From 8269f3adadaa05cdaad3edc797598a24a04627c3 Mon Sep 17 00:00:00 2001
From: ManInDark <61268856+ManInDark@users.noreply.github.com>
Date: Sat, 9 Aug 2025 18:57:04 +0200
Subject: [PATCH] fix: refactored code & removed unused parts

---
 app/actions/data.ts              |  46 ++++-------
 app/layout.tsx                   |  10 +--
 components/AddEditHabitModal.tsx |   2 +-
 hooks/useCoins.tsx               |  53 ++++---------
 hooks/useHabits.tsx              |  58 ++++----------
 hooks/useWishlist.tsx            |  39 ++--------
 lib/atoms.ts                     |  12 +--
 lib/client-helpers.ts            |   5 +-
 lib/types.ts                     |   3 +-
 lib/utils.test.ts                |  51 +-----------
 lib/utils.ts                     | 128 ++++++++++++-------------------
 package.json                     |   3 -
 12 files changed, 104 insertions(+), 306 deletions(-)

diff --git a/app/actions/data.ts b/app/actions/data.ts
index 0d8d68f..5948946 100644
--- a/app/actions/data.ts
+++ b/app/actions/data.ts
@@ -21,7 +21,7 @@ import {
   WishlistData,
   WishlistItemType
 } from '@/lib/types';
-import { d2t, generateCryptoHash, getNow, prepareDataForHashing, uuid } from '@/lib/utils';
+import { d2t, generateCryptoHash, getNow, prepareDataForHashing } from '@/lib/utils';
 import { signInSchema } from '@/lib/zod';
 import fs from 'fs/promises';
 import _ from 'lodash';
@@ -33,21 +33,6 @@ type ResourceType = 'habit' | 'wishlist' | 'coins'
 type ActionType = 'write' | 'interact'
 
 
-async function verifyPermission(
-  resource: ResourceType,
-  action: ActionType
-): Promise<void> {
-  // const user = await getCurrentUser()
-
-  // if (!user) throw new PermissionError('User not authenticated')
-  // if (user.isAdmin) return // Admins bypass permission checks
-
-  // if (!checkPermission(user.permissions, resource, action)) {
-  //   throw new PermissionError(`User does not have ${action} permission for ${resource}`)
-  // }
-  return
-}
-
 function getDefaultData<T>(type: DataType): T {
   return DATA_DEFAULTS[type]() as T;
 }
@@ -126,11 +111,13 @@ async function saveData<T>(type: DataType, data: T): Promise<void> {
  */
 async function calculateServerFreshnessToken(): Promise<string | null> {
   try {
-    const settings = await loadSettings();
-    const habits = await loadHabitsData();
-    const coins = await loadCoinsData();
-    const wishlist = await loadWishlistData();
-    const users = await loadUsersData();
+    const [settings, habits, coins, wishlist, users] = await Promise.all([
+      loadSettings(),
+      loadHabitsData(),
+      loadCoinsData(),
+      loadWishlistData(),
+      loadUsersData()
+    ]);
 
     const dataString = prepareDataForHashing(
       settings,
@@ -139,8 +126,7 @@ async function calculateServerFreshnessToken(): Promise<string | null> {
       wishlist,
       users
     );
-    const serverToken = await generateCryptoHash(dataString);
-    return serverToken;
+    return generateCryptoHash(dataString);
   } catch (error) {
     console.error("Error calculating server freshness token:", error);
     throw error;
@@ -165,7 +151,6 @@ export async function loadWishlistItems(): Promise<WishlistItemType[]> {
 }
 
 export async function saveWishlistItems(data: WishlistData): Promise<void> {
-  await verifyPermission('wishlist', 'write')
   const user = await getCurrentUser()
 
   data.items = data.items.map(wishlist => ({
@@ -191,14 +176,11 @@ export async function loadHabitsData(): Promise<HabitsData> {
   if (!user) return getDefaultHabitsData()
   const data = await loadData<HabitsData>('habits')
   return {
-    ...data,
     habits: data.habits.filter(x => user.isAdmin || x.userIds?.includes(user.id))
   }
 }
 
 export async function saveHabitsData(data: HabitsData): Promise<void> {
-  await verifyPermission('habit', 'write')
-
   const user = await getCurrentUser()
   // Create clone of input data
   const newData = _.cloneDeep(data)
@@ -210,7 +192,7 @@ export async function saveHabitsData(data: HabitsData): Promise<void> {
   }))
 
