#define FSM_DEBUG 1
#include "sound.hpp"
#include "ai.hpp"
#include "animation.hpp"
#include <iostream>
#include "shaders.hpp"
#include "backend.hpp"
#include "constants.hpp"
#include "animate2.hpp"
#include "tools/animator.hpp"
#include <unistd.h>

/*
 * TODO:
 *
 * - Easing functions from strings in json.
 * - Map of animation forms.
 * - Bring back shaders.
 */

using namespace std::chrono_literals;

bool YES_SYNC=true;

namespace animator {

  void FSM::init(const std::string &sprite_name, const std::string &anim_name, const std::string &background) {
    $timer.start();
    $sprite_name = sprite_name;
    $anim_name = anim_name;
    $background = background;

    // this loads the animation
    reload();

    sf::Vector2u new_size{(unsigned int)$anim.sheet.frame_width, (unsigned int)$anim.sheet.frame_height};
    $window = sf::RenderWindow(sf::VideoMode(new_size), "Animation Crafting Tool");
    $window.setPosition({0,0});

    $ui.init($sprite_name, $background, new_size.x, new_size.y);
    $sprite = $ui.get_sprite();

    // need to keep these aroung
    $pos = $sprite->getPosition();
    $scale = $sprite->getScale();

    if(YES_SYNC) {
      $window.setVerticalSyncEnabled(VSYNC);
      if(FRAME_LIMIT) $window.setFramerateLimit(FRAME_LIMIT);
    }
  }

  void FSM::event(Event ev, std::any data) {
    switch($state) {
      FSM_STATE(State, START, ev);
      FSM_STATE(State, ANIMATE, ev);
      FSM_STATE(State, END, ev);
    }
  }

  void FSM::START(Event ev) {
    switch(ev) {
      case Event::TICK:
        state(State::ANIMATE);
        break;
      default:
        state(State::START);
    }
  }

  void FSM::ANIMATE(Event ev) {
    switch(ev) {
      case Event::TICK:
        run_animation();
        break;
      case Event::PLAY_STOP:
        if($anim.playing) {
          $anim.stop();
        } else {
          $anim.play();
        }
        break;
      case Event::RELOAD:
        reload();
        state(State::START);
        break;
      default:
        state(State::START);
    }
  }

  void FSM::END(Event ev) {
  }

  void FSM::run_animation() {
    if($anim.playing) {
      $anim.update();
      if(!$anim.transform.simple) $anim.apply(*$sprite);
      $anim.motion(*$sprite, $pos, $scale);
    }
  }

  void FSM::tick() {
    auto [ticks, alpha] = $anim.commit();

    for(int i = 0; i < ticks; i++) {
      event(animator::Event::TICK, {});
    }
  }

  void FSM::check_update() {
    if($timer.getElapsedTime().toDuration() > 500ms) {
      auto mod_time = std::filesystem::last_write_time("assets/animate2.json");

      if($last_mod_time < mod_time) {
        event(Event::RELOAD);
      }

      $timer.restart();
    }
  }

  void FSM::reload() {
    $anim = animate2::load("assets/animate2.json", $anim_name);
    $anim.play();
    $last_mod_time = std::filesystem::last_write_time("assets/animate2.json");
  }

  void FSM::handle_keyboard_mouse() {
    while(const auto ev = $window.pollEvent()) {
      using enum game::Event;
      using KEY = sf::Keyboard::Scan;
      auto gui_ev = $router.process_event(ev);
      auto mouse_pos = $window.mapPixelToCoords($router.position);

      switch(gui_ev) {
        case KEY_PRESS:
          if($router.scancode == KEY::Space) {
            event(Event::PLAY_STOP);
          }
          break;
        case MOUSE_CLICK:
          $ui.mouse(mouse_pos.x, mouse_pos.y, guecs::NO_MODS);
          break;
        case MOUSE_MOVE:
          $ui.mouse(mouse_pos.x, mouse_pos.y, {1 << guecs::ModBit::hover});
          break;
        case QUIT:
          state(State::END);
        default:
          break; // ignored
      }
    }
  }

  void FSM::render() {
    $window.clear();
    $ui.render($window, true);
    $window.display();
  }

  bool FSM::active() {
    return !in_state(State::END);
  }

  void UI::init(const std::string& sprite_name, const std::string& background, int width, int height) {
    $ui.position(0,0, width, height);
    $ui.layout("[=viewer]");

    if(background != "") {
      $ui.set<guecs::Background>($ui.MAIN, {$ui.$parser, guecs::THEME.TRANSPARENT});
      auto& bg = $ui.get<guecs::Background>($ui.MAIN);
      bg.set_sprite(background, true);
    }

    auto viewer = $ui.entity("viewer");
    $ui.set<guecs::Sprite>(viewer, { sprite_name, 0, false});

    $ui.init();
  }

  void UI::render(sf::RenderWindow& window, bool debug) {
    $ui.render(window);

    if(debug) {
      $ui.debug_layout(window);
    }
  }

  bool UI::mouse(float x, float y, guecs::Modifiers mods) {
    return $ui.mouse(x, y, mods);
  }

  std::shared_ptr<sf::Sprite> UI::get_sprite() {
    auto viewer = $ui.entity("viewer");
    return $ui.get<guecs::Sprite>(viewer).sprite;
  }
}

int error() {
  fmt::println("USAGE: animator -h -b <background> -s <sprite> -a <animation>");
  return 1;
}

int main(int argc, char* argv[]) {
  shaders::init();
  components::init();
  sfml::Backend backend;
  guecs::init(&backend);
  ai::init("ai");
  animation::init();

  std::string sprite_name;
  std::string background;
  std::string anim_name;
  int opt = 0;

  while((opt = getopt(argc, argv, "hb:s:a:")) != -1) {
    switch(opt) {
      case 'b':
        background = optarg;
        break;
      case 's':
        sprite_name = optarg;
        break;
      case 'a':
        anim_name = optarg;
        break;
      case 'h': // fallthrough
        error();
        break;
      default:
        return error();
        break;
    }
  }

  if(sprite_name == "") {
    return error();
  } else if(anim_name == "") {
    anim_name = sprite_name; // default to the same
  }

  sound::mute(true);
  sound::play("ambient_1", true);

  animator::FSM main;
  main.init(sprite_name, anim_name, background);

  while(main.active()) {
    main.tick();
    main.check_update();
    main.render();
    main.handle_keyboard_mouse();
  }

  return 0;
}