#include "rive/animation/keyframe_uint.hpp"
#include "rive/animation/keyframe_interpolator.hpp"
#include "rive/generated/core_registry.hpp"
#include <cmath>

using namespace rive;

// Uints hold by default -- most are enums, ids or mode flags. Defs opting in
// with "interpolates": true tween instead, via the generated
// CoreRegistry::isInterpolatableUint. Rounding and mixing must match
// packages/rive_core/lib/animation/keyframe_uint.dart or editor preview and
// runtime playback drift.

// Clamps negatives to zero: a cubic interpolator can overshoot below zero and
// the destination property is unsigned.
static uint32_t roundToUint(float value)
{
  return value <= 0.0f ? 0u : static_cast<uint32_t>(std::lround(value));
}

static void applyUint(Core* object, int propertyKey, float mix, uint32_t value)
{
  if (mix == 1.0f)
  {
    CoreRegistry::setUint(object, propertyKey, value);
  }
  else
  {
    float mixi = 1.0f - mix;
    CoreRegistry::setUint(
        object,
        propertyKey,
        roundToUint(
            CoreRegistry::getUint(object, propertyKey) * mixi + value * mix));
  }
}

void KeyFrameUint::apply(
    Core* object,
    int propertyKey,
    float mix,
    const LinearAnimationInstance* context)
{
  (void)context;
  if (CoreRegistry::isInterpolatableUint(propertyKey))
  {
    applyUint(object, propertyKey, mix, value());
    return;
  }
  CoreRegistry::setUint(object, propertyKey, value());
}

void KeyFrameUint::applyInterpolation(
    Core* object,
    int propertyKey,
    float currentTime,
    const KeyFrame* nextFrame,
    float mix,
    const LinearAnimationInstance* context)
{
  if (!CoreRegistry::isInterpolatableUint(propertyKey))
  {
    CoreRegistry::setUint(object, propertyKey, value());
    return;
  }

  const KeyFrameUint& nextUint = *nextFrame->as<KeyFrameUint>();
  float fromValue = static_cast<float>(value());
  float toValue = static_cast<float>(nextUint.value());
  float f = (currentTime - seconds()) / (nextUint.seconds() - seconds());

  float frameValue;
  if (KeyFrameInterpolator* keyframeInterpolator = effectiveInterpolator(
          context))
  {
    frameValue = keyframeInterpolator->transformValue(fromValue, toValue, f);
  }
  else
  {
    frameValue = fromValue + (toValue - fromValue) * f;
  }

  applyUint(object, propertyKey, mix, roundToUint(frameValue));
}