package game.world;

import java.util.ArrayList;
import java.util.List;
import java.util.Random;

import org.jsfml.graphics.Drawable;
import org.jsfml.graphics.RenderStates;
import org.jsfml.graphics.RenderTarget;
import org.jsfml.graphics.Texture;
import org.jsfml.system.Clock;
import org.jsfml.system.Vector2f;

import game.Resources;
import game.ui.GameWindow;
import game.ui.InputHandler;
import game.world.object.Enemy;
import game.world.object.GameObject;
import game.world.object.PlayerBeta;
import game.world.object.Projectile;

/**
 * The World class holds all game objects and establishes communication among them. Handles creation and destruction of entities.
 */
public class World implements Drawable {
    private List<Enemy> enemies = new ArrayList<>();
    private List<Projectile> projectiles = new ArrayList<>();
    private PlayerBeta player;

    private Clock timer = new Clock();
    private Clock timerShoot = new Clock();

    private Texture projectileTexture, playerTexture, enemyTexture;

    public World(Resources resources, InputHandler inputHandler) {
        projectileTexture = resources.textures.get(3);
        enemyTexture = resources.textures.get(1);
        playerTexture = resources.textures.get(0);

        player = new PlayerBeta(enemyTexture, inputHandler);
    }

    /**
     * Handles creation and destruction of entities and also resolves collision.
     */
    public void update() {
        handlePlayerProjectile();
        spawnEnemy();
        updateEntities();
        resolveBulletCollisions();
        checkForDeallocations();
    }

    private void updateEntities() {
        player.update();
        enemies.forEach(enemy -> enemy.chaseTarget(player));
        projectiles.forEach(Projectile::update);
    }

    private void spawnEnemy() {
        if (timer.getElapsedTime().asSeconds() > 0.2f) {
            Enemy enemy = Enemy.newEnemy(enemyTexture, generateRandomPosition(), player.sprite);
            enemies.add(enemy);
            timer.restart();
        }
    }

    private void handlePlayerProjectile() {
        if (GameWindow.inputHandler.isMouseClicked && timerShoot.getElapsedTime().asSeconds() > 0.1f) {
            timerShoot.restart();
            projectiles.add(Projectile.newProjectile(projectileTexture, player.getPosition(), player.direction));
        }
    }

    private void resolveBulletCollisions() {
        projectiles.forEach(bullet -> enemies.forEach(enemy -> {
            if(bullet.isCollidingWith(enemy)) {
                enemy.status = GameObject.Status.DEAD;
            }
        }));
    }

    private void checkForDeallocations() {
        projectiles.removeIf(Projectile::isOutOfBounds);
        enemies.removeIf(Enemy::isDead);
    }

    private Vector2f generateRandomPosition() {
        int angle = new Random().nextInt(360);
        return new Vector2f(((float) Math.sin(Math.toRadians(angle))) * 500.0f + GameWindow.SCREEN_WIDTH / 2, ((float) Math.cos(Math.toRadians(angle))) * 500.0f + GameWindow.SCREEN_HEIGHT / 2);
    }

    @Override
    public void draw(RenderTarget target, RenderStates states) {
        target.draw(player);
        enemies.forEach(target::draw);
        projectiles.forEach(target::draw);
    }
}