//
//  KRModel.cpp
//  Kraken Engine
//
//  Copyright 2024 Kearwood Gilbert. All rights reserved.
//  
//  Redistribution and use in source and binary forms, with or without modification, are
//  permitted provided that the following conditions are met:
//  
//  1. Redistributions of source code must retain the above copyright notice, this list of
//  conditions and the following disclaimer.
//  
//  2. Redistributions in binary form must reproduce the above copyright notice, this list
//  of conditions and the following disclaimer in the documentation and/or other materials
//  provided with the distribution.
//  
//  THIS SOFTWARE IS PROVIDED BY KEARWOOD GILBERT ''AS IS'' AND ANY EXPRESS OR IMPLIED
//  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
//  FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL KEARWOOD GILBERT OR
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//

#include "KREngine-common.h"

#include "KRModel.h"
#include "KRContext.h"
#include "resources/mesh/KRMesh.h"
#include "KRNode.h"
#include "KRRenderPass.h"

using namespace hydra;

/* static */
void KRModel::InitNodeInfo(KrNodeInfo* nodeInfo)
{
  KRNode::InitNodeInfo(nodeInfo);
  nodeInfo->model.faces_camera = false;
  nodeInfo->model.light_map_texture = -1;
  nodeInfo->model.lod_min_coverage = 0.0f;
  nodeInfo->model.mesh = -1;
  nodeInfo->model.receives_shadow = true;
  nodeInfo->model.rim_color = Vector3::Zero();
  nodeInfo->model.rim_power = 0.0f;
}

KRModel::KRModel(KRScene& scene, std::string name)
  : KRNode(scene, name)
  , m_pLightMap(nullptr)
  , m_min_lod_coverage(0.0f)
  , m_receivesShadow(true)
  , m_faces_camera(false)
  , m_rim_color(Vector3::Zero())
  , m_rim_power(0.0f)
{
  m_boundsCachedMat.c[0] = -1.0f;
  m_boundsCachedMat.c[1] = -1.0f;
  m_boundsCachedMat.c[2] = -1.0f;
  m_boundsCachedMat.c[3] = -1.0f;
  m_boundsCachedMat.c[4] = -1.0f;
  m_boundsCachedMat.c[5] = -1.0f;
  m_boundsCachedMat.c[6] = -1.0f;
  m_boundsCachedMat.c[7] = -1.0f;
  m_boundsCachedMat.c[8] = -1.0f;
  m_boundsCachedMat.c[9] = -1.0f;
  m_boundsCachedMat.c[10] = -1.0f;
  m_boundsCachedMat.c[11] = -1.0f;
  m_boundsCachedMat.c[12] = -1.0f;
  m_boundsCachedMat.c[13] = -1.0f;
  m_boundsCachedMat.c[14] = -1.0f;
  m_boundsCachedMat.c[15] = -1.0f;
}

KRModel::KRModel(KRScene& scene, std::string instance_name, std::string model_name, std::string light_map, float lod_min_coverage, bool receives_shadow, bool faces_camera, Vector3 rim_color, float rim_power)
  : KRNode(scene, instance_name)
{
  m_lightMap = light_map;
  m_pLightMap = NULL;
  m_model_name = model_name;
  m_min_lod_coverage = lod_min_coverage;
  m_receivesShadow = receives_shadow;
  m_faces_camera = faces_camera;
  m_rim_color = rim_color;
  m_rim_power = rim_power;

  m_boundsCachedMat.c[0] = -1.0f;
  m_boundsCachedMat.c[1] = -1.0f;
  m_boundsCachedMat.c[2] = -1.0f;
  m_boundsCachedMat.c[3] = -1.0f;
  m_boundsCachedMat.c[4] = -1.0f;
  m_boundsCachedMat.c[5] = -1.0f;
  m_boundsCachedMat.c[6] = -1.0f;
  m_boundsCachedMat.c[7] = -1.0f;
  m_boundsCachedMat.c[8] = -1.0f;
  m_boundsCachedMat.c[9] = -1.0f;
  m_boundsCachedMat.c[10] = -1.0f;
  m_boundsCachedMat.c[11] = -1.0f;
  m_boundsCachedMat.c[12] = -1.0f;
  m_boundsCachedMat.c[13] = -1.0f;
  m_boundsCachedMat.c[14] = -1.0f;
  m_boundsCachedMat.c[15] = -1.0f;
}

