int CurveEditorDefault::HitTestHandle(CCurveEx* pValue, CPoint point)
{
	if (pValue == nullptr) return -1;
	
	CRect rt;
	for (int i = 0; i < pValue->num; i++)
	{
		rt = GetDoc()->m_itemTracker.GetHandleRect(
			GetDC()->GetSX(pValue->x[i]), 
			GetDC()->GetSY(pValue->y[i]));
		if (rt.PtInRect(point))
			return i;
	}
	return -1;
}

bool CurveEditorDefault::IsDragging(int nFlags) const
{
	return nFlags & 1;
}

int CurveEditorDefault::HandleMouseDrag(CXyDC* pDC, CPoint point)
{
	m_bLButtonDownWhenMouseMove = true;

	// 处理线段拖动
	if (m_nDragSegmentIndex >= 0)
	{
		// 1. [擦除]：此时 c_last 还是上一次的坐标
		DrawMoveSegment(GetScreenDC());
		
		// 2. [更新]：将 c_last 更新为当前鼠标位置的真实坐标
		NBase::CPoint2D rawMouse = GetDC()->GetReal(point);
		c_last = CalculateSnappedMousePos(rawMouse, m_nDragSegmentIndex);
		
		// 3. [绘制]：使用新的 c_last 画出新线
		DrawMoveSegment(GetScreenDC());
		
		return 1;
	}

	// 当没有选择节点，而且能增加时，只要左键按下移动时自动增加一个节点
	int i = GetHandleIndex();
	if (i < 0)
	{
		CSize8 sz = GetDoc()->GetSelectSize();
		if (AfxGetPublicFunction()->Distance(m_nLButtonDownPoint.x, m_nLButtonDownPoint.y, point.x, point.y) > sz.cx)
		{
			i = AddHandle(m_nLButtonDownPoint);
			if (i < 0) return 1;

			SetHandleIndex(i);
			c_down = GetDC()->GetReal(m_nLButtonDownPoint);
			c_last = c_down;

			// 第一次绘制预览线
			OnDrawDragPreview();
		}
		else
			return 1;
	}

	// 擦除上一次的预览
	OnDrawDragPreview();

	// 更新位置
	c_last = pDC->GetReal(point);

	CPointList list;
	OnCalculateDragEffect(&list);

	// 绘制新的预览（使用更新后的 NewPointList）
	OnDrawDragPreview();
	CString str, string;
	auto curve = std::make_unique<CCurveEx>();
	curve->SetPoints(list, 2);
	COne* pOne = GetDoc()->GetDraw()->GetAt(GetPos());
	CCurveEx* pValue = (CCurveEx*)pOne->GetValue();

	OnDragMove(GetHandleIndex(), c_last);

	return 1;

}

int CurveEditorDefault::HandleMouseHover(CDC* dc, CPoint point)
{
	// 鼠标移动时的控制点高亮显示
	CCurveEx* pValue = GetControlCurve();
	if (pValue == 0)
	{
		SetHandleIndex(-1);
		int handleIndex = m_handleDrawer->EreaseFocusHandle(dc);
		m_handleDrawer->DrawOneHandle(dc, handleIndex);
	}
	else
	{
		int i = HitTestHandle(pValue, point);
		if (i >= 0)
		{
			SetHandleIndex(i);
		}
		else
		{
			SetHandleIndex(-1);
			int handleIndex = m_handleDrawer->EreaseFocusHandle(dc);
			m_handleDrawer->DrawOneHandle(dc, handleIndex);
		}
	}

	return 1;
}

void CurveEditorDefault::DeleteHandle(int nIndex)
{
	CCurveEx* pValue = GetControlCurve();
	BOOL bAttachProcess = TRUE;
	CPointList oldPoints;
	CPointList newPoints;
	
	if (bAttachProcess)
	{
		dfPoint pt;
		if (nIndex != 0)
		{
			pValue->GetPoint(nIndex - 1, pt);
			oldPoints.AddTail(pt);
			newPoints.AddTail(pt);
		}
		pValue->GetPoint(nIndex, pt);
		oldPoints.AddTail(pt);
		if (nIndex < pValue->num - 1)
		{
			pValue->GetPoint(nIndex + 1, pt);
			oldPoints.AddTail(pt);
			newPoints.AddTail(pt);
		}
	}

