#include "animation.hpp"
#include "rand.hpp"

namespace components {
  void Animation::play() {
    if(!playing) {
      current = 0;
      subframe = 0.0f;
      playing = true;
    }
  }

  float Animation::twitching() {
    float tick = ease::sine(float(frames) / (subframe + 0.0001) * ease_rate);

    switch(easing) {
      case ease::NONE:
        return 0.0;
      case ease::SINE:
        return std::abs(std::sin(subframe * ease_rate));
      case ease::OUT_CIRC:
        return ease::out_circ(tick);
      case ease::OUT_BOUNCE:
        return ease::sine(ease::out_bounce(tick));
      case ease::IN_OUT_BACK:
        return ease::sine(ease::in_out_back(tick));
      case ease::RANDOM:
        return Random::uniform_real(0.0001f, 1.0f);
      case ease::NORM_DIST:
        return Random::normal(0.5f, 0.1f);
      default:
        dbc::sentinel(
            fmt::format("Invalid easing {} given to animation",
              int(easing)));
    }
  }

  void Animation::step(sf::Vector2f& scale_out, sf::Vector2f& pos_out, sf::IntRect& rect_out) {
    dbc::check(rect_out.size.x > 0, "step given rect_out with size.x <= 0, must be >");
    dbc::check(rect_out.size.y > 0, "step given rect_out with size.y <= 0, must be >");

    if(playing && current < frames) {
      float tick = twitching();

      if(stationary) {
        switch(motion) {
          case ease::SHAKE: {
            pos_out.x += std::lerp(min_x, max_x, tick);
           } break;
          case ease::BOUNCE: {
            pos_out.y -= std::lerp(min_y, max_y, tick);
          } break;
          case ease::RUSH: {
            scale_out.x = std::lerp(min_x, max_x, tick);
            scale_out.y = std::lerp(min_y, max_y, tick);
            pos_out.y = pos_out.y - (pos_out.y * scale_out.y - pos_out.y);
           } break;
          case ease::SQUEEZE: {
            scale_out.x *= std::lerp(min_x, max_x, tick);

          } break;
          case ease::SQUASH: {
            scale_out.y *= std::lerp(min_y, max_y, tick);
          } break;
          case ease::STRETCH: {
            scale_out.x = std::lerp(min_x, max_x, tick);
          } break;
          case ease::GROW: {
            scale_out.y = std::lerp(min_y, max_y, tick);
          } break;
          default:
            dbc::sentinel("Unknown animation.motion setting.");
        }
      } else {
        scale_out.x = std::lerp(scale_out.x * min_x, scale_out.x * max_x, tick);
        scale_out.y = std::lerp(scale_out.y * min_y, scale_out.y * max_y, tick);
      }

      if(!simple) {
        rect_out.position.x += current * frame_width;
      }

      subframe += speed;
      current = looped ? int(subframe) % frames : int(subframe);
    } else if(toggled) {
      playing = false;
      current = frames - 1;
      subframe = float(frames - 1);

      if(!simple) {
        rect_out.position.x += current * frame_width;
      }
    } else {
      scale_out.x = min_x;
      scale_out.y = min_y;
      playing = false;
      current = 0;
      subframe = 0.0f;
    }

    if(flipped) {
      scale_out.x *= -1;
    }
  }
}

namespace animation {
  using namespace components;
  using namespace textures;

  static AnimationManager MGR;
  static bool initialized = false;

  bool apply(Animation& anim, sf::Sprite& sprite, sf::Vector2f pos) {
    sf::IntRect rect{{0,0}, {anim.frame_width, anim.frame_height}};
    sf::Vector2f scale{anim.min_x, anim.min_y};

    anim.step(scale, pos, rect);

    sprite.setTextureRect(rect);
    sprite.setPosition(pos);

    // BUG: make this an option: apply_scale, apply_position and ranges for x y
    if(anim.scaled) {
        sprite.setScale(scale);
    }

    return anim.playing;
  }

  void rotate(sf::Sprite& target, float degrees) {
    target.rotate(sf::degrees(degrees));
  }

  void center(sf::Sprite& target, sf::Vector2f pos) {
    auto bounds = target.getLocalBounds();
    target.setPosition({pos.x + bounds.size.x / 2,
        pos.y + bounds.size.y / 2});
    target.setOrigin({bounds.size.x / 2, bounds.size.y / 2});
  }

  void init() {
    if(!initialized) {
      auto animations = settings::get("animations");
      auto config = settings::get("config");
      auto& sprites = config["sprites"];

      for(auto& [name, data] : animations.json().items()) {
        try {
          auto anim = components::convert<Animation>(data);

          if(!sprites.contains(name)) {
            fmt::println("animation '{}' doesn't have sprite, spelled wrong in config.json?", name);
          } else {
            auto& sprite_config = sprites[name];

            anim.frame_width = sprite_config["frame_width"];
            anim.frame_height = sprite_config["frame_height"];

            dbc::check(anim.frame_width > 0 && anim.frame_height > 0,
                fmt::format("invalid frame width/height for animation: {}",
                  name));
          }

          MGR.animations.insert_or_assign(name, anim);
        } catch(...) {
          dbc::log(fmt::format("error in sprite config: {}", name));
          throw;
        }
      }

      initialized = true;
    }
  }

  bool has(const std::string& name) {
    return MGR.animations.contains(name);
  }

  Animation load(const std::string& name, const std::string& state) {
    dbc::check(initialized, "You forgot to initialize animation.");
    return MGR.animations.at(name + state);
  }

  void configure(DinkyECS::World& world, DinkyECS::Entity entity) {
    auto sprite = world.get_if<Sprite>(entity);
    if(sprite != nullptr && animation::has(sprite->name)) {
      world.set<Animation>(entity, animation::load(sprite->name));
  }
}

  void step_animation(DinkyECS::World& world, DinkyECS::Entity entity, sf::Vector2f& scale_out, sf::Vector2f& pos_out, sf::IntRect& rect_out) {
    if(auto animation = world.get_if<components::Animation>(entity)) {
      if(animation->playing) animation->step(scale_out, pos_out, rect_out);
    }
  }

  void animate_entity(DinkyECS::World &world, DinkyECS::Entity entity) {
    if(world.has<Animation>(entity)) {
      auto& animation = world.get<Animation>(entity);
      animation.play();
    }
  }
}