/**
BSD 3-Clause License

This file is part of the Basalt project.
https://gitlab.com/VladyslavUsenko/basalt.git

Copyright (c) 2019, Vladyslav Usenko and Nikolaus Demmel.
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

* Redistributions of source code must retain the above copyright notice, this
  list of conditions and the following disclaimer.

* 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.

* Neither the name of the copyright holder nor the names of its
  contributors may be used to endorse or promote products derived from
  this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#include <algorithm>
#include <chrono>
#include <condition_variable>
#include <iostream>
#include <thread>

#include <sophus/se3.hpp>

#include <tbb/concurrent_unordered_map.h>
#include <tbb/tbb.h>

#include <pangolin/display/image_view.h>
#include <pangolin/gl/gldraw.h>
#include <pangolin/image/image.h>
#include <pangolin/image/image_io.h>
#include <pangolin/image/typed_image.h>
#include <pangolin/pangolin.h>

#include <CLI/CLI.hpp>

#include <basalt/io/dataset_io.h>
#include <basalt/io/marg_data_io.h>
#include <basalt/spline/se3_spline.h>
#include <basalt/vi_estimator/vio_estimator.h>
#include <basalt/calibration/calibration.hpp>

#include <basalt/serialization/headers_serialization.h>

#include <basalt/utils/vis_utils.h>

// GUI functions
void draw_image_overlay(pangolin::View& v, size_t cam_id);
void draw_scene();
void load_data(const std::string& calib_path);
bool next_step();
bool prev_step();
void draw_plots();
void alignButton();

// Pangolin variables
constexpr int UI_WIDTH = 200;

using Button = pangolin::Var<std::function<void(void)>>;

pangolin::DataLog imu_data_log, vio_data_log, error_data_log;
pangolin::Plotter* plotter;

pangolin::Var<int> show_frame("ui.show_frame", 0, 0, 1500);

pangolin::Var<bool> show_obs("ui.show_obs", true, false, true);
pangolin::Var<bool> show_ids("ui.show_ids", false, false, true);

pangolin::Var<bool> show_est_pos("ui.show_est_pos", true, false, true);
pangolin::Var<bool> show_est_vel("ui.show_est_vel", false, false, true);
pangolin::Var<bool> show_est_bg("ui.show_est_bg", false, false, true);
pangolin::Var<bool> show_est_ba("ui.show_est_ba", false, false, true);

pangolin::Var<bool> show_gt("ui.show_gt", true, false, true);

Button next_step_btn("ui.next_step", &next_step);
Button prev_step_btn("ui.prev_step", &prev_step);

pangolin::Var<bool> continue_btn("ui.continue_btn", false, false, true);
pangolin::Var<bool> continue_fast("ui.continue_fast", true, false, true);

Button align_svd_btn("ui.align_svd", &alignButton);

pangolin::Var<bool> follow("ui.follow", true, false, true);

// Visualization variables
std::unordered_map<int64_t, basalt::VioVisualizationData::Ptr> vis_map;

tbb::concurrent_bounded_queue<basalt::VioVisualizationData::Ptr> out_vis_queue;
tbb::concurrent_bounded_queue<basalt::PoseVelBiasState::Ptr> out_state_queue;

std::vector<int64_t> vio_t_ns;
Eigen::vector<Eigen::Vector3d> vio_t_w_i;

std::vector<int64_t> gt_t_ns;
Eigen::vector<Eigen::Vector3d> gt_t_w_i;

std::string marg_data_path;
size_t last_frame_processed = 0;

tbb::concurrent_unordered_map<int64_t, int> timestamp_to_id;

std::mutex m;
std::condition_variable cv;
bool step_by_step = false;

// VIO variables
basalt::Calibration<double> calib;

basalt::VioDatasetPtr vio_dataset;
basalt::VioConfig vio_config;
basalt::OpticalFlowBase::Ptr opt_flow_ptr;
basalt::VioEstimatorBase::Ptr vio;