	PointList.RemoveAll();
	dfPoint dd;
	for (int i = 0; i < pValue->num; i++)
	{
		dd.x0 = pValue->x[i];
		dd.y0 = pValue->y[i];
		dd.z0 = pValue->z[i];
		dd.l = pValue->l[i];
		if (i == nIndex) continue;
		PointList.AddTail(dd);
	}
	pValue->SetPoints(PointList, pValue->nPoint, pValue->bAutoLocation);
	PointList.RemoveAll();
	SetModifiedFlag(TRUE);
	
	this->SetHandleIndex(-1);

	if (bAttachProcess)
	{
		if (oldPoints.GetCount() > 0)
			AttachProcess(oldPoints, newPoints);
	}
}

int CurveEditorDefault::AddHandle(double l0)
{
	CCurveEx* pValue = (CCurveEx*)GetDoc()->GetDraw()->GetAtValue(GetPos());
	dfPoint add;
	add.l = l0;
	pValue->GetCoordinate(add.l, add.x0, add.y0, add.z0);
	return AddHandle(pValue, add);
}

int CurveEditorDefault::AddHandle(CCurveEx* pValue, dfPoint add)
{
	if (pValue == nullptr) return -1;

	int nIndex = -1;
	PointList.RemoveAll();
	if (add.l < pValue->l[0])
	{
		pValue->GetPoint(PointList);
		PointList.AddHead(add);
		nIndex = 0;
	}
	else if (add.l > pValue->l[pValue->num - 1])
	{
		pValue->GetPoint(PointList);
		PointList.AddTail(add);
		nIndex = (int)PointList.GetCount() - 1;
	}
	else
	{
		dfPoint dd;
		for (int i = 0; i < pValue->num; i++)
		{
			dd.x0 = pValue->x[i];
			dd.y0 = pValue->y[i];
			dd.z0 = pValue->z[i];
			dd.l = pValue->l[i];
			PointList.AddTail(dd);
			if (i == pValue->num - 1) break;
			if (add.l > pValue->l[i] && add.l < pValue->l[i + 1])
			{
				PointList.AddTail(add);
				nIndex = i + 1;
			}
		}
	}

	pValue->SetPoints(PointList, pValue->nPoint, pValue->bAutoLocation);
	PointList.RemoveAll();
	GetDoc()->Modified();
	SetModifiedFlag(TRUE);
	return nIndex;
}

int CurveEditorDefault::AddHandle(CPoint point)
{
	double l0;
	if (!IsCanAddHandle(point, &l0)) return -1;
	return AddHandle(l0);
}

BOOL CurveEditorDefault::IsCanAddHandle(CPoint point, double* pl0)
{
	POSITION pos = GetPos();
	if (pos == nullptr) return FALSE;

	CCurveEx* pValue = (CCurveEx*)GetDoc()->GetDraw()->GetAtValue(pos);
	if (pValue == nullptr) return FALSE;
	
	CPoint2D pt = GetDC()->GetReal(point);
	double l0;
	double dis = pValue->PointDistance(pt.x0, pt.y0, l0);
	CSize8 sz = GetDoc()->GetSelectSize();
	int dx = GetDC()->GetScreenWidth(dis);
	int dy = GetDC()->GetScreenHeight(dis);
	if (pl0) *pl0 = l0;
	if (dx > sz.cx || dy > sz.cy) return FALSE;
	return TRUE;
}

void CurveEditorDefault::AttachProcess(CPointList& oldPoints, CPointList& newPoints)
{
}

void CurveEditorDefault::DrawMoveLine(void)
{
	OnDrawDragPreview();
}

void CurveEditorDefault::GetMarkCurve(void)
{
}

CPoint2D CurveEditorDefault::GetCDown() const
{
	return c_down;
}

CPoint2D CurveEditorDefault::GetCLast() const
{
	return c_last;
}

void CurveEditorDefault::DrawHandle(CXyDC* pDC, CCurveEx* pCurve)
{
	if (pCurve == nullptr) return;

