added month localizations

lib/services/tools.dart

@@ -1,12 +1,97 @@
-import 'package:resume/constants.dart' show months;
+import 'package:flutter/material.dart';
+import 'package:flutter_gen/gen_l10n/app_localizations.dart';
 
 class Tools {
-  /// builds timespan-String out of two date-Strings.
-  /// Date has to be formatted as yyyy-MM
-  static buildTimeString(String startDate, String endDate) {
-    if (startDate.isEmpty || endDate.isEmpty) return '';
-    final firstDate = DateTime.parse('$startDate-01');
-    final secondDate = DateTime.parse('$endDate-01');
-    return '${months[firstDate.month - 1]} ${firstDate.year} - ${months[secondDate.month - 1]} ${secondDate.year}';
+  /// Builds a formatted time string from two date strings in the format 'YYYY-MM'.
+  ///
+  /// Returns a string in the format 'Month Year - Month Year' using localized month names.
+  /// Returns an empty string if either input is empty or invalid.
+  ///
+  /// Parameters:
+  /// - [startDate]: String in 'YYYY-MM' format (e.g., '2024-03')
+  /// - [endDate]: String in 'YYYY-MM' format (e.g., '2024-12')
+  /// - [context]: BuildContext for accessing localizations
+  ///
+  /// Example:
+  /// ```dart
+  /// final timeString = buildTimeString('2024-03', '2024-12', context);
+  /// // Returns "March 2024 - December 2024" (or localized equivalent)
+  /// ```
+  static String buildTimeString(
+      String startDate, String endDate, BuildContext context) {
+    // Check for empty or null inputs
+    if (startDate.isEmpty || endDate.isEmpty) {
+      return '';
+    }
+
+    try {
+      // Validate date format
+      if (!startDate.contains(RegExp(r'^\d{4}-\d{2}$')) ||
+          !endDate.contains(RegExp(r'^\d{4}-\d{2}$'))) {
+        return '';
+      }
+
+      // Parse dates with validation
+      final firstDate = DateTime.tryParse('$startDate-01');
+      final secondDate = DateTime.tryParse('$endDate-01');
+
+      // Check if parsing was successful
+      if (firstDate == null || secondDate == null) {
+        return '';
+      }
+
+      // Build the formatted string
+      return '${getLocalizedMonth(context, firstDate.month)} ${firstDate.year} - '
+          '${getLocalizedMonth(context, secondDate.month)} ${secondDate.year}';
+    } catch (e) {
+      // Handle any unexpected errors
+      debugPrint('Error building time string: $e');
+      return '';
+    }
+  }
+
+  /// Returns the localized month name as a [String] based on the provided month number.
+  ///
+  /// The [context] is used to access the app's localizations.
+  /// The [monthNumber] must be between 1 and 12, where 1 represents January
+  /// and 12 represents December.
+  ///
+  /// Throws an [ArgumentError] if the month number is not between 1 and 12.
+  ///
+  /// Example:
+  /// ```dart
+  /// final monthName = getLocalizedMonth(context, 3); // Returns "March" or "März"
+  /// ```
+  static String getLocalizedMonth(BuildContext context, int monthNumber) {
+    final localizations = AppLocalizations.of(context)!;
+
+    switch (monthNumber) {
+      case 1:
+        return localizations.january;
+      case 2:
+        return localizations.february;
+      case 3:
+        return localizations.march;
+      case 4:
+        return localizations.april;
+      case 5:
+        return localizations.may;
+      case 6:
+        return localizations.june;
+      case 7:
+        return localizations.july;
+      case 8:
+        return localizations.august;
+      case 9:
+        return localizations.september;
+      case 10:
+        return localizations.october;
+      case 11:
+        return localizations.november;
+      case 12:
+        return localizations.december;
+      default:
+        throw ArgumentError('Month number must be between 1 and 12');
+    }
   }
 }