   if (!user?.isAdmin) {
-    const existingData = await loadData<HabitsData>('habits')
+    const existingData = await loadHabitsData();
     const existingHabits = existingData.habits.filter(x => user?.id && !x.userIds?.includes(user?.id))
     newData.habits = [
       ...existingHabits,
@@ -273,11 +255,10 @@ export async function addCoins({
   note?: string
   userId?: string
 }): Promise<CoinsData> {
-  await verifyPermission('coins', type === 'MANUAL_ADJUSTMENT' ? 'write' : 'interact')
   const currentUser = await getCurrentUser()
   const data = await loadCoinsData()
   const newTransaction: CoinTransaction = {
-    id: uuid(),
+    id: crypto.randomUUID(),
     amount,
     type,
     description,
@@ -328,11 +309,10 @@ export async function removeCoins({
   note?: string
   userId?: string
 }): Promise<CoinsData> {
-  await verifyPermission('coins', type === 'MANUAL_ADJUSTMENT' ? 'write' : 'interact')
   const currentUser = await getCurrentUser()
   const data = await loadCoinsData()
   const newTransaction: CoinTransaction = {
-    id: uuid(),
+    id: crypto.randomUUID(),
     amount: -amount,
     type,
     description,
@@ -434,7 +414,7 @@ export async function createUser(formData: FormData): Promise<User> {
 
 
   const newUser: User = {
-    id: uuid(),
+    id: crypto.randomUUID(),
     username,
     password: hashedPassword,
     permissions,
diff --git a/app/layout.tsx b/app/layout.tsx
index f7ac3e7..04438c0 100644
--- a/app/layout.tsx
+++ b/app/layout.tsx
@@ -12,20 +12,12 @@ import { Suspense } from 'react'
 import { loadCoinsData, loadHabitsData, loadServerSettings, loadSettings, loadUsersData, loadWishlistData } from './actions/data'
 import './globals.css'
 
-// Inter (clean, modern, excellent readability)
-// const inter = Inter({
-//   subsets: ['latin'],
-//   weight: ['400', '500', '600', '700']
-// })
-
 // Clean and contemporary
-const dmSans = DM_Sans({
+const activeFont = DM_Sans({
   subsets: ['latin'],
   weight: ['400', '500', '600', '700']
 })
 
-const activeFont = dmSans
-
 export const metadata = {
   title: 'HabitTrove',
   description: 'Track your habits and get rewarded',
diff --git a/components/AddEditHabitModal.tsx b/components/AddEditHabitModal.tsx
index 1355c71..fb5c909 100644
--- a/components/AddEditHabitModal.tsx
+++ b/components/AddEditHabitModal.tsx
@@ -123,7 +123,7 @@ export default function AddEditHabitModal({ onClose, onSave, habit, isTask }: Ad
                     }}
                   />
                 </div>
-              </div>ohsimpson
+              </div>
               <div className="grid grid-cols-4 items-center gap-4">
                 <Label htmlFor="description" className="text-right">
                   {t('descriptionLabel')}
diff --git a/hooks/useCoins.tsx b/hooks/useCoins.tsx
index 168e753..332da80 100644
--- a/hooks/useCoins.tsx
+++ b/hooks/useCoins.tsx
@@ -1,50 +1,23 @@
-import { useAtom } from 'jotai';
-import { useState, useEffect, useMemo } from 'react';
-import { useTranslations } from 'next-intl';
-import { calculateCoinsEarnedToday, calculateCoinsSpentToday, calculateTotalEarned, calculateTotalSpent, calculateTransactionsToday, checkPermission, roundToInteger } from '@/lib/utils'
+import { addCoins, removeCoins, saveCoinsData } from '@/app/actions/data';
+import { toast } from '@/hooks/use-toast';
 import {
   coinsAtom,
+  coinsBalanceAtom,
   coinsEarnedTodayAtom,
+  coinsSpentTodayAtom,
+  currentUserAtom,
+  settingsAtom,
   totalEarnedAtom,
   totalSpentAtom,
-  coinsSpentTodayAtom,
   transactionsTodayAtom,
-  coinsBalanceAtom,
-  settingsAtom,
   usersAtom,
-  currentUserAtom,
-} from '@/lib/atoms'
-import { addCoins, removeCoins, saveCoinsData } from '@/app/actions/data'
-import { CoinsData, User } from '@/lib/types'
-import { toast } from '@/hooks/use-toast'
-import { MAX_COIN_LIMIT } from '@/lib/constants'
-
-function handlePermissionCheck(
-  user: User | undefined,
-  resource: 'habit' | 'wishlist' | 'coins',
-  action: 'write' | 'interact',
-  tCommon: (key: string, values?: Record<string, any>) => string
-): boolean {
-  if (!user) {
-    toast({
-      title: tCommon("authenticationRequiredTitle"),
-      description: tCommon("authenticationRequiredDescription"),
-      variant: "destructive",
-    })
-    return false
-  }
-
-  if (!user.isAdmin && !checkPermission(user.permissions, resource, action)) {
-    toast({
-      title: tCommon("permissionDeniedTitle"),
-      description: tCommon("permissionDeniedDescription", { action, resource }),
-      variant: "destructive",
-    })
-    return false
-  }
-
-  return true
-}
+} from '@/lib/atoms';
+import { MAX_COIN_LIMIT } from '@/lib/constants';
+import { CoinsData } from '@/lib/types';
+import { calculateCoinsEarnedToday, calculateCoinsSpentToday, calculateTotalEarned, calculateTotalSpent, calculateTransactionsToday, handlePermissionCheck, roundToInteger } from '@/lib/utils';
+import { useAtom } from 'jotai';
+import { useTranslations } from 'next-intl';
+import { useEffect, useMemo, useState } from 'react';
 