	CPoint ptPrev;
	CRect rt;
	dfPoint pt;
	CPoint point;
	for (int i = 0; i < pCurve->num; i++)
	{
		GetXY(pCurve, i, pt);
		point.x = pDC->GetSX(pt.x0);
		point.y = pDC->GetSY(pt.y0);
		if (i > 0)
		{
			if (point.x == ptPrev.x && point.y == ptPrev.y && i != GetHandleIndex())
				continue;
		}
		if (i == GetHandleIndex())
		{
			if (i == 0)
				rt = GetFirstNodeHandleRectFocus(point);
			else
				rt = GetDoc()->m_itemTracker.GetHandleRectFocus(point);
		}
		else
		{
			if (i == 0)
				rt = GetDoc()->m_itemTracker.GetHandleRectFocus(point);
			else
				rt = GetDoc()->m_itemTracker.GetHandleRect(point);
		}
		GetDoc()->m_itemTracker.DrawHandle(m_pScreenDC, rt, TRACKER_CIRCLE);
		ptPrev = point;
	}
}

void CurveEditorDefault::DrawHandlesByCDC(CDC* pDC, CCurveEx* pCurve)
{
	if (pCurve == nullptr) return;
	m_handleDrawer->ClearAll(pDC);
	m_handleDrawer->Init(pCurve);
	m_handleDrawer->DrawAll(pDC);
}

void CurveEditorDefault::DrawSelectHandle(int nHandle)
{
	CCurveEx* pValue = GetControlCurve();
	if (pValue == nullptr) return;
	if (nHandle < 0 || nHandle >= pValue->num) return;

	CPoint point;
	point.x = GetDC()->GetSX(pValue->x[nHandle]);
	point.y = GetDC()->GetSY(pValue->y[nHandle]);
	CRect rt;
	if (nHandle == 0)
		rt = GetDoc()->m_itemTracker.GetHandleRectFocus(point);
	else
		rt = GetDoc()->m_itemTracker.GetHandleRect(point);

	GetDoc()->m_itemTracker.DrawHandle(m_pScreenDC, rt, m_nHandleDrawMode);
	if (nHandle == 0)
		rt = GetFirstNodeHandleRectFocus(point);
	else
		rt = GetDoc()->m_itemTracker.GetHandleRectFocus(point);

	GetDoc()->m_itemTracker.DrawHandle(m_pScreenDC, rt, m_nHandleDrawMode);
}

CRect CurveEditorDefault::GetRangeWidthIndex(int nIndex)
{
	CCurveEx* pValue = GetControlCurve();
	if (pValue == nullptr || nIndex < 0 || nIndex >= pValue->num)
	{
		return CRect(0, 0, 0, 0);
	}

	CRect8 rt(pValue->x[nIndex], pValue->y[nIndex], pValue->x[nIndex], pValue->y[nIndex]);
	if (nIndex > 0)
		rt.CombinRect(pValue->x[nIndex - 1], pValue->y[nIndex - 1], pValue->x[nIndex - 1], pValue->y[nIndex - 1]);
	if (nIndex < pValue->num - 1)
		rt.CombinRect(pValue->x[nIndex + 1], pValue->y[nIndex + 1], pValue->x[nIndex + 1], pValue->y[nIndex + 1]);
	CRect rect = GetDC()->GetScreen(rt);
	rect.InflateRect(GetDoc()->GetHandleSize());
	return rect;
}

CRect CurveEditorDefault::GetFirstNodeHandleRectFocus(CPoint point)
{
	CRect rt = GetDoc()->m_itemTracker.GetHandleRectFocus(point);
	rt.InflateRect(1, 1);
	return rt;
}

void CurveEditorDefault::SetDrawMode(int nModeX, int nModeY)
{
	m_nModeX = nModeX;
	m_nModeY = nModeY;
}

int CurveEditorDefault::GetOffsetMode(void)
{
	return GetDoc()->GetEditLineStatus() % 4;
}

void CurveEditorDefault::OnDrawDragPreview()
{
	// ========== 默认模式：只绘制两条线段 ==========
	int i = GetHandleIndex();
	if (i < 0) return;

