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

#include "AnimationController.h"

#include <imgui.h>
#include <ozz/animation/runtime/blending_job.h>
#include <ozz/animation/runtime/local_to_model_job.h>
#include <ozz/animation/runtime/sampling_job.h>

#include "AnimNodes/AnimSamplerNode.h"
#include "AnimNodes/BlendNode.h"
#include "AnimNodes/SpeedScaleNode.h"
#include "SkinnedMesh.h"

AnimationController::AnimationController(SkinnedMesh* skinned_mesh)
    : m_current_time(0.f), m_skinned_mesh(skinned_mesh) {
  const int num_soa_joints = skinned_mesh->m_skeleton.num_soa_joints();
  const int num_joints = skinned_mesh->m_skeleton.num_joints();
  skinned_mesh->m_local_matrices.resize(num_soa_joints);
  skinned_mesh->m_model_matrices.resize(num_joints);

  m_local_matrices.resize(num_soa_joints);

  assert(skinned_mesh->m_animations.size() > 1);
  SetBlendAnims(skinned_mesh->m_animations[1], skinned_mesh->m_animations[0]);
  ResetAnims();

  AnimSamplerNode* sampler_node0 = new AnimSamplerNode(this);
  sampler_node0->m_name = "AnimSampler0";
  sampler_node0->SetAnimation(skinned_mesh->m_animations[1]);
  m_anim_nodes.push_back(sampler_node0);

  AnimSamplerNode* sampler_node1 = new AnimSamplerNode(this);
  sampler_node1->m_name = "AnimSampler0";
  sampler_node1->SetAnimation(skinned_mesh->m_animations[2]);
  m_anim_nodes.push_back(sampler_node1);

  SpeedScaleNode* speed_node = new SpeedScaleNode(this);
  speed_node->m_name = "SpeedNode0";
  speed_node->m_input_node = sampler_node0;
  m_anim_nodes.push_back(speed_node);

  BlendNode* blend_node = new BlendNode(this);
  blend_node->m_name = "Blend0";
  blend_node->m_input_A = speed_node;
  blend_node->m_input_B = sampler_node1;
  m_anim_nodes.push_back(blend_node);

  m_output_node = blend_node;

  m_output_node->CollectNodeOrdering(m_ordered_nodes);

  std::cout << "Have " << m_ordered_nodes.size() << " nodes in blend tree." << std::endl;
  m_output_node->Reset();
}



AnimationController::~AnimationController() {
  while (m_anim_nodes.size() > 0) {
    delete m_anim_nodes[m_anim_nodes.size() - 1];
    m_anim_nodes.pop_back();
  }

  m_output_node = nullptr;
}



void AnimationController::Update(float dt) {
  if (m_output_node == nullptr) {
    return;
  }

  m_output_node->Update(dt);
}



void AnimationController::Evaluate() {
  if (m_output_node == nullptr) {
    return;
  }
  m_output_node->Evaluate(&m_local_matrices);

  // convert joint matrices from local to model space
  ozz::animation::LocalToModelJob ltm_job;
  ltm_job.skeleton = &m_skinned_mesh->m_skeleton;
  ltm_job.input = make_span(m_local_matrices);
  ltm_job.output = make_span(m_skinned_mesh->m_model_matrices);
  ltm_job.Run();
};



void AnimationController::DrawDebugUi() {
  ImGui::Begin("AnimationController");
  if (m_output_node && ImGui::TreeNode("Output")) {
    m_output_node->DrawDebugUi();

    ImGui::TreePop();
  }

  if (m_output_node && ImGui::TreeNode("Nodes")) {
    for (int i = 0; i < m_ordered_nodes.size(); i++) {
      ImGui::Text(m_ordered_nodes[i]->m_name.c_str());
    }

    ImGui::TreePop();
  }

  ImGui::End();
}