#include <QLayout>
#include <QLabel>
#include "breadcrumb.h"

using namespace craftlab::ui;

Breadcrumb::Breadcrumb(QWidget* parent): QWidget(parent), inner(std::make_unique<QListWidget>(this))
{
	new QVBoxLayout(this);
	layout()->setContentsMargins(0, 0, 0, 0);
	layout()->addWidget(inner.get());
	inner->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
	inner->setEditTriggers(QAbstractItemView::NoEditTriggers);
	inner->setSelectionMode(QAbstractItemView::SingleSelection);
	inner->setFlow(QListView::Flow::LeftToRight);
	inner->setSizePolicy(QSizePolicy(QSizePolicy::Policy::Expanding, QSizePolicy::Policy::Fixed));
	inner->setSizeAdjustPolicy(QAbstractScrollArea::SizeAdjustPolicy::AdjustToContentsOnFirstShow);
	inner->setUniformItemSizes(false);
	connect(inner.get(), &QListWidget::itemSelectionChanged, this, [this]()
	{
		QList<QListWidgetItem*> selection = inner->selectedItems();
		if (!selection.isEmpty())
		{
			QModelIndex index = inner->indexFromItem(selection.first());
			if (index.isValid())
				emit SelectionChanged(index.row());
		}
	});
}

void Breadcrumb::addItem(const QString& label)
{
	addItem(new QListWidgetItem(label, inner.get()));
}

void Breadcrumb::addItem(const QIcon& icon, const QString& label)
{
	addItem(new QListWidgetItem(icon, label, inner.get()));
}

QWidget* Breadcrumb::BuildItemWidget(const QListWidgetItem& item)
{
	QSizePolicy sizePolicy(QSizePolicy::Policy::Ignored, QSizePolicy::Policy::Minimum);
	QWidget* result = new QWidget(this);
	result->setSizePolicy(QSizePolicy(QSizePolicy::Policy::Ignored, QSizePolicy::Policy::Minimum));
	new QHBoxLayout(result);

	QLabel* label = new QLabel(this);
	label->setText(item.text());
	label->setSizePolicy(QSizePolicy(QSizePolicy::Policy::MinimumExpanding, QSizePolicy::Policy::Minimum));
	result->layout()->addWidget(label);

	label = new QLabel(this);
	label->setText("\uE017");
	label->setSizePolicy(QSizePolicy(QSizePolicy::Policy::Minimum, QSizePolicy::Policy::Minimum));
	result->layout()->addWidget(label);

	return result;
}

void Breadcrumb::addItem(QListWidgetItem* item)
{
	QWidget* child = BuildItemWidget(*item);
	QSize childSize = child->layout()->totalMinimumSize();
	if (!item->data(Qt::DecorationRole).isNull())
	{
		QStyleOption opt;
		opt.initFrom(this);
		childSize.setWidth(childSize.width() + style()->pixelMetric(QStyle::PM_LineEditIconSize, &opt) + 2*(style()->pixelMetric(QStyle::PM_LineEditIconMargin)));
	}
	item->setSizeHint(childSize);
	inner->addItem(item);
	inner->setItemWidget(item, child);
}

void Breadcrumb::clear()
{
	inner->clear();
}