//
// Created by martin on 12.11.21.
//

#ifndef ANIMTESTBED_SKINNEDMESH_H
#define ANIMTESTBED_SKINNEDMESH_H

// ozz-animation headers
#include <cmath>   // fmodf
#include <memory>  // std::unique_ptr, std::make_unique

#include "ozz/animation/runtime/animation.h"
#include "ozz/animation/runtime/local_to_model_job.h"
#include "ozz/animation/runtime/sampling_job.h"
#include "ozz/animation/runtime/skeleton.h"
#include "ozz/base/containers/vector.h"
#include "ozz/base/io/archive.h"
#include "ozz/base/io/stream.h"
#include "ozz/base/log.h"
#include "ozz/base/maths/soa_transform.h"
#include "ozz/base/maths/vec_float.h"

constexpr int cSyncTrackMaxIntervals = 8;

struct SyncTrack {
  float m_duration;
  int m_num_intervals;
  float m_interval_durations[cSyncTrackMaxIntervals];

  float CalcSyncFromAbsTime (float abs_time) {
    float sync_time = fmodf (abs_time, m_duration) / m_duration;

    int interval_index = 0;
    while (sync_time >= m_interval_durations[interval_index]) {
      sync_time -= m_interval_durations[interval_index];
      interval_index ++;
    }

    return float(interval_index) + sync_time / m_interval_durations[interval_index];
  }

  float CalcRatioFromSyncTime (float sync_time) {
    float interval_ratio = fmodf(sync_time, 1.0f);
    int interval = int(sync_time - interval_ratio);

    float result = 0.f;
    int i = 0;
    while (i < interval) {
      result += m_interval_durations[i];
      i++;
    }

    result += m_interval_durations[i] * interval_ratio;

    return result;
  }

  static SyncTrack Blend(float weight, const SyncTrack& track_A, const SyncTrack& track_B) {
    SyncTrack result;

    assert (track_A.m_num_intervals == track_B.m_num_intervals);
    result.m_num_intervals = track_A.m_num_intervals;

    result.m_duration = (1.0f - weight) * track_A.m_duration + weight * track_B.m_duration;

    for (int i = 0; i < result.m_num_intervals; i++) {
      result.m_interval_durations[i] = (1.0f - weight) * track_A.m_interval_durations[i] + weight * track_B.m_interval_durations[i];
    }

    return result;
  }
};


struct SkinnedMesh {
  virtual ~SkinnedMesh();
  bool LoadSkeleton(const char* filename);
  bool LoadAnimation(const char* filename);
  //bool LoadMesh (const char* filename);

  void SetCurrentAnimation(int index);
  const ozz::animation::Animation* GetCurrentAnimation() {return m_current_animation; };
  float GetCurrentAnimationDuration() {return m_current_animation->duration(); };

  void EvalAnimation(float in_time);
  void DrawSkeleton();
  void DrawJoint(int joint_index, int parent_joint_index);

  void DrawDebugUi();
  // void DrawSkinnedMesh();

  ozz::vector<ozz::animation::Animation*> m_animations;
  std::vector<std::string> m_animation_names;
  std::vector<SyncTrack> m_animation_sync_track;
  ozz::animation::Skeleton m_skeleton;
  ozz::animation::Animation* m_current_animation;
  ozz::animation::SamplingCache m_cache;
  ozz::vector<ozz::math::SoaTransform> m_local_matrices;
  ozz::vector<ozz::math::Float4x4> m_model_matrices;
};

#endif  //ANIMTESTBED_SKINNEDMESH_H