	CCurveEx* pValue = GetControlCurve();
	if (pValue == nullptr || i >= pValue->num)
	{
		return;
	}

	CXyDC* pDC = GetDC();
	CPen pen(PS_SOLID, 0, DRAG_LINE_COLOR);
	CPen* op = (CPen*)m_pScreenDC->SelectObject(&pen);
	int od = m_pScreenDC->SetROP2(R2_NOTXORPEN);

	double dx = c_last.x0 - c_down.x0;
	double dy = c_last.y0 - c_down.y0;
	dfPoint pt;
	
	// 绘制前一段线（当前节点到前一个节点）
	if (i > 0)
	{
		GetXY(pValue, i - 1, pt);
		CPoint ptS1 = pDC->GetScreen(pt);
		m_pScreenDC->MoveTo(ptS1);

		GetXY(pValue, i, pt);
		pt.x0 += dx;
		pt.y0 += dy;
		CPoint ptS2 = pDC->GetScreen(pt);
		m_pScreenDC->LineTo(ptS2.x, ptS2.y);
	}
	
	// 绘制后一段线（当前节点到后一个节点）
	if (i < pValue->num - 1)
	{
		GetXY(pValue, i + 1, pt);
		CPoint ptS1 = pDC->GetScreen(pt);
		m_pScreenDC->MoveTo(ptS1);

		GetXY(pValue, i, pt);
		pt.x0 += dx;
		pt.y0 += dy;
		CPoint ptS2 = pDC->GetScreen(pt);
		m_pScreenDC->LineTo(ptS2.x, ptS2.y);
	}
	
	m_pScreenDC->SetROP2(od);
	m_pScreenDC->SelectObject(op);
}

void CurveEditorDefault::OnCalculateDragEffect(CPointList* pList)
{
	// pList != nullptr：预览模式（不实际修改曲线，用于状态栏显示）
	// pList == nullptr：实际修改模式（创建 Undo/Redo 动作）
	BOOL bRedraw = TRUE;
	BOOL bAttachProcess = TRUE;  // 是否处理绑定曲线
	CCurveEx* pValue = (CCurveEx*)GetDoc()->GetDraw()->GetAtValue(GetPos());
	
	if (pList)
	{
		// 预览模式：创建临时副本
		CCurveEx* pc = new CCurveEx;
		*pc = *pValue;
		pValue = pc;
		bRedraw = FALSE;
		bAttachProcess = FALSE;
	}

	CPointList oldPoints;  // 记录移动前的坐标（用于绑定处理）
	CPointList newPoints;  // 记录移动后的坐标（用于绑定处理）
	dfPoint pt;
	CRect rt;

	// ========== 默认模式：直接移动当前节点 ==========
	int i = GetHandleIndex();
	if (bRedraw)
	{
		// 基类中已经有 GetRangeWidthIndex，这里注释掉避免重复
		// rt = GetRangeWidthIndex(i);
	}

	// 为了绑定处理，记录原坐标点
	if (bAttachProcess)
	{
		if (i - 1 >= 0)
		{
			pValue->GetPoint(i - 1, pt);	oldPoints.AddTail(pt);
		}
		pValue->GetPoint(i, pt);	oldPoints.AddTail(pt);
		if (i + 1 <= pValue->num - 1)
		{
			pValue->GetPoint(i + 1, pt);	oldPoints.AddTail(pt);
		}
	}