 export function useCoins(options?: { selectedUser?: string }) {
   const t = useTranslations('useCoins');
diff --git a/hooks/useHabits.tsx b/hooks/useHabits.tsx
index adcbdac..347d34a 100644
--- a/hooks/useHabits.tsx
+++ b/hooks/useHabits.tsx
@@ -1,54 +1,24 @@
-import { useAtom, atom } from 'jotai'
-import { useTranslations } from 'next-intl'
-import { habitsAtom, coinsAtom, settingsAtom, usersAtom, habitFreqMapAtom, currentUserAtom } from '@/lib/atoms'
 import { addCoins, removeCoins, saveHabitsData } from '@/app/actions/data'
-import { Habit, Permission, SafeUser, User } from '@/lib/types'
+import { ToastAction } from '@/components/ui/toast'
 import { toast } from '@/hooks/use-toast'
-import { DateTime } from 'luxon'
+import { coinsAtom, currentUserAtom, habitFreqMapAtom, habitsAtom, settingsAtom, usersAtom } from '@/lib/atoms'
+import { Habit } from '@/lib/types'
 import {
-  getNowInMilliseconds,
-  getTodayInTimezone,
-  isSameDate,
-  t2d,
+  d2s,
   d2t,
-  getNow,
   getCompletionsForDate,
   getISODate,
-  d2s,
+  getNow,
+  getTodayInTimezone,
+  handlePermissionCheck,
+  isSameDate,
   playSound,
-  checkPermission
+  t2d
 } from '@/lib/utils'
-import { ToastAction } from '@/components/ui/toast'
+import { useAtom } from 'jotai'
 import { Undo2 } from 'lucide-react'
-
-
-function handlePermissionCheck(
-  user: SafeUser | User | undefined,
-  resource: 'habit' | 'wishlist' | 'coins',
-  action: 'write' | 'interact',
-  tCommon: (key: string, values?: Record<string, any>) => string
-): boolean {
-  if (!user) {
-    toast({
-      title: tCommon("authenticationRequiredTitle"),
-      description: tCommon("authenticationRequiredDescription"),
-      variant: "destructive",
-    })
-    return false
-  }
-
-  if (!user.isAdmin && !checkPermission(user.permissions, resource, action)) {
-    toast({
-      title: tCommon("permissionDeniedTitle"),
-      description: tCommon("permissionDeniedDescription", { action, resource }),
-      variant: "destructive",
-    })
-    return false
-  }
-
-  return true
-}
-
+import { DateTime } from 'luxon'
+import { useTranslations } from 'next-intl'
 
