/******************************************************************************
 * The MIT License (MIT)
 *
 * Copyright (c) 2016-2018 Baldur Karlsson
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 ******************************************************************************/

#pragma once

#include <QWidget>

class RangeHistogram : public QWidget
{
  Q_OBJECT

public:
  explicit RangeHistogram(QWidget *parent = 0);
  ~RangeHistogram();

  void setHistogramRange(float min, float max);
  void setRange(float min, float max);

  void setHistogramData(const QVector<uint32_t> &histogram);

  float blackPoint() { return m_BlackPoint; }
  void setBlackPoint(float val);

  float whitePoint() { return m_WhitePoint; }
  void setWhitePoint(float val);

  float rangeMin() { return m_RangeMin; }
  float rangeMax() { return m_RangeMax; }
signals:
  void rangeUpdated();

protected:
  void mousePressEvent(QMouseEvent *e) override;
  void mouseReleaseEvent(QMouseEvent *e) override;
  void mouseMoveEvent(QMouseEvent *e) override;
  void paintEvent(QPaintEvent *e) override;

private:
  bool ValidRange() const;
  float delta(float val) const;

  static const int m_Margin = 4;
  static const int m_Border = 1;
  static const int m_MarkerSize = 6;

  int totalSpace() const { return m_Margin + m_Border; }
  int regionWidth() const { return rect().width() - totalSpace() * 2; }
  float blackDelta();
  void setBlackDelta(float value);
  float whiteDelta();
  void setWhiteDelta(float value);

  QPoint m_MousePrev = QPoint(-1, -1);

  enum class DraggingMode
  {
    None,
    White,
    Black,
  } m_DragMode = DraggingMode::None;

  QVector<uint32_t> m_HistogramData;
  float m_HistogramMin = 0.0f;
  float m_HistogramMax = 1.0f;

  float m_RangeMin = 0.0f;
  float m_RangeMax = 1.0f;

  float m_BlackPoint = 0.0f;
  float m_WhitePoint = 1.0f;

  float m_MinRangeSize = 1.0e-6f;
};
