From b557942124c5a48b0a932c2abc7385c0ea421d9b Mon Sep 17 00:00:00 2001
From: tiennm99 <tiennm99@outlook.com>
Date: Tue, 7 Apr 2026 21:01:22 +0700
Subject: [PATCH] feat: add shared game state manager with EventEmitter

---
 superpowers/src/game/state.ts        | 122 +++++++++++++++++++++++++++
 superpowers/tests/game/state.test.ts | 108 ++++++++++++++++++++++++
 2 files changed, 230 insertions(+)
 create mode 100644 superpowers/src/game/state.ts
 create mode 100644 superpowers/tests/game/state.test.ts

diff --git a/superpowers/src/game/state.ts b/superpowers/src/game/state.ts
new file mode 100644
index 0000000..86b6742
--- /dev/null
+++ b/superpowers/src/game/state.ts
@@ -0,0 +1,122 @@
+import { Difficulty, GameStatus } from "../types";
+import { DIFFICULTY_CONFIGS } from "./constants";
+
+type Listener = () => void;
+
+interface GameState {
+  status: GameStatus;
+  difficulty: Difficulty | null;
+  score: number;
+  timerSeconds: number;
+  hintsRemaining: number;
+  shufflesRemaining: number;
+  combo: number;
+  lastMatchTime: number;
+}
+
+export class GameStateManager {
+  private state: GameState;
+  private listeners: Map<string, Listener[]> = new Map();
+
+  constructor() {
+    this.state = {
+      status: "menu",
+      difficulty: null,
+      score: 0,
+      timerSeconds: 0,
+      hintsRemaining: 0,
+      shufflesRemaining: 0,
+      combo: 1,
+      lastMatchTime: 0,
+    };
+  }
+
+  getState(): Readonly<GameState> {
+    return { ...this.state };
+  }
+
+  on(event: string, listener: Listener): void {
+    if (!this.listeners.has(event)) {
+      this.listeners.set(event, []);
+    }
+    this.listeners.get(event)!.push(listener);
+  }
+
+  off(event: string, listener: Listener): void {
+    const listeners = this.listeners.get(event);
+    if (listeners) {
+      const idx = listeners.indexOf(listener);
+      if (idx !== -1) listeners.splice(idx, 1);
+    }
+  }
+
+  emit(event: string): void {
+    const listeners = this.listeners.get(event);
+    if (listeners) {
+      for (const l of listeners) l();
+    }
+  }
+
+  startGame(difficulty: Difficulty): void {
+    const config = DIFFICULTY_CONFIGS[difficulty];
+    this.state = {
+      status: "playing",
+      difficulty,
+      score: 0,
+      timerSeconds: config.timerSeconds,
+      hintsRemaining: config.hints,
+      shufflesRemaining: config.shuffles,
+      combo: 1,
+      lastMatchTime: Date.now(),
+    };
+    this.emit("stateChange");
+  }
+
+  addScore(points: number): void {
+    this.state.score += points;
+    this.emit("stateChange");
+  }
+
+  useHint(): boolean {
+    if (this.state.hintsRemaining <= 0) return false;
+    this.state.hintsRemaining--;
+    this.emit("stateChange");
+    return true;
+  }
+
+  useShuffle(): boolean {
+    if (this.state.shufflesRemaining <= 0) return false;
+    this.state.shufflesRemaining--;
+    this.emit("stateChange");
+    return true;
+  }
+
+  tick(): void {
+    if (this.state.status !== "playing") return;
+    this.state.timerSeconds--;
+    if (this.state.timerSeconds <= 0) {
+      this.state.timerSeconds = 0;
+      this.state.status = "lost";
+    }
+    this.emit("stateChange");
+  }
+
+  incrementCombo(): void {
+    this.state.combo++;
+    this.emit("stateChange");
+  }
+
+  resetCombo(): void {
+    this.state.combo = 1;
+    this.emit("stateChange");
+  }
+
+  setStatus(status: GameStatus): void {
+    this.state.status = status;
+    this.emit("stateChange");
+  }
+
+  setLastMatchTime(time: number): void {