 export function useHabits() {
   const t = useTranslations('useHabits');
@@ -106,7 +76,7 @@ export function useHabits() {
         type: habit.isTask ? 'TASK_COMPLETION' : 'HABIT_COMPLETION',
         relatedItemId: habit.id,
       })
-      isTargetReached && playSound()
+      playSound()
       toast({
         title: t("completedTitle"),
         description: t("earnedCoinsDescription", { coinReward: habit.coinReward }),
@@ -207,7 +177,7 @@ export function useHabits() {
     if (!handlePermissionCheck(currentUser, 'habit', 'write', tCommon)) return
     const newHabit = {
       ...habit,
-      id: habit.id || getNowInMilliseconds().toString()
+      id: habit.id || crypto.randomUUID()
     }
     const updatedHabits = habit.id
       ? habitsData.habits.map(h => h.id === habit.id ? newHabit : h)
diff --git a/hooks/useWishlist.tsx b/hooks/useWishlist.tsx
index fd7f6f1..b69635f 100644
--- a/hooks/useWishlist.tsx
+++ b/hooks/useWishlist.tsx
@@ -1,40 +1,13 @@
+import { removeCoins, saveWishlistItems } from '@/app/actions/data'
+import { toast } from '@/hooks/use-toast'
+import { coinsAtom, currentUserAtom, wishlistAtom } from '@/lib/atoms'
+import { WishlistItemType } from '@/lib/types'
+import { handlePermissionCheck } from '@/lib/utils'
+import { celebrations } from '@/utils/celebrations'
 import { useAtom } from 'jotai'
 import { useTranslations } from 'next-intl'
-import { wishlistAtom, coinsAtom, currentUserAtom } from '@/lib/atoms'
-import { saveWishlistItems, removeCoins } from '@/app/actions/data'
-import { toast } from '@/hooks/use-toast'
-import { WishlistItemType, User, SafeUser } from '@/lib/types'
-import { celebrations } from '@/utils/celebrations'
-import { checkPermission } from '@/lib/utils'
 import { useCoins } from './useCoins'
 
-function handlePermissionCheck(
-  user: User | SafeUser | undefined,
-  resource: 'habit' | 'wishlist' | 'coins',
-  action: 'write' | 'interact',
-  tCommon: (key: string, values?: Record<string, any>) => string
-): boolean {
-  if (!user) {
-    toast({
-      title: tCommon("authenticationRequiredTitle"),
-      description: tCommon("authenticationRequiredDescription"),
-      variant: "destructive",
-    })
-    return false
-  }
-  
-  if (!user.isAdmin && !checkPermission(user.permissions, resource, action)) {
-    toast({
-      title: tCommon("permissionDeniedTitle"),
-      description: tCommon("permissionDeniedDescription", { action, resource }),
-      variant: "destructive",
-    })
-    return false
-  }
-  
-  return true
-}
-
 export function useWishlist() {
   const t = useTranslations('useWishlist');
   const tCommon = useTranslations('Common');
diff --git a/lib/atoms.ts b/lib/atoms.ts
index 49bbdf0..750a5fa 100644
--- a/lib/atoms.ts
+++ b/lib/atoms.ts
@@ -4,10 +4,11 @@ import {
   calculateTotalEarned,
   calculateTotalSpent,
   calculateTransactionsToday,
+  generateCryptoHash,
   getCompletionsForToday,
   getHabitFreq,
-  getTodayInTimezone,
   isHabitDue,
+  prepareDataForHashing,
   roundToInteger,
   t2d
 } from "@/lib/utils";
@@ -121,8 +122,6 @@ export const pomodoroAtom = atom<PomodoroAtom>({
   minimized: false,
 })
 
-import { generateCryptoHash, prepareDataForHashing } from '@/lib/utils';
-
 export const userSelectAtom = atom<boolean>(false)
 export const aboutOpenAtom = atom<boolean>(false)
 
