#include <functional>
#include <mutex>
#include <thread>
#include <stdlib.h>

#include <filament/LightManager.h>

#include "c_api/APIBoundaryTypes.h"
#include "c_api/TView.h"
#include "c_api/TSceneAsset.h"
#include "c_api/TSceneManager.h"
#include "c_api/TAnimationManager.h"
#include "c_api/ThermionDartRenderThreadApi.h"

#include "FilamentViewer.hpp"
#include "Log.hpp"

#include "ThreadPool.hpp"

using namespace thermion;
using namespace std::chrono_literals;
#include <time.h>

class RenderLoop
{
public:
  explicit RenderLoop()
  {
    srand(time(NULL));
    t = new std::thread([this]()
                        { start(); });
  }

  ~RenderLoop()
  {
    _stop = true;
    _cv.notify_one();
    t->join();
  }

  static void mainLoop(void *arg)
  {
    ((RenderLoop *)arg)->iter();
  }

  static void *startHelper(void *parm)
  {
    ((RenderLoop *)parm)->start();
    return nullptr;
  }

  void start()
  {
    while (!_stop)
    {
      iter();
    }
  }

  void requestFrame(void (*callback)())
  {
    std::unique_lock<std::mutex> lock(_mutex);
    this->_requestFrameRenderCallback = callback;
    _cv.notify_one();
  }

  void iter()
  {
    {
      std::unique_lock<std::mutex> lock(_mutex);
      if (_requestFrameRenderCallback)
      {
        doRender();
        lock.unlock();
        this->_requestFrameRenderCallback();
        this->_requestFrameRenderCallback = nullptr;

        // Calculate and print FPS
        auto currentTime = std::chrono::high_resolution_clock::now();
        float deltaTime = std::chrono::duration<float, std::chrono::seconds::period>(currentTime - _lastFrameTime).count();
        _lastFrameTime = currentTime;

        _frameCount++;
        _accumulatedTime += deltaTime;

        if (_accumulatedTime >= 1.0f) // Update FPS every second
        {
          _fps = _frameCount / _accumulatedTime;
          // std::cout << "FPS: " << _fps << std::endl;
          _frameCount = 0;
          _accumulatedTime = 0.0f;
        }
      }
    }
    std::unique_lock<std::mutex> taskLock(_taskMutex);

    if (!_tasks.empty())
    {
      auto task = std::move(_tasks.front());
      _tasks.pop_front();
      taskLock.unlock();
      task();
      taskLock.lock();
    }

    _cv.wait_for(taskLock, std::chrono::microseconds(2000), [this]
                 { return !_tasks.empty() || _stop; });
  }

  void createViewer(void *const context,
                    void *const platform,
                    const char *uberArchivePath,
                    const ResourceLoaderWrapper *const loader,
                    void (*renderCallback)(void *),
                    void *const owner,
                    void (*callback)(TViewer *))
  {
    _renderCallback = renderCallback;
    _renderCallbackOwner = owner;
    std::packaged_task<void()> lambda([=]() mutable
                                      {
                                        auto viewer = (FilamentViewer *)Viewer_create(context, loader, platform, uberArchivePath);
                                        _viewer = reinterpret_cast<TViewer*>(viewer);
                                        callback(_viewer); });
    auto fut = add_task(lambda);
  }

  void destroyViewer(FilamentViewer *viewer)
  {
    std::packaged_task<void()> lambda([=]() mutable
                                      {
      _viewer = nullptr;
      Viewer_destroy(reinterpret_cast<TViewer*>(viewer)); });
    auto fut = add_task(lambda);
    fut.wait();
  }

  void doRender()
  {
    Viewer_render(_viewer);
    if (_renderCallback)
    {
      _renderCallback(_renderCallbackOwner);
    }
  }

  void setFrameIntervalInMilliseconds(float frameIntervalInMilliseconds)
  {
    _frameIntervalInMicroseconds = static_cast<int>(1000.0f * frameIntervalInMilliseconds);
  }

