#include "completionview.h"

#include <QHeaderView>

namespace {

constexpr int kMaxVisibleRows = 12;

} // namespace

CompletionView::CompletionView(QWidget *parent)
    : QTreeWidget(parent)
{
    setObjectName(QStringLiteral("completion"));
    setFocusPolicy(Qt::NoFocus);
    setColumnCount(2);
    setHeaderHidden(true);
    setRootIsDecorated(false);
    setUniformRowHeights(true);
    setFrameShape(QFrame::NoFrame);
    setSelectionMode(QAbstractItemView::SingleSelection);
    setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
    setTextElideMode(Qt::ElideRight);
    header()->setStretchLastSection(false);
    header()->setSectionResizeMode(QHeaderView::Stretch);
    hide();
}

void CompletionView::setEntries(const QList<History::Entry> &entries)
{
    clear();
    if (entries.isEmpty()) {
        hide();
        return;
    }

    QList<QTreeWidgetItem *> items;
    items.reserve(entries.size());
    for (const History::Entry &entry : entries) {
        auto *item = new QTreeWidgetItem({entry.url, entry.title});
        item->setToolTip(0, entry.url);
        items.append(item);
    }
    addTopLevelItems(items);

    const int rows = qMin(int(entries.size()), kMaxVisibleRows);
    setFixedHeight(rows * sizeHintForRow(0) + 2 * frameWidth());
    show();
}

QString CompletionView::cycle(int step)
{
    const int count = topLevelItemCount();
    if (count == 0)
        return {};

    QTreeWidgetItem *current = currentItem();
    int row = current && current->isSelected() ? indexOfTopLevelItem(current) + step
                                               : (step > 0 ? 0 : count - 1);
    row = ((row % count) + count) % count;

    QTreeWidgetItem *item = topLevelItem(row);
    setCurrentItem(item);
    scrollToItem(item);
    return item->text(0);
}