/********************************************************************************
* FaceTrackNoIR		This program is a private project of some enthusiastic		*
*					gamers from Holland, who don't like to pay much for			*
*					head-tracking.												*
*																				*
* Copyright (C) 2012	Wim Vriend (Developing)									*
*						Ron Hendriks (Researching and Testing)					*
*																				*
* Homepage	http://facetracknoir.sourceforge.net/home/default.htm				*
*																				*
* This program is free software; you can redistribute it and/or modify it		*
* under the terms of the GNU General Public License as published by the			*
* Free Software Foundation; either version 3 of the License, or (at your		*
* option) any later version.													*
*																				*
* This program is distributed in the hope that it will be useful, but			*
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY	*
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for	*
* more details.																	*
*																				*
* You should have received a copy of the GNU General Public License along		*
* with this program; if not, see <http://www.gnu.org/licenses/>.				*
*																				*
* The FunctionConfigurator was made by Stanislaw Halik, and adapted to          *
* FaceTrackNoIR.																*
*																				*
* All credits for this nice piece of code should go to Stanislaw.				*
*																				*
* Copyright (c) 2011-2012, Stanislaw Halik <sthalik@misaki.pl>					*
* Permission to use, copy, modify, and/or distribute this						*
* software for any purpose with or without fee is hereby granted,				*
* provided that the above copyright notice and this permission					*
* notice appear in all copies.													*
********************************************************************************/
/*
	Modifications (last one on top):
		20120830 - WVR: Changed functionality a bit. Now only draw the handles, when the function is drawn.
						Only check mouseMoves, when they occur 'in range'. Redraw the curve, when a resize occurs.
						Somehow, the curve was not drawn correctly, when this was not done (all points were too high). 
						After a 'Reset' this would disappear...
		20120828 - WVR: Removed bSkipText, which was used to not show a number below each vertical gridline.
*/
#include "qfunctionconfigurator/qfunctionconfigurator.h"
#include <QPainter>
#include <QPaintEvent>
#include <QPainterPathStroker>
#include <QPainterPath>
#include <QBrush>
#include <QFileDialog>
#include <QPen>
#include <QMessageBox>
#include <QImage>
#include <QPixmap>
#include <QTimer>

#include <QtDebug>

#include <math.h>

static const int pointSize = 5;

QFunctionConfigurator::QFunctionConfigurator(QWidget *parent)
    : QWidget(parent)
{

	//
	// Defaults, for when the widget has no values different from the domXML()
	//
	MaxInput = 50;					// Maximum input limit
	MaxOutput = 180;				// Maximum output limit
	pPerEGU_Output = 1;				// Number of pixels, per EGU
	pPerEGU_Input = 4;				// Number of pixels, per EGU
	gDistEGU_Input = 5;				// Distance of gridlines
	gDistEGU_Output = 10;			// Distance of gridlines

	
	// Change compared to BezierConfigurator: X = horizontal (input), Y = vertical (output)
	// This will require the Curve-Dialog to be higher (which was the reason it was reversed in the first place..)
	range = QRectF(40, 20, MaxInput * pPerEGU_Input, MaxOutput * pPerEGU_Output);

    setMouseTracking(true);
    movingPoint = -1;				// Index of that same point

	//
	// Variables for FunctionConfig
	//
	_config = 0;
	_points = QList<QPointF>();
	_draw_points = QList<QPointF>();
	_draw_background = true;
	_draw_function = true;

//	qDebug() << "QFunctionConfigurator::QFunctionConfigurator object created.";

}

//
// Attach an existing FunctionConfig to the Widget.
//
void QFunctionConfigurator::setConfig(FunctionConfig* config, QString settingsFile) {
QPointF currentPoint;
QPointF drawPoint;
qreal x;

	_config = config;
	_points = config->getPoints();
	strSettingsFile = settingsFile;													// Remember for Reset()

	qDebug() << "QFunctionConfigurator::setConfig" << config->getTitle();
	setCaption(config->getTitle());

	//
	// Get the Function Points, one for each pixel in the horizontal range.
	// If the curve does not change, there is no need to run this code every time (it slows down drawing).
	//
	_draw_points.clear();
	for (int j = 0; j < MaxInput * pPerEGU_Input; j++) {
		//
		// Weird: not casting to float causes C++ to round the number...
		//
		x = (float) j / (float) pPerEGU_Input;
		currentPoint.setX ( x );
		currentPoint.setY (_config->getValue( x ));
		drawPoint = graphicalizePoint(currentPoint, "setConfig");
		if (withinRect(drawPoint, range)) {
			_draw_points.append(drawPoint);
//	qDebug() << "QFunctionConfigurator::setConfig _draw_Point to add = " << drawPoint;
		}
	}
	
