🚧 Refactor basic services

frontend/src/common/utils/formatter.ts

@@ -0,0 +1,65 @@
+/**
+ * Formatter utility functions
+ */
+
+export interface DateTimeFormatOptions {
+  locale?: string;
+  includeTime?: boolean;
+  hour12?: boolean;
+}
+
+/**
+ * Format date time string to localized format
+ * @param dateString - ISO date string or null
+ * @param options - Formatting options
+ * @returns Formatted date string or error message
+ */
+export const formatDateTime = (
+  dateString: string | null,
+  options: DateTimeFormatOptions = {}
+): string => {
+  const {
+    locale = 'en-US',
+    includeTime = true,
+    hour12 = false
+  } = options;
+
+  if (!dateString) {
+    return 'Unknown time';
+  }
+
+  try {
+    const date = new Date(dateString);
+    
+    if (isNaN(date.getTime())) {
+      return 'Invalid date';
+    }
+
+    const formatOptions: Intl.DateTimeFormatOptions = {
+      year: 'numeric',
+      month: '2-digit',
+      day: '2-digit',
+    };
+
+    if (includeTime) {
+      formatOptions.hour = '2-digit';
+      formatOptions.minute = '2-digit';
+      formatOptions.hour12 = hour12;
+    }
+
+    return date.toLocaleString(locale, formatOptions);
+  } catch {
+    return 'Time error';
+  }
+};
+
+/**
+ * Truncate string with ellipsis
+ * @param str - String to truncate
+ * @param maxLength - Maximum length before truncation
+ * @returns Truncated string with ellipsis if needed
+ */
+export const truncateString = (str: string, maxLength: number): string => {
+  if (!str) return '';
+  return str.length > maxLength ? str.substring(0, maxLength) + '...' : str;
+};

frontend/src/common/utils/validation.ts

@@ -0,0 +1,42 @@
+/**
+ * Validation utility functions
+ */
+
+/**
+ * Validate document title
+ * @param title - The title to validate
+ * @param maxLength - Maximum allowed length (default: 50)
+ * @returns Error message if invalid, null if valid
+ */
+export const validateDocumentTitle = (title: string, maxLength: number = 50): string | null => {
+  const trimmed = title.trim();
+  
+  if (!trimmed) {
+    return 'Document name cannot be empty';
+  }
+  
+  if (trimmed.length > maxLength) {
+    return `Document name cannot exceed ${maxLength} characters`;
+  }
+  
+  return null;
+};
+
+/**
+ * Check if a string is empty or whitespace only
+ * @param value - The string to check
+ * @returns true if empty or whitespace only
+ */
+export const isEmpty = (value: string | null | undefined): boolean => {
+  return !value || value.trim().length === 0;
+};
+
+/**
+ * Check if a string exceeds max length
+ * @param value - The string to check
+ * @param maxLength - Maximum allowed length
+ * @returns true if exceeds max length
+ */
+export const exceedsMaxLength = (value: string, maxLength: number): boolean => {
+  return value.trim().length > maxLength;
+};