/*
 *  Copyright (C) 2003 by Unai Garro <ugarro@users.sourceforge.net>
 *  Copyright (C) 2004 by Enrico Ros <rosenric@dei.unipd.it>
 *  Copyright (C) 2004 by Stephan Kulow <coolo@kde.org>
 *  Copyright (C) 2004 by Oswald Buddenhagen <ossi@kde.org>
 *
 *  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.
 *
 *  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, write to the Free Software
 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

#include "kdmlayout.h"
#include "kdmitem.h"

KdmLayoutFixed::KdmLayoutFixed(const QDomNode &/*node*/)
{
    //Parsing FIXED parameters on 'node' [NONE!]
}

void
KdmLayoutFixed::update(QStack<QSize> &parentSizes, const QRect &parentGeometry, bool force)
{
    enter("Fixed::update") << parentGeometry << "depth" << parentSizes.size();

    // I can't layout children if the parent rectangle is not valid
    if (parentGeometry.width() < 0 || parentGeometry.height() < 0) {
        leave() << "invalid geometry";
        return;
    }
    // For each child in list I ask their hinted size and set it!
    parentSizes.push(parentGeometry.size());
    forEachChild (itm)
        itm->setGeometry(parentSizes, itm->placementHint(parentSizes, parentGeometry.topLeft()), force);
    parentSizes.pop();
    leave() << "done";
}

KdmLayoutBox::KdmLayoutBox(const QDomNode &node)
{
    //Parsing BOX parameters
    QDomNode n = node;
    QDomElement el = n.toElement();
    box.isVertical = el.attribute("orientation", "vertical") != "horizontal";
    box.xpadding = el.attribute("xpadding", "0").toInt();
    box.ypadding = el.attribute("ypadding", "0").toInt();
    box.spacing = el.attribute("spacing", "0").toInt();
    box.minwidth = el.attribute("min-width", "0").toInt();
    box.minheight = el.attribute("min-height", "0").toInt();
    box.homogeneous = el.attribute("homogeneous", "false") == "true";
}

struct LayoutHint {
    int min, opt, max, set;
    bool done;

    LayoutHint() : done(false)
    {
    }
};

void
KdmLayoutBox::update(QStack<QSize> &parentSizes, const QRect &parentGeometry, bool force)
{
    enter("Box::update") << parentGeometry << "depth" << parentSizes.size();

    // I can't layout children if the parent rectangle is not valid
    if (!parentGeometry.isValid() || parentGeometry.isEmpty()) {
        leave() << "invalid geometry";
        return;
    }

    QRect childrenRect = parentGeometry;
    // Begin cutting the parent rectangle to attach children on the right place
    childrenRect.adjust(box.xpadding, box.ypadding, -box.xpadding, -box.ypadding);

    debug() << "childrenRect" << childrenRect;

