#include <scwx/qt/gl/draw/rectangle.hpp>
#include <scwx/util/logger.hpp>

#include <optional>

namespace scwx
{
namespace qt
{
namespace gl
{
namespace draw
{

static const std::string logPrefix_ = "scwx::qt::gl::draw::rectangle";
static const auto        logger_    = scwx::util::Logger::Create(logPrefix_);

static constexpr size_t NUM_RECTANGLES         = 5;
static constexpr size_t NUM_TRIANGLES          = NUM_RECTANGLES * 2;
static constexpr size_t VERTICES_PER_TRIANGLE  = 3;
static constexpr size_t VERTICES_PER_RECTANGLE = VERTICES_PER_TRIANGLE * 2;
static constexpr size_t POINTS_PER_VERTEX      = 7;
static constexpr size_t BUFFER_LENGTH =
   NUM_TRIANGLES * VERTICES_PER_TRIANGLE * POINTS_PER_VERTEX;

class Rectangle::Impl
{
public:
   explicit Impl(std::shared_ptr<GlContext> context) :
       context_ {context},
       dirty_ {false},
       visible_ {true},
       x_ {0.0f},
       y_ {0.0f},
       z_ {0.0f},
       width_ {0.0f},
       height_ {0.0f},
       borderColor_ {0, 0, 0, 0},
       borderWidth_ {0.0f},
       fillColor_ {std::nullopt},
       shaderProgram_ {nullptr},
       uMVPMatrixLocation_(GL_INVALID_INDEX),
       vao_ {GL_INVALID_INDEX},
       vbo_ {GL_INVALID_INDEX}
   {
   }

   ~Impl() {}

   std::shared_ptr<GlContext> context_;

   bool dirty_;

   bool  visible_;
   float x_;
   float y_;
   float z_;
   float width_;
   float height_;

   float                     borderWidth_;
   boost::gil::rgba8_pixel_t borderColor_;

   std::optional<boost::gil::rgba8_pixel_t> fillColor_;

   std::shared_ptr<ShaderProgram> shaderProgram_;
   GLint                          uMVPMatrixLocation_;

   GLuint vao_;
   GLuint vbo_;

   void Update();
};

Rectangle::Rectangle(std::shared_ptr<GlContext> context) :
    DrawItem(context->gl()), p(std::make_unique<Impl>(context))
{
}
Rectangle::~Rectangle() = default;

Rectangle::Rectangle(Rectangle&&) noexcept            = default;
Rectangle& Rectangle::operator=(Rectangle&&) noexcept = default;

void Rectangle::Initialize()
{
   gl::OpenGLFunctions& gl = p->context_->gl();

   p->shaderProgram_ =
      p->context_->GetShaderProgram(":/gl/color.vert", ":/gl/color.frag");

   p->uMVPMatrixLocation_ =
      gl.glGetUniformLocation(p->shaderProgram_->id(), "uMVPMatrix");
   if (p->uMVPMatrixLocation_ == -1)
   {
      logger_->warn("Could not find uMVPMatrix");
   }

   gl.glGenVertexArrays(1, &p->vao_);
   gl.glGenBuffers(1, &p->vbo_);

   gl.glBindVertexArray(p->vao_);
   gl.glBindBuffer(GL_ARRAY_BUFFER, p->vbo_);
   gl.glBufferData(
      GL_ARRAY_BUFFER, sizeof(float) * BUFFER_LENGTH, nullptr, GL_DYNAMIC_DRAW);

   gl.glVertexAttribPointer(0,
                            3,
                            GL_FLOAT,
                            GL_FALSE,
                            POINTS_PER_VERTEX * sizeof(float),
                            static_cast<void*>(0));
   gl.glEnableVertexAttribArray(0);

   gl.glVertexAttribPointer(1,
                            4,
                            GL_FLOAT,
                            GL_FALSE,
                            POINTS_PER_VERTEX * sizeof(float),
                            reinterpret_cast<void*>(3 * sizeof(float)));
   gl.glEnableVertexAttribArray(1);

   p->dirty_ = true;
}

void Rectangle::Render(const QMapbox::CustomLayerRenderParameters& params)
{
   if (p->visible_)
   {
      gl::OpenGLFunctions& gl = p->context_->gl();

      gl.glBindVertexArray(p->vao_);
      gl.glBindBuffer(GL_ARRAY_BUFFER, p->vbo_);

      p->Update();
      p->shaderProgram_->Use();
      UseDefaultProjection(params, p->uMVPMatrixLocation_);

      if (p->fillColor_.has_value())
      {
         // Draw fill
         gl.glDrawArrays(GL_TRIANGLES, 24, 6);
      }

      if (p->borderWidth_ > 0.0f)
      {
         // Draw border
         gl.glDrawArrays(GL_TRIANGLES, 0, 24);
      }
   }
}

void Rectangle::Deinitialize()
{
   gl::OpenGLFunctions& gl = p->context_->gl();

   gl.glDeleteVertexArrays(1, &p->vao_);
   gl.glDeleteBuffers(1, &p->vbo_);
}

void Rectangle::SetBorder(float width, boost::gil::rgba8_pixel_t color)
{
   if (p->borderWidth_ != width || p->borderColor_ != color)
   {
      p->borderWidth_ = width;
      p->borderColor_ = color;
      p->dirty_       = true;
   }
}

void Rectangle::SetFill(boost::gil::rgba8_pixel_t color)
{
   if (p->fillColor_ != color)
   {
      p->fillColor_ = color;
      p->dirty_     = true;
   }
}

void Rectangle::SetPosition(float x, float y, float z)
{
   if (p->x_ != x || p->y_ != y || p->z_ != z)
   {
      p->x_     = x;
      p->y_     = y;
      p->z_     = z;
      p->dirty_ = true;
   }
}

void Rectangle::SetSize(float width, float height)
{
   if (p->width_ != width || p->height_ != height)
   {
      p->width_  = width;
      p->height_ = height;
      p->dirty_  = true;
   }
}

void Rectangle::SetVisible(bool visible)
{
   p->visible_ = visible;
}

void Rectangle::Impl::Update()
{
   if (dirty_)
   {
      gl::OpenGLFunctions& gl = context_->gl();

      const float lox = x_;
      const float rox = x_ + width_;
      const float boy = y_;
      const float toy = y_ + height_;

      const float lix = lox + borderWidth_;
      const float rix = rox - borderWidth_;

      const float biy = boy + borderWidth_;
      const float tiy = toy - borderWidth_;

      const float bc0 = borderColor_[0] / 255.0f;
      const float bc1 = borderColor_[1] / 255.0f;
      const float bc2 = borderColor_[2] / 255.0f;
      const float bc3 = borderColor_[3] / 255.0f;

      float fc0 = 0.0f;
      float fc1 = 0.0f;
      float fc2 = 0.0f;
      float fc3 = 0.0f;

      if (fillColor_.has_value())
      {
         boost::gil::rgba8_pixel_t& fc = fillColor_.value();

         fc0 = fc[0] / 255.0f;
         fc1 = fc[1] / 255.0f;
         fc2 = fc[2] / 255.0f;
         fc3 = fc[3] / 255.0f;
      }

      const float buffer[NUM_RECTANGLES][VERTICES_PER_RECTANGLE]
                        [POINTS_PER_VERTEX] = //
         {                                    //

          // Left Border
          {
             {lox, boy, z_, bc0, bc1, bc2, bc3}, // BL
             {lox, toy, z_, bc0, bc1, bc2, bc3}, // TL
             {lix, boy, z_, bc0, bc1, bc2, bc3}, // BR
             {lix, boy, z_, bc0, bc1, bc2, bc3}, // BR
             {lix, toy, z_, bc0, bc1, bc2, bc3}, // TR
             {lox, toy, z_, bc0, bc1, bc2, bc3}  // TL
          },
          // Right Border
          {
             {rox, boy, z_, bc0, bc1, bc2, bc3}, // BR
             {rox, toy, z_, bc0, bc1, bc2, bc3}, // TR
             {rix, boy, z_, bc0, bc1, bc2, bc3}, // BL
             {rix, boy, z_, bc0, bc1, bc2, bc3}, // BL
             {rix, toy, z_, bc0, bc1, bc2, bc3}, // TL
             {rox, toy, z_, bc0, bc1, bc2, bc3}  // TR
          },
          // Top Border
          {
             {lox, toy, z_, bc0, bc1, bc2, bc3}, // TL
             {rox, toy, z_, bc0, bc1, bc2, bc3}, // TR
             {rox, tiy, z_, bc0, bc1, bc2, bc3}, // BR
             {rox, tiy, z_, bc0, bc1, bc2, bc3}, // BR
             {lox, tiy, z_, bc0, bc1, bc2, bc3}, // BL
             {lox, toy, z_, bc0, bc1, bc2, bc3}  // TL
          },
          // Bottom Border
          {
             {lox, boy, z_, bc0, bc1, bc2, bc3}, // BL
             {rox, boy, z_, bc0, bc1, bc2, bc3}, // BR
             {rox, biy, z_, bc0, bc1, bc2, bc3}, // TR
             {rox, biy, z_, bc0, bc1, bc2, bc3}, // TR
             {lox, biy, z_, bc0, bc1, bc2, bc3}, // TL
             {lox, boy, z_, bc0, bc1, bc2, bc3}  // BL
          },
          // Fill
          {
             {lox, toy, z_, fc0, fc1, fc2, fc3}, // TL
             {rox, toy, z_, fc0, fc1, fc2, fc3}, // TR
             {rox, boy, z_, fc0, fc1, fc2, fc3}, // BR
             {rox, boy, z_, fc0, fc1, fc2, fc3}, // BR
             {lox, boy, z_, fc0, fc1, fc2, fc3}, // BL
             {lox, toy, z_, fc0, fc1, fc2, fc3}  // TL
          }};

      gl.glBufferData(GL_ARRAY_BUFFER,
                      sizeof(float) * BUFFER_LENGTH,
                      buffer,
                      GL_DYNAMIC_DRAW);

      dirty_ = false;
   }
}

} // namespace draw
} // namespace gl
} // namespace qt
} // namespace scwx