#include "lts_grid_layout.h"
#include <QResizeEvent>

namespace LtsWidgets
{

LtsGridLayout::LtsGridLayout(LtsWidgets::ButtonSize buttonSize, QWidget *parent, int maxColumn)
  : QGridLayout(parent)
  , m_buttonSize(buttonSize)
  , m_defaultMaxColumn(maxColumn)
  , m_maxColumn(maxColumn)
  , m_colSize(0)
  , m_autoSize(maxColumn < 0)
{
  setSizeConstraint(SizeConstraint::SetNoConstraint);
  
  setVerticalSpacing(1);
  setMargin(0);
}

void LtsGridLayout::add_widget(QWidget *widget)
{
  for (auto it = m_widgetList.cbegin(); it != m_widgetList.cend(); ++it)
  {
    if (*it == widget)
      return;
  }
  connect(widget, &QWidget::destroyed, this, &LtsGridLayout::onWidgetDestroyed);
  addWidgetInternal(widget);
  m_widgetList.push_back(widget);
}

void LtsGridLayout::setAutoSize(bool enable)
{
  m_autoSize = enable;
  if (m_autoSize == false)
    setMaxColumn(1);
  else
  {
    m_maxColumn = -1;
    m_oldSize = QSize();
    m_oldGeo = QRect();
    QResizeEvent e(sizeHint(), sizeHint());
    onParentResize(&e);
    setGeometry(QRect(0, 0, sizeHint().width(), sizeHint().height()));
  }
}

void LtsGridLayout::setMaxColumn(int max)
{
  m_maxColumn = max;
  m_defaultMaxColumn = max;

  
  m_colSize = 0;

  for (QWidget *wid : qAsConst(m_widgetList))
    removeWidget(wid);

  for (QWidget *wid : qAsConst(m_widgetList))
    addWidgetInternal(wid);

}

void LtsGridLayout::addWidgetInternal(QWidget *widget)
{
  int current_row = 0;
  int current_column = 0;

  while (QLayoutItem *item = itemAtPosition(current_row, current_column))
  {
    if (!item->widget())
    {
      removeItem(item);
      continue;
    }

    if (current_column == (m_maxColumn - 1))
    {
      current_column = 0;
      ++current_row;
    }
    else
      ++current_column;
  }

  if (current_row == 0)
    m_colSize += 1;

  QGridLayout::addWidget(widget, current_row, current_column);
}


void LtsGridLayout::onParentResize(QResizeEvent *e)
{
  if (m_autoSize && m_oldSize != e->size())
  {
    bool bigger = (e->size().width() > m_oldSize.width());
    m_oldSize = e->size();
    int newWidth = m_oldSize.width();
    int maxIconsInRow = newWidth / (static_cast<int>(m_buttonSize) + 4);

    if (!bigger && newWidth <= (static_cast<int>(m_buttonSize)*m_colSize - static_cast<int>(m_buttonSize) / 2))
      maxIconsInRow--;
    if (m_maxColumn != maxIconsInRow)
      setMaxColumn(maxIconsInRow);
  }
}

void LtsGridLayout::onWidgetDestroyed()
{
  QWidget *s = qobject_cast<QWidget*>(sender());
  for (auto it = m_widgetList.begin(); it != m_widgetList.end(); ++it)
  {
    if (*it == s)
    {
      QGridLayout::removeWidget(s);
      m_widgetList.erase(it);
      setMaxColumn(m_maxColumn);  
      break;
    }
  }
}

}