	CActionCurveEdit* pAction = 0;
	if (pList == nullptr)
	{
		pAction = new CActionCurveEdit(GetDoc(), 0, GetPos());
		pAction->BackupUndoNode(i, pValue->x[i], pValue->y[i]);
	}
	
	pValue->x[i] += (c_last.x0 - c_down.x0);
	pValue->y[i] += (c_last.y0 - c_down.y0);
	if (pValue->bAutoLocation) pValue->GetLocation();

	if (pList == nullptr)
	{
		pAction->BackupRedoNode(i, pValue->x[i], pValue->y[i]);
		GetDoc()->SetActionItem(pAction);
	}
	
	if (bAttachProcess)
	{
		// 为了绑定处理，记录新坐标点
		if (i - 1 >= 0)
		{
			pValue->GetPoint(i - 1, pt);	newPoints.AddTail(pt);
		}
		pValue->GetPoint(i, pt);	newPoints.AddTail(pt);
		if (i + 1 <= pValue->num - 1)
		{
			pValue->GetPoint(i + 1, pt);	newPoints.AddTail(pt);
		}
		AttachProcess(oldPoints, newPoints);
	}

	if (bRedraw)
	{
		// rt = GetRangeWidthIndex(i);
	}

	if (pList)
	{
		pValue->GetPoint(*pList);
		delete pValue;
	}
}

void CurveEditorDefault::OnModeInitialize()
{
	// Default implementation - does nothing
}

void CurveEditorDefault::OnDragMove(int nIndex, CPoint2D pt)
{
	// Default implementation - does nothing
}

// ========== 线段拖动相关辅助函数实现 ==========

int CurveEditorDefault::HitTestSegment(CPoint point)
{
	CCurveEx* pValue = GetControlCurve();
	if (!pValue || pValue->num < 2) return -1;

	CXyDC* pDC = GetDC();
	double distThreshold = 5.0; // 选中容差（像素）

	for (int i = 0; i < pValue->num - 1; i++)
	{
		// 获取线段两端的屏幕坐标
		CPoint p1 = pDC->GetScreen(pValue->x[i], pValue->y[i]);
		CPoint p2 = pDC->GetScreen(pValue->x[i + 1], pValue->y[i + 1]);

		// 计算点到线段的距离
		double dist = DistancePointToLine(point.x, point.y, p1.x, p1.y, p2.x, p2.y);

		// 简单判断范围：鼠标必须在以此线段为对角线的矩形稍微外扩的范围内
		CRect rt(p1, p2);
		rt.NormalizeRect();
		rt.InflateRect((int)distThreshold + 2, (int)distThreshold + 2);

		if (rt.PtInRect(point) && dist < distThreshold)
		{
			return i; // 返回线段起始点索引
		}
	}
	return -1;
}

void CurveEditorDefault::DrawMoveSegment(CDC* pDC)
{
	// 1. 基础校验：如果没有正在拖动的线段，直接返回
	if (m_nDragSegmentIndex < 0) return;

	CCurveEx* pValue = GetControlCurve();
	// 校验索引范围：确保不会越界访问
	if (m_nDragSegmentIndex >= pValue->num - 1) return;

	// 2. 获取原始线段的起点和终点坐标 (从曲线数据中读取)
	dfPoint pt1, pt2;
	GetXY(pValue, m_nDragSegmentIndex, pt1);
	GetXY(pValue, m_nDragSegmentIndex + 1, pt2);

	// 定义最终用于绘制的屏幕坐标变量
	double drawX1, drawY1, drawX2, drawY2;

	// ========================================================================
	// 核心分支：根据吸附类型决定绘制策略
	// ========================================================================
	bool isSnapping = (m_lastSnapResult.snapType == Geometry::SnapType::PARALLEL_LINE);
	if (isSnapping)
	{
		// 策略 A：平行吸附 -> 投影显示 (Projection)
		const Geometry::Segment& targetSeg = m_lastSnapResult.targetSegment;

		// 构造几何点
		Geometry::Point pStart = { pt1.x0, pt1.y0 };
		Geometry::Point pEnd = { pt2.x0, pt2.y0 };

		// 计算投影因子 t (相对于目标线段)
		double t1 = Geometry::GeometryUtils::getProjectionFactor(pStart, targetSeg);
		double t2 = Geometry::GeometryUtils::getProjectionFactor(pEnd, targetSeg);

		// 获取目标线段的方向向量
		Geometry::Point dir = targetSeg.direction();

