/*
  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
  2 of the License, or (at your option) any later version.
*/

#include <QFontMetrics>
#include <QPainter>

#include "graphbarwidget.h"

GraphBarWidget::GraphBarWidget(const QList<QList<QVariant> > data, QWidget *parent) : QWidget(parent), mMargin(10), mData(data) {
	mBarHeight = fontMetrics().height();
}

int GraphBarWidget::maxValue() const {
	int retval = -1;
	foreach(QList<QVariant> l, mData){
		if(l.at(1).toInt() > retval){
			retval = l.at(1).toInt();
		}
	}
	return retval;
}

QSize GraphBarWidget::maxDescr() const {
	QFont f = font();
	f.setBold(true);
	QFontMetrics fm(f);
	QSize retval(0,0);
	foreach(QList<QVariant> l, mData){
		QString descr = l.at(0).toString();
		QSize curSize = fm.size(Qt::TextSingleLine, descr);
		if(curSize.width() > retval.width()){
			retval = curSize;
		}
	}
	return retval;
}

QSize GraphBarWidget::maxCount() const {
	QFontMetrics fm = fontMetrics();
	QSize retval(0,0);
	foreach(QList<QVariant> l, mData){
		QString curCount = QString("(%1)").arg(l.at(2).toString());
		QSize curSize = fm.size(Qt::TextSingleLine, curCount);
		if(curSize.width() > retval.width()){
			retval = curSize;
		}
	}
	return retval;
}

QSize GraphBarWidget::sizeHint() const {
	int height = mData.count() * mBarHeight;
	height += mData.count() * mMargin;
	height += mBarHeight + mMargin;
	return QSize(400, height);
}

void GraphBarWidget::paintEvent(QPaintEvent *){
	QPainter p(this);
	QHash<QString, qreal> length; //int
	QList<QList<QVariant> >::const_iterator it;

	//draw background
	QPen pen(Qt::red, 2);
	p.setPen(pen);
	QLinearGradient bgGradient(QPointF(0.0, height() / 2), QPointF(width(), height() / 2));
	bgGradient.setColorAt(0, QColor(221, 107, 80));
	bgGradient.setColorAt(1, QColor(251, 179, 150));
	QBrush brush(bgGradient);
	p.setBrush(brush);
	p.drawRect(contentsRect());

	//draw caption
	QFont f = font();
	f.setUnderline(true);
	f.setBold(true);
	p.setFont(f);
	QString cap(caption());
	QFontMetrics fm(f);
	int captionStartx = (width() - fm.width(cap)) / 2;
	int captionStarty = fm.height();
	p.drawText(captionStartx, captionStarty, cap);

	//prepare drawing data
	int barsStarty = fm.height() +  2 * mMargin + 10;
	f.setUnderline(false);
	f.setBold(true);
	p.setFont(f);
	int maxdescr = maxDescr().width();
	int maxcount = maxCount().width();

	int barsStartx = maxdescr + 2 * mMargin;
	int marginRight = maxcount + 2 * mMargin;
	int maxWidth = width() - barsStartx - marginRight;
	p.setRenderHints(QPainter::Antialiasing);
	p.setPen(QPen(Qt::red, 1));

	//calculate real lengths based on widget width
	for(it = mData.constBegin(); it != mData.constEnd(); ++it){
		qreal value = it->at(1).toDouble();
		value = value / maxValue() * maxWidth;
		length[it->at(0).toString()] = value;
	}

	//draw the bars and numbers
	int ctr(0);
	for(QList<QList<QVariant> >::const_iterator itr = mData.constBegin(); itr != mData.constEnd() ; ++itr, ++ctr){
		int starty = barsStarty + ctr * p.fontMetrics().height() + ctr * mMargin;
		p.drawText(mMargin, starty, itr->at(0).toString());
		QLinearGradient barGradient(QPointF(barsStartx, starty), QPointF(width(), starty));
		barGradient.setColorAt(0, QColor(0, 128, 170));
		barGradient.setColorAt(1, QColor(131, 205, 214));
		QBrush b(barGradient);
		p.setBrush(b);
		qreal len = length.value(itr->at(0).toString());
		QRect bar(barsStartx, starty - p.fontMetrics().height() + p.fontMetrics().descent(), len, p.fontMetrics().height());
		p.drawRect(bar);
		int nStartx = barsStartx + len + mMargin;
		p.drawText(nStartx, starty, QString(tr("(%1)")).arg(itr->at(2).toString()));
	}
}