/****************************************************************************
 **
 ** Copyright (C) 2012 Digia Plc
 ** All rights reserved.
 ** For any questions to Digia, please use contact form at http://qt.digia.com
 **
 ** This file is part of the Qt Commercial Charts Add-on.
 **
 ** $QT_BEGIN_LICENSE$
 ** Licensees holding valid Qt Commercial licenses may use this file in
 ** accordance with the Qt Commercial License Agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and Digia.
 **
 ** If you have questions regarding the use of this file, please use
 ** contact form at http://qt.digia.com
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/

#include "chartbarcategoryaxisy_p.h"
#include "chartpresenter_p.h"
#include "qbarcategoryaxis_p.h"
#include <qmath.h>
#include <QDebug>

static int label_padding = 5;

QTCOMMERCIALCHART_BEGIN_NAMESPACE

ChartBarCategoryAxisY::ChartBarCategoryAxisY(QBarCategoryAxis *axis,ChartPresenter *presenter) : ChartAxis(axis,presenter),
m_categoriesAxis(axis)
{
}

ChartBarCategoryAxisY::~ChartBarCategoryAxisY()
{
}

QVector<qreal> ChartBarCategoryAxisY::calculateLayout() const
{
    int count = m_categoriesAxis->d_ptr->count();

    Q_ASSERT(count>=1);

    QVector<qreal> points;
    points.resize(count+2);

    const qreal delta = m_rect.height()/(count);
    qreal offset = - m_min - 0.5;

    if(delta<1) return points;

    if(offset<=0) {
        offset = int(offset * m_rect.height()/(m_max - m_min))%int(delta) + delta;
    }
    else {
        offset = int(offset * m_rect.height()/(m_max - m_min))%int(delta);
    }

    points[0] = m_rect.bottom();
    points[count+1] = m_rect.top();

    for (int i = 0; i < count; ++i) {
        int y = m_rect.bottom() - i * delta - offset;
        points[i+1] = y;
    }
    return points;
}

QStringList ChartBarCategoryAxisY::createCategoryLabels(const QVector<qreal>& layout) const
{
    QStringList result;
    qreal d = (m_max - m_min)/m_rect.height();
    for (int i = 0;i < layout.count()-1; ++i) {
        qreal x = qFloor(((m_rect.height()- (layout[i+1] + layout[i])/2 + m_rect.top())*d + m_min+0.5));
        if ((x < m_categoriesAxis->categories().count()) && (x >= 0)) {
            result << m_categoriesAxis->categories().at(x);
        }
        else {
            // No label for x coordinate
            result << "";
        }
    }
    result << "";
    return result;
}

void ChartBarCategoryAxisY::updateGeometry()
{
    const QVector<qreal>& layout = ChartAxis::layout();

    m_minWidth = 0;
    m_minHeight = 0;

    if(layout.isEmpty()) return;

    QStringList ticksList = createCategoryLabels(layout);

    QList<QGraphicsItem *> lines = m_grid->childItems();
    QList<QGraphicsItem *> labels = m_labels->childItems();
    QList<QGraphicsItem *> shades = m_shades->childItems();
    QList<QGraphicsItem *> axis = m_arrow->childItems();

    Q_ASSERT(labels.size() == ticksList.size());
    Q_ASSERT(layout.size() == ticksList.size());

    const qreal delta = m_rect.height()/(m_categoriesAxis->d_ptr->count());

    QGraphicsLineItem *lineItem = static_cast<QGraphicsLineItem*>(axis.at(0));
    lineItem->setLine(m_rect.left() , m_rect.top(), m_rect.left(), m_rect.bottom());

    qreal height = m_rect.bottom();
    for (int i = 0; i < layout.size(); ++i) {
        QGraphicsLineItem *lineItem = static_cast<QGraphicsLineItem*>(lines.at(i));
        lineItem->setLine(m_rect.left() , layout[i], m_rect.right(), layout[i]);
        QGraphicsSimpleTextItem *labelItem = static_cast<QGraphicsSimpleTextItem*>(labels.at(i));
        labelItem->setText(ticksList.at(i));
        const QRectF& rect = labelItem->boundingRect();
        QPointF center = rect.center();
        labelItem->setTransformOriginPoint(center.x(), center.y());

        if(i==0) {
           labelItem->setPos(m_rect.left() - rect.width() - label_padding ,layout[i+1] + (delta)/2 - center.y());
        }
        else {
            labelItem->setPos(m_rect.left() - rect.width() - label_padding ,layout[i] - (delta)/2 - center.y());
        }

        if(labelItem->pos().y()+rect.height()>= height || labelItem->pos().y() < m_rect.top()) {
            labelItem->setVisible(false);
        }
        else {
            labelItem->setVisible(true);
            height=labelItem->pos().y();
        }

        m_minWidth=qMax(rect.width()+label_padding,m_minWidth);
        m_minHeight+=rect.height();

        if ((i+1)%2 && i>1) {
            QGraphicsRectItem *rectItem = static_cast<QGraphicsRectItem*>(shades.at(i/2-1));
            rectItem->setRect(m_rect.left(),layout[i],m_rect.width(),layout[i-1]-layout[i]);
        }
        lineItem = static_cast<QGraphicsLineItem*>(axis.at(i+1));
        lineItem->setLine(m_rect.left()-5,layout[i],m_rect.left(),layout[i]);
    }
}

void ChartBarCategoryAxisY::handleAxisUpdated()
{

    if(m_categoriesAxis->categories()!=m_categories)
    {
        m_categories=m_categoriesAxis->categories();
        if(ChartAxis::layout().count()==m_categoriesAxis->d_ptr->count()+2) {
            updateGeometry();
        }
    }
    ChartAxis::handleAxisUpdated();
}

QTCOMMERCIALCHART_END_NAMESPACE