/*
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * The Original Code is Copyright (C) 2013 Blender Foundation.
 * All rights reserved.
 */

/** \file
 * \ingroup GHOST
 */

#pragma once

#include "GHOST_Context.h"
#include "GHOST_System.h"

#include <GL/eglew.h>

#ifndef GHOST_OPENGL_EGL_CONTEXT_FLAGS
#  define GHOST_OPENGL_EGL_CONTEXT_FLAGS 0
#endif

#ifndef GHOST_OPENGL_EGL_RESET_NOTIFICATION_STRATEGY
#  define GHOST_OPENGL_EGL_RESET_NOTIFICATION_STRATEGY 0
#endif

class GHOST_ContextEGL : public GHOST_Context {
  /* XR code needs low level graphics data to send to OpenXR. */
  friend class GHOST_XrGraphicsBindingOpenGL;

 public:
  /**
   * Constructor.
   */
  GHOST_ContextEGL(const GHOST_System *const system,
                   bool stereoVisual,
                   EGLNativeWindowType nativeWindow,
                   EGLNativeDisplayType nativeDisplay,
                   EGLint contextProfileMask,
                   EGLint contextMajorVersion,
                   EGLint contextMinorVersion,
                   EGLint contextFlags,
                   EGLint contextResetNotificationStrategy,
                   EGLenum api);

  /**
   * Destructor.
   */
  ~GHOST_ContextEGL();

  /**
   * Swaps front and back buffers of a window.
   * \return A boolean success indicator.
   */
  GHOST_TSuccess swapBuffers();

  /**
   * Activates the drawing context of this window.
   * \return A boolean success indicator.
   */
  GHOST_TSuccess activateDrawingContext();

  /**
   * Release the drawing context of the calling thread.
   * \return A boolean success indicator.
   */
  GHOST_TSuccess releaseDrawingContext();

  /**
   * Call immediately after new to initialize.  If this fails then immediately delete the object.
   * \return Indication as to whether initialization has succeeded.
   */
  GHOST_TSuccess initializeDrawingContext();

  /**
   * Removes references to native handles from this context and then returns
   * \return GHOST_kSuccess if it is OK for the parent to release the handles and
   * GHOST_kFailure if releasing the handles will interfere with sharing
   */
  GHOST_TSuccess releaseNativeHandles();

  /**
   * Sets the swap interval for #swapBuffers.
   * \param interval: The swap interval to use.
   * \return A boolean success indicator.
   */
  GHOST_TSuccess setSwapInterval(int interval);

  /**
   * Gets the current swap interval for #swapBuffers.
   * \param intervalOut: Variable to store the swap interval if it can be read.
   * \return Whether the swap interval can be read.
   */
  GHOST_TSuccess getSwapInterval(int &intervalOut);

  EGLDisplay getDisplay() const;

  EGLConfig getConfig() const;

  EGLContext getContext() const;

 private:
  bool initContextEGLEW();

  const GHOST_System *const m_system;

  EGLNativeDisplayType m_nativeDisplay;
  EGLNativeWindowType m_nativeWindow;

  const EGLint m_contextProfileMask;
  const EGLint m_contextMajorVersion;
  const EGLint m_contextMinorVersion;
  const EGLint m_contextFlags;
  const EGLint m_contextResetNotificationStrategy;

  const EGLenum m_api;

  EGLContext m_context;
  EGLSurface m_surface;
  EGLDisplay m_display;
  EGLConfig m_config;

  EGLint m_swap_interval;

  EGLContext &m_sharedContext;
  EGLint &m_sharedCount;

  static EGLContext s_gl_sharedContext;
  static EGLint s_gl_sharedCount;

  static EGLContext s_gles_sharedContext;
  static EGLint s_gles_sharedCount;

  static EGLContext s_vg_sharedContext;
  static EGLint s_vg_sharedCount;

#ifdef WITH_GL_ANGLE
  static HMODULE s_d3dcompiler;
#endif
};