#include <catch2/catch_test_macros.hpp>
#include "dinkyecs.hpp"
#include <iostream>
#include <fmt/core.h>

using namespace fmt;
using DinkyECS::Entity;

struct Player {
  std::string name;
  Entity eid;
};

struct Position {
  double x, y;
};

struct Velocity {
  double x, y;
};

struct Gravity {
  double level;
};

struct DaGUI {
  int event;
};

/*
 * Using a function catches instances where I'm not copying
 * the data into the world.
 */
void configure(DinkyECS::World &world, Entity &test) {
  println("---Configuring the base system.");
  Entity test2 = world.entity();

  world.set<Position>(test, {10,20});
  world.set<Velocity>(test, {1,2});

  world.set<Position>(test2, {1,1});
  world.set<Velocity>(test2, {9,19});

  println("---- Setting up the player as a fact in the system.");

  auto player_eid = world.entity();
  Player player_info{"Zed", player_eid};
  // just set some player info as a fact with the entity id
  world.set_the<Player>(player_info);

  world.set<Velocity>(player_eid, {0,0});
  world.set<Position>(player_eid, {0,0});

  auto enemy = world.entity();
  world.set<Velocity>(enemy, {0,0});
  world.set<Position>(enemy, {0,0});

  println("--- Creating facts (singletons)");
  world.set_the<Gravity>({0.9});
}

TEST_CASE("confirm ECS system works", "[ecs]") {
  DinkyECS::World world;
  Entity test = world.entity();

  configure(world, test);

  Position &pos = world.get<Position>(test);
  REQUIRE(pos.x == 10);
  REQUIRE(pos.y == 20);

  Velocity &vel = world.get<Velocity>(test);
  REQUIRE(vel.x == 1);
  REQUIRE(vel.y == 2);

  world.query<Position>([](const auto &ent, auto &pos) {
      REQUIRE(ent > 0);
      REQUIRE(pos.x >= 0);
      REQUIRE(pos.y >= 0);
  });

  world.query<Velocity>([](const auto &ent, auto &vel) {
      REQUIRE(ent > 0);
      REQUIRE(vel.x >= 0);
      REQUIRE(vel.y >= 0);
  });

  println("--- Manually get the velocity in position system:");
  world.query<Position>([&](const auto &ent, auto &pos) {
      Velocity &vel = world.get<Velocity>(ent);

      REQUIRE(ent > 0);
      REQUIRE(pos.x >= 0);
      REQUIRE(pos.y >= 0);
      REQUIRE(ent > 0);
      REQUIRE(vel.x >= 0);
      REQUIRE(vel.y >= 0);
  });

  println("--- Query only entities with Position and Velocity:");
  world.query<Position, Velocity>([&](const auto &ent, auto &pos, auto &vel) {
      Gravity &grav = world.get_the<Gravity>();
      REQUIRE(grav.level <= 1.0f);
      REQUIRE(grav.level > 0.5f);
      REQUIRE(ent > 0);
      REQUIRE(pos.x >= 0);
      REQUIRE(pos.y >= 0);
      REQUIRE(ent > 0);
      REQUIRE(vel.x >= 0);
      REQUIRE(vel.y >= 0);
  });

  // now remove Velocity
  world.remove<Velocity>(test);
  REQUIRE_THROWS(world.get<Velocity>(test));

  println("--- After remove test, should only result in test2:");
  world.query<Position, Velocity>([&](const auto &ent, auto &pos, auto &vel) {
      REQUIRE(pos.x >= 0);
      REQUIRE(pos.y >= 0);
  });
}

enum FakeEvent {
  HIT_EVENT, MISS_EVENT
};

TEST_CASE("confirm that the event system works", "[ecs]") {
  DinkyECS::World world;
  DinkyECS::Entity gui_ent = world.entity();
  DinkyECS::Entity player = world.entity();
  DaGUI gui{384};

  world.set<DaGUI>(gui_ent, gui);
  DaGUI &gui_test = world.get<DaGUI>(gui_ent);
  REQUIRE(gui.event == gui_test.event);

  world.send<DaGUI>(FakeEvent::HIT_EVENT, player);

  bool ready = world.has_event<DaGUI>();
  REQUIRE(ready == true);

  auto [event, entity] = world.recv<DaGUI>();
  REQUIRE(event == FakeEvent::HIT_EVENT);
  REQUIRE(entity == player);

  ready = world.has_event<DaGUI>();
  REQUIRE(ready == false);
}