/**
  * @RDE_HEADER@
  * Helper Classes to manage requirements for end-users to ui elements
  * $Id$
  * $HeadURL$
  * $Author$
  *
  * Created by Mike Wille, SLSE, 2016-08-19
  */

#pragma once

#include "lts_widgets_export.h"

#include <QWidget>
#include <QVector>
#include <functional>


class QLabel;


namespace LtsWidgets
{
/**
 * @brief The UiRequirement class describes a single UiRequirement. An UiRequirement is used to check that (valid) data is entered
 * by a user into an editable Widget. After an UiRequirement is created, it automatically changes the description Label of the
 * editable Widget by adding "[*]" to visualize that this Widget must be filled. If an UiRequirement is not met after executing the
 * checkRequirement-Method, the Label is colored red to visualize an error to the user.
 *
 */
class LTSWIDGETS_EXPORT UiRequirement // TODO: optional requirements => simply non-marked labels with advanced requirement checks (MessageDialog with message that e.g. "val of [widget-description] is too small")
{
public:
  explicit UiRequirement() = default;

  /**
   * @brief UiRequirement
   * @param descriptionLabel the Label, usually left of the editable Widget in a Form Layout, which describes the editable Widget to be checked
   * @param requirementCheck the routine (c++11) to check if requirements are met for the editable Widget to be checked - return values: true when requirement(s) are met, false when not
   */
  UiRequirement(QLabel *descriptionLabel, const std::function<bool()> &requirementCheck, const QString &userWarningMessage = QString());

  void reset();

  /**
   * @brief checkRequirement executes the requirementCheck function. If the description Label of the editable Widget is not visible,
   * the requirement check is ignored (as, logically, the Widget is then optional). If the requirement is not met, the
   * description Label of the editable Widget is colored red.
   * @return true if requirement is met (or description Label of Widget is hidden (optional)), false if not met
   */
  bool checkRequirement();

  bool isValid() const { return m_descriptionLabel != nullptr; }

  void retranslate();

private:
  void setTexts();

  QLabel *m_descriptionLabel;
  std::function<bool()> m_requirementCheck;
  QString m_originalText;
  QString m_originalTooltip;
  bool m_lastResult;
  QString m_userWarningMessage;
};


/**
 * @brief The UiRequirementList class provides a list which contains UiRequirements, that can all be checked by one method call.
 */
class LTSWIDGETS_EXPORT UiRequirementList
{
public:
  UiRequirementList() = default;

  /**
   * @brief checkRequirements checks every requirement in this list. If one or more requirements are not met, this method returns false.
   * @param messageOnThisParent set this pointer to a QWidget to let the UiRequirementList generate a LtsMessageDialog which states that there are non-met requirements for the user, set to nullptr to not show a message
   * @return true if all requirements are met, false if one or more requirements have NOT met
   */
  bool checkRequirements(QWidget *messageOnThisParent = nullptr);

  /**
   * @brief addRequirement adds an UiRequirement to this list.
   * @param uiRequirement the UiRequirement to be copied & added.
   */
  void addRequirement(const UiRequirement &uiRequirement);

  void clear();

  void retranslate(); // TODO: remove after every UiReq is inside retranslate()-method

private:
  QVector<UiRequirement> m_requirementList; // TODo: to ptr as QVector does a graceful copy of the UiReq class, causing the original class to be destroyed
};
} // namespace LtsWidgets