#include "WindowAppItemLinkLine.h"
#include "WindowAppItemLink.h"

WindowAppItemLinkLine::WindowAppItemLinkLine(
	QPointF ptStart, 
	QPointF ptEnd, 
	QGraphicsItemGroup* parent,
	LINK_MODE linkMode
)
	: m_bLinkEndLine(false)
	, m_bLinkStartLine(false)
	, m_bIsDragging(false)
	, m_mode(linkMode)
	, m_nLineIndex(-1)
{
	// 接收悬停事件，用于显示鼠标切换效果
	setAcceptHoverEvents(true);

	// 设置风格，可选择可拖动
	// setFlag(QGraphicsItem::ItemIsMovable, true); 
	setFlag(QGraphicsItem::ItemIsSelectable, true);
	// 接收Item移动消息
	// setFlag(QGraphicsItem::ItemSendsGeometryChanges);

	this->setParentItem(parent);

	m_parentGroup = qgraphicsitem_cast<WindowAppItemLink*>(parent);

	this->setLine(QLineF(ptStart, ptEnd));

	// 设置画笔
	setPen(QPen(COLOR_INF_LINE, PEN_LINE_WIDTH, Qt::SolidLine, Qt::RoundCap, Qt::RoundJoin));
}


/// <summary>
/// 更新连线位置
/// </summary>
/// <param name="ptStart"></param>
/// <param name="ptEnd"></param>
void WindowAppItemLinkLine::updateLine(QPointF ptStart, QPointF ptEnd)
{
	this->setLine(QLineF(ptStart, ptEnd));
}


/// <summary>
/// 更新线段的起点坐标
/// </summary>
/// <param name="pt"></param>
void WindowAppItemLinkLine::setP1(const QPointF pt)
{
	QLineF ajustLine = this->line();

	ajustLine.setP1(pt);
	this->setLine(ajustLine);
}


/// <summary>
/// 更新线段的终点坐标
/// </summary>
/// <param name="pt"></param>
void WindowAppItemLinkLine::setP2(const QPointF pt)
{
	QLineF ajustLine = this->line();

	ajustLine.setP2(pt);
	this->setLine(ajustLine);
}


/// <summary>
/// 返回边界区域
/// </summary>
/// <returns></returns>
QRectF WindowAppItemLinkLine::boundingRect() const
{
	qreal extra = (pen().width()) * 4.0;

	QRectF rc = QRectF(
		line().p1(),
		QSizeF(line().p2().x() - line().p1().x(),
			line().p2().y() - line().p1().y()
		))
		.normalized()
		.adjusted(-extra, -extra, extra, extra);

	return rc;
}


/// <summary>
/// 形状边界（为了扩大线条的可点击范围）
/// </summary>
/// <returns></returns>
QPainterPath WindowAppItemLinkLine::shape() const
{
	QPainterPath path = QGraphicsLineItem::shape();
	qreal extra = (pen().width()) * 4.0;
	extra *= 1.414;
	path = QGraphicsLineItem::shape();

	// 通过Stroker设置精确Shape
	QPainterPathStroker stroker;
	stroker.setWidth(extra);
	path = stroker.createStroke(path);
	return path;
}


/// <summary>
/// 绘制线条
/// </summary>
/// <param name="painter"></param>
/// <param name="option"></param>
/// <param name="widget"></param>
void WindowAppItemLinkLine::paint(QPainter* painter, const QStyleOptionGraphicsItem* option, QWidget* widget /*= nullptr*/)
{
	Q_UNUSED(option);
	Q_UNUSED(widget);

	painter->setRenderHint(QPainter::Antialiasing, true);

	painter->save();

	// 如果父类的选中状态发生了变更的话
	if (this->parentItem()->isSelected())
	{
		painter->setPen(QPen(COLOR_INF_LINE, PEN_LINE_WIDTH_SEL, Qt::SolidLine, Qt::RoundCap, Qt::RoundJoin));
	}
	else
	{
		painter->setPen(QPen(COLOR_INF_LINE, PEN_LINE_WIDTH, Qt::SolidLine, Qt::RoundCap, Qt::RoundJoin));
	}

	// 绘制线条
	painter->drawLine(line());

	// 如果是终点连接线，需要绘制箭头
	if (this->m_bLinkEndLine)
	{
		double angle = atan2(line().dy(), -line().dx());

		QPointF arrowP1 = line().p2() + QPointF(sin(angle + M_PI / 3) * LINE_ARROW_SIZE,
			cos(angle + M_PI / 3) * LINE_ARROW_SIZE);
		QPointF arrowP2 = line().p2() + QPointF(sin(angle + M_PI - M_PI / 3) * LINE_ARROW_SIZE,
			cos(angle + M_PI - M_PI / 3) * LINE_ARROW_SIZE);

		painter->drawLine(line().p2(), arrowP1);
		painter->drawLine(line().p2(), arrowP2);
	}

	painter->restore();
}


/// <summary>
/// 跳过Group，自行处理部分消息
/// </summary>
/// <param name="event"></param>
/// <returns></returns>
bool WindowAppItemLinkLine::sceneEvent(QEvent* event)
{
	switch (event->type())
	{
		// 处理鼠标Hover消息，很奇怪不知道为什么在Group中无法触发这个消息，只能放到子线段中了
	case QEvent::GraphicsSceneHoverEnter:
		hoverEnterEvent(static_cast<QGraphicsSceneHoverEvent*>(event));
		break;

	case QEvent::GraphicsSceneMousePress:
		mousePressEvent(static_cast<QGraphicsSceneMouseEvent*>(event));
		break;

