//===========================================
//  Lumina Desktop source code
//  Copyright (c) 2017, Ken Moore
//  Available under the 3-clause BSD license
//  See the LICENSE file for full details
//===========================================
// Simple subclass of QPrintPreviewWidget to provide
// notification when a context menu is requested
//===========================================
#ifndef _PRINT_GRAPHICS_H
#define _PRINT_GRAPHICS_H

#include <QMouseEvent>
#include <QDebug>
#include <QGraphicsView>
#include <QGraphicsItem>
#include <QBoxLayout>
#include <QScrollBar>
#include <QStyleOptionGraphicsItem>
#include <QtMath>
#include <QPageLayout>

class PageItem : public QGraphicsItem {
public:
	PageItem(int _pageNum, const QImage _pagePicture, QSize _paperSize)
        : pageNum(_pageNum), pagePicture(_pagePicture), paperSize(_paperSize)
	{
          brect = QRectF(QPointF(-25, -25),
                      QSizeF(paperSize)+QSizeF(50, 50));
          setCacheMode(DeviceCoordinateCache);
	}

	QRectF boundingRect() const Q_DECL_OVERRIDE
		{ return brect; }

	inline int pageNumber() const
		{ return pageNum; }

	void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget) Q_DECL_OVERRIDE
	{
	  Q_UNUSED(widget);
	  //Ensure all the antialiasing/smoothing options are turned on
	  painter->setRenderHint(QPainter::Antialiasing);
	  painter->setRenderHint(QPainter::TextAntialiasing);
	  painter->setRenderHint(QPainter::SmoothPixmapTransform);

	  QRectF paperRect(0,0, paperSize.width(), paperSize.height());

	  // Draw shadow
	  painter->setClipRect(option->exposedRect);
	  qreal shWidth = paperRect.width()/100;
	  QRectF rshadow(paperRect.topRight() + QPointF(0, shWidth),
	         paperRect.bottomRight() + QPointF(shWidth, 0));
	  QLinearGradient rgrad(rshadow.topLeft(), rshadow.topRight());
	  rgrad.setColorAt(0.0, QColor(0,0,0,255));
	  rgrad.setColorAt(1.0, QColor(0,0,0,0));
	  painter->fillRect(rshadow, QBrush(rgrad));
	  QRectF bshadow(paperRect.bottomLeft() + QPointF(shWidth, 0),
	         paperRect.bottomRight() + QPointF(0, shWidth));
	  QLinearGradient bgrad(bshadow.topLeft(), bshadow.bottomLeft());
	  bgrad.setColorAt(0.0, QColor(0,0,0,255));
	  bgrad.setColorAt(1.0, QColor(0,0,0,0));
	  painter->fillRect(bshadow, QBrush(bgrad));
	  QRectF cshadow(paperRect.bottomRight(),
	         paperRect.bottomRight() + QPointF(shWidth, shWidth));
	  QRadialGradient cgrad(cshadow.topLeft(), shWidth, cshadow.topLeft());
	  cgrad.setColorAt(0.0, QColor(0,0,0,255));
	  cgrad.setColorAt(1.0, QColor(0,0,0,0));
	  painter->fillRect(cshadow, QBrush(cgrad));

	  painter->setClipRect(paperRect & option->exposedRect);
	  painter->fillRect(paperRect, Qt::white);
	  if (pagePicture.isNull()){
	    qDebug() << "NULL";
	    return;
	  }
	  painter->drawImage(QPoint(0,0), pagePicture);
	}

private:
    int pageNum;
    const QImage pagePicture;
    QSize paperSize;
    QRectF brect;
};


class PrintWidget : public QGraphicsView
{
	Q_OBJECT
public:
	enum ViewMode {
		SinglePageView,
		FacingPagesView,
		AllPagesView
	};

	enum ZoomMode {
		CustomZoom,
		FitToWidth,
		FitInView
	};

private:
	void generatePreview();
	void layoutPages();
	void populateScene();
	void setViewMode(ViewMode);
	void setZoomMode(ZoomMode);

	QGraphicsScene *scene;

	int curPage, publicPageNum;
	ViewMode viewMode;
	ZoomMode zoomMode;
	QPageLayout::Orientation orientation;
	double zoomFactor;
	bool initialized, fitting;
	QList<QGraphicsItem*> pages;
	QHash<int, QImage> *pictures;

public:
	PrintWidget(QWidget *parent = 0);
	~PrintWidget();

	double getZoomFactor() const { return this->zoomFactor; };
	ZoomMode getZoomMode() const { return this->zoomMode; };
	int currentPage() const { return publicPageNum; };
	void setPictures(QHash<int, QImage>*);

signals:
	void resized();
	void customContextMenuRequested(const QPoint&);
	void currentPageChanged();

public slots:
	void zoomIn(double factor=1.2);
	void zoomOut(double factor=1.2);
	void setCurrentPage(int);
	void setVisible(bool) Q_DECL_OVERRIDE;
	void setOrientation(QPageLayout::Orientation);
	void highlightText(int, QRectF);

	void updatePreview();
	void fitView();
	void fitToWidth();
	void setAllPagesViewMode();
	void setSinglePageViewMode();
	void setFacingPagesViewMode();

private slots:
	void updateCurrentPage();
	int calcCurrentPage();
	void fit(bool doFitting=false);

protected:
	void resizeEvent(QResizeEvent* e) Q_DECL_OVERRIDE {
		/*{
			const QSignalBlocker blocker(verticalScrollBar()); // Don't change page, QTBUG-14517
			QGraphicsView::resizeEvent(e);
		}*/
		QGraphicsView::resizeEvent(e);
		emit resized();
 	}

	void showEvent(QShowEvent* e) Q_DECL_OVERRIDE {
	  QGraphicsView::showEvent(e);
		emit resized();
	}
};
#endif