/**
 * Entity class - represents a game object with a unique ID
 * Entities are just containers for components
 */
export class Entity {
  static nextId = 0;

  constructor() {
    this.id = Entity.nextId++;
    this.components = new Map();
    this.active = true;
  }

  /**
     * Add a component to this entity
     */
  addComponent(component) {
    this.components.set(component.type, component);
    return this;
  }

  /**
     * Get a component by type
     */
  getComponent(type) {
    return this.components.get(type);
  }

  /**
     * Check if entity has a component
     */
  hasComponent(type) {
    return this.components.has(type);
  }

  /**
     * Check if entity has all specified components
     */
  hasComponents(...types) {
    return types.every(type => this.components.has(type));
  }

  /**
     * Remove a component
     */
  removeComponent(type) {
    this.components.delete(type);
    return this;
  }

  /**
     * Get all components
     */
  getAllComponents() {
    return Array.from(this.components.values());
  }
}