#include "timeline_header_view_mouse_handler.h"
#include "timeline_header_view.h"
#include "timeline_view.h"

#include <QApplication>
#include <QMouseEvent>
#include <QWheelEvent>
#include <QDebug>


namespace LtsTimeline
{

TimelineHeaderViewMouseHandler::TimelineHeaderViewMouseHandler(TimelineHeaderView *header)
  : m_header(header)
{}





void TimelineHeaderViewMouseHandler::mouseMoveEvent(QMouseEvent *e)
{
  if (m_isLeftButtonPressed)
    m_hasMouseMovedLeft = true;
  if (m_isRightButtonPressed)
    m_hasMouseMovedRight = true;

  if (!m_isResizingSection)
  {
    if (m_header->sectionPosition(Section::eItems) - 10 < e->pos().x() && e->pos().x() < m_header->sectionPosition(Section::eItems))
      m_header->m_timelineView->setCursor(QCursor(Qt::SizeHorCursor));
    else if (e->pos().y() <= m_header->geometry().bottom()) 
      m_header->m_timelineView->setCursor(QCursor(Qt::ArrowCursor));
  }
  else
    m_header->resizeSection(Section::eActuator, std::min(e->pos().x(), m_header->geometry().width() / 2));

  const bool isWithinRangeX = isMouseWithinRangeX(e->pos().x());
  if (!isWithinRangeX && !m_isLeftButtonPressed)
  {
    m_header->setHoverPosition(-1);
    return;
  }

  if (isWithinRangeX)
    m_header->setHoverPosition(e->pos().x());
  if (m_isLeftButtonPressed)
  {
    if (m_isIndicatorSelected && !m_header->m_isIndicatorLocked)
    {
      m_header->m_timelineView->setCursor(QCursor(Qt::ClosedHandCursor));
      if (isWithinRangeX)
        m_header->setIndicatorPosition(e->pos().x());
    }
  }
  else
  {
    if (isMouseOverIndicator(e->pos()) && m_header->m_isIndicatorVisible && !m_header->m_isIndicatorLocked)
      m_header->m_timelineView->setCursor(QCursor(Qt::OpenHandCursor));
    else if (e->pos().y() <= m_header->geometry().bottom()) 
      m_header->m_timelineView->setCursor(QCursor(Qt::ArrowCursor));
  }
}

void TimelineHeaderViewMouseHandler::mousePressEvent(QMouseEvent *e)
{
  if (e->button() == Qt::LeftButton)
  {
    m_lastPos = e->pos();
    m_isLeftButtonPressed = true;
    if (isMouseOverIndicator(e->pos()) && m_header->m_isIndicatorVisible && !m_header->m_isIndicatorLocked)
    {
      m_header->m_timelineView->setCursor(QCursor(Qt::ClosedHandCursor));
      m_isIndicatorSelected = true;
    }
    else if (m_header->m_timelineView->cursor().shape() == Qt::SizeHorCursor)
    {
      m_isResizingSection = true;
    }
  }
  if (e->button() == Qt::RightButton)
    m_isRightButtonPressed = true;
}

void TimelineHeaderViewMouseHandler::mouseReleaseEvent(QMouseEvent *e)
{
  if (e->button() == Qt::LeftButton)
  {
    if (!m_hasMouseMovedLeft && isMouseWithinRangeX(e->pos().x()) && !m_header->m_isIndicatorLocked)
      m_header->setIndicatorPosition(e->pos().x());
    if (isMouseOverIndicator(e->pos()))
      m_header->m_timelineView->setCursor(QCursor(Qt::OpenHandCursor));
    else
      m_header->m_timelineView->setCursor(QCursor(Qt::ArrowCursor));
    m_lastPos = {};
    m_isIndicatorSelected = false;
    m_isResizingSection = false;
    m_isLeftButtonPressed = false;
    m_hasMouseMovedLeft = false;
  }
  if (e->button() == Qt::RightButton)
  {
    m_header->setDateTimeFormat(static_cast<DateTimeFormat>((m_header->dateTimeFormat() + 1) % DateTime::numberOfDateTimeFormats())); 
    m_isRightButtonPressed = false;
    m_hasMouseMovedRight = false;
  }
}

void TimelineHeaderViewMouseHandler::wheelEvent(QWheelEvent *e)
{
  if (!m_header->m_timelineView)
    return;

  if (QGuiApplication::queryKeyboardModifiers() == Qt::ControlModifier)
  {
    if (e->angleDelta().y() < 0)
      m_header->m_timelineView->setZoomFactor(Zoom::increment(m_header->m_timelineView->zoomFactor()));
    else
      m_header->m_timelineView->setZoomFactor(Zoom::decrement(m_header->m_timelineView->zoomFactor()));
  }
  else
  {
    if (e->angleDelta().y() > 0)
      m_header->m_timelineView->setCurrentTime(
        m_header->m_timelineView->currentTime() - Zoom::majorInterval(m_header->m_timelineView->zoomFactor())
      );
    else
      m_header->m_timelineView->setCurrentTime(
        m_header->m_timelineView->currentTime() + Zoom::majorInterval(m_header->m_timelineView->zoomFactor())
      );
  }
}









bool TimelineHeaderViewMouseHandler::isMouseWithinRangeX(int x) const
{
  return m_header->sectionPosition(Section::eItems) < x && x < m_header->geometry().right();
}

bool TimelineHeaderViewMouseHandler::isMouseWithinRangeY(int y) const
{
  return m_header->geometry().top() < y && y < m_header->geometry().bottom();
}

bool TimelineHeaderViewMouseHandler::isMouseOverIndicator(const QPoint &pos) const
{
  const int height = m_header->height();
  return m_header->indicatorPosition() - height / 4 <= pos.x() && pos.x() <= m_header->indicatorPosition() + height / 4 &&
         m_header->geometry().center().y() <= pos.y() && pos.y() < m_header->geometry().bottom();
}

}