KRModel::~KRModel()
{

}

std::string KRModel::getElementName()
{
  return "model";
}

tinyxml2::XMLElement* KRModel::saveXML(tinyxml2::XMLNode* parent)
{
  tinyxml2::XMLElement* e = KRNode::saveXML(parent);
  e->SetAttribute("mesh", m_model_name.c_str());
  e->SetAttribute("light_map", m_lightMap.c_str());
  e->SetAttribute("lod_min_coverage", m_min_lod_coverage);
  e->SetAttribute("receives_shadow", m_receivesShadow ? "true" : "false");
  e->SetAttribute("faces_camera", m_faces_camera ? "true" : "false");
  kraken::setXMLAttribute("rim_color", e, m_rim_color, Vector3::Zero());
  e->SetAttribute("rim_power", m_rim_power);
  return e;
}

void KRModel::setRimColor(const Vector3& rim_color)
{
  m_rim_color = rim_color;
}

void KRModel::setRimPower(float rim_power)
{
  m_rim_power = rim_power;
}

Vector3 KRModel::getRimColor()
{
  return m_rim_color;
}

float KRModel::getRimPower()
{
  return m_rim_power;
}

void KRModel::setLightMap(const std::string& name)
{
  m_lightMap = name;
  m_pLightMap = NULL;
}

std::string KRModel::getLightMap()
{
  return m_lightMap;
}

void KRModel::loadModel()
{
  if (m_models.size() == 0) {
    std::vector<KRMesh*> models = m_pContext->getMeshManager()->getModel(m_model_name.c_str()); // The model manager returns the LOD levels in sorted order, with the highest detail first
    unordered_map<KRMesh*, std::vector<KRBone*> > bones;
    if (models.size() > 0) {
      bool all_bones_found = true;
      for (std::vector<KRMesh*>::iterator model_itr = models.begin(); model_itr != models.end(); model_itr++) {
        KRMesh* model = *model_itr;
        std::vector<KRBone*> model_bones;
        int bone_count = model->getBoneCount();
        for (int bone_index = 0; bone_index < bone_count; bone_index++) {
          KRBone* matching_bone = dynamic_cast<KRBone*>(getScene().getRootNode()->find<KRNode>(model->getBoneName(bone_index)));
          if (matching_bone) {
            model_bones.push_back(matching_bone);
          } else {
            all_bones_found = false; // Reject when there are any missing bones or multiple matches
          }
        }
        bones[model] = model_bones;
      }
      if (all_bones_found) {
        m_models = models;
        m_bones = bones;
        getScene().notify_sceneGraphModify(this);
      }

      invalidateBounds();
    }
  }
}

void KRModel::render(KRNode::RenderInfo& ri)
{

  if (m_lod_visible >= LOD_VISIBILITY_PRESTREAM && ri.renderPass->getType() == RenderPassType::RENDER_PASS_PRESTREAM) {
    preStream(ri.viewport);
  }

  if (m_lod_visible <= LOD_VISIBILITY_PRESTREAM) return;

  KRNode::render(ri);

  if (ri.renderPass->getType() != RenderPassType::RENDER_PASS_DEFERRED_LIGHTS
    && ri.renderPass->getType() != RenderPassType::RENDER_PASS_ADDITIVE_PARTICLES
    && ri.renderPass->getType() != RenderPassType::RENDER_PASS_PARTICLE_OCCLUSION
    && ri.renderPass->getType()!= RenderPassType::RENDER_PASS_VOLUMETRIC_EFFECTS_ADDITIVE
    && ri.renderPass->getType() != RenderPassType::RENDER_PASS_SHADOWMAP
    && ri.renderPass->getType() != RenderPassType::RENDER_PASS_PRESTREAM) {
    loadModel();

    if (m_models.size() > 0) {
      // Don't render meshes on second pass of the deferred lighting renderer, as only lights will be applied