@@ -229,10 +228,3 @@ export const habitsByDateFamily = atomFamily((dateString: string) =>
     return habits.filter(habit => isHabitDue({ habit, timezone, date }));
   })
 );
-
-// Derived atom for daily habits
-export const dailyHabitsAtom = atom((get) => {
-  const settings = get(settingsAtom);
-  const today = getTodayInTimezone(settings.system.timezone);
-  return get(habitsByDateFamily(today));
-});
diff --git a/lib/client-helpers.ts b/lib/client-helpers.ts
index 2125e63..070a200 100644
--- a/lib/client-helpers.ts
+++ b/lib/client-helpers.ts
@@ -4,7 +4,7 @@
 import { useAtom } from 'jotai'
 import { useSession } from "next-auth/react"
 import { usersAtom } from './atoms'
-import { checkPermission } from './utils'
+import { hasPermission } from './utils'
 
 export function useHelpers() {
   const { data: session, status } = useSession()
@@ -30,8 +30,7 @@ export function useHelpers() {
     currentUser,
     usersData,
     status,
-    hasPermission: (resource: 'habit' | 'wishlist' | 'coins', action: 'write' | 'interact') => currentUser?.isAdmin ||
-      checkPermission(currentUser?.permissions, resource, action),
+    hasPermission,
     isIOS: iOS(),
   }
 }
diff --git a/lib/types.ts b/lib/types.ts
index eb9609c..51462d6 100644
--- a/lib/types.ts
+++ b/lib/types.ts
@@ -1,5 +1,4 @@
 import { RRule } from "rrule"
-import { uuid } from "./utils"
 import { DateTime } from "luxon"
 
 export type UserId = string
@@ -100,7 +99,7 @@ export interface WishlistData {
 export const getDefaultUsersData = (): UserData => ({
   users: [
     {
-      id: uuid(),
+      id: crypto.randomUUID(),
       username: 'admin',
       // password: '', // No default password for admin initially? Or set a secure default?
       isAdmin: true,
diff --git a/lib/utils.test.ts b/lib/utils.test.ts
index 3e68d8a..21bdac7 100644
--- a/lib/utils.test.ts
+++ b/lib/utils.test.ts
@@ -3,12 +3,9 @@ import {
   cn,
   getTodayInTimezone,
   getNow,
-  getNowInMilliseconds,
   t2d,
   d2t,
   d2s,
-  d2sDate,
-  d2n,
   isSameDate,
   calculateCoinsEarnedToday,
   calculateTotalEarned,
@@ -16,16 +13,15 @@ import {
   calculateCoinsSpentToday,
   isHabitDueToday,
   isHabitDue,
-  uuid,
   isTaskOverdue,
   deserializeRRule,
   serializeRRule,
   convertHumanReadableFrequencyToMachineReadable,
   convertMachineReadableFrequencyToHumanReadable,
   prepareDataForHashing,
-  generateCryptoHash,
   getUnsupportedRRuleReason,
-  roundToInteger
+  roundToInteger,
+  generateCryptoHash
 } from './utils'
 import { CoinTransaction, ParsedResultType, Settings, HabitsData, CoinsData, WishlistData, UserData } from './types'
 import { DateTime } from "luxon";
@@ -178,32 +174,6 @@ describe('isTaskOverdue', () => {
   })
 })
 
-describe('uuid', () => {
-  test('should generate valid UUIDs', () => {
-    const id = uuid()
-    // UUID v4 format: 8-4-4-4-12 hex digits
-    expect(id).toMatch(/^[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/)
-  })
-
-  test('should generate unique UUIDs', () => {
-    const ids = new Set()
-    for (let i = 0; i < 1000; i++) {
-      ids.add(uuid())
-    }
-    // All 1000 UUIDs should be unique
-    expect(ids.size).toBe(1000)
-  })
-
-  test('should generate v4 UUIDs', () => {
-    const id = uuid()
-    // Version 4 UUID has specific bits set:
-    // - 13th character is '4'
-    // - 17th character is '8', '9', 'a', or 'b'
-    expect(id.charAt(14)).toBe('4')
-    expect('89ab').toContain(id.charAt(19))
-  })
-})
-
 describe('datetime utilities', () => {
   let fixedNow: DateTime;
   let currentDateIndex = 0;
@@ -321,13 +291,6 @@ describe('getNow', () => {
   })
 })
 