// Feed functions
void feed_images() {
  std::cout << "Started input_data thread " << std::endl;

  for (size_t i = 0; i < vio_dataset->get_image_timestamps().size(); i++) {
    if (step_by_step) {
      std::unique_lock<std::mutex> lk(m);
      cv.wait(lk);
    }

    basalt::OpticalFlowInput::Ptr data(new basalt::OpticalFlowInput);

    data->t_ns = vio_dataset->get_image_timestamps()[i];
    data->img_data = vio_dataset->get_image_data(data->t_ns);

    timestamp_to_id[data->t_ns] = i;

    opt_flow_ptr->input_queue.push(data);
  }

  // Indicate the end of the sequence
  opt_flow_ptr->input_queue.push(nullptr);

  std::cout << "Finished input_data thread " << std::endl;
}

void feed_imu() {
  for (size_t i = 0; i < vio_dataset->get_gyro_data().size(); i++) {
    basalt::ImuData::Ptr data(new basalt::ImuData);
    data->t_ns = vio_dataset->get_gyro_data()[i].timestamp_ns;

    data->accel = vio_dataset->get_accel_data()[i].data;
    data->gyro = vio_dataset->get_gyro_data()[i].data;

    const double accel_noise_std = calib.dicreete_time_accel_noise_std();
    const double gyro_noise_std = calib.dicreete_time_gyro_noise_std();

    data->accel_cov.setConstant(accel_noise_std * accel_noise_std);
    data->gyro_cov.setConstant(gyro_noise_std * gyro_noise_std);

    vio->imu_data_queue.push(data);
  }
  vio->imu_data_queue.push(nullptr);
}

int main(int argc, char** argv) {
  bool show_gui = true;
  bool print_queue = false;
  std::string cam_calib_path;
  std::string dataset_path;
  std::string dataset_type;
  std::string config_path;
  std::string result_path;
  int num_threads = 0;

  CLI::App app{"App description"};

  app.add_option("--show-gui", show_gui, "Show GUI");
  app.add_option("--cam-calib", cam_calib_path,
                 "Ground-truth camera calibration used for simulation.")
      ->required();

  app.add_option("--dataset-path", dataset_path, "Path to dataset.")
      ->required();

  app.add_option("--dataset-type", dataset_type, "Dataset type <euroc, bag>.")
      ->required();

  app.add_option("--marg-data", marg_data_path,
                 "Path to folder where marginalization data will be stored.");

  app.add_option("--print-queue", print_queue, "Print queue.");
  app.add_option("--config-path", config_path, "Path to config file.");
  app.add_option("--result-path", result_path,
                 "Path to result file where the system will write RMSE ATE.");
  app.add_option("--num-threads", num_threads, "Number of threads.");
  app.add_option("--step-by-step", step_by_step, "Path to config file.");

  if (num_threads > 0) {
    tbb::task_scheduler_init init(num_threads);
  }

  try {
    app.parse(argc, argv);
  } catch (const CLI::ParseError& e) {
    return app.exit(e);
  }

  if (!config_path.empty()) {
    vio_config.load(config_path);
  }

  load_data(cam_calib_path);

  {
    basalt::DatasetIoInterfacePtr dataset_io =
        basalt::DatasetIoFactory::getDatasetIo(dataset_type);

    dataset_io->read(dataset_path);

    vio_dataset = dataset_io->get_data();
    vio_dataset->get_image_timestamps().erase(
        vio_dataset->get_image_timestamps().begin());

    show_frame.Meta().range[1] = vio_dataset->get_image_timestamps().size() - 1;
    show_frame.Meta().gui_changed = true;

    opt_flow_ptr =
        basalt::OpticalFlowFactory::getOpticalFlow(vio_config, calib);

    for (size_t i = 0; i < vio_dataset->get_gt_pose_data().size(); i++) {
      gt_t_ns.push_back(vio_dataset->get_gt_timestamps()[i]);
      gt_t_w_i.push_back(vio_dataset->get_gt_pose_data()[i].translation());
    }
  }

  const int64_t start_t_ns = vio_dataset->get_image_timestamps().front();
  Sophus::SE3d T_w_i_init;
  Eigen::Vector3d vel_w_i_init;

