/****************************************************************************
**
** 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 "legendlayout_p.h"
#include "chartpresenter_p.h"
#include "legendmarker_p.h"
#include "qlegend_p.h"
#include <QDebug>

QTCOMMERCIALCHART_BEGIN_NAMESPACE

LegendLayout::LegendLayout(QLegend* legend):
m_legend(legend)
{

}

LegendLayout::~LegendLayout()
{

}

void LegendLayout::setOffset(qreal x, qreal y)
{
    bool scrollHorizontal = true;
    switch(m_legend->alignment()) {
        case Qt::AlignTop:
        case Qt::AlignBottom: {
            scrollHorizontal = true;
            break;
        }
        case Qt::AlignLeft:
        case Qt::AlignRight: {
            scrollHorizontal = false;
            break;
        }
    }

    // If detached, the scrolling direction is vertical instead of horizontal and vice versa.
    if (!m_legend->isAttachedToChart()) {
        scrollHorizontal = !scrollHorizontal;
    }

    QRectF boundingRect = geometry();

    // Limit offset between m_minOffset and m_maxOffset
    if (scrollHorizontal) {
        if(m_width<=boundingRect.width()) return;

        if (x != m_offsetX) {
            m_offsetX = qBound(m_minOffsetX, x, m_maxOffsetX);
            m_legend->d_ptr->items()->setPos(-m_offsetX,boundingRect.top());
        }
    }
    else {
        if(m_height<=boundingRect.height()) return;

        if (y != m_offsetY) {
            m_offsetY = qBound(m_minOffsetY, y, m_maxOffsetY);
            m_legend->d_ptr->items()->setPos(boundingRect.left(),-m_offsetY);
        }
    }
}

QPointF LegendLayout::offset() const
{
    return QPointF(m_offsetX,m_offsetY);
}

void LegendLayout::setGeometry(const QRectF& rect)
{

    QGraphicsLayout::setGeometry(rect);

    if(m_legend->isAttachedToChart()) {
        setAttachedGeometry(rect);
    }
    else {
        setDettachedGeometry(rect);
    }
}

void LegendLayout::setAttachedGeometry(const QRectF& rect)
{
    if (!rect.isValid()) return;

    m_offsetX=0;
    m_offsetY=0;

    QSizeF size(0,0);

    if( m_legend->d_ptr->markers().isEmpty()) return;

    m_width=0;
    m_height=0;

    switch(m_legend->alignment()) {

        case Qt::AlignTop:

        case Qt::AlignBottom: {
            QPointF point(0,0);
            foreach (LegendMarker* marker, m_legend->d_ptr->markers()) {
                if (marker->isVisible()) {
                    marker->setGeometry(QRectF(QPointF(0,0),marker->effectiveSizeHint(Qt::PreferredSize)));
                    marker->setPos(point.x(),rect.height()/2 - marker->boundingRect().height()/2);
                    const QRectF& rect = marker->boundingRect();
                    size = size.expandedTo(rect.size());
                    qreal w = rect.width();
                    m_width+=w;
                    point.setX(point.x() + w);
                }
            }
            if(m_width<rect.width()) {
                m_legend->d_ptr->items()->setPos(rect.width()/2-m_width/2,rect.top());

            }
            else {
                m_legend->d_ptr->items()->setPos(rect.topLeft());
            }
            m_height=size.height();
        }
        break;
        case Qt::AlignLeft:
        case Qt::AlignRight: {
            QPointF point(0,0);
            foreach (LegendMarker* marker, m_legend->d_ptr->markers()) {
                if (marker->isVisible()) {
                    marker->setGeometry(QRectF(QPointF(0,0),marker->effectiveSizeHint(Qt::PreferredSize)));
                    marker->setPos(point);
                    const QRectF& rect = marker->boundingRect();
                    qreal h = rect.height();
                    size = size.expandedTo(rect.size());
                    m_height+=h;
                    point.setY(point.y() + h);
                }
            }
            if(m_height<rect.height()) {
                m_legend->d_ptr->items()->setPos(rect.left(),rect.height()/2-m_height/2);
            }
            else {
                m_legend->d_ptr->items()->setPos(rect.topLeft());
            }
            m_width=size.width();
        }
        break;
    }

    m_minOffsetX = 0;
    m_minOffsetY = 0;
    m_maxOffsetX = m_width - rect.width();
    m_maxOffsetY = m_height - rect.height();
}

void LegendLayout::setDettachedGeometry(const QRectF& rect)
{
    if (!rect.isValid()) return;