-describe('getNowInMilliseconds', () => {
-  test('should return current time in milliseconds', () => {
-    const now = DateTime.now().setZone('UTC')
-    expect(getNowInMilliseconds()).toBe(now.toMillis().toString())
-  })
-})
-
 describe('timestamp conversion utilities', () => {
   const testTimestamp = '2024-01-01T00:00:00.000Z';
   const testDateTime = DateTime.fromISO(testTimestamp);
@@ -351,16 +314,6 @@ describe('timestamp conversion utilities', () => {
     const customFormat = d2s({ dateTime: testDateTime, format: 'yyyy-MM-dd', timezone: 'utc' });
     expect(customFormat).toBe('2024-01-01')
   })
-
-  test('d2sDate should format DateTime as date string', () => {
-    const result = d2sDate({ dateTime: testDateTime });
-    expect(result).toBeString()
-  })
-
-  test('d2n should convert DateTime to milliseconds string', () => {
-    const result = d2n({ dateTime: testDateTime });
-    expect(result).toBe('1704067200000')
-  })
 })
 
 describe('isSameDate', () => {
diff --git a/lib/utils.ts b/lib/utils.ts
index d9aede3..8fb4df5 100644
--- a/lib/utils.ts
+++ b/lib/utils.ts
@@ -1,13 +1,12 @@
-import { clsx, type ClassValue } from "clsx"
-import { twMerge } from "tailwind-merge"
-import { DateTime, DateTimeFormatOptions } from "luxon"
-import { datetime, RRule } from 'rrule'
-import { Freq, Habit, CoinTransaction, Permission, ParsedFrequencyResult, ParsedResultType, User, Settings, HabitsData, CoinsData, WishlistData, UserData } from '@/lib/types'
-import { DUE_MAP, INITIAL_DUE, RECURRENCE_RULE_MAP } from "./constants"
+import { toast } from "@/hooks/use-toast"
+import { CoinsData, CoinTransaction, Freq, Habit, HabitsData, ParsedFrequencyResult, ParsedResultType, SafeUser, Settings, User, UserData, WishlistData } from '@/lib/types'
 import * as chrono from 'chrono-node'
-import _ from "lodash"
-import { v4 as uuidv4 } from 'uuid'
-import stableStringify from 'json-stable-stringify';
+import { clsx, type ClassValue } from "clsx"
+import { DateTime, DateTimeFormatOptions } from "luxon"
+import { Formats } from "next-intl"
+import { datetime, RRule } from 'rrule'
+import { twMerge } from "tailwind-merge"
+import { DUE_MAP, INITIAL_DUE, RECURRENCE_RULE_MAP } from "./constants"
 
 export function cn(...inputs: ClassValue[]) {
   return twMerge(clsx(inputs))
@@ -33,12 +32,6 @@ export function getNow({ timezone = 'utc', keepLocalTime }: { timezone?: string,
   return DateTime.now().setZone(timezone, { keepLocalTime });
 }
 
-// get current time in epoch milliseconds
-export function getNowInMilliseconds() {
-  const now = getNow({});
-  return d2n({ dateTime: now });
-}
-
 // iso timestamp to datetime object, most for storage read
 export function t2d({ timestamp, timezone }: { timestamp: string; timezone: string }) {
   return DateTime.fromISO(timestamp).setZone(timezone);
@@ -61,30 +54,11 @@ export function d2s({ dateTime, format, timezone }: { dateTime: DateTime, format
   return dateTime.setZone(timezone).toLocaleString(DateTime.DATETIME_MED);
 }
 
-// convert datetime object to date string, mostly for display
-export function d2sDate({ dateTime }: { dateTime: DateTime }) {
-  return dateTime.toLocaleString(DateTime.DATE_MED);
-}
-
-// convert datetime object to epoch milliseconds string, mostly for storage write
-export function d2n({ dateTime }: { dateTime: DateTime }) {
-  return dateTime.toMillis().toString();
-}
-
 // compare the date portion of two datetime objects (i.e. same year, month, day)
 export function isSameDate(a: DateTime, b: DateTime) {
   return a.hasSame(b, 'day');
 }
 
-export function normalizeCompletionDate(date: string, timezone: string): string {
-  // If already in ISO format, return as is
-  if (date.includes('T')) {
-    return date;
-  }
-  // Convert from yyyy-MM-dd to ISO format
-  return DateTime.fromFormat(date, 'yyyy-MM-dd', { zone: timezone }).toUTC().toISO()!;
-}
-
 export function getCompletionsForDate({
   habit,
   date,
@@ -438,22 +412,20 @@ export const openWindow = (url: string): boolean => {
   return true
 }
 
