#include "stdafx.h"
#include <iostream>
#include <cmath>

#include <QWheelEvent>
#include <QPoint>

#include "ImageViewer.h"
#include "RasterLayer.h"
#include "MapTool.h"


#define VIEW_CENTER viewport()->rect().center()
#define VIEW_WIDTH  viewport()->rect().width()
#define VIEW_HEIGHT viewport()->rect().height()

Mapcavas::Mapcavas(QWidget* pParent) :QGraphicsView(pParent)
{
    setRenderHint(QPainter::Antialiasing);
    setRenderHint(QPainter::SmoothPixmapTransform);
    setDragMode(QGraphicsView::ScrollHandDrag);

    // 使用 Qt 默认 anchor 行为以外的配置
    setTransformationAnchor(QGraphicsView::NoAnchor);
    setResizeAnchor(QGraphicsView::NoAnchor);

    m_qtGraphicsScene = new QGraphicsScene(this);
    this->setScene(m_qtGraphicsScene);
    m_qtGraphicsScene->setSceneRect(-1e6, -1e6, 2e6, 2e6);

    m_framNumberLabel = new QLabel(this);
    m_framNumberLabel->setAlignment(Qt::AlignHCenter);
    m_framNumberLabel->setAlignment(Qt::AlignVCenter);

    QFont ft;
    ft.setPointSize(14);
    m_framNumberLabel->setFont(ft);
	m_framNumberLabel->setText("0");


    m_GraphicsPixmapItemHandle = nullptr;

    m_scale = 1.0;
    m_zoomDelta = 0.1;
    m_translateSpeed = 1.0;
    m_bMouseTranslate = false;

    setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
    setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
    setFrameShape(QFrame::NoFrame);
}

Mapcavas::~Mapcavas()
{

}

void Mapcavas::DisplayFrameNumber(int frameNumber)
{
    m_framNumberLabel->setText(QString::number(frameNumber));
    m_framNumberLabel->adjustSize();
}

void Mapcavas::SetImage(QPixmap *image)
{
    if (!HasImage())
    {
        m_GraphicsPixmapItemHandle = m_qtGraphicsScene->addPixmap(*image);
    }
    else
    {
        m_GraphicsPixmapItemHandle->setPixmap(*image);
    }
    ensureSceneVisible();
}

void Mapcavas::ensureSceneVisible()
{
    resetTransform();

    auto view_rect = viewport()->rect();
    auto scene_rect = this->scene()->itemsBoundingRect();

    double x_ratio = view_rect.width() / scene_rect.width();
    double y_ratio = view_rect.height() / scene_rect.height();
    double scale_factor = std::min(x_ratio, y_ratio) * 0.9;

    scale(scale_factor, scale_factor);
    m_scale *= scale_factor;

    centerOn(scene_rect.center());
}

bool Mapcavas::HasImage()
{
    if (m_GraphicsPixmapItemHandle == nullptr)
    {
        return false;
    }
    else
    {
        return true;
    }
}

void Mapcavas::updateCrosshair(double sceneX, double sceneY)
{
    QPen pen(Qt::red, 2.0);
    pen.setCosmetic(true);  // constant screen-width regardless of zoom

    if (!m_hLine)
    {
        m_hLine = m_qtGraphicsScene->addLine(0, 0, 0, 0, pen);
        m_hLine->setZValue(1e9);
    }
    if (!m_vLine)
    {
        m_vLine = m_qtGraphicsScene->addLine(0, 0, 0, 0, pen);
        m_vLine->setZValue(1e9);
    }

    m_hLine->setPen(pen);
    m_vLine->setPen(pen);

    m_hLine->setLine(sceneX - m_CrosshairHalfLen, sceneY,
        sceneX + m_CrosshairHalfLen, sceneY);
    m_vLine->setLine(sceneX, sceneY - m_CrosshairHalfLen,
        sceneX, sceneY + m_CrosshairHalfLen);
}

void Mapcavas::removeCrosshair()
{
    if (m_hLine)
    {
        if (m_hLine->scene())
            m_hLine->scene()->removeItem(m_hLine);
        delete m_hLine;
        m_hLine = nullptr;
    }
    if (m_vLine)
    {
        if (m_vLine->scene())
            m_vLine->scene()->removeItem(m_vLine);
        delete m_vLine;
        m_vLine = nullptr;
    }
}


void Mapcavas::wheelEvent(QWheelEvent *event)
{
    // Always let the tool have a chance first
    if (m_mapTool)
    {
        m_mapTool->canvasWheelEvent(event);
    }

    if (HasImage())
    {
        QPointF oldPos = mapToScene(event->pos());