	_draw_function = true;
	this->update();
}

//
// Load the FunctionConfig (points) from the INI-file.
//
void QFunctionConfigurator::loadSettings(QString settingsFile) {

	QSettings iniFile( settingsFile, QSettings::IniFormat );						// Application settings (in INI-file)
	strSettingsFile = settingsFile;													// Remember for Reset()
	qDebug() << "QFunctionConfigurator::loadSettings = " << settingsFile;
	if (_config) {
		_config->loadSettings(iniFile);
		setConfig(_config, settingsFile);
	}
}

//
// Save the FunctionConfig (points) to the INI-file.
//
void QFunctionConfigurator::saveSettings(QString settingsFile) {
	QSettings iniFile( settingsFile, QSettings::IniFormat );						// Application settings (in INI-file)
	strSettingsFile = settingsFile;													// Remember for Reset()
	qDebug() << "QFunctionConfigurator::saveSettings = " << settingsFile;

	if (_config) {
		_config->saveSettings(iniFile);
	}
}

//
// Draw the Background for the graph, the gridlines and the gridpoints.
// The static objects are drawn on a Pixmap, so it does not have to be repeated every paintEvent. Hope this speeds things up...
//
void QFunctionConfigurator::drawBackground(const QRectF &fullRect)
{
int i;
QRect scale;

	qDebug() << "QFunctionConfigurator::drawBackground.";

	_background = QPixmap(fullRect.width(), fullRect.height());
	QPainter painter(&_background);

	painter.save();
	painter.setRenderHint(QPainter::Antialiasing);
	painter.fillRect(fullRect, colBackground);
	QColor bg_color(112, 154, 209);
	painter.fillRect(range, bg_color);

	QFont font("ComicSans", 4);
    font.setPointSize(8);
    painter.setFont(font);

    QPen pen(QColor(55, 104, 170, 127), 1, Qt::SolidLine);

	//
	// Draw the Caption
	//
	if (_config) {
		strCaption = _config->getTitle();
	}

	scale.setCoords(range.left(), 0, range.right(), 20);
	painter.drawText(scale, Qt::AlignCenter, strCaption);

	//
	// Draw the horizontal grid
	//
	for (i = range.bottom() - gDistEGU_Output * pPerEGU_Output; i >= range.top(); i -= gDistEGU_Output * pPerEGU_Output) {
		drawLine(&painter, QPointF(40, i), QPointF(range.right(), i), pen);
		scale.setCoords(0, i - 5, range.left() - 5, i + 5);
		painter.drawText(scale, Qt::AlignRight, tr("%1").arg(((range.bottom() - i))/pPerEGU_Output));
	}

	//
	// Draw the vertical guidelines
	//
	for (i = range.left(); i <= range.right(); i += gDistEGU_Input * pPerEGU_Input) {
		drawLine(&painter, QPointF(i, range.top()), QPointF(i, range.bottom()), pen);
		scale.setCoords(i - 10, range.bottom() + 2, i + 10, range.bottom() + 15);
		painter.drawText(scale, Qt::AlignCenter, tr("%1").arg(abs(((range.left() - i))/pPerEGU_Input)));
	}

	scale.setCoords(range.left(), range.bottom() + 20, range.right(), range.bottom() + 35);
	painter.drawText(scale, Qt::AlignRight, strInputEGU);

	//
	// Draw the EGU of the vertical axis (vertically!)
	//
	font.setPointSize(10);
	painter.translate(range.topLeft().x() - 35, range.topLeft().y());
	painter.rotate(90);
	painter.drawText(0,0,strOutputEGU );

	//
	// Draw the two axis
	//
	pen.setWidth(2);
	pen.setColor( Qt::black );
	drawLine(&painter, range.topLeft() - QPointF(2,0), range.bottomLeft() - QPointF(2,0), pen);
	drawLine(&painter, range.bottomLeft(), range.bottomRight(), pen);

	painter.restore();
}


//
// Draw the Function for the graph, on a Pixmap.
//
void QFunctionConfigurator::drawFunction(const QRectF &fullRect)
{
	if (!_config)
		return;
int i;
QPointF prevPoint;
QPointF currentPoint;

	//
	// Use the background picture to draw on.
	// ToDo: find out how to add Pixmaps, without getting it all green...
	//
	_function = QPixmap(_background);
	QPainter painter(&_function);

	painter.save();
    painter.setRenderHint(QPainter::Antialiasing, true);