-export function deepMerge<T>(a: T, b: T) {
-  return _.merge(a, b, (x: unknown, y: unknown) => {
-    if (_.isArray(a)) {
-      return a.concat(b)
-    }
-  })
-}
-
-export function checkPermission(
-  permissions: Permission[] | undefined,
+export function hasPermission(
+  user: User | undefined,
   resource: 'habit' | 'wishlist' | 'coins',
   action: 'write' | 'interact'
 ): boolean {
-  if (!permissions) return false
-
-  return permissions.some(permission => {
+  if (!user || !user.permissions) {
+    return false;
+  }
+  // If user is admin, they have all permissions.
+  if (user.isAdmin) {
+    return true;
+  }
+  // Otherwise, check specific permissions.
+  return user.permissions.some(permission => {
     switch (resource) {
       case 'habit':
         return permission.habit[action]
@@ -467,27 +439,6 @@ export function checkPermission(
   })
 }
 
-export function uuid() {
-  return uuidv4()
-}
-
-export function hasPermission(
-  currentUser: User | undefined,
-  resource: 'habit' | 'wishlist' | 'coins',
-  action: 'write' | 'interact'
-): boolean {
-  // If no current user, no permissions.
-  if (!currentUser) {
-    return false;
-  }
-  // If user is admin, they have all permissions.
-  if (currentUser.isAdmin) {
-    return true;
-  }
-  // Otherwise, check specific permissions.
-  return checkPermission(currentUser.permissions, resource, action);
-}
-
 /**
  * Prepares a consistent string representation of the data for hashing.
  * It combines all relevant data pieces into a single object and then stringifies it stably.
@@ -499,22 +450,13 @@ export function prepareDataForHashing(
   wishlist: WishlistData,
   users: UserData
 ): string {
-  // Combine all data into a single object.
-  // The order of keys in this object itself doesn't matter due to stableStringify,
-  // but being explicit helps in understanding what's being hashed.
-  const combinedData = {
+  return JSON.stringify({
     settings,
     habits,
     coins,
     wishlist,
     users,
-  };
-  const stringifiedData = stableStringify(combinedData);
-  // Handle cases where stringify might return undefined.
-  if (stringifiedData === undefined) {
-    throw new Error("Failed to stringify data for hashing. stableStringify returned undefined.");
-  }
-  return stringifiedData;
+  });
 }
 
 /**
@@ -539,3 +481,31 @@ export async function generateCryptoHash(dataString: string): Promise<string | n
     return null;
   }
 }
+
+export function handlePermissionCheck(
+  user: User | SafeUser | undefined,
+  resource: 'habit' | 'wishlist' | 'coins',
+  action: 'write' | 'interact',
+  tCommon: (key: string, values?: Record<string, string | number | Date> | undefined, formats?: Formats | undefined) => string
+): boolean {
+
+  if (!user) {
+    toast({
+      title: tCommon("authenticationRequiredTitle"),
+      description: tCommon("authenticationRequiredDescription"),
+      variant: "destructive",
+    })
+    return false
+  }
+
+  if (!hasPermission(user, resource, action)) {
+    toast({
+      title: tCommon("permissionDeniedTitle"),
+      description: tCommon("permissionDeniedDescription", { action, resource }),
+      variant: "destructive",
+    })
+    return false
+  }
+
+  return true
+}
\ No newline at end of file
diff --git a/package.json b/package.json
index 1a1cd8d..4322f4f 100644
--- a/package.json
+++ b/package.json
@@ -43,7 +43,6 @@
     "date-fns": "^3.6.0",
     "jotai": "^2.8.0",
     "js-confetti": "^0.12.0",
-    "json-stable-stringify": "^1.3.0",
     "linkify": "^0.2.1",
     "linkify-react": "^4.2.0",
     "lodash": "^4.17.21",
@@ -63,7 +62,6 @@
     "rrule": "^2.8.1",
     "tailwind-merge": "^2.6.0",
     "tailwindcss-animate": "^1.0.7",
-    "uuid": "^11.0.5",
     "web-push": "^3.6.7",
     "zod": "^3.24.1"
   },
@@ -72,7 +70,6 @@
     "@tailwindcss/typography": "^0.5.15",
     "@types/archiver": "^6.0.3",
     "@types/bun": "^1.1.14",
-    "@types/json-stable-stringify": "^1.1.0",
     "@types/lodash": "^4.17.15",
     "@types/luxon": "^3.4.2",
     "@types/node": "^20.17.10",