  template <class Rt>
  auto add_task(std::packaged_task<Rt()> &pt) -> std::future<Rt>
  {
    std::unique_lock<std::mutex> lock(_taskMutex);
    auto ret = pt.get_future();
    _tasks.push_back([pt = std::make_shared<std::packaged_task<Rt()>>(
                          std::move(pt))]
                     { (*pt)(); });
    _cv.notify_one();
    return ret;
  }

private:
  void (*_requestFrameRenderCallback)() = nullptr;
  bool _stop = false;
  int _frameIntervalInMicroseconds = 1000000 / 60;
  std::mutex _mutex;
  std::mutex _taskMutex;
  std::condition_variable _cv;
  void (*_renderCallback)(void *const) = nullptr;
  void *_renderCallbackOwner = nullptr;
  std::deque<std::function<void()>> _tasks;
  TViewer *_viewer = nullptr;
  std::chrono::high_resolution_clock::time_point _lastFrameTime;
  int _frameCount = 0;
  float _accumulatedTime = 0.0f;
  float _fps = 0.0f;
  std::thread *t = nullptr;
};

extern "C"
{

  static RenderLoop *_rl;

  EMSCRIPTEN_KEEPALIVE void Viewer_createOnRenderThread(
      void *const context, void *const platform, const char *uberArchivePath,
      const void *const loader,
      void (*renderCallback)(void *const renderCallbackOwner),
      void *const renderCallbackOwner,
      void (*callback)(TViewer *))
  {

    if (!_rl)
    {
      _rl = new RenderLoop();
    }
    _rl->createViewer(context, platform, uberArchivePath, (const ResourceLoaderWrapper *const)loader,
                      renderCallback, renderCallbackOwner, callback);
  }

  EMSCRIPTEN_KEEPALIVE void Viewer_destroyOnRenderThread(TViewer *viewer)
  {
    _rl->destroyViewer((FilamentViewer *)viewer);
    delete _rl;
    _rl = nullptr;
  }

  EMSCRIPTEN_KEEPALIVE void Viewer_createHeadlessSwapChainRenderThread(TViewer *viewer,
                                                                       uint32_t width,
                                                                       uint32_t height,
                                                                       void (*onComplete)(TSwapChain *))
  {
    std::packaged_task<void()> lambda(
        [=]() mutable
        {
          auto *swapChain = Viewer_createHeadlessSwapChain(viewer, width, height);
          onComplete(swapChain);
        });
    auto fut = _rl->add_task(lambda);
  }

  EMSCRIPTEN_KEEPALIVE void Viewer_createSwapChainRenderThread(TViewer *viewer,
                                                               void *const surface,
                                                               void (*onComplete)(TSwapChain *))
  {
    std::packaged_task<void()> lambda(
        [=]() mutable
        {
          auto *swapChain = Viewer_createSwapChain(viewer, surface);
          onComplete(swapChain);
        });
    auto fut = _rl->add_task(lambda);
  }

  EMSCRIPTEN_KEEPALIVE void Viewer_destroySwapChainRenderThread(TViewer *viewer, TSwapChain *swapChain, void (*onComplete)())
  {
    std::packaged_task<void()> lambda(
        [=]() mutable
        {
          Viewer_destroySwapChain(viewer, swapChain);
          onComplete();
        });
    auto fut = _rl->add_task(lambda);
  }

  EMSCRIPTEN_KEEPALIVE void Viewer_requestFrameRenderThread(TViewer *viewer, void (*onComplete)())
  {
    if (!_rl)
    {
      Log("No render loop!"); // PANIC?
    }
    else
    {
      _rl->requestFrame(onComplete);
    }
  }

  EMSCRIPTEN_KEEPALIVE void Viewer_loadIblRenderThread(TViewer *viewer, const char *iblPath, float intensity, void (*onComplete)())
  {
    std::packaged_task<void()> lambda(
        [=]() mutable
        {
          Viewer_loadIbl(viewer, iblPath, intensity);
          onComplete();
        });
    auto fut = _rl->add_task(lambda);
  }