    // Detached layout is different.
    // In detached mode legend may have multiple rows and columns, so layout calculations
    // differ a log from attached mode.
    // Also the scrolling logic is bit different.

    m_offsetX=0;
    m_offsetY=0;

    QSizeF size(0,0);

    QList<LegendMarker *> markers = m_legend->d_ptr->markers();

    if(markers.isEmpty()) return;

    switch (m_legend->alignment()) {
        case Qt::AlignTop: {
            QPointF point = rect.topLeft();
            m_width = 0;
            m_height = 0;
            for (int i=0; i<markers.count(); i++) {
                LegendMarker *marker = markers.at(i);
                if (marker->isVisible()) {
                    marker->setGeometry(QRectF(QPointF(0,0),marker->effectiveSizeHint(Qt::PreferredSize)));
                    marker->setPos(point.x(),point.y());
                    const QRectF& boundingRect = marker->boundingRect();
                    qreal w = boundingRect.width();
                    qreal h = boundingRect.height();
                    m_width = qMax(m_width,w);
                    m_height = qMax(m_height,h);
                    point.setX(point.x() + w);
                    if (point.x() + w > rect.topLeft().x() + rect.width()) {
                        // Next item would go off rect.
                        point.setX(rect.topLeft().x());
                        point.setY(point.y() + h);
                        if (i+1 < markers.count()) {
                            m_height += h;
                        }
                    }
                }
            }
            m_legend->d_ptr->items()->setPos(rect.topLeft());

            m_minOffsetX = 0;
            m_minOffsetY = 0;
            m_maxOffsetX = m_width - rect.width();
            m_maxOffsetY = m_height - rect.height();
        }
        break;
        case Qt::AlignBottom: {
            QPointF point = rect.bottomLeft();
            m_width = 0;
            m_height = 0;
            for (int i=0; i<markers.count(); i++) {
                LegendMarker *marker = markers.at(i);
                if (marker->isVisible()) {
                    marker->setGeometry(QRectF(QPointF(0,0),marker->effectiveSizeHint(Qt::PreferredSize)));
                    const QRectF& boundingRect = marker->boundingRect();
                    qreal w = boundingRect.width();
                    qreal h = boundingRect.height();
                    m_width = qMax(m_width,w);
                    m_height = qMax(m_height,h);
                    marker->setPos(point.x(),point.y() - h);
                    point.setX(point.x() + w);
                    if (point.x() + w > rect.bottomLeft().x() + rect.width()) {
                        // Next item would go off rect.
                        point.setX(rect.bottomLeft().x());
                        point.setY(point.y() - h);
                        if (i+1 < markers.count()) {
                            m_height += h;
                        }
                    }
                }
            }
            m_legend->d_ptr->items()->setPos(rect.topLeft());

            m_minOffsetX = 0;
            m_minOffsetY = qMin(rect.topLeft().y(), rect.topLeft().y() - m_height + rect.height());
            m_maxOffsetX = m_width - rect.width();
            m_maxOffsetY = 0;
        }
        break;
        case Qt::AlignLeft: {
            QPointF point = rect.topLeft();
            m_width = 0;
            m_height = 0;
            qreal maxWidth = 0;
            for (int i=0; i<markers.count(); i++) {
                LegendMarker *marker = markers.at(i);
                if (marker->isVisible()) {
                    marker->setGeometry(QRectF(QPointF(0,0),marker->effectiveSizeHint(Qt::PreferredSize)));
                    const QRectF& boundingRect = marker->boundingRect();
                    qreal w = boundingRect.width();
                    qreal h = boundingRect.height();
                    m_height = qMax(m_height,h);
                    maxWidth = qMax(maxWidth,w);
                    marker->setPos(point.x(),point.y());
                    point.setY(point.y() + h);
                    if (point.y() + h > rect.topLeft().y() + rect.height()) {
                        // Next item would go off rect.
                        point.setX(point.x() + maxWidth);
                        point.setY(rect.topLeft().y());
                        if (i+1 < markers.count()) {
                            m_width += maxWidth;
                            maxWidth = 0;
                        }
                    }
                }
            }
            m_width += maxWidth;
            m_legend->d_ptr->items()->setPos(rect.topLeft());

