setting up test functionality

lib/habits-storage.ts

@@ -0,0 +1,135 @@
+import { catalogHabitIds, habitCatalog } from "@/lib/habit-catalog";
+import { notifyHabitPetDataUpdated } from "@/lib/app-events";
+
+export type Habit = {
+  id: string;
+  label: string;
+  streak: number;
+  lastCompletedDate: string | null;
+  isCustom: boolean;
+};
+
+const STORAGE_KEY = "habit-pet-habits";
+
+export const defaultHabits: Habit[] = habitCatalog.map((entry) => ({
+  id: entry.id,
+  label: entry.label,
+  streak: 0,
+  lastCompletedDate: null,
+  isCustom: false,
+}));
+
+export function getTodayDateKey(date = new Date()) {
+  return date.toISOString().slice(0, 10);
+}
+
+function getYesterdayDateKey(date = new Date()) {
+  const yesterday = new Date(date);
+  yesterday.setDate(yesterday.getDate() - 1);
+  return getTodayDateKey(yesterday);
+}
+
+function normalizeHabit(habit: Partial<Habit> & { id: string; label: string }): Habit {
+  return {
+    id: habit.id,
+    label: habit.label,
+    streak: habit.streak ?? 0,
+    lastCompletedDate: habit.lastCompletedDate ?? null,
+    isCustom: habit.isCustom ?? !catalogHabitIds.has(habit.id),
+  };
+}
+
+export function isHabitCompletedToday(habit: Habit, today = getTodayDateKey()) {
+  return habit.lastCompletedDate === today;
+}
+
+export function getHabits(): Habit[] {
+  if (typeof window === "undefined") {
+    return defaultHabits;
+  }
+
+  const raw = window.localStorage.getItem(STORAGE_KEY);
+
+  if (!raw) {
+    return defaultHabits;
+  }
+
+  try {
+    const habits = (JSON.parse(raw) as Habit[]).map(normalizeHabit);
+    return habits.length > 0 ? habits : defaultHabits;
+  } catch {
+    return defaultHabits;
+  }
+}
+
+export function saveHabits(habits: Habit[], options?: { notify?: boolean }) {
+  window.localStorage.setItem(STORAGE_KEY, JSON.stringify(habits));
+
+  if (options?.notify !== false) {
+    notifyHabitPetDataUpdated();
+  }
+}
+
+export function toggleHabitCompletion(habitId: string): Habit[] {
+  const today = getTodayDateKey();
+  const yesterday = getYesterdayDateKey();
+  const habits = getHabits().map((habit) => {
+    if (habit.id !== habitId) {
+      return habit;
+    }
+
+    if (isHabitCompletedToday(habit, today)) {
+      return {
+        ...habit,
+        lastCompletedDate: null,
+        streak: Math.max(0, habit.streak - 1),
+      };
+    }
+
+    const nextStreak =
+      habit.lastCompletedDate === yesterday ? habit.streak + 1 : 1;
+
+    return {
+      ...habit,
+      lastCompletedDate: today,
+      streak: nextStreak,
+    };
+  });
+
+  saveHabits(habits);
+  return habits;
+}
+
+export function addHabit(label: string): Habit[] {
+  const trimmedLabel = label.trim();
+
+  if (!trimmedLabel) {
+    return getHabits();
+  }
+
+  const habits = [
+    ...getHabits(),
+    normalizeHabit({
+      id: crypto.randomUUID(),
+      label: trimmedLabel,
+      streak: 0,
+      lastCompletedDate: null,
+      isCustom: true,
+    }),
+  ];
+
+  saveHabits(habits);
+  return habits;
+}
+
+export function removeHabit(habitId: string): Habit[] {
+  const habits = getHabits().filter(
+    (habit) => habit.id !== habitId || !habit.isCustom,
+  );
+  saveHabits(habits);
+  return habits;
+}
+
+export function getCustomHabits() {
+  return getHabits().filter((habit) => habit.isCustom);
+}