  EMSCRIPTEN_KEEPALIVE void Viewer_createRenderTargetRenderThread(TViewer *viewer, intptr_t texture, uint32_t width, uint32_t height, void (*onComplete)(TRenderTarget *))
  {
    std::packaged_task<void()> lambda(
        [=]() mutable
        {
          auto renderTarget = Viewer_createRenderTarget(viewer, texture, width, height);
          onComplete(renderTarget);
        });
    auto fut = _rl->add_task(lambda);
  }

  EMSCRIPTEN_KEEPALIVE void Engine_buildMaterialRenderThread(TEngine *tEngine, const uint8_t *materialData, size_t length, void (*onComplete)(TMaterial *))
  {
    std::packaged_task<void()> lambda(
        [=]() mutable
        {
          auto material = Engine_buildMaterial(tEngine, materialData, length);
          onComplete(material);
        });
    auto fut = _rl->add_task(lambda);
  }

  EMSCRIPTEN_KEEPALIVE void Engine_destroyMaterialRenderThread(TEngine *tEngine, TMaterial *tMaterial, void (*onComplete)())
  {
    std::packaged_task<void()> lambda(
        [=]() mutable
        {
          Engine_destroyMaterial(tEngine, tMaterial);
          onComplete();
        });
    auto fut = _rl->add_task(lambda);
  }

  EMSCRIPTEN_KEEPALIVE void Material_createInstanceRenderThread(TMaterial *tMaterial, void (*onComplete)(TMaterialInstance *))
  {
    std::packaged_task<void()> lambda(
        [=]() mutable
        {
          auto *instance = Material_createInstance(tMaterial);
          onComplete(instance);
        });
    auto fut = _rl->add_task(lambda);
  }

  EMSCRIPTEN_KEEPALIVE void
  set_frame_interval_render_thread(TViewer *viewer, float frameIntervalInMilliseconds)
  {
    _rl->setFrameIntervalInMilliseconds(frameIntervalInMilliseconds);
    std::packaged_task<void()> lambda([=]() mutable
                                      { ((FilamentViewer *)viewer)->setFrameInterval(frameIntervalInMilliseconds); });
    auto fut = _rl->add_task(lambda);
  }

  EMSCRIPTEN_KEEPALIVE void Viewer_renderRenderThread(TViewer *viewer, TView *tView, TSwapChain *tSwapChain)
  {
    std::packaged_task<void()> lambda([=]() mutable
                                      { _rl->doRender(); });
    auto fut = _rl->add_task(lambda);
  }

  EMSCRIPTEN_KEEPALIVE void Viewer_captureRenderThread(TViewer *viewer, TView *view, TSwapChain *tSwapChain, uint8_t *pixelBuffer, void (*onComplete)())
  {
    std::packaged_task<void()> lambda([=]() mutable
                                      { Viewer_capture(viewer, view, tSwapChain, pixelBuffer, onComplete); });
    auto fut = _rl->add_task(lambda);
  }

  EMSCRIPTEN_KEEPALIVE void Viewer_captureRenderTargetRenderThread(TViewer *viewer, TView *view, TSwapChain *tSwapChain, TRenderTarget *tRenderTarget, uint8_t *pixelBuffer, void (*onComplete)())
  {
    std::packaged_task<void()> lambda([=]() mutable
                                      { Viewer_captureRenderTarget(viewer, view, tSwapChain, tRenderTarget, pixelBuffer, onComplete); });
    auto fut = _rl->add_task(lambda);
  }

  EMSCRIPTEN_KEEPALIVE void
  set_background_color_render_thread(TViewer *viewer, const float r, const float g,
                                     const float b, const float a)
  {
    std::packaged_task<void()> lambda(
        [=]() mutable
        { set_background_color(viewer, r, g, b, a); });
    auto fut = _rl->add_task(lambda);
  }