            m_minOffsetX = 0;
            m_minOffsetY = 0;
            m_maxOffsetX = m_width - rect.width();
            m_maxOffsetY = m_height - rect.height();
        }
        break;
        case Qt::AlignRight: {
            QPointF point = rect.topRight();
            m_width = 0;
            m_height = 0;
            qreal maxWidth = 0;
            for (int i=0; i<markers.count(); i++) {
                LegendMarker *marker = markers.at(i);
                if (marker->isVisible()) {
                    marker->setGeometry(QRectF(QPointF(0,0),marker->effectiveSizeHint(Qt::PreferredSize)));
                    const QRectF& boundingRect = marker->boundingRect();
                    qreal w = boundingRect.width();
                    qreal h = boundingRect.height();
                    m_height = qMax(m_height,h);
                    maxWidth = qMax(maxWidth,w);
                    marker->setPos(point.x() - w,point.y());
                    point.setY(point.y() + h);
                    if (point.y() + h > rect.topLeft().y() + rect.height()) {
                        // Next item would go off rect.
                        point.setX(point.x() - maxWidth);
                        point.setY(rect.topLeft().y());
                        if (i+1 < markers.count()) {
                            m_width += maxWidth;
                            maxWidth = 0;
                        }
                    }
                }
            }
            m_width += maxWidth;
            m_legend->d_ptr->items()->setPos(rect.topLeft());

            m_minOffsetX = qMin(rect.topLeft().x(), rect.topLeft().x() - m_width + rect.width());
            m_minOffsetY = 0;
            m_maxOffsetX = 0;
            m_maxOffsetY = m_height - rect.height();
        }
        break;
        default:
        break;
    }

}

QSizeF LegendLayout::sizeHint ( Qt::SizeHint which, const QSizeF & constraint) const
{
    QSizeF size(0, 0);
    qreal left, top, right, bottom;
    getContentsMargins(&left, &top, &right, &bottom);

    if(which!=Qt::PreferredSize) return QSizeF(-1,-1);

    if(constraint.isValid()) {
        foreach(LegendMarker* marker, m_legend->d_ptr->markers()) {
            size = size.expandedTo(marker->effectiveSizeHint(which));
        }
        size = size.boundedTo(constraint);
    }
    else if (constraint.width() >= 0) {
        qreal width = 0;
        qreal height = 0;
        foreach(LegendMarker* marker, m_legend->d_ptr->markers()) {
            width+=marker->effectiveSizeHint(which).width();
            height=qMax(height,marker->effectiveSizeHint(which).height());
        }

        size = QSizeF(qMin(constraint.width(),width), height);
    }
    else if (constraint.height() >= 0) {
        qreal width = 0;
        qreal height = 0;
        foreach(LegendMarker* marker, m_legend->d_ptr->markers()) {
            width=qMax(width,marker->effectiveSizeHint(which).width());
            height+=height,marker->effectiveSizeHint(which).height();
        }
        size = QSizeF(width,qMin(constraint.height(),height));
    }
    else {
        foreach(LegendMarker* marker, m_legend->d_ptr->markers()) {
            size = size.expandedTo(marker->effectiveSizeHint(which));
        }
    }
    size += QSize(left + right, top + bottom);

    return size;


}

QTCOMMERCIALCHART_END_NAMESPACE