/*=========================================================================
 *
 *  Copyright NumFOCUS
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *         https://www.apache.org/licenses/LICENSE-2.0.txt
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 *=========================================================================*/
/*=========================================================================
 *
 *  Portions of this file are subject to the VTK Toolkit Version 3 copyright.
 *
 *  Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
 *
 *  For complete copyright, license and disclaimer of warranty information
 *  please refer to the NOTICE file at the top of the ITK source tree.
 *
 *=========================================================================*/
#ifndef itkOutputWindow_h
#define itkOutputWindow_h

#include <atomic>
#include <mutex>
#include "itkObject.h"

namespace itk
{


struct OutputWindowGlobals;

/** \class OutputWindow
 * \brief Messages sent from the system are collected by this object.
 *
 * Text messages that the system should display to the user are sent to
 * this object (or subclasses of this object).
 *
 * \ingroup OSSystemObjects
 * \ingroup ITKCommon
 */
class ITKCommon_EXPORT OutputWindow : public Object
{
public:
  ITK_DISALLOW_COPY_AND_MOVE(OutputWindow);

  /** Standard class type aliases. */
  using Self = OutputWindow;
  using Superclass = Object;
  using Pointer = SmartPointer<Self>;
  using ConstPointer = SmartPointer<const Self>;

  /** \see LightObject::GetNameOfClass() */
  itkOverrideGetNameOfClassMacro(OutputWindow);

  /** This is a singleton pattern New.  There will only be ONE
   * reference to a OutputWindow object per process.  Clients that
   * call this must call Delete on the object so that the reference
   * counting will work.   The single instance will be unreferenced when
   * the program exits. */
  static Pointer
  New();

  /** Return the singleton instance with no reference counting. */
  static Pointer
  GetInstance();

  /** Supply a user defined output window. Call ->Delete() on the supplied
   * instance after setting it. */
  static void
  SetInstance(OutputWindow * instance);

  /** Send a string to display. */
  virtual void
  DisplayText(const char *);

  /** Send a string as an error message to display.
   * The default implementation calls DisplayText() but subclasses
   * could present this message differently. */
  virtual void
  DisplayErrorText(const char * t)
  {
    this->DisplayText(t);
  }

  /** Send a string as a warningmessage to display.
   * The default implementation calls DisplayText() but subclasses
   * could present this message differently. */
  virtual void
  DisplayWarningText(const char * t)
  {
    this->DisplayText(t);
  }

  /** Send a string as a message to display.
   * The default implementation calls DisplayText() but subclasses
   * could present this message differently. */
  virtual void
  DisplayGenericOutputText(const char * t)
  {
    this->DisplayText(t);
  }

  /** Send a string as a debug message to display.
   * The default implementation calls DisplayText() but subclasses
   * could present this message differently. */
  virtual void
  DisplayDebugText(const char * t)
  {
    this->DisplayText(t);
  }

  /** If PromptUser is set to true then each time a line of text
   * is displayed, the user is asked if they want to keep getting
   * messages. */
  itkSetMacro(PromptUser, bool);
  itkGetConstMacro(PromptUser, bool);
  itkBooleanMacro(PromptUser);

protected:
  OutputWindow();
  ~OutputWindow() override;
  void
  PrintSelf(std::ostream & os, Indent indent) const override;

private:
  itkGetGlobalDeclarationMacro(OutputWindowGlobals, PimplGlobals);

  std::atomic<bool>            m_PromptUser{};
  std::mutex                   m_cerrMutex{};
  static OutputWindowGlobals * m_PimplGlobals;
};
} // end namespace itk

#endif