	case QEvent::GraphicsSceneMouseMove:
		mouseMoveEvent(static_cast<QGraphicsSceneMouseEvent*>(event));
		break;

	case QEvent::GraphicsSceneMouseRelease:
		mouseReleaseEvent(static_cast<QGraphicsSceneMouseEvent*>(event));
		break;
	}

	event->accept();
	return QGraphicsLineItem::sceneEvent(event);
}

///// <summary>
///// 鼠标悬浮事件（用于显示移动用的鼠标）
///// </summary>
///// <param name="event"></param>
//void WindowAppItemLinkLine::hoverMoveEvent(QGraphicsSceneHoverEvent* event)
//{
//	// 如果控件处于选中状态，则根据鼠标位置显示拉伸鼠标
//	if (this->isSelected())
//	{
//		//setCursor(Qt::SizeVerCursor);
//		// setCursor(Qt::SizeHorCursor);
//	}
//
//	qDebug() << "WindowAppItemLinkLine::hoverMoveEvent";
//
//	QGraphicsLineItem::hoverMoveEvent(event);
//}





//=============================================================================
//
//							线条拖动相关代码
//
//=============================================================================

/// <summary>
/// 鼠标进入悬浮事件（用于显示拖动用的鼠标）
/// </summary>
/// <param name="event"></param>
void WindowAppItemLinkLine::hoverEnterEvent(QGraphicsSceneHoverEvent* event)
{
	// qDebug() << "WindowAppItemLinkLine::hoverEnterEvent";

	// 如果不支持拖拽，则干脆不能改变鼠标样式
	if (!isSupportDrag())
	{
		return;
	}

	// 根据是水平线还是垂直线显示不同的鼠标
	if (isVertical())
	{
		setCursor(Qt::SizeHorCursor);
	}
	else if(isHorizontal())
	{
		setCursor(Qt::SizeVerCursor);
	}
	// Error
	else
	{

	}

	QGraphicsLineItem::hoverEnterEvent(event);
}


/// <summary>
/// 鼠标按下事件（用于触发Link移动）
/// </summary>
/// <param name="event"></param>
void WindowAppItemLinkLine::mousePressEvent(QGraphicsSceneMouseEvent* event)
{
	// qDebug() << "WindowAppItemLinkLine::mousePressEvent";
	
	// QPointF mousePoint = event->pos();

	if (!this->isSupportDrag())
	{
		return;
	}

	m_bIsDragging = true;	

	QGraphicsLineItem::mousePressEvent(event);
}


/// <summary>
/// 鼠标移动事件（用于移动Link）
/// </summary>
/// <param name="event"></param>
void WindowAppItemLinkLine::mouseMoveEvent(QGraphicsSceneMouseEvent* event)
{
	// qDebug() << "WindowAppItemLinkLine::mouseMoveEvent";

	QPointF mousePoint = event->pos();

	if (!m_bIsDragging)
	{
		return;
	}

	QPointF lineP1 = this->line().p1();
	QPointF lineP2 = this->line().p2();

	// 水平线移动
	if (isVertical())
	{
		lineP1.setX(mousePoint.x());
		lineP2.setX(mousePoint.x());

		// 交给Group检查一下本次移动是否可行
		if (m_parentGroup->canMove(lineP1, lineP2))
		{
			this->setLine(QLineF(lineP1, lineP2));

			// 发送线段移动信号，用于在Group中同步移动其他线段
			emit lineMoveSignal(this);
		}
	}
	// 垂直线移动
	else if(isHorizontal())
	{
		lineP1.setY(mousePoint.y());
		lineP2.setY(mousePoint.y());

		// 交给Group检查一下本次移动是否可行
		if (m_parentGroup->canMove(lineP1, lineP2))
		{
			this->setLine(QLineF(lineP1, lineP2));

			// 发送线段移动信号，用于在Group中同步移动其他线段
			emit lineMoveSignal(this);
		}
	}
	// Error
	else 
	{

	}

	QGraphicsLineItem::mouseMoveEvent(event);
}


/// <summary>
/// 鼠标释放事件（用于鼠标还原以及接收拉伸状态）
/// </summary>
/// <param name="event"></param>
void WindowAppItemLinkLine::mouseReleaseEvent(QGraphicsSceneMouseEvent* event)
{
	// qDebug() << "WindowAppItemLinkLine::mouseReleaseEvent";

	// 还原鼠标
	// setCursor(Qt::ArrowCursor);

	m_bIsDragging = false;

	QGraphicsLineItem::mouseReleaseEvent(event);
}


/// <summary>
/// 是否是垂直线条
/// </summary>
/// <returns></returns>
bool WindowAppItemLinkLine::isVertical()
{
	QLine seg = this->line().toLine();

	return (seg.x1() == seg.x2());
}


/// <summary>
/// 是否是水平线条
/// </summary>
/// <returns></returns>
bool WindowAppItemLinkLine::isHorizontal()
{
	QLine seg = this->line().toLine();

	return (seg.y1() == seg.y2());
}


/// <summary>
/// 本线段是否支持拖拽
/// </summary>
/// <returns></returns>
bool WindowAppItemLinkLine::isSupportDrag()
{
	// 如果终点连线，则不支持拖拽功能
	if (m_bLinkEndLine)
	{
		return false;
	}

	// 如果是普通模式下的起点连线，也不支持拖拽功能
	if (m_bLinkStartLine && m_mode == LINK_MODE::LINK_NORMAL)
	{
		return false;
	}

	return true;
}