  {
    int64_t t_init_ns = vio_dataset->get_image_timestamps()[0];

    {
      T_w_i_init.setQuaternion(Eigen::Quaterniond::FromTwoVectors(
          vio_dataset->get_accel_data()[0].data, Eigen::Vector3d::UnitZ()));

      std::cout << "T_w_i_init\n" << T_w_i_init.matrix() << std::endl;
      std::cout
          << "accel_w "
          << (T_w_i_init * vio_dataset->get_accel_data()[0].data).transpose()
          << std::endl;
    }

    vel_w_i_init.setZero();

    std::cout << "Setting up filter: t_ns " << t_init_ns << std::endl;
    std::cout << "T_w_i\n" << T_w_i_init.matrix() << std::endl;
    std::cout << "vel_w_i " << vel_w_i_init.transpose() << std::endl;

    vio = basalt::VioEstimatorFactory::getVioEstimator(
        vio_config, calib, t_init_ns, T_w_i_init, vel_w_i_init,
        Eigen::Vector3d::Zero(), Eigen::Vector3d::Zero(), 0.0001,
        basalt::constants::g);

    opt_flow_ptr->output_queue = &vio->vision_data_queue;
    if (show_gui) vio->out_vis_queue = &out_vis_queue;
    vio->out_state_queue = &out_state_queue;
  }

  basalt::MargDataSaver::Ptr marg_data_saver;

  if (!marg_data_path.empty()) {
    marg_data_saver.reset(new basalt::MargDataSaver(marg_data_path));
    vio->out_marg_queue = &marg_data_saver->in_marg_queue;

    // Save gt.
    {
      std::string p = marg_data_path + "/gt.cereal";
      std::ofstream os(p, std::ios::binary);

      {
        cereal::BinaryOutputArchive archive(os);
        archive(gt_t_ns);
        archive(gt_t_w_i);
      }
      os.close();
    }
  }

  vio_data_log.Clear();

  std::thread t1(&feed_images);
  std::thread t2(&feed_imu);

  std::shared_ptr<std::thread> t3;

  if (show_gui)
    t3.reset(new std::thread([&]() {
      basalt::VioVisualizationData::Ptr data;

      while (true) {
        out_vis_queue.pop(data);

        if (data.get()) {
          vis_map[data->t_ns] = data;
        } else {
          break;
        }
      }

      std::cout << "Finished t3" << std::endl;
    }));

  std::thread t4([&]() {
    basalt::PoseVelBiasState::Ptr data;

    while (true) {
      out_state_queue.pop(data);

      if (!data.get()) break;

      int64_t t_ns = data->t_ns;

      // std::cerr << "t_ns " << t_ns << std::endl;
      Sophus::SE3d T_w_i = data->T_w_i;
      Eigen::Vector3d vel_w_i = data->vel_w_i;
      Eigen::Vector3d bg = data->bias_gyro;
      Eigen::Vector3d ba = data->bias_accel;

      vio_t_ns.emplace_back(data->t_ns);
      vio_t_w_i.emplace_back(T_w_i.translation());

      if (show_gui) {
        std::vector<float> vals;
        vals.push_back((t_ns - start_t_ns) * 1e-9);

        for (int i = 0; i < 3; i++) vals.push_back(vel_w_i[i]);
        for (int i = 0; i < 3; i++) vals.push_back(T_w_i.translation()[i]);
        for (int i = 0; i < 3; i++) vals.push_back(bg[i]);
        for (int i = 0; i < 3; i++) vals.push_back(ba[i]);

        vio_data_log.Log(vals);
      }
    }

    std::cout << "Finished t4" << std::endl;
  });