		// 计算投影后的新坐标
		Geometry::Point newStart = targetSeg.start + (dir * t1);
		Geometry::Point newEnd = targetSeg.start + (dir * t2);

		// 赋值给绘制变量
		drawX1 = newStart.x;
		drawY1 = newStart.y;
		drawX2 = newEnd.x;
		drawY2 = newEnd.y;
	}
	else
	{
		// 策略 B：普通移动 -> 刚体平移 (Rigid Translation)
		double mouseDx = c_last.x0 - c_down.x0;
		double mouseDy = c_last.y0 - c_down.y0;

		// 计算沿法线的投影偏移量
		NBase::CPoint2D offset = CalculateNormalOffset(pt1, pt2, mouseDx, mouseDy);

		// 原始坐标 + 偏移量 = 绘制坐标
		drawX1 = pt1.x0 + offset.x0;
		drawY1 = pt1.y0 + offset.y0;
		drawX2 = pt2.x0 + offset.x0;
		drawY2 = pt2.y0 + offset.y0;
	}

	// ========================================================================
	// 屏幕绘制 (XOR 模式)
	// ========================================================================

	// 获取坐标转换器
	CXyDC* pXyDC = GetDC();

	COLORREF penColor = isSnapping ? RGB(255, 0, 0) : DRAG_LINE_COLOR;

	// 设置画笔：实线，颜色由 DRAG_LINE_COLOR 定义
	CPen pen(PS_SOLID, 0, penColor);
	CPen* op = m_pScreenDC->SelectObject(&pen);

	// 设置绘图模式为 R2_NOTXORPEN (异或模式)
	int od = m_pScreenDC->SetROP2(R2_NOTXORPEN);

	// 将真实坐标转换为屏幕像素坐标
	CPoint sp1 = pXyDC->GetScreen(drawX1, drawY1);
	CPoint sp2 = pXyDC->GetScreen(drawX2, drawY2);

	// 绘制线条
	m_pScreenDC->MoveTo(sp1);
	m_pScreenDC->LineTo(sp2);

	// 恢复绘图上下文环境
	m_pScreenDC->SetROP2(od);
	m_pScreenDC->SelectObject(op);
}

NBase::CPoint2D CurveEditorDefault::CalculateNormalOffset(dfPoint p1, dfPoint p2, double dx, double dy)
{
	// 线段向量
	double segX = p2.x0 - p1.x0;
	double segY = p2.y0 - p1.y0;

	// 法线向量 (-y, x)
	double normX = -segY;
	double normY = segX;

	// 归一化
	double len = sqrt(normX * normX + normY * normY);
	if (len < 1e-9) return { 0.0, 0.0 };
	normX /= len;
	normY /= len;

	// 点积投影：鼠标位移在法线上的长度
	double projection = dx * normX + dy * normY;

	// 返回最终的偏移向量
	return { projection * normX, projection * normY };
}

double CurveEditorDefault::DistancePointToLine(double px, double py, double x1, double y1, double x2, double y2)
{
	// 线段长度的平方
	double l2 = (x2 - x1) * (x2 - x1) + (y2 - y1) * (y2 - y1);

	// 如果线段长度为0（起点和终点重合），直接计算点到点的距离
	if (l2 == 0.0)
		return sqrt((px - x1) * (px - x1) + (py - y1) * (py - y1));

	// 计算投影参数 t = ((P - A) . (B - A)) / |B - A|^2
	double t = ((px - x1) * (x2 - x1) + (py - y1) * (y2 - y1)) / l2;

	// 限制 t 在 [0, 1] 范围内，从而将计算限制在线段上
	if (t < 0.0) t = 0.0;
	else if (t > 1.0) t = 1.0;

	// 计算线段上最近的投影点坐标
	double projX = x1 + t * (x2 - x1);
	double projY = y1 + t * (y2 - y1);

	// 返回点到投影点的欧几里得距离
	return sqrt((px - projX) * (px - projX) + (py - projY) * (py - projY));
}

