#include "map_simulation.hpp"
#include "../../config.h"

MapSimulation::MapSimulation()
{
    mapPlayersById = std::map<int, std::shared_ptr<MapPlayer>>();
}

std::shared_ptr<MapSimulation> MapSimulation::getInstance()
{
    if (singletonInstance == nullptr)
    {
        singletonInstance = std::make_shared<MapSimulation>();
    }
    return singletonInstance;
}

void MapSimulation::updateSimulation()
{
    // Get player positions
    for (auto &mapPlayer: mapPlayersById)
    {
        auto player = mapPlayer.second->player;
        auto body = mapPlayer.second->body;

        auto coordinates = player->coordinates->world();
        b2Vec2 playerPosition = b2Vec2(coordinates.x, coordinates.y);
        body->SetTransform(playerPosition, 0);
    }

    world->Step(FRAME_TIME.asSeconds(), MAPSIM_VELOCITY_ITERATIONS, MAPSIM_POSITION_ITERATIONS);

    // Update player positions
    for (auto &mapPlayer: mapPlayersById)
    {
        auto player = mapPlayer.second->player;
        auto body = mapPlayer.second->body;

        b2Vec2 playerPosition = body->GetPosition();
        player->coordinates->set(sf::Vector2f(playerPosition.x, playerPosition.y));
    }
}

void MapSimulation::resetMap(sf::Vector2f worldMapSize)
{
    // No gravity, since this a top-down view of the map
    world = std::make_shared<b2World>(b2Vec2(0.0f, 0.0f));
    mapPlayersById.clear();

    // Create map borders
    constructSquareObstacle(-1, 0, 0, worldMapSize.y);
    constructSquareObstacle(0, -1, worldMapSize.x, 0);
    constructSquareObstacle(worldMapSize.x, 0, worldMapSize.x + 1, worldMapSize.y);
    constructSquareObstacle(0, worldMapSize.y, worldMapSize.x, worldMapSize.y + 1);
}

void MapSimulation::constructSquareObstacle(float minX, float minY, float maxX, float maxY)
{
    b2BodyDef bodyDef;
    bodyDef.type = b2_staticBody;
    bodyDef.position.Set((maxX - minX) / 2.f, (maxY - minY) / 2.f);
    b2Body *body = world->CreateBody(&bodyDef);

    b2PolygonShape shape;
    shape.SetAsBox(maxX - minX, maxY - minY);

    b2FixtureDef fixtureDef;
    fixtureDef.shape = &shape;
    fixtureDef.density = 1.0f;

    body->CreateFixture(&fixtureDef);
}

void MapSimulation::addPlayer(Player *player)
{
    b2BodyDef bodyDef;
    bodyDef.type = b2_kinematicBody;
    bodyDef.position.Set(player->getTrackablePosition().x, player->getTrackablePosition().y);
    b2Body *body = world->CreateBody(&bodyDef);

    b2CircleShape shape;
    shape.m_radius = MAPSIM_PLAYER_RADIUS;
    shape.m_p.Set(0, 0);

    b2FixtureDef fixtureDef;
    fixtureDef.shape = &shape;
    fixtureDef.density = 1.0f;

    body->CreateFixture(&fixtureDef);
    mapPlayersById[player->getPlayerId()] = std::make_shared<MapPlayer>(player, body);
}