the-tip-top-frontend/utils/helpers.ts

import { STORAGE_KEYS } from './constants';

// Local Storage Helpers
export const storage = {
  get: (key: string): string | null => {
    if (typeof window === 'undefined') return null;
    try {
      return localStorage.getItem(key);
    } catch (error) {
      console.error('Error reading from localStorage:', error);
      return null;
    }
  },
  set: (key: string, value: string): void => {
    if (typeof window === 'undefined') return;
    try {
      localStorage.setItem(key, value);
    } catch (error) {
      console.error('Error writing to localStorage:', error);
    }
  },
  remove: (key: string): void => {
    if (typeof window === 'undefined') return;
    try {
      localStorage.removeItem(key);
    } catch (error) {
      console.error('Error removing from localStorage:', error);
    }
  },
  clear: (): void => {
    if (typeof window === 'undefined') return;
    try {
      localStorage.clear();
    } catch (error) {
      console.error('Error clearing localStorage:', error);
    }
  },
};

// Cookie Helpers
export const setCookie = (name: string, value: string, days: number = 7): void => {
  if (typeof window === 'undefined') return;
  const expires = new Date();
  expires.setTime(expires.getTime() + days * 24 * 60 * 60 * 1000);
  document.cookie = `${name}=${value};expires=${expires.toUTCString()};path=/;SameSite=Strict`;
};

export const getCookie = (name: string): string | null => {
  if (typeof window === 'undefined') return null;
  const nameEQ = name + '=';
  const ca = document.cookie.split(';');
  for (let i = 0; i < ca.length; i++) {
    let c = ca[i];
    while (c.charAt(0) === ' ') c = c.substring(1, c.length);
    if (c.indexOf(nameEQ) === 0) return c.substring(nameEQ.length, c.length);
  }
  return null;
};

export const removeCookie = (name: string): void => {
  if (typeof window === 'undefined') return;
  document.cookie = `${name}=;expires=Thu, 01 Jan 1970 00:00:01 GMT;path=/;SameSite=Strict`;
};

// Token Helpers
export const getToken = (): string | null => {
  // Try to get from localStorage first, then cookies
  return storage.get(STORAGE_KEYS.TOKEN) || getCookie(STORAGE_KEYS.TOKEN);
};

export const setToken = (token: string): void => {
  // Store in both localStorage and cookies for better compatibility
  storage.set(STORAGE_KEYS.TOKEN, token);
  setCookie(STORAGE_KEYS.TOKEN, token, 7); // 7 days expiration
};

export const removeToken = (): void => {
  // Remove from both localStorage and cookies
  storage.remove(STORAGE_KEYS.TOKEN);
  removeCookie(STORAGE_KEYS.TOKEN);
};

// Date Formatting
export const formatDate = (date: string | Date): string => {
  if (!date) return '-';
  const d = new Date(date);
  if (isNaN(d.getTime())) return '-';
  return new Intl.DateTimeFormat('fr-FR', {
    year: 'numeric',
    month: 'long',
    day: 'numeric',
  }).format(d);
};

export const formatDateTime = (date: string | Date): string => {
  if (!date) return '-';
  const d = new Date(date);
  if (isNaN(d.getTime())) return '-';
  return new Intl.DateTimeFormat('fr-FR', {
    year: 'numeric',
    month: 'long',
    day: 'numeric',
    hour: '2-digit',
    minute: '2-digit',
  }).format(d);
};

// Number Formatting
export const formatCurrency = (amount: number): string => {
  return new Intl.NumberFormat('fr-FR', {
    style: 'currency',
    currency: 'EUR',
  }).format(amount);
};

export const formatPercentage = (value: number): string => {
  return new Intl.NumberFormat('fr-FR', {
    style: 'percent',
    minimumFractionDigits: 1,
    maximumFractionDigits: 1,
  }).format(value);
};

// String Helpers
export const truncate = (str: string, length: number): string => {
  if (str.length <= length) return str;
  return str.slice(0, length) + '...';
};

export const capitalize = (str: string): string => {
  return str.charAt(0).toUpperCase() + str.slice(1).toLowerCase();
};

// Validation Helpers
export const isValidEmail = (email: string): boolean => {
  // Limit input length to prevent ReDoS attacks
  if (!email || email.length > 254) return false;
  // Simple and safe email regex (non-backtracking)
  const emailRegex = /^[a-zA-Z0-9.!#$%&'*+/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$/;
  return emailRegex.test(email);
};

export const isValidPhone = (phone: string): boolean => {
  const phoneRegex = /^(\+33|0)[1-9](\d{2}){4}$/;
  return phoneRegex.test(phone);
};

// Class Name Helper
export const cn = (...classes: (string | boolean | undefined | null)[]): string => {
  return classes.filter(Boolean).join(' ');
};

// Delay Helper
export const delay = (ms: number): Promise<void> => {
  return new Promise(resolve => setTimeout(resolve, ms));
};

// Deep Clone
export const deepClone = <T>(obj: T): T => {
  return JSON.parse(JSON.stringify(obj));
};

// Generate Random ID (cryptographically secure)
export const generateId = (): string => {
  const timestamp = Date.now().toString(36);
  if (typeof window !== 'undefined' && window.crypto) {
    const array = new Uint32Array(2);
    window.crypto.getRandomValues(array);
    return array[0].toString(36) + array[1].toString(36) + timestamp;
  }
  // SSR fallback using Node.js crypto
  if (typeof globalThis !== 'undefined' && globalThis.crypto) {
    const array = new Uint32Array(2);
    globalThis.crypto.getRandomValues(array);
    return array[0].toString(36) + array[1].toString(36) + timestamp;
  }
  // Last resort: timestamp-based only (no Math.random)
  const counter = (Date.now() % 1000000).toString(36);
  return timestamp + counter + process.hrtime?.()[1]?.toString(36) || timestamp + counter;
};

// Debounce Function
export function debounce<T extends (...args: any[]) => any>(
  func: T,
  wait: number
): (...args: Parameters<T>) => void {
  let timeout: NodeJS.Timeout | null = null;
  return (...args: Parameters<T>) => {
    if (timeout) clearTimeout(timeout);
    timeout = setTimeout(() => func(...args), wait);
  };
}

// Throttle Function
export function throttle<T extends (...args: any[]) => any>(
  func: T,
  limit: number
): (...args: Parameters<T>) => void {
  let inThrottle: boolean;
  return (...args: Parameters<T>) => {
    if (!inThrottle) {
      func(...args);
      inThrottle = true;
      setTimeout(() => (inThrottle = false), limit);
    }
  };
}