feat: Add traps

src/engine/ecs/EntityBuilder.ts

@@ -0,0 +1,243 @@
+import { type ECSWorld } from "./World";
+import { type ComponentMap } from "./components";
+import { type EntityId, type Stats, type EnemyAIState, type ActorType } from "../../core/types";
+import { GAME_CONFIG } from "../../core/config/GameConfig";
+
+/**
+ * Fluent builder for creating ECS entities with components.
+ * Makes entity creation declarative and easy to extend.
+ * 
+ * @example
+ * // Create a simple trap
+ * EntityBuilder.create(world)
+ *   .withPosition(5, 10)
+ *   .asTrap(15)
+ *   .build();
+ * 
+ * @example
+ * // Create an enemy
+ * EntityBuilder.create(world)
+ *   .withPosition(3, 7)
+ *   .asEnemy("rat")
+ *   .build();
+ */
+export class EntityBuilder {
+  private world: ECSWorld;
+  private entityId: EntityId;
+  private components: Partial<{ [K in keyof ComponentMap]: ComponentMap[K] }> = {};
+
+  private constructor(world: ECSWorld) {
+    this.world = world;
+    this.entityId = world.createEntity();
+  }
+
+  /**
+   * Start building a new entity.
+   */
+  static create(world: ECSWorld): EntityBuilder {
+    return new EntityBuilder(world);
+  }
+
+  /**
+   * Add a position component.
+   */
+  withPosition(x: number, y: number): this {
+    this.components.position = { x, y };
+    return this;
+  }
+
+  /**
+   * Add a name component.
+   */
+  withName(name: string): this {
+    this.components.name = { name };
+    return this;
+  }
+
+  /**
+   * Add a sprite component.
+   */
+  withSprite(texture: string, index: number): this {
+    this.components.sprite = { texture, index };
+    return this;
+  }
+
+  /**
+   * Add stats component with partial stats (fills defaults).
+   */
+  withStats(stats: Partial<Stats>): this {
+    const defaultStats: Stats = {
+      maxHp: 10, hp: 10,
+      maxMana: 0, mana: 0,
+      attack: 1, defense: 0,
+      level: 1, exp: 0, expToNextLevel: 10,
+      critChance: 0, critMultiplier: 100, accuracy: 100, lifesteal: 0,
+      evasion: 0, blockChance: 0, luck: 0,
+      statPoints: 0, skillPoints: 0,
+      strength: 10, dexterity: 10, intelligence: 10,
+      passiveNodes: []
+    };
+    this.components.stats = { ...defaultStats, ...stats };
+    return this;
+  }
+
+  /**
+   * Add energy component for turn scheduling.
+   */
+  withEnergy(speed: number, current: number = 0): this {
+    this.components.energy = { current, speed };
+    return this;
+  }
+
+  /**
+   * Add AI component for enemy behavior.
+   */
+  withAI(state: EnemyAIState = "wandering"): this {
+    this.components.ai = { state };
+    return this;
+  }
+
+  /**
+   * Add player tag component.
+   */
+  asPlayer(): this {
+    this.components.player = {};
+    this.components.actorType = { type: "player" };
+    return this;
+  }
+
+  /**
+   * Configure as an enemy with stats from GameConfig.
+   */
+  asEnemy(type: ActorType): this {
+    if (type === "player") {
+      throw new Error("Use asPlayer() for player entities");
+    }
+    
+    this.components.actorType = { type };
+    this.withAI("wandering");
+    
+    // Apply enemy stats from config
+    const config = GAME_CONFIG.enemies[type as keyof typeof GAME_CONFIG.enemies];
+    if (config) {
+      const speed = config.minSpeed + Math.random() * (config.maxSpeed - config.minSpeed);
+      this.withStats({
+        maxHp: config.baseHp,
+        hp: config.baseHp,
+        attack: config.baseAttack,
+        defense: config.baseDefense
+      });
+      this.withEnergy(speed);
+    }
+    
+    return this;
+  }
+
+  /**
+   * Configure as a trap that deals damage when stepped on.
+   */
+  asTrap(damage: number, oneShot: boolean = false): this {
+    this.components.trigger = {
+      onEnter: true,
+      oneShot,
+      damage
+    };
+    return this;
+  }
+
+  /**
+   * Configure as a trigger zone (pressure plate, etc).
+   */
+  asTrigger(options: {
+    onEnter?: boolean;
+    onExit?: boolean;
+    oneShot?: boolean;
+    effect?: string;
+    effectDuration?: number;
+  }): this {
+    this.components.trigger = {
+      onEnter: options.onEnter ?? true,
+      onExit: options.onExit,
+      oneShot: options.oneShot,
+      effect: options.effect,
+      effectDuration: options.effectDuration
+    };
+    return this;
+  }
+
+  /**
+   * Configure as a destructible object.
+   */
+  asDestructible(hp: number, maxHp?: number, options?: {
+    destroyedTile?: number;
+    lootTable?: string;
+  }): this {
+    this.components.destructible = {
+      hp,
+      maxHp: maxHp ?? hp,
+      destroyedTile: options?.destroyedTile,
+      lootTable: options?.lootTable
+    };
+    return this;
+  }
+
+  /**
+   * Configure as a collectible (exp orb, etc).
+   */
+  asCollectible(type: "exp_orb", amount: number): this {
+    this.components.collectible = { type, amount };
+    return this;
+  }
+
+  /**
+   * Configure as an item on the ground.
+   */
+  asGroundItem(itemId: string, quantity: number = 1): this {
+    this.components.groundItem = { itemId, quantity };
+    return this;
+  }
+
+  /**
+   * Add initial status effects.
+   */
+  withStatusEffects(effects: ComponentMap["statusEffects"]["effects"]): this {
+    this.components.statusEffects = { effects };
+    return this;
+  }
+
+  /**
+   * Add combat tracking component.
+   */
+  withCombat(): this {
+    this.components.combat = {};
+    return this;
+  }
+
+  /**
+   * Add a raw component directly.
+   */
+  with<K extends keyof ComponentMap>(type: K, data: ComponentMap[K]): this {
+    this.components[type] = data;
+    return this;
+  }
+
+  /**
+   * Finalize and register all components with the ECS world.
+   * @returns The created entity ID
+   */
+  build(): EntityId {
+    for (const [type, data] of Object.entries(this.components)) {
+      if (data !== undefined) {
+        this.world.addComponent(this.entityId, type as keyof ComponentMap, data as any);
+      }
+    }
+    return this.entityId;
+  }
+
+  /**
+   * Get the entity ID (even before build is called).
+   */
+  getId(): EntityId {
+    return this.entityId;
+  }
+}