  EMSCRIPTEN_KEEPALIVE void SceneManager_createGridRenderThread(TSceneManager *tSceneManager, TMaterial *tMaterial, void (*callback)(TSceneAsset *))
  {
    std::packaged_task<void()> lambda([=]() mutable
                                      {
      auto *sceneAsset = SceneManager_createGrid(tSceneManager, tMaterial);
      callback(sceneAsset); 
    });
    auto fut = _rl->add_task(lambda);
  }

  EMSCRIPTEN_KEEPALIVE void SceneManager_loadGltfRenderThread(TSceneManager *sceneManager,
                                                              const char *path,
                                                              const char *relativeResourcePath,
                                                              bool keepData,
                                                              void (*callback)(TSceneAsset *))
  {
    std::packaged_task<void()> lambda([=]() mutable
                                      {
      auto entity = SceneManager_loadGltf(sceneManager, path, relativeResourcePath, keepData);
      callback(entity); });
    auto fut = _rl->add_task(lambda);
  }

  EMSCRIPTEN_KEEPALIVE void SceneManager_loadGlbRenderThread(TSceneManager *sceneManager,
                                                             const char *path,
                                                             int numInstances,
                                                             bool keepData,
                                                             void (*callback)(TSceneAsset *))
  {
    std::packaged_task<void()> lambda(
        [=]() mutable
        {
          auto asset = SceneManager_loadGlb(sceneManager, path, numInstances, keepData);
          callback(asset);
        });
    auto fut = _rl->add_task(lambda);
  }

  EMSCRIPTEN_KEEPALIVE void SceneManager_createGeometryRenderThread(
      TSceneManager *sceneManager,
      float *vertices,
      int numVertices,
      float *normals,
      int numNormals,
      float *uvs,
      int numUvs,
      uint16_t *indices,
      int numIndices,
      int primitiveType,
      TMaterialInstance **materialInstances,
      int materialInstanceCount,
      bool keepData,
      void (*callback)(TSceneAsset *))
  {
    std::packaged_task<void()> lambda(
        [=]
        {
          auto *asset = SceneManager_createGeometry(sceneManager, vertices, numVertices, normals, numNormals, uvs, numUvs, indices, numIndices, primitiveType, materialInstances, materialInstanceCount, keepData);
          callback(asset);
        });
    auto fut = _rl->add_task(lambda);
  }

  EMSCRIPTEN_KEEPALIVE void SceneAsset_createInstanceRenderThread(
      TSceneAsset *asset, TMaterialInstance **tMaterialInstances,
      int materialInstanceCount,
      void (*callback)(TSceneAsset *))
  {
    std::packaged_task<void()> lambda(
        [=]
        {
          auto instanceAsset = SceneAsset_createInstance(asset, tMaterialInstances, materialInstanceCount);
          callback(instanceAsset);
        });
    auto fut = _rl->add_task(lambda);
  }

  EMSCRIPTEN_KEEPALIVE void MaterialProvider_createMaterialInstanceRenderThread(TMaterialProvider *tMaterialProvider, TMaterialKey *tKey, void (*callback)(TMaterialInstance *))
  {
    std::packaged_task<void()> lambda(
        [=]
        {
          auto materialInstance = MaterialProvider_createMaterialInstance(tMaterialProvider, tKey);
          callback(materialInstance);
        });
    auto fut = _rl->add_task(lambda);
  }

  EMSCRIPTEN_KEEPALIVE void SceneManager_destroyMaterialInstanceRenderThread(TSceneManager *tSceneManager, TMaterialInstance *tMaterialInstance, void (*callback)()) { 
    std::packaged_task<void()> lambda(
        [=]
        {
          SceneManager_destroyMaterialInstance(tSceneManager, tMaterialInstance);
          callback();
        });
    auto fut = _rl->add_task(lambda);
  }