	//
	// Draw the handles for the Points
	//
	for (i = 0; i < _points.size(); i++) {
		currentPoint = graphicalizePoint( _points[i], "drawFunction handles" );		// Get the next point and convert it to Widget measures 
	    drawPoint(&painter, currentPoint, QColor(200, 200, 210, 120));
		lastPoint = currentPoint;											// Remember which point is the rightmost in the graph
//qDebug() << "QFunctionConfigurator::paintEvent, drawing handle for " << currentPoint;
	}


    QPen pen(colBezier, 1.2, Qt::SolidLine);

	prevPoint = graphicalizePoint( QPointF(0,0), "drawFunction lines" );		// Start at the Axis
	double max = maxInputEGU();
	QPointF prev = graphicalizePoint(QPointF(0, 0));
    double step = 1e-1 / (double) pixPerEGU_Input();
	for (double i = 0; i < max; i += step) {
	    double val = _config->getValue(i);
	    QPointF cur = graphicalizePoint(QPointF(i, val));
	    drawLine(&painter, prev, cur, pen);
		prev = cur;
	}
	painter.restore();
}

//
// The Widget paints the surface every x msecs.
//
void QFunctionConfigurator::paintEvent(QPaintEvent *e)
{
QPointF prevPoint;
QPointF currentPoint;
QPointF actualPos;
int i;

//	qDebug() << "QFunctionConfigurator::paintEvent.";

	QPainter p(this);
    p.setRenderHint(QPainter::Antialiasing);
    p.setClipRect(e->rect());

	if (_draw_background) {
		drawBackground(e->rect());						// Draw the static parts on a Pixmap
		p.drawPixmap(0, 0, _background);				// Paint the background
		_draw_background = false;
	}

	if (_draw_function) {
		drawFunction(e->rect());						// Draw the Function on a Pixmap
		_draw_function = false;
	}
	p.drawPixmap(0, 0, _function);						// Always draw the background and the function

	QPen pen(Qt::white, 1, Qt::SolidLine);

	//
	// Draw the Points, that make up the Curve
	//
	if (_config) {
		//
		// When moving, also draw a sketched version of the Function.
		//
        if (movingPoint >= 0 && movingPoint < _points.size()) {
			prevPoint = graphicalizePoint( QPointF(0,0), "paintEvent moving" );				// Start at the Axis
			for (i = 0; i < _points.size(); i++) {
				currentPoint = graphicalizePoint( _points[i], "paintEvent moving" );		// Get the next point and convert it to Widget measures 
				drawLine(&p, prevPoint, currentPoint, pen);
				prevPoint = currentPoint;
//	qDebug() << "QFunctionConfigurator::paintEvent, drawing while moving " << currentPoint;
			}

			//
			// When moving, also draw a few help-lines, so positioning the point gets easier.
			//
			pen.setWidth(1);
			pen.setColor( Qt::white );
			pen.setStyle( Qt::DashLine );
            actualPos = graphicalizePoint(_points[movingPoint], "paintEvent moving help line(s)");
			drawLine(&p, QPoint(range.left(), actualPos.y()), QPoint(actualPos.x(), actualPos.y()), pen);
			drawLine(&p, QPoint(actualPos.x(), actualPos.y()), QPoint(actualPos.x(), range.bottom()), pen);
		}

		//
		// If the Tracker is active, the 'Last Point' it requested is recorded.
		// Show that point on the graph, with some lines to assist.
		// This new feature is very handy for tweaking the curves!
		//
		if (_config->getLastPoint( currentPoint )) {

//	qDebug() << "QFunctionConfigurator::paintEvent, drawing tracked Point " << currentPoint;

			actualPos = graphicalizePoint( currentPoint, "paintEvent tracking" );
			drawPoint(&p, actualPos, QColor(255, 0, 0, 120));

			pen.setWidth(1);
			pen.setColor( Qt::black );
			pen.setStyle( Qt::SolidLine );
			drawLine(&p, QPoint(range.left(), actualPos.y()), QPoint(actualPos.x(), actualPos.y()), pen);
			drawLine(&p, QPoint(actualPos.x(), actualPos.y()), QPoint(actualPos.x(), range.bottom()), pen);
		}

	}

	//
	// Draw the delimiters
	//
	pen.setWidth(1);
	pen.setColor( Qt::white );
	pen.setStyle( Qt::SolidLine );
	drawLine(&p, QPoint(lastPoint.x(), range.top()), QPoint(lastPoint.x(), range.bottom()), pen);
	drawLine(&p, QPoint(range.left(), lastPoint.y()), QPoint(range.right(), lastPoint.y()), pen);

