examjam-frontend/stores/timerStore.ts

"use client";

import { create } from "zustand";

interface TimerState {
  timeRemaining: number;
  timerRef: NodeJS.Timeout | null;

  resetTimer: (duration: number, onComplete?: () => void) => void;
  stopTimer: () => void;
  setInitialTime: (duration: number) => void;
}

export const useTimerStore = create<TimerState>((set, get) => ({
  timeRemaining: 0,
  timerRef: null,

  resetTimer: (duration, onComplete) => {
    const { timerRef } = get();

    if (timerRef) clearInterval(timerRef);

    const newRef = setInterval(() => {
      set((state) => {
        if (state.timeRemaining <= 1) {
          clearInterval(newRef);
          if (onComplete) onComplete(); // ✅ call callback when timer ends
          return { timeRemaining: 0, timerRef: null };
        }
        return { timeRemaining: state.timeRemaining - 1 };
      });
    }, 1000);

    set({ timeRemaining: duration, timerRef: newRef });
  },

  stopTimer: () => {
    const { timerRef } = get();
    if (timerRef) clearInterval(timerRef);
    set({ timeRemaining: 0, timerRef: null });
  },

  setInitialTime: (duration) => {
    const { timerRef } = get();
    if (timerRef) clearInterval(timerRef);
    set({ timeRemaining: duration, timerRef: null });
  },
}));