/*##############################################################################
## Author: Shaun Reed                                                         ##
## Legal: All Content (c) 2021 Shaun Reed, all rights reserved                ##
## About: Texture class to help with texture and image initializations        ##
##                                                                            ##
## Contact: shaunrd0@gmail.com  | URL: www.shaunreed.com | GitHub: shaunrd0   ##
##############################################################################*/

#include <QDebug>
#include <QImageReader>

#include <texture.h>


QImage * Texture::initImage(const char * image, bool flipX, bool flipY)
{
  auto loadedImage = new QImage(QImage(image).mirrored(flipX, flipY));
  if (loadedImage->isNull()) {
    qDebug() << "Error loading image: " << image << "\n";
    qDebug() << QImageReader::supportedImageFormats();
    return Q_NULLPTR;
  }

  return loadedImage;
}

QOpenGLTexture * Texture::initTexture2D(const char * texture,
                                        bool flipX, bool flipY)
{
  QImage * image = initImage(texture, flipX, flipY);
  auto newTexture = new QOpenGLTexture(QOpenGLTexture::Target2D);
  newTexture->setData(*image);
  newTexture->setWrapMode(QOpenGLTexture::Repeat);
  newTexture->setMinMagFilters(QOpenGLTexture::LinearMipMapLinear,
                               QOpenGLTexture::Linear);
  delete image;
  return newTexture;
}

QOpenGLTexture * Texture::initCubeMap(const char * tile)
{
  return initCubeMap(QImage(tile), QImage(tile),
                     QImage(tile), QImage(tile),
                     QImage(tile), QImage(tile));
}

QOpenGLTexture * Texture::initCubeMap(
    const char * right, const char * top,
    const char * front, const char * left,
    const char * bottom, const char * back)
{
  return initCubeMap(QImage(right), QImage(top),
                     QImage(front), QImage(left),
                     QImage(bottom), QImage(back));
}

QOpenGLTexture * Texture::initCubeMap(
    QImage right, QImage top,
    QImage front, QImage left,
    QImage bottom, QImage back)
{
  auto texture = new QOpenGLTexture(QOpenGLTexture::TargetCubeMap);
  std::vector<QImage> faceTextures = {
      right, top, front,
      left, bottom, back
  };
  // Initialize skybox cubemap texture
  texture->create();
  texture->bind();
  // For each cube map face
  std::vector<QOpenGLTexture::CubeMapFace> faces = {
      QOpenGLTexture::CubeMapPositiveX, QOpenGLTexture::CubeMapPositiveY,
      QOpenGLTexture::CubeMapPositiveZ, QOpenGLTexture::CubeMapNegativeX,
      QOpenGLTexture::CubeMapNegativeY, QOpenGLTexture::CubeMapNegativeZ
  };
  int i = 0;
  for (const auto & face : faces) {
    QImage faceImage(faceTextures[i]);
    if (faceImage.isNull()) {
      qDebug() << "Error loading cube map image\n";
    }
    faceImage = faceImage.convertToFormat(QImage::Format_RGBA8888);

    // On the first iteration, set format and allocate texture storage
    if (face == QOpenGLTexture::CubeMapPositiveX) {
      // This also needs to happen on the first iteration, anyways
      texture->setSize(faceImage.width(), faceImage.height(), faceImage.depth());
      texture->setFormat(QOpenGLTexture::RGBA8_UNorm);
      texture->allocateStorage();
    }

    texture->setData(0, 0, face,
                     QOpenGLTexture::RGBA, QOpenGLTexture::UInt8,
                     faceImage.constBits());
    i++;
  }

  texture->setWrapMode(QOpenGLTexture::ClampToEdge);
  texture->generateMipMaps();
  texture->setMinificationFilter(QOpenGLTexture::LinearMipMapLinear);
  texture->setMagnificationFilter(QOpenGLTexture::Linear);
  texture->release();
  return texture;
}