  EMSCRIPTEN_KEEPALIVE void SceneManager_createUnlitMaterialInstanceRenderThread(TSceneManager *sceneManager, void (*callback)(TMaterialInstance *))
  {
    std::packaged_task<void()> lambda(
        [=]() mutable
        {
          auto instance = SceneManager_createUnlitMaterialInstance(sceneManager);
          callback(instance);
        });
    auto fut = _rl->add_task(lambda);
  }

  EMSCRIPTEN_KEEPALIVE void SceneManager_createUnlitFixedSizeMaterialInstanceRenderThread(TSceneManager *sceneManager, void (*callback)(TMaterialInstance *))
  {
    std::packaged_task<void()> lambda(
        [=]() mutable
        {
          auto instance = SceneManager_createUnlitFixedSizeMaterialInstance(sceneManager);
          callback(instance);
        });
    auto fut = _rl->add_task(lambda);
  }

  EMSCRIPTEN_KEEPALIVE void SceneManager_loadGlbFromBufferRenderThread(TSceneManager *sceneManager,
                                                                       const uint8_t *const data,
                                                                       size_t length,
                                                                       int numInstances,
                                                                       bool keepData,
                                                                       int priority,
                                                                       int layer,
                                                                       bool loadResourcesAsync,
                                                                       void (*callback)(TSceneAsset *))
  {
    std::packaged_task<void()> lambda(
        [=]() mutable
        {
          auto *asset = SceneManager_loadGlbFromBuffer(sceneManager, data, length, keepData, priority, layer, loadResourcesAsync);
          callback(asset);
        });
    auto fut = _rl->add_task(lambda);
  }

  EMSCRIPTEN_KEEPALIVE void clear_background_image_render_thread(TViewer *viewer)
  {
    std::packaged_task<void()> lambda([=]
                                      { clear_background_image(viewer); });
    auto fut = _rl->add_task(lambda);
  }

  EMSCRIPTEN_KEEPALIVE void set_background_image_render_thread(TViewer *viewer,
                                                               const char *path,
                                                               bool fillHeight, void (*callback)())
  {
    std::packaged_task<void()> lambda(
        [=]
        {
          set_background_image(viewer, path, fillHeight);
          callback();
        });
    auto fut = _rl->add_task(lambda);
  }

  EMSCRIPTEN_KEEPALIVE void set_background_image_position_render_thread(TViewer *viewer,
                                                                        float x, float y,
                                                                        bool clamp)
  {
    std::packaged_task<void()> lambda(
        [=]
        { set_background_image_position(viewer, x, y, clamp); });
    auto fut = _rl->add_task(lambda);
  }

  EMSCRIPTEN_KEEPALIVE void load_skybox_render_thread(TViewer *viewer,
                                                      const char *skyboxPath,
                                                      void (*onComplete)())
  {
    std::packaged_task<void()> lambda([=]
                                      {
                                        load_skybox(viewer, skyboxPath);
                                        onComplete(); });
    auto fut = _rl->add_task(lambda);
  }

  EMSCRIPTEN_KEEPALIVE void remove_skybox_render_thread(TViewer *viewer)
  {
    std::packaged_task<void()> lambda([=]
                                      { remove_skybox(viewer); });
    auto fut = _rl->add_task(lambda);
  }

  EMSCRIPTEN_KEEPALIVE void remove_ibl_render_thread(TViewer *viewer)
  {
    std::packaged_task<void()> lambda([=]
                                      { remove_ibl(viewer); });
    auto fut = _rl->add_task(lambda);
  }

  EMSCRIPTEN_KEEPALIVE void View_setToneMappingRenderThread(TView *tView, TEngine *tEngine, thermion::ToneMapping toneMapping)
  {
    std::packaged_task<void()> lambda(
        [=]
        {
          View_setToneMapping(tView, tEngine, toneMapping);
        });
    auto fut = _rl->add_task(lambda);
  }

