#include "imgui.h"
#include "imgui-SFML.h"
#define _USE_MATH_DEFINES
#include <math.h>
#include <fmt/core.h>
#include <SFML/Graphics/Sprite.hpp>
#include <SFML/Graphics/Texture.hpp>
#include <SFML/Graphics/RenderWindow.hpp>
#include <SFML/System.hpp>
#include <SFML/Audio.hpp>
#include <SFML/Window/Event.hpp>

constexpr int FPS=30;
constexpr int X_DIM = 1920 / 2;
constexpr int Y_DIM = 1080 / 2;

void ImGui_setup(sf::RenderWindow &window) {
  bool res = ImGui::SFML::Init(window);
  fmt::println("IMGUI returned {}", res);
}

void ImGui_update(sf::RenderWindow &window, sf::Clock &deltaClock, sf::Time &tick) {
  ImGui::SFML::Update(window, deltaClock.restart());
  // ImGui::ShowDemoWindow();
  ImGui::Begin("Clock");
  sf::Vector2u size = window.getSize();
  ImGui::SetWindowPos(ImVec2(size.x - 150, 0));
  ImGui::SetWindowSize(ImVec2(150, 50));
  std::string msg = fmt::format("Time: {}\n", tick.asSeconds());
  ImGui::Button(msg.c_str());
  ImGui::End();
}

void Window_update(sf::RenderWindow &window) {
    window.clear();
    ImGui::SFML::Render(window);
    window.display();
}

void Handle_events(sf::RenderWindow &window) {
  sf::Event event;

  // is this a main event loop
  while (window.pollEvent(event)) {
    ImGui::SFML::ProcessEvent(window, event);

    switch(event.type) {

      case sf::Event::Closed:
        fmt::print("Exiting...\n");
        window.close();
        break;
      case sf::Event::KeyPressed:
        if(sf::Keyboard::isKeyPressed(sf::Keyboard::Escape)) {
          window.close();
        }
        break;
      default:
        // do nothing
        break;
    }
  }
}

sf::Time Update_entities(sf::RenderWindow &window, sf::Clock &clock, sf::Clock &deltaClock, sf::Time &tick) {
  sf::Vector2u winSize = window.getSize();
  float timeStep = 1.0f / FPS;
  sf::Time since = clock.getElapsedTime();
  sf::Time nextTick = since - tick > sf::seconds(1) ? since : tick;

  ImGui_update(window, deltaClock, tick);
  Window_update(window);

  return nextTick;
}


int main() {
  fmt::print("Setting up a window for you...\n");

  sf::ContextSettings settings;
  settings.antialiasingLevel = 8;

  sf::RenderWindow window(sf::VideoMode(X_DIM, Y_DIM), "Turing's Tarpit", sf::Style::None, settings);
  window.setPosition({.x=0,.y=0});

  window.setFramerateLimit(FPS);
  window.setVerticalSyncEnabled(true);
  ImGui_setup(window);

  sf::Clock deltaClock;
  sf::Clock clock;
  sf::Time tick = clock.getElapsedTime();

  while (window.isOpen()) {
    Handle_events(window);
    // preparing for refactoring this into a class or struct for everything
    tick = Update_entities(window, clock, deltaClock, tick);
  }

  ImGui::SFML::Shutdown();
}