    //QTimer::singleShot(50, this, SLOT(update()));
}

//
// Draw the handle, to move the Bezier-curve.
//
void QFunctionConfigurator::drawPoint(QPainter *painter, const QPointF &pos, QColor colBG )
{
    painter->save();
    painter->setPen(QColor(50, 100, 120, 200));
    painter->setBrush( colBG );
    painter->drawEllipse(QRectF(pos.x() - pointSize,
                                pos.y() - pointSize,
                                pointSize*2, pointSize*2));
    painter->restore();
}

void QFunctionConfigurator::drawLine(QPainter *painter, const QPointF &start, const QPointF &end, QPen pen)
{
    painter->save();
    painter->setPen(pen);
    painter->setBrush(Qt::NoBrush);
    painter->drawLine(start, end);
    painter->restore();
}

//
// If the mousebutton is pressed, check if it is inside one of the Points.
// If so: start moving that Point, until mouse release.
//
void QFunctionConfigurator::mousePressEvent(QMouseEvent *e)
{
	//
	// First: check the left mouse-button
	//
	if (e->button() == Qt::LeftButton) {

		//
		// Check to see if the cursor is touching one of the points.
		//
		bool bTouchingPoint = false;
		movingPoint = -1;
		if (_config) {

			for (int i = 0; i < _points.size(); i++) {
				if ( markContains( graphicalizePoint( _points[i], "mousePressEvent markContains" ), e->pos() ) ) {
					bTouchingPoint = true;
					movingPoint = i;
                    break;
				}
			}

			//
			// If the Left Mouse-button was clicked without touching a Point, add a new Point
			//
			if (!bTouchingPoint) {
				if (withinRect(e->pos(), range)) {
					_config->addPoint(normalizePoint(e->pos()));
					setConfig(_config, strSettingsFile);
                    movingPoint = -1;
					emit CurveChanged( true );
				}
			}
		}
	}

	//
	// Then: check the right mouse-button
	//
	if (e->button() == Qt::RightButton) {

		//
		// Check to see if the cursor is touching one of the points.
		//
		if (_config) {

			for (int i = 0; i < _points.size(); i++) {
				if ( markContains( graphicalizePoint( _points[i], "mousePressEvent RightButton" ), e->pos() ) ) {
					movingPoint = i;
                    break;
				}
			}

			//
			// If the Right Mouse-button was clicked while touching a Point, remove the Point
			//
            if (movingPoint >= 0 && movingPoint < _points.size()) {
				_config->removePoint(movingPoint);
                movingPoint = -1;
				setConfig(_config, strSettingsFile);
				emit CurveChanged( true );
			}
            else
                movingPoint = -1;
        }
	}
}

//
// If the mouse if moving, make sure the Bezier moves along.
// Of course, only when a Point is selected...
//
void QFunctionConfigurator::mouseMoveEvent(QMouseEvent *e)
{

    if (movingPoint >= 0 && movingPoint < _points.size()) {

		setCursor(Qt::ClosedHandCursor);		

		//
		// Change the currently moving Point.
		//
        _points[movingPoint] = normalizePoint(e->pos());
		update();
    }
	else {

		//
		// Check to see if the cursor is touching one of the points.
		//
		bool bTouchingPoint = false;
		if (_config) {

			for (int i = 0; i < _points.size(); i++) {
				if ( markContains( graphicalizePoint( _points[i], "mouseMoveEvent" ), e->pos() ) ) {
					bTouchingPoint = true;
				}
			}
		}

		if ( bTouchingPoint ) {
			setCursor(Qt::OpenHandCursor);
		}
		else {
			setCursor(Qt::ArrowCursor);
		}

	}
}

void QFunctionConfigurator::mouseReleaseEvent(QMouseEvent *e)
{
    if (e->button() == Qt::LeftButton) {
        //qDebug()<<"releasing";
        if (movingPoint >= 0 && movingPoint < _points.size()) {
            emit CurveChanged( true );

            //
            // Update the Point in the _config
            //
            if (_config) {
                _config->movePoint(movingPoint, normalizePoint(e->pos()));
                setConfig(_config, strSettingsFile);
            }
        }
        setCursor(Qt::ArrowCursor);
        movingPoint = -1;
    }
}