    // For each child in list ...
    if (box.homogeneous) {
        int ccnt = 0;
        forEachVisibleChild (itm)
            ccnt++;
        forEachVisibleChild (itm) {
            QRect temp = childrenRect;
            if (box.isVertical) {
                int height = (temp.height() - (ccnt - 1) * box.spacing) / ccnt;
                temp.setHeight(height);
                childrenRect.setTop(childrenRect.top() + height + box.spacing);
            } else {
                int width = (temp.width() - (ccnt - 1) * box.spacing) / ccnt;
                temp.setWidth(width);
                childrenRect.setLeft(childrenRect.left() + width + box.spacing);
            }
            parentSizes.push(temp.size());
            QRect itemRect = itm->placementHint(parentSizes, temp.topLeft());
            parentSizes.pop();
            parentSizes.push(parentGeometry.size());
            itm->setGeometry(parentSizes, itemRect, force);
            parentSizes.pop();
            ccnt--;
        }
    } else {
        QVector<LayoutHint> lhs;
        int ccnt = 0, mintot = 0, opttot = 0, esum = 0;
        parentSizes.push(QSize(0, 0));
        forEachVisibleChild (itm) {
            SizeHint sh;
            itm->sizingHint(parentSizes, sh);
            lhs.resize(ccnt + 1);
            if (box.isVertical) {
                lhs[ccnt].min = sh.min.height();
                lhs[ccnt].opt = sh.opt.height();
                lhs[ccnt].max = sh.max.height();
            } else {
                lhs[ccnt].min = sh.min.width();
                lhs[ccnt].opt = sh.opt.width();
                lhs[ccnt].max = sh.max.width();
            }
            mintot += lhs[ccnt].min;
            opttot += lhs[ccnt].opt;
            if (itm->geom.expand) {
                esum += itm->geom.expand;
            } else {
                lhs[ccnt].done = true;
                lhs[ccnt].set = lhs[ccnt].opt;
            }
            ccnt++;
        }
        parentSizes.pop();
        int havetot = box.isVertical ? childrenRect.size().height() : childrenRect.size().width();
        int spacing;
        if (havetot < opttot) {
            // fix your theme, dude
            if (havetot < mintot) {
                for (int i = 0; i < ccnt; i++) {
                    lhs[i].set = lhs[i].min * havetot / mintot;
                    havetot -= lhs[i].set;
                    mintot -= lhs[i].min;
                }
            } else {
                for (int i = 0; i < ccnt; i++) {
                    lhs[i].set = lhs[i].opt * havetot / opttot;
                    havetot -= lhs[i].set;
                    opttot -= lhs[i].opt;
                }
            }
            spacing = 0;
        } else {
            spacing = box.spacing;
            if (havetot < opttot + (ccnt - 1) * spacing)
                spacing = (havetot - opttot) / (ccnt - 1);
            int extra = havetot - opttot - (ccnt - 1) * spacing;
            int tesum, wesum, textra, wextra;
            do {
                tesum = wesum = esum;
                textra = wextra = extra;
                int idx = 0;
                forEachVisibleChild (itm) {
                    if (!lhs[idx].done) {
                        int mex = itm->geom.expand * wextra / wesum;
                        wextra -= mex;
                        wesum -= itm->geom.expand;
                        if (lhs[idx].opt + mex > lhs[idx].max) {
                            lhs[idx].set = lhs[idx].max;
                            lhs[idx].done = true;
                            esum -= itm->geom.expand;
                            extra -= lhs[idx].opt;
                        } else {
                            lhs[idx].set = lhs[idx].opt + mex;
                        }
                    }
                    idx++;
                }
            } while (tesum != esum);
        }
        int idx = 0;
        forEachVisibleChild (itm) {
            QRect temp = childrenRect;
            if (box.isVertical) {
                temp.setHeight(lhs[idx].set);
                childrenRect.setTop(childrenRect.top() + lhs[idx].set + spacing);
            } else {
                temp.setWidth(lhs[idx].set);
                childrenRect.setLeft(childrenRect.left() + lhs[idx].set + spacing);
            }
            parentSizes.push(temp.size());
            QRect itemRect = itm->placementHint(parentSizes, temp.topLeft());
            parentSizes.pop();
            debug() << "placementHint for" << itm << "temp" << temp << "final"
                << itemRect << "childrenRect now" << childrenRect;
            parentSizes.push(parentGeometry.size());
            itm->setGeometry(parentSizes, itemRect, force);
            parentSizes.pop();
            idx++;
        }
    }
    leave() << "done";
}

QSize
KdmLayoutBox::sizeHint(QStack<QSize> &parentSizes)
{
    enter("Box::sizeHint") << NoSpace << "parentSize #" << parentSizes.size()
        << Space << parentSizes.top();

    int ccnt = 0;
    QSize bounds(0, 0), sum(0, 0);

    // Sum up area taken by children
    parentSizes.push(QSize(0, 0));
    forEachVisibleChild (itm) {
        SizeHint sh;
        itm->sizingHint(parentSizes, sh);
        bounds = bounds.expandedTo(sh.opt);
        sum += sh.opt;
        ccnt++;
    }
    parentSizes.pop();

    if (box.homogeneous) {
        if (box.isVertical)
            bounds.rheight() *= ccnt;
        else
            bounds.rwidth() *= ccnt;
    } else {
        if (box.isVertical)
            bounds.rheight() = sum.height();
        else
            bounds.rwidth() = sum.width();
    }

    // Add padding and items spacing
    int totspc = box.spacing * (ccnt - 1);
    if (box.isVertical)
        bounds.rheight() += totspc;
    else
        bounds.rwidth() += totspc;
    bounds += QSize(2 * box.xpadding, 2 * box.ypadding);

    leave() << "bounds" << bounds;

    // Make hint at least equal to minimum size (if set)
    return bounds.expandedTo(QSize(box.minwidth, box.minheight));
}