  std::shared_ptr<std::thread> t5;

  if (print_queue) {
    t5.reset(new std::thread([&]() {
      while (true) {
        std::cout << "opt_flow_ptr->input_queue "
                  << opt_flow_ptr->input_queue.size()
                  << " opt_flow_ptr->output_queue "
                  << opt_flow_ptr->output_queue->size() << " out_state_queue "
                  << out_state_queue.size() << std::endl;
        sleep(1);
      }
    }));
  }

  if (show_gui) {
    pangolin::CreateWindowAndBind("Main", 1800, 1000);

    glEnable(GL_DEPTH_TEST);

    pangolin::View& img_view_display =
        pangolin::CreateDisplay()
            .SetBounds(0.4, 1.0, pangolin::Attach::Pix(UI_WIDTH), 0.4)
            .SetLayout(pangolin::LayoutEqual);

    pangolin::View& plot_display = pangolin::CreateDisplay().SetBounds(
        0.0, 0.4, pangolin::Attach::Pix(UI_WIDTH), 1.0);

    plotter = new pangolin::Plotter(&imu_data_log, 0.0, 100, -10.0, 10.0, 0.01f,
                                    0.01f);
    plot_display.AddDisplay(*plotter);

    pangolin::CreatePanel("ui").SetBounds(0.0, 1.0, 0.0,
                                          pangolin::Attach::Pix(UI_WIDTH));

    std::vector<std::shared_ptr<pangolin::ImageView>> img_view;
    while (img_view.size() < calib.intrinsics.size()) {
      std::shared_ptr<pangolin::ImageView> iv(new pangolin::ImageView);

      size_t idx = img_view.size();
      img_view.push_back(iv);

      img_view_display.AddDisplay(*iv);
      iv->extern_draw_function =
          std::bind(&draw_image_overlay, std::placeholders::_1, idx);
    }

    Eigen::Vector3d cam_p(-0.5, -3, -5);
    cam_p = T_w_i_init.so3() * calib.T_i_c[0].so3() * cam_p;

    pangolin::OpenGlRenderState camera(
        pangolin::ProjectionMatrix(640, 480, 400, 400, 320, 240, 0.001, 10000),
        pangolin::ModelViewLookAt(cam_p[0], cam_p[1], cam_p[2], 0, 0, 0,
                                  pangolin::AxisZ));

    pangolin::View& display3D =
        pangolin::CreateDisplay()
            .SetAspect(-640 / 480.0)
            .SetBounds(0.4, 1.0, 0.4, 1.0)
            .SetHandler(new pangolin::Handler3D(camera));

    while (!pangolin::ShouldQuit()) {
      glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

      if (follow) {
        size_t frame_id = show_frame;
        int64_t t_ns = vio_dataset->get_image_timestamps()[frame_id];
        auto it = vis_map.find(t_ns);

        if (it != vis_map.end()) {
          auto T_w_i = it->second->states.back();
          T_w_i.so3() = Sophus::SO3d();

          camera.Follow(T_w_i.matrix());
        }
      }

      display3D.Activate(camera);
      glClearColor(1.0f, 1.0f, 1.0f, 1.0f);

      draw_scene();

      img_view_display.Activate();

      if (show_frame.GuiChanged()) {
        for (size_t cam_id = 0; cam_id < calib.intrinsics.size(); cam_id++) {
          size_t frame_id = static_cast<size_t>(show_frame);
          int64_t timestamp = vio_dataset->get_image_timestamps()[frame_id];

          std::vector<basalt::ImageData> img_vec =
              vio_dataset->get_image_data(timestamp);

          pangolin::GlPixFormat fmt;
          fmt.glformat = GL_LUMINANCE;
          fmt.gltype = GL_UNSIGNED_SHORT;
          fmt.scalable_internal_format = GL_LUMINANCE16;