      /*
      float lod_coverage = 0.0f;
      if(m_models.size() > 1) {
          lod_coverage = viewport.coverage(getBounds()); // This also checks the view frustrum culling
      } else if(viewport.visible(getBounds())) {
          lod_coverage = 1.0f;
      }
      */

      float lod_coverage = ri.viewport.coverage(getBounds()); // This also checks the view frustrum culling

      if (lod_coverage > m_min_lod_coverage) {

        // ---===--- Select the best LOD model based on screen coverage ---===---
        std::vector<KRMesh*>::iterator itr = m_models.begin();
        KRMesh* pModel = *itr++;

        while (itr != m_models.end()) {
          KRMesh* pLODModel = *itr++;
          if ((float)pLODModel->getLODCoverage() / 100.0f > lod_coverage && pLODModel->getLODCoverage() < pModel->getLODCoverage()) {
            pModel = pLODModel;
          } else {
            break;
          }
        }

        if (m_pLightMap == NULL && m_lightMap.size()) {
          m_pLightMap = getContext().getTextureManager()->getTexture(m_lightMap);
        }

        if (m_pLightMap && ri.camera->settings.bEnableLightMap && ri.renderPass->getType() != RENDER_PASS_SHADOWMAP && ri.renderPass->getType() != RENDER_PASS_SHADOWMAP) {
          m_pLightMap->resetPoolExpiry(lod_coverage, KRTexture::TEXTURE_USAGE_LIGHT_MAP);
          // TODO - Vulkan refactoring.  We need to bind the shadow map in KRMesh::Render
          // m_pContext->getTextureManager()->selectTexture(5, m_pLightMap, lod_coverage, KRTexture::TEXTURE_USAGE_LIGHT_MAP);
        }

        Matrix4 matModel = getModelMatrix();
        if (m_faces_camera) {
          Vector3 model_center = Matrix4::Dot(matModel, Vector3::Zero());
          Vector3 camera_pos = ri.viewport.getCameraPosition();
          matModel = Quaternion::Create(Vector3::Forward(), Vector3::Normalize(camera_pos - model_center)).rotationMatrix() * matModel;
        }

        pModel->render(ri, getName(), matModel, m_pLightMap, m_bones[pModel], m_rim_color, m_rim_power, lod_coverage);
      }
    }
  }
}

void KRModel::preStream(const KRViewport& viewport)
{
  loadModel();
  float lod_coverage = viewport.coverage(getBounds());

  for (auto itr = m_models.begin(); itr != m_models.end(); itr++) {
    (*itr)->preStream(lod_coverage);
  }

  if (m_pLightMap == NULL && m_lightMap.size()) {
    m_pLightMap = getContext().getTextureManager()->getTexture(m_lightMap);
  }

  if (m_pLightMap) {
    m_pLightMap->resetPoolExpiry(lod_coverage, KRTexture::TEXTURE_USAGE_LIGHT_MAP);
  }
}


kraken_stream_level KRModel::getStreamLevel(const KRViewport& viewport)
{
  kraken_stream_level stream_level = KRNode::getStreamLevel(viewport);

  loadModel();

  for (auto itr = m_models.begin(); itr != m_models.end(); itr++) {
    stream_level = KRMIN(stream_level, (*itr)->getStreamLevel());
  }

  return stream_level;
}

AABB KRModel::getBounds()
{
  loadModel();
  if (m_models.size() > 0) {
    if (m_faces_camera) {
      AABB normal_bounds = AABB::Create(m_models[0]->getMinPoint(), m_models[0]->getMaxPoint(), getModelMatrix());
      float max_dimension = normal_bounds.longest_radius();
      return AABB::Create(normal_bounds.center() - Vector3::Create(max_dimension), normal_bounds.center() + Vector3::Create(max_dimension));
    } else {

      if (!(m_boundsCachedMat == getModelMatrix())) {
        m_boundsCachedMat = getModelMatrix();
        m_boundsCached = AABB::Create(m_models[0]->getMinPoint(), m_models[0]->getMaxPoint(), getModelMatrix());
      }
      return m_boundsCached;
    }
  } else {
    return AABB::Infinite();
  }
}