+    this.state.lastMatchTime = time;
+  }
+}
diff --git a/superpowers/tests/game/state.test.ts b/superpowers/tests/game/state.test.ts
new file mode 100644
index 0000000..a5796f9
--- /dev/null
+++ b/superpowers/tests/game/state.test.ts
@@ -0,0 +1,108 @@
+import { describe, it, expect, vi, beforeEach } from "vitest";
+import { GameStateManager } from "../../src/game/state";
+
+describe("GameStateManager", () => {
+  let state: GameStateManager;
+
+  beforeEach(() => {
+    state = new GameStateManager();
+  });
+
+  it("initializes with menu status", () => {
+    expect(state.getState().status).toBe("menu");
+  });
+
+  it("startGame sets state for given difficulty", () => {
+    state.startGame("easy");
+    const s = state.getState();
+    expect(s.status).toBe("playing");
+    expect(s.score).toBe(0);
+    expect(s.hintsRemaining).toBe(5);
+    expect(s.shufflesRemaining).toBe(3);
+    expect(s.timerSeconds).toBe(300);
+    expect(s.difficulty).toBe("easy");
+    expect(s.combo).toBe(1);
+  });
+
+  it("addScore increases score", () => {
+    state.startGame("easy");
+    state.addScore(150);
+    expect(state.getState().score).toBe(150);
+    state.addScore(100);
+    expect(state.getState().score).toBe(250);
+  });
+
+  it("useHint decrements hints", () => {
+    state.startGame("easy");
+    expect(state.useHint()).toBe(true);
+    expect(state.getState().hintsRemaining).toBe(4);
+  });
+
+  it("useHint returns false when no hints left", () => {
+    state.startGame("hard");
+    expect(state.useHint()).toBe(true);
+    expect(state.useHint()).toBe(false);
+    expect(state.getState().hintsRemaining).toBe(0);
+  });
+
+  it("useShuffle decrements shuffles", () => {
+    state.startGame("easy");
+    expect(state.useShuffle()).toBe(true);
+    expect(state.getState().shufflesRemaining).toBe(2);
+  });
+
+  it("useShuffle returns false when no shuffles left", () => {
+    state.startGame("hard");
+    expect(state.useShuffle()).toBe(true);
+    expect(state.useShuffle()).toBe(false);
+  });
+
+  it("tick decrements timer", () => {
+    state.startGame("easy");
+    state.tick();
+    expect(state.getState().timerSeconds).toBe(299);
+  });
+
+  it("tick sets status to lost when timer reaches 0", () => {
+    state.startGame("easy");
+    for (let i = 0; i < 300; i++) {
+      state.tick();
+    }
+    expect(state.getState().status).toBe("lost");
+    expect(state.getState().timerSeconds).toBe(0);
+  });
+
+  it("emits events on state change", () => {
+    const listener = vi.fn();
+    state.on("stateChange", listener);
+    state.startGame("easy");
+    expect(listener).toHaveBeenCalled();
+  });
+
+  it("incrementCombo and resetCombo work", () => {
+    state.startGame("easy");
+    state.incrementCombo();
+    expect(state.getState().combo).toBe(2);
+    state.incrementCombo();
+    expect(state.getState().combo).toBe(3);
+    state.resetCombo();
+    expect(state.getState().combo).toBe(1);
+  });
+
+  it("setStatus changes status and emits", () => {
+    state.startGame("easy");
+    const listener = vi.fn();
+    state.on("stateChange", listener);
+    state.setStatus("won");
+    expect(state.getState().status).toBe("won");
+    expect(listener).toHaveBeenCalled();
+  });
+
+  it("pause and resume toggle status", () => {
+    state.startGame("easy");
+    state.setStatus("paused");
+    expect(state.getState().status).toBe("paused");
+    state.setStatus("playing");
+    expect(state.getState().status).toBe("playing");
+  });
+});