          img_view[cam_id]->SetImage(
              img_vec[cam_id].img->ptr, img_vec[cam_id].img->w,
              img_vec[cam_id].img->h, img_vec[cam_id].img->pitch, fmt);
        }

        draw_plots();
      }

      if (show_est_vel.GuiChanged() || show_est_pos.GuiChanged() ||
          show_est_ba.GuiChanged() || show_est_bg.GuiChanged()) {
        draw_plots();
      }

      pangolin::FinishFrame();

      if (continue_btn) {
        if (!next_step())
          std::this_thread::sleep_for(std::chrono::milliseconds(50));
      } else {
        std::this_thread::sleep_for(std::chrono::milliseconds(50));
      }

      if (continue_fast) {
        int64_t t_ns = vio->last_processed_t_ns;
        if (timestamp_to_id.count(t_ns)) {
          show_frame = timestamp_to_id[t_ns];
          show_frame.Meta().gui_changed = true;
        }

        if (vio->finished) {
          continue_fast = false;
        }
      }
    }
  }

  t1.join();
  t2.join();
  if (t3.get()) t3->join();
  t4.join();

  if (!result_path.empty()) {
    double error = basalt::alignSVD(vio_t_ns, vio_t_w_i, gt_t_ns, gt_t_w_i);

    std::ofstream os(result_path);
    os << error << std::endl;
    os.close();
  }

  return 0;
}

void draw_image_overlay(pangolin::View& v, size_t cam_id) {
  //  size_t frame_id = show_frame;
  //  basalt::TimeCamId tcid =
  //      std::make_pair(vio_dataset->get_image_timestamps()[frame_id],
  //      cam_id);

  size_t frame_id = show_frame;
  auto it = vis_map.find(vio_dataset->get_image_timestamps()[frame_id]);

  if (show_obs) {
    glLineWidth(1.0);
    glColor3f(1.0, 0.0, 0.0);
    glEnable(GL_BLEND);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

    if (it != vis_map.end() && cam_id < it->second->projections.size()) {
      const auto& points = it->second->projections[cam_id];

      if (points.size() > 0) {
        double min_id = points[0][2], max_id = points[0][2];

        for (const auto& points2 : it->second->projections)
          for (const auto& p : points2) {
            min_id = std::min(min_id, p[2]);
            max_id = std::max(max_id, p[2]);
          }

        for (const auto& c : points) {
          const float radius = 6.5;

          float r, g, b;
          getcolor(c[2] - min_id, max_id - min_id, b, g, r);
          glColor3f(r, g, b);

          pangolin::glDrawCirclePerimeter(c[0], c[1], radius);

          if (show_ids)
            pangolin::GlFont::I().Text("%d", int(c[3])).Draw(c[0], c[1]);
        }
      }

      glColor3f(1.0, 0.0, 0.0);
      pangolin::GlFont::I()
          .Text("Tracked %d points", points.size())
          .Draw(5, 20);
    }
  }
}

void draw_scene() {
  glPointSize(3);
  glColor3f(1.0, 0.0, 0.0);
  glEnable(GL_BLEND);
  glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

  glColor3ubv(cam_color);
  Eigen::vector<Eigen::Vector3d> sub_gt(vio_t_w_i.begin(),
                                        vio_t_w_i.begin() + show_frame);
  pangolin::glDrawLineStrip(sub_gt);

  glColor3ubv(gt_color);
  if (show_gt) pangolin::glDrawLineStrip(gt_t_w_i);

  size_t frame_id = show_frame;
  int64_t t_ns = vio_dataset->get_image_timestamps()[frame_id];
  auto it = vis_map.find(t_ns);

  if (it != vis_map.end()) {
    for (const auto& p : it->second->states)
      for (size_t i = 0; i < calib.T_i_c.size(); i++)
        render_camera((p * calib.T_i_c[i]).matrix(), 2.0f, state_color, 0.1f);

    for (const auto& p : it->second->frames)
      for (size_t i = 0; i < calib.T_i_c.size(); i++)
        render_camera((p * calib.T_i_c[i]).matrix(), 2.0f, pose_color, 0.1f);

