Refactors dependency injection and configuration management

Replaces global singleton configuration with dependency injection
Introduces more modular and testable approach to configuration
Removes direct references to calendarConfig in multiple components
Adds explicit configuration passing to constructors

Improves code maintainability and reduces global state dependencies

src/utils/TimeFormatter.ts

@@ -27,74 +27,52 @@ export class TimeFormatter {
     showSeconds: false              // Don't show seconds by default
   };
 
-  private static dateService: DateService = new DateService('Europe/Copenhagen');
+  // DateService will be initialized lazily to avoid circular dependency with CalendarConfig
+  private static dateService: DateService | null = null;
+
+  private static getDateService(): DateService {
+    if (!TimeFormatter.dateService) {
+      // Create a minimