#include "shared/elements/__ELEMENT_CLASS_NAME__.h"

#include <algorithm>
#include <cmath>

// This shared texture backend depends on LynxNativeView C API surface handles.
bool Draw__ELEMENT_SYMBOL_NAME__TextureSurface(
    lynx_surface_handle_t* handle,
    int width_px,
    int height_px,
    const char* text);

namespace {

constexpr float kYFlipTransform[3 * 3] = {1, 0, 0, 0, -1, 1, 0, 0, 1};

class __ELEMENT_SYMBOL_NAME__TextureView : public __ELEMENT_SYMBOL_NAME__View {
 public:
  explicit __ELEMENT_SYMBOL_NAME__TextureView(void* opaque)
      : __ELEMENT_SYMBOL_NAME__View(opaque) {}

  bool IsSurfaceEnabled() override { return true; }
  lynx_surface_buffer_mode_t SurfaceBufferMode() override {
    return kTripleBuffer;
  }

  void OnAttach() override {
    attached_ = true;
    Render();
  }

  void OnDetach() override { attached_ = false; }

  void OnLayoutChanged(
      float left,
      float top,
      float width,
      float height,
      float pixel_ratio) override {
    (void)left;
    (void)top;
    const float ratio = pixel_ratio > 0 ? pixel_ratio : 1;
    width_px_ = std::max(1, static_cast<int>(std::lround(width * ratio)));
    height_px_ = std::max(1, static_cast<int>(std::lround(height * ratio)));
    Render();
  }

 private:
  void OnValueChanged(const std::string& value) override {
    (void)value;
    Render();
  }

  void Render() {
    if (!attached_ || width_px_ <= 0 || height_px_ <= 0) {
      return;
    }

    lynx_surface_handle_t* surface = AcquireSurface(width_px_, height_px_);
    if (surface == nullptr) {
      return;
    }

    if (Draw__ELEMENT_SYMBOL_NAME__TextureSurface(
            surface,
            width_px_,
            height_px_,
            value().c_str())) {
      PresentSurface(width_px_, height_px_, kYFlipTransform, surface);
    }
  }

  bool attached_ = false;
  int width_px_ = 0;
  int height_px_ = 0;
};

}  // namespace

lynx_native_view_t* Create__ELEMENT_SYMBOL_NAME__TextureNativeView(void* opaque) {
  auto* view = new __ELEMENT_SYMBOL_NAME__TextureView(opaque);
  return view->native_view();
}