/*
 Copyright 2020-2021 Brad Parker

   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

       http://www.apache.org/licenses/LICENSE-2.0

   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.
*/

#include <QOpenGLContext>
#include <QOpenGLFramebufferObject>
#include <iostream>
#include "core.h"
#include "../common/video.h"

void Core::videoRefresh(const void *data, unsigned width, unsigned height, size_t pitch) {
  if(!data || m_isHWRender) {
    return;
  }

  if(width != m_width || height != m_height || pitch != m_pitch) {
    std::cout << "new video size: " << width << "x" << height << " (pitch " << pitch << ")" << std::endl;

    if(m_imgData) {
      delete []m_imgData;
    }

    m_width = width;
    m_height = height;
    m_pitch = pitch;

    m_imgData = new unsigned char[pitch * height];
  }

  memcpy(m_imgData, data, pitch * height);

  if(m_pixFmt == RETRO_PIXEL_FORMAT_0RGB1555) {
    m_img = QImage(m_imgData, width, height, pitch, QImage::Format_RGB555);
  }else if(m_pixFmt == RETRO_PIXEL_FORMAT_XRGB8888) {
    m_img = QImage(m_imgData, width, height, pitch, QImage::Format_RGB32);
  }else if(m_pixFmt == RETRO_PIXEL_FORMAT_RGB565) {
    m_img = QImage(m_imgData, width, height, pitch, QImage::Format_RGB16);
  }

  m_img = m_img.mirrored(true, false);
  m_img = m_img.mirrored(true, false);
}

float Core::getVideoRate() {
  return VideoState::instance()->avInfo()->timing.fps;
}

void Core::render() {
  if(m_timer.isActive())
    return;

  emit repaint();

  emit doneRendering();
}

void Core::onGotFrameSwap() {
  if(m_timer.isActive())
    return;

  if(m_doRender) {
    m_elapsedTimer.start();

    QOpenGLContext *ctx = VideoState::instance()->context();
    QOpenGLFramebufferObject *fbo = VideoState::instance()->fbo();

    if(ctx) {
      ctx->makeCurrent(ctx->surface());

      if(m_isHWRender && fbo) {
        fbo->bind();
      }

      m_retroRun();

      if(m_isHWRender && fbo) {
        fbo->release();
      }
    }

    m_timer.disconnect();

    connect(&m_timer, &QTimer::timeout, this, &Core::render);

    m_timer.start(0);
  }
}

uintptr_t Core::getCurrentFramebuffer() {
  QOpenGLContext *ctx = VideoState::instance()->context();

  if(ctx) {
    QOpenGLFramebufferObject *fbo = VideoState::instance()->fbo();

    if(fbo) {
      return fbo->handle();
    }
  }

  return 0;
}

void* Core::getProcAddress(const char *sym) {
  QOpenGLContext *ctx = VideoState::instance()->context();

  if(ctx)
    return reinterpret_cast<void*>(ctx->getProcAddress(sym));

  return nullptr;
}

bool Core::isHWRender() {
  return m_isHWRender;
}

void Core::blitFBO() {
  // hardware-accelerated cores draw into their own frame buffer object, we must push that to the screen now
  auto videoState = VideoState::instance();
  QOpenGLContext *ctx = videoState->context();
  QOpenGLFramebufferObject *fbo = videoState->fbo();
  struct retro_system_av_info *avInfo = videoState->avInfo();

  if(ctx && fbo && fbo->isValid() && fbo->hasOpenGLFramebufferBlit()) {
    fbo->bind();
    // Copy the rendered frame buffer data from the core directly onto the screen.
    QOpenGLFramebufferObject::blitFramebuffer(0, videoState->aspectCorrectedRect(), fbo, QRect(0, 0, avInfo->geometry.base_width, avInfo->geometry.base_height), GL_COLOR_BUFFER_BIT, GL_NEAREST);
    fbo->release();
  }
}

QImage* Core::getImage() {
  return &m_img;
}