/*
 * SPDX-FileCopyrightText: 2001-2015 Klaralvdalens Datakonsult AB. All rights reserved.
 *
 * This file is part of the KD Chart library.
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 */

#include "KChartNormalLyingBarDiagram_p.h"

#include <QModelIndex>

#include "KChartAbstractCartesianDiagram.h"
#include "KChartAttributesModel.h"
#include "KChartBarDiagram.h"
#include "KChartTextAttributes.h"

using namespace KChart;
using namespace std;

NormalLyingBarDiagram::NormalLyingBarDiagram(BarDiagram *d)
    : BarDiagramType(d)
{
}

BarDiagram::BarType NormalLyingBarDiagram::type() const
{
    return BarDiagram::Normal;
}

// TODO there is a lot of duplication between this and the non-lying bar diagram, fix it someday...
const QPair<QPointF, QPointF> NormalLyingBarDiagram::calculateDataBoundaries() const
{
    const int rowCount = compressor().modelDataRows();
    const int colCount = compressor().modelDataColumns();

    const qreal xMin = 0.0;
    const qreal xMax = rowCount;
    qreal yMin = 0.0;
    qreal yMax = 0.0;

    bool isFirst = true;
    for (int column = 0; column < colCount; ++column) {
        for (int row = 0; row < rowCount; ++row) {
            const CartesianDiagramDataCompressor::CachePosition position(row, column);
            const CartesianDiagramDataCompressor::DataPoint point = compressor().data(position);
            const qreal value = ISNAN(point.value) ? 0.0 : point.value;
            // this is always true yMin can be 0 in case all values
            // are the same
            // same for yMax it can be zero if all values are negative
            if (isFirst) {
                yMin = value;
                yMax = value;
                isFirst = false;
            } else {
                yMin = qMin(yMin, value);
                yMax = qMax(yMax, value);
            }
        }
    }

    // special cases
    if (yMax == yMin) {
        if (yMin == 0.0) {
            yMax = 0.1; // we need at least a range
        } else if (yMax < 0.0) {
            yMax = 0.0; // they are the same and negative
        } else if (yMin > 0.0) {
            yMin = 0.0; // they are the same but positive
        }
    }
    const QPointF bottomLeft(QPointF(yMin, xMin));
    const QPointF topRight(QPointF(yMax, xMax));

    return QPair<QPointF, QPointF>(bottomLeft, topRight);
}

void NormalLyingBarDiagram::paint(PaintContext *ctx)
{
    // FIXME: in all LyingBarDiagram types, the datasets are rendered top to bottom, but the abscissa
    // (in that case Y axis) ticks are still bottom to top. So tick labels are in reverse order.
    reverseMapper().clear();

    const QPair<QPointF, QPointF> boundaries = diagram()->dataBoundaries(); // cached

    const QPointF boundLeft = ctx->coordinatePlane()->translate(boundaries.first);
    const QPointF boundRight = ctx->coordinatePlane()->translate(boundaries.second);

    const int rowCount = attributesModel()->rowCount(attributesModelRootIndex());
    const int colCount = attributesModel()->columnCount(attributesModelRootIndex());

    BarAttributes ba = diagram()->barAttributes();
    qreal barWidth = 0;
    qreal maxDepth = 0;
    qreal width = boundLeft.y() - boundRight.y();
    qreal groupWidth = width / rowCount;
    qreal spaceBetweenBars = 0;
    qreal spaceBetweenGroups = 0;

    if (ba.useFixedBarWidth()) {
        barWidth = ba.fixedBarWidth();
        groupWidth += barWidth;

        // Pending Michel set a min and max value for the groupWidth
        // related to the area.width
        if (groupWidth < 0)
            groupWidth = 0;

        if (groupWidth * rowCount > width)
            groupWidth = width / rowCount;
    }

    // maxLimit: allow the space between bars to be larger until area.width()
    // is covered by the groups.
    qreal maxLimit = rowCount * (groupWidth + (colCount - 1) * ba.fixedDataValueGap());

    // Pending Michel: FixMe
    if (ba.useFixedDataValueGap()) {
        if (width > maxLimit)
            spaceBetweenBars += ba.fixedDataValueGap();
        else
            spaceBetweenBars = (width / rowCount - groupWidth) / (colCount - 1);
    }

    if (ba.useFixedValueBlockGap()) {
        spaceBetweenGroups += ba.fixedValueBlockGap();
    }

    calculateValueAndGapWidths(rowCount, colCount, groupWidth, barWidth, spaceBetweenBars, spaceBetweenGroups);

    LabelPaintCache lpc;

    for (int row = 0; row < rowCount; row++) {
        qreal offset = -groupWidth / 2 + spaceBetweenGroups / 2;

        if (ba.useFixedDataValueGap()) {
            if (spaceBetweenBars > 0) {
                if (width > maxLimit) {
                    offset -= ba.fixedDataValueGap();
                } else {
                    offset -= (width / rowCount - groupWidth) / (colCount - 1);
                }
            } else {
                offset += barWidth / 2;
            }
        }

        for (int column = colCount - 1; column >= 0; --column) {
            // paint one group
            const CartesianDiagramDataCompressor::CachePosition position(row, column);
            const CartesianDiagramDataCompressor::DataPoint point = compressor().data(position);
            const QModelIndex sourceIndex = attributesModel()->mapToSource(point.index);

            QPointF dataPoint(0, (point.key + 0.5));
            const QPointF topLeft = ctx->coordinatePlane()->translate(dataPoint);
            dataPoint.rx() += point.value;
            const QPointF bottomRight = ctx->coordinatePlane()->translate(dataPoint) + QPointF(0, barWidth);

            const QRectF rect = QRectF(topLeft, bottomRight).translated(1.0, offset);
            m_private->addLabel(&lpc, sourceIndex, nullptr, PositionPoints(rect), Position::North, Position::South, point.value);

            paintBars(ctx, sourceIndex, rect, maxDepth);

            offset += barWidth + spaceBetweenBars;
        }
    }
    m_private->paintDataValueTextsAndMarkers(ctx, lpc, false);
}