//
// Determine if the mousebutton was pressed within the range of the Point.
//
bool QFunctionConfigurator::markContains(const QPointF &pos, const QPointF &coord) const
{
    QRectF rect(pos.x() - pointSize,
                pos.y() - pointSize,
                pointSize*2, pointSize*2);
    QPainterPath path;
    path.addEllipse(rect);
    return path.contains(coord);
}

bool QFunctionConfigurator::withinRect( const QPointF &coord, const QRectF &rect ) const
{
    QPainterPath path;
    path.addRect(rect);
    return path.contains(coord);
}

//
// Convert the Point in the graph, to the real-life Point.
//
QPointF QFunctionConfigurator::normalizePoint(QPointF point) const
{
	QPointF norm;

	norm.setX( (point.x() - range.left()) / pPerEGU_Input );
    norm.setY( (range.bottom() - point.y()) / pPerEGU_Output );

	if (norm.x() > maxInputEGU())
		norm.setX(maxInputEGU());
	else if (norm.x() < 0)
		norm.setX(0);
	if (norm.y() > maxOutputEGU())
		norm.setY(maxOutputEGU());
	else if (norm.y() < 0)
		norm.setY(0);

	return norm;
}

//
// Convert the real-life Point into the graphical Point.
//
QPointF QFunctionConfigurator::graphicalizePoint(QPointF point, QString source) const
{
QPointF graph;

	graph.setX( range.left() + (fabs(point.x()) * pPerEGU_Input) );
	graph.setY( range.bottom() - (fabs(point.y()) * pPerEGU_Output) );

//	qDebug() << "QFunctionConfigurator::graphicalizePoint source = " << source << ", point = " << point << ", graph = " << graph;

	return graph;
}

void QFunctionConfigurator::setmaxInputEGU(int value)
{
    MaxInput = value;
	setMinimumWidth(MaxInput * pPerEGU_Input + 55);
//	resetCurve();
	resize( MaxInput * pPerEGU_Input + 55, MaxOutput * pPerEGU_Output + 60 );
}
void QFunctionConfigurator::setmaxOutputEGU(int value)
{
    MaxOutput = value;
	setMinimumHeight(MaxOutput * pPerEGU_Output + 60);
//	resetCurve();
	resize( MaxInput * pPerEGU_Input + 55, MaxOutput * pPerEGU_Output + 60 );
}

//
// To make configuration more visibly attractive, the number of pixels 'per EGU' can be defined.
//
void QFunctionConfigurator::setpixPerEGU_Input(int value)
{
    pPerEGU_Input = value;
	setMinimumWidth(MaxInput * pPerEGU_Input + 55);
	resize( MaxInput * pPerEGU_Input + 55, MaxOutput * pPerEGU_Output + 60 );
}

//
// To make configuration more visibly attractive, the number of pixels 'per EGU' can be defined.
//
void QFunctionConfigurator::setpixPerEGU_Output(int value)
{
    pPerEGU_Output = value;
	setMinimumHeight(MaxOutput * pPerEGU_Output + 60);
	resize( MaxInput * pPerEGU_Input + 55, MaxOutput * pPerEGU_Output + 60 );
}

//
// Define the distance of the grid 'in EGU' points.
//
void QFunctionConfigurator::setgridDistEGU_Input(int value)
{
    gDistEGU_Input = value;
	_draw_background = true;
	_draw_function = true;
	repaint();
}

//
// Define the distance of the grid 'in EGU' points.
//
void QFunctionConfigurator::setgridDistEGU_Output(int value)
{
    gDistEGU_Output = value;
	_draw_background = true;
	_draw_function = true;
	repaint();
}

void QFunctionConfigurator::setColorBezier(QColor color)
{
    colBezier = color;
    update();
}
void QFunctionConfigurator::setColorBackground(QColor color)
{
    colBackground = color;
    update();
}

void QFunctionConfigurator::setInputEGU(QString egu)
{
    strInputEGU = egu;
    update();
}
void QFunctionConfigurator::setOutputEGU(QString egu)
{
    strOutputEGU = egu;
    update();
}
void QFunctionConfigurator::setCaption(QString cap)
{
    strCaption = cap;
    update();
}

void QFunctionConfigurator::resizeEvent(QResizeEvent *e)
{
	range = QRectF(40, 20, MaxInput * pPerEGU_Input, MaxOutput * pPerEGU_Output);

	qDebug() << "QFunctionConfigurator::resizeEvent, name = " << strCaption << ",range = " << range;

	if (_config) {
		setConfig(_config, strSettingsFile);
	}
	_draw_background = true;
	_draw_function = true;
	repaint();
}