feat: migrate JavaScript files to TypeScript, enhancing type safety and maintainability across the codebase

src/core/System.ts

@@ -0,0 +1,64 @@
+import { Entity } from './Entity.ts';
+import type { Engine } from './Engine.ts';
+
+/**
+ * Base System class for ECS architecture.
+ * Systems contain logic that operates on entities with specific components.
+ */
+export class System {
+  /** Unique identifier for the system */
+  readonly name: string;
+
+  /** List of component types required by this system */
+  requiredComponents: string[];
+
+  /** Execution priority (lower runs first) */
+  priority: number;
+
+  /** Reference to the game engine */
+  protected engine!: Engine;
+
+  /**
+   * @param name - The unique name of the system
+   */
+  constructor(name: string) {
+    this.name = name;
+    this.requiredComponents = [];
+    this.priority = 0;
+  }
+
+  /**
+   * Check if an entity matches this system's requirements.
+   * @param entity - The entity to check
+   * @returns True if the entity is active and has all required components
+   */
+  matches(entity: Entity): boolean {
+    if (!entity.active) return false;
+    return this.requiredComponents.every((componentType) => entity.hasComponent(componentType));
+  }
+
+  /**
+   * Main update entry point called every frame.
+   * @param deltaTime - Time elapsed since last frame in seconds
+   * @param entities - All entities in the engine
+   */
+  update(deltaTime: number, entities: Entity[]): void {
+    const matchingEntities = entities.filter((entity) => this.matches(entity));
+    this.process(deltaTime, matchingEntities);
+  }
+
+  /**
+   * Process matching entities. To be implemented by subclasses.
+   * @param _deltaTime - Time elapsed since last frame in seconds
+   * @param _entities - Filtered entities that match this system
+   */
+  process(_deltaTime: number, _entities: Entity[]): void {}
+
+  /**
+   * Called when system is added to engine.
+   * @param engine - The game engine instance
+   */
+  init(engine: Engine): void {
+    this.engine = engine;
+  }
+}