  EMSCRIPTEN_KEEPALIVE void View_setBloomRenderThread(TView *tView, double bloom)
  {
    std::packaged_task<void()> lambda(
        [=]
        {
          View_setBloom(tView, bloom);
        });
    auto fut = _rl->add_task(lambda);
  }

  EMSCRIPTEN_KEEPALIVE void View_setCameraRenderThread(TView *tView, TCamera *tCamera, void (*callback)())
  {
    std::packaged_task<void()> lambda(
        [=]
        {
          View_setCamera(tView, tCamera);
          callback();
        });
    auto fut = _rl->add_task(lambda);
  }

  EMSCRIPTEN_KEEPALIVE void *SceneManager_destroyAllRenderThread(TSceneManager *tSceneManager, void (*callback)())
  {
    std::packaged_task<void()> lambda(
        [=]() mutable
        {
          SceneManager_destroyAll(tSceneManager);
          callback();
        });
    auto fut = _rl->add_task(lambda);
    return nullptr;
  }

  EMSCRIPTEN_KEEPALIVE TGizmo *SceneManager_createGizmoRenderThread(
      TSceneManager *tSceneManager,
      TView *tView,
      TScene *tScene,
      TGizmoType tGizmoType,
      void (*onComplete)(TGizmo *))
  {
    std::packaged_task<void()> lambda(
        [=]() mutable
        {
          auto *gizmo = SceneManager_createGizmo(tSceneManager, tView, tScene, tGizmoType);
          onComplete(gizmo);
        });
    auto fut = _rl->add_task(lambda);
    return nullptr;
  }

  EMSCRIPTEN_KEEPALIVE void *SceneManager_destroyAssetRenderThread(TSceneManager *tSceneManager, TSceneAsset *tSceneAsset, void (*callback)())
  {
    std::packaged_task<void()> lambda(
        [=]() mutable
        {
          SceneManager_destroyAsset(tSceneManager, tSceneAsset);
          callback();
        });
    auto fut = _rl->add_task(lambda);
    return nullptr;
  }

  EMSCRIPTEN_KEEPALIVE void SceneManager_createCameraRenderThread(TSceneManager *tSceneManager, void (*callback)(TCamera *))
  {
    std::packaged_task<void()> lambda(
        [=]() mutable
        {
          auto *camera = SceneManager_createCamera(tSceneManager);
          callback(reinterpret_cast<TCamera *>(camera));
        });
    auto fut = _rl->add_task(lambda);
  }

  EMSCRIPTEN_KEEPALIVE void unproject_texture_render_thread(TViewer *viewer, EntityId entity, uint8_t *input, uint32_t inputWidth, uint32_t inputHeight, uint8_t *out, uint32_t outWidth, uint32_t outHeight, void (*callback)())
  {
    std::packaged_task<void()> lambda(
        [=]
        {
          unproject_texture(viewer, entity, input, inputWidth, inputHeight, out, outWidth, outHeight);
          callback();
        });
    auto fut = _rl->add_task(lambda);
  }

  EMSCRIPTEN_KEEPALIVE void AnimationManager_updateBoneMatricesRenderThread(
      TAnimationManager *tAnimationManager,
      TSceneAsset *sceneAsset,
      void (*callback)(bool))
  {
    std::packaged_task<void()> lambda(
        [=]() mutable
        {
          bool result = AnimationManager_updateBoneMatrices(tAnimationManager, sceneAsset);
          callback(result);
        });
    auto fut = _rl->add_task(lambda);
  }

  EMSCRIPTEN_KEEPALIVE void AnimationManager_setMorphTargetWeightsRenderThread(
      TAnimationManager *tAnimationManager,
      EntityId entityId,
      const float *const morphData,
      int numWeights,
      void (*callback)(bool))
  {
    std::packaged_task<void()> lambda(
        [=]() mutable
        {
          bool result = AnimationManager_setMorphTargetWeights(tAnimationManager, entityId, morphData, numWeights);
          callback(result);
        });
    auto fut = _rl->add_task(lambda);
  }
}