        QPoint scrollAmount = event->angleDelta();
        scrollAmount.y() > 0 ? zoomIn() : zoomOut();

        QPointF newPos = mapToScene(event->pos());

        QPointF delta = newPos - oldPos;
        translate(delta.x(), delta.y());
    }
}

void Mapcavas::scaling(qreal scaleFactor)
{
    scale(scaleFactor, scaleFactor);
}

void Mapcavas::mousePressEvent(QMouseEvent *event)
{
    if (m_mapTool)
    {
        m_mapTool->canvasMousePressEvent(event);
        QGraphicsView::mousePressEvent(event);
        return;
    }
    QGraphicsView::mousePressEvent(event);
}

void Mapcavas::mouseMoveEvent(QMouseEvent *event)
{
    if (m_mapTool)
    {
        m_mapTool->canvasMouseMoveEvent(event);
        QGraphicsView::mousePressEvent(event);
        return;
    }

    QGraphicsView::mousePressEvent(event);
}

void Mapcavas::mouseReleaseEvent(QMouseEvent *event)
{
    if (m_mapTool)
    {
        m_mapTool->canvasMouseReleaseEvent(event);
        QGraphicsView::mouseReleaseEvent(event);
        return;
    }

    QGraphicsView::mouseReleaseEvent(event);
}

void Mapcavas::mouseDoubleClickEvent(QMouseEvent *event)
{
    if (m_mapTool)
    {
        m_mapTool->canvasMouseDoubleClickEvent(event);
        return;
    }

    QGraphicsView::mouseDoubleClickEvent(event);
}

void Mapcavas::zoomIn()
{
    zoom(1 + m_zoomDelta);
}

void Mapcavas::zoomOut()
{
    zoom(1 - m_zoomDelta);
}

void Mapcavas::zoom(float scaleFactor)
{
    qreal factor = transform().scale(scaleFactor, scaleFactor).mapRect(QRectF(0, 0, 1, 1)).width();
    if (factor < 0.07 || factor > 100)
        return;

    scale(scaleFactor, scaleFactor);
    m_scale *= scaleFactor;
}

void Mapcavas::setTranslateSpeed(qreal speed)
{
    Q_ASSERT_X(speed >= 0.0 && speed <= 2.0,
        "InteractiveView::setTranslateSpeed", "Speed should be in range [0.0, 2.0].");
    m_translateSpeed = speed;
}

qreal Mapcavas::translateSpeed() const
{
    return m_translateSpeed;
}

void Mapcavas::setZoomDelta(qreal delta)
{
    Q_ASSERT_X(delta >= 0.0 && delta <= 1.0,
        "InteractiveView::setZoomDelta", "Delta should be in range [0.0, 1.0].");
    m_zoomDelta = delta;
}

qreal Mapcavas::zoomDelta() const
{
    return m_zoomDelta;
}

// new: set associated raster layer
void Mapcavas::setLayers(RasterLayer* layer)
{
    m_rasterLayer = layer;
}

RasterLayer* Mapcavas::rasterLayer() const
{
    return m_rasterLayer;
}

// new: refresh the map by rendering using the RasterLayer's render method
void Mapcavas::freshmap()
{
    if (!m_rasterLayer) return;

    RasterLayer::RenderParams params = m_rasterLayer->currentRenderParams();
    QImage img = m_rasterLayer->render(params);
    if (img.isNull()) return;

    QPixmap pm = QPixmap::fromImage(img);
    SetImage(&pm);
}

void Mapcavas::freshmap(const RasterLayer::RenderParams& params)
{
    if (!m_rasterLayer) return;

    QImage img = m_rasterLayer->render(params);
    if (img.isNull()) return;

    QPixmap pm = QPixmap::fromImage(img);
    SetImage(&pm);
}

// MapTool management
void Mapcavas::setMapTool(MapTool* tool)
{
    if (m_mapTool)
    {
        m_mapTool->deactivate();
    }

    m_mapTool = tool;

    if (m_mapTool)
    {
        // Disable built-in drag mode so the tool controls everything
        setDragMode(QGraphicsView::NoDrag);
        m_mapTool->activate();
    }
    else
    {
        // Restore legacy drag mode when no tool
        setDragMode(QGraphicsView::ScrollHandDrag);
    }
}

void Mapcavas::unsetMapTool(MapTool* tool)
{
    if (m_mapTool && m_mapTool == tool)
    {
        m_mapTool->deactivate();
        m_mapTool = nullptr;
        setDragMode(QGraphicsView::ScrollHandDrag);
    }
}

MapTool* Mapcavas::mapTool() const
{
    return m_mapTool;
}