// Copyright (c) 2018, ETH Zurich and UNC Chapel Hill.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
//     * Redistributions of source code must retain the above copyright
//       notice, this list of conditions and the following disclaimer.
//
//     * Redistributions in binary form must reproduce the above copyright
//       notice, this list of conditions and the following disclaimer in the
//       documentation and/or other materials provided with the distribution.
//
//     * Neither the name of ETH Zurich and UNC Chapel Hill nor the names of
//       its contributors may be used to endorse or promote products derived
//       from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
//
// Author: Johannes L. Schoenberger (jsch at inf.ethz.ch)

#include "util/opengl_utils.h"

#include <QApplication>

#include "util/logging.h"

namespace colmap {

OpenGLContextManager::OpenGLContextManager()
    : parent_thread_(QThread::currentThread()),
      current_thread_(nullptr),
      make_current_action_(new QAction(this)) {
  CHECK_NOTNULL(QCoreApplication::instance());
  CHECK_EQ(QCoreApplication::instance()->thread(), QThread::currentThread());

  QSurfaceFormat format;
  format.setDepthBufferSize(24);
  format.setMajorVersion(3);
  format.setMinorVersion(2);
  format.setSamples(4);
  format.setProfile(QSurfaceFormat::CompatibilityProfile);
  context_.setFormat(format);

  surface_.create();
  CHECK(context_.create());
  context_.makeCurrent(&surface_);
  CHECK(context_.isValid()) << "Could not create valid OpenGL context";

  connect(make_current_action_, &QAction::triggered, this,
          [this]() {
            CHECK_NOTNULL(current_thread_);
            context_.doneCurrent();
            context_.moveToThread(current_thread_);
          },
          Qt::BlockingQueuedConnection);
}

void OpenGLContextManager::MakeCurrent() {
  current_thread_ = QThread::currentThread();
  make_current_action_->trigger();
  context_.makeCurrent(&surface_);
  CHECK(context_.isValid()) << "Could not make current valid OpenGL context";
}

bool OpenGLContextManager::HasOpenGL() {
#ifdef OPENGL_ENABLED
  QOffscreenSurface surface;
  QOpenGLContext context;
  surface.create();
  context.create();
  return surface.isValid() && context.isValid();
#else   // OPENGL_ENABLED
  return false;
#endif  // OPENGL_ENABLED
}

void RunThreadWithOpenGLContext(Thread* thread) {
  std::thread opengl_thread([thread]() {
    thread->Start();
    thread->Wait();
    CHECK_NOTNULL(QCoreApplication::instance())->exit();
  });
  CHECK_NOTNULL(QCoreApplication::instance())->exec();
  opengl_thread.join();
  // Make sure that all triggered OpenGLContextManager events are processed in
  // case the application exits before the contexts were made current.
  QCoreApplication::processEvents();
}

void GLError(const char* file, const int line) {
  GLenum error_code(glGetError());
  while (error_code != GL_NO_ERROR) {
    std::string error_name;
    switch (error_code) {
      case GL_INVALID_OPERATION:
        error_name = "INVALID_OPERATION";
        break;
      case GL_INVALID_ENUM:
        error_name = "INVALID_ENUM";
        break;
      case GL_INVALID_VALUE:
        error_name = "INVALID_VALUE";
        break;
      case GL_OUT_OF_MEMORY:
        error_name = "OUT_OF_MEMORY";
        break;
      case GL_INVALID_FRAMEBUFFER_OPERATION:
        error_name = "INVALID_FRAMEBUFFER_OPERATION";
        break;
      default:
        error_name = "UNKNOWN_ERROR";
        break;
    }
    fprintf(stderr, "OpenGL error [%s, line %i]: GL_%s", file, line,
            error_name.c_str());
    error_code = glGetError();
  }
}

}  // namespace colmap