CRect8 CurveEditorDefault::GetLineSegmentAABB(const dfPoint& point1, const dfPoint& point2, double width) const
{
	double halfWidth = width / 2.0;
	double rawMinX = min(point1.x0, point2.x0);
	double rawMaxX = max(point1.x0, point2.x0);
	double rawMinY = min(point1.y0, point2.y0);
	double rawMaxY = max(point1.y0, point2.y0);

	return CRect8(rawMinX - halfWidth, rawMaxY + halfWidth, rawMaxX + halfWidth, rawMinY - halfWidth);
}

NBase::CPoint2D CurveEditorDefault::CalculateSnappedMousePos(NBase::CPoint2D rawMouse, int segmentIndex)
{
	if (!GetDoc()->IsSnapEnabled())
	{
		return rawMouse;
	}

	CCurveEx* pValue = GetControlCurve();
	if (!pValue || segmentIndex < 0 || segmentIndex >= pValue->num - 1)
		return rawMouse;

	// 1. 准备数据
	dfPoint pt1, pt2;
	GetXY(pValue, segmentIndex, pt1);
	GetXY(pValue, segmentIndex + 1, pt2);

	// 计算当前线段的单位法线 (这是我们的移动轨道)
	double segDx = pt2.x0 - pt1.x0;
	double segDy = pt2.y0 - pt1.y0;
	double nx = -segDy;
	double ny = segDx;
	double len = std::hypot(nx, ny);
	if (len < 1e-9) return rawMouse;
	nx /= len;
	ny /= len;

	// 2. 计算"幽灵"线段位置
	double mouseDx = rawMouse.x0 - c_down.x0;
	double mouseDy = rawMouse.y0 - c_down.y0;
	double projLen = mouseDx * nx + mouseDy * ny;
	NBase::CPoint2D normalOffset = { projLen * nx, projLen * ny };

	Geometry::Segment currentSeg;
	currentSeg.start = { pt1.x0 + normalOffset.x0, pt1.y0 + normalOffset.y0 };
	currentSeg.end = { pt2.x0 + normalOffset.x0, pt2.y0 + normalOffset.y0 };

	// 3. 调用吸附引擎 (标准接口，不需要传法线)
	Geometry::SnapConfig config;
	config.snapDistance = GetDC()->GetRealWidth(20.0);
	config.angleTolerance = 5.0;
	Geometry::SnappingEngine engine(GetDoc()->m_pXy, GetSpatialIndex(), config);

	Geometry::SnapResult res = engine.getSnapResult(currentSeg);

	m_lastSnapResult = res;

	// 4. 编辑器层面的后期处理：计算共线补偿
	if (res.snapType != Geometry::SnapType::NONE)
	{
		double finalOffsetX = res.offset.x;
		double finalOffsetY = res.offset.y;

		// 【改动点】如果是平行线吸附，使用目标线段计算交点
		if (res.snapType == Geometry::SnapType::PARALLEL_LINE)
		{
			// P_target
			double tx = res.targetSegment.start.x;
			double ty = res.targetSegment.start.y;
			// Target Direction (V)
			double vx = res.targetSegment.end.x - tx;
			double vy = res.targetSegment.end.y - ty;

			// 我们需要求解方程: 
			// CurrentStart + t * Normal = TargetStart + u * TargetDir
			// 这等价于求两个向量叉乘

			double dx = currentSeg.start.x - tx;
			double dy = currentSeg.start.y - ty;

			// 二维叉积: A cross B = Ax * By - Ay * Bx
			double det = nx * vy - ny * vx;

			// 只要 det != 0 (即法线不平行于目标线，也就是说原线段不垂直于目标线)
			if (std::abs(det) > 1e-9)
			{
				// 根据克拉默法则 (Cramer's Rule) 求 t (沿法线移动的距离)
				double t = (vx * dy - vy * dx) / det;

				finalOffsetX = nx * t;
				finalOffsetY = ny * t;
			}
		}

		rawMouse.x0 += finalOffsetX;
		rawMouse.y0 += finalOffsetY;
	}

	return rawMouse;
}