    for (size_t i = 0; i < calib.T_i_c.size(); i++)
      render_camera((it->second->states.back() * calib.T_i_c[i]).matrix(), 2.0f,
                    cam_color, 0.1f);

    glColor3ubv(pose_color);
    pangolin::glDrawPoints(it->second->points);
  }

  pangolin::glDrawAxis(Sophus::SE3d().matrix(), 1.0);
}

void load_data(const std::string& calib_path) {
  std::ifstream os(calib_path, std::ios::binary);

  if (os.is_open()) {
    cereal::JSONInputArchive archive(os);
    archive(calib);
    std::cout << "Loaded camera with " << calib.intrinsics.size() << " cameras"
              << std::endl;

  } else {
    std::cerr << "could not load camera calibration " << calib_path
              << std::endl;
    std::abort();
  }
}

bool next_step() {
  if (show_frame < int(vio_dataset->get_image_timestamps().size()) - 1) {
    show_frame = show_frame + 1;
    show_frame.Meta().gui_changed = true;
    cv.notify_one();
    return true;
  } else {
    return false;
  }
}

bool prev_step() {
  if (show_frame > 1) {
    show_frame = show_frame - 1;
    show_frame.Meta().gui_changed = true;
    return true;
  } else {
    return false;
  }
}

void draw_plots() {
  plotter->ClearSeries();
  plotter->ClearMarkers();

  if (show_est_pos) {
    plotter->AddSeries("$0", "$4", pangolin::DrawingModeLine,
                       pangolin::Colour::Red(), "position x", &vio_data_log);
    plotter->AddSeries("$0", "$5", pangolin::DrawingModeLine,
                       pangolin::Colour::Green(), "position y", &vio_data_log);
    plotter->AddSeries("$0", "$6", pangolin::DrawingModeLine,
                       pangolin::Colour::Blue(), "position z", &vio_data_log);
  }

  if (show_est_vel) {
    plotter->AddSeries("$0", "$1", pangolin::DrawingModeLine,
                       pangolin::Colour::Red(), "velocity x", &vio_data_log);
    plotter->AddSeries("$0", "$2", pangolin::DrawingModeLine,
                       pangolin::Colour::Green(), "velocity y", &vio_data_log);
    plotter->AddSeries("$0", "$3", pangolin::DrawingModeLine,
                       pangolin::Colour::Blue(), "velocity z", &vio_data_log);
  }

  if (show_est_bg) {
    plotter->AddSeries("$0", "$7", pangolin::DrawingModeLine,
                       pangolin::Colour::Red(), "gyro bias x", &vio_data_log);
    plotter->AddSeries("$0", "$8", pangolin::DrawingModeLine,
                       pangolin::Colour::Green(), "gyro bias y", &vio_data_log);
    plotter->AddSeries("$0", "$9", pangolin::DrawingModeLine,
                       pangolin::Colour::Blue(), "gyro bias z", &vio_data_log);
  }

  if (show_est_ba) {
    plotter->AddSeries("$0", "$10", pangolin::DrawingModeLine,
                       pangolin::Colour::Red(), "accel bias x", &vio_data_log);
    plotter->AddSeries("$0", "$11", pangolin::DrawingModeLine,
                       pangolin::Colour::Green(), "accel bias y",
                       &vio_data_log);
    plotter->AddSeries("$0", "$12", pangolin::DrawingModeLine,
                       pangolin::Colour::Blue(), "accel bias z", &vio_data_log);
  }

  double t = vio_dataset->get_image_timestamps()[show_frame] * 1e-9;
  plotter->AddMarker(pangolin::Marker::Vertical, t, pangolin::Marker::Equal,
                     pangolin::Colour::White());
}

void alignButton() { basalt::alignSVD(vio_t_ns, vio_t_w_i, gt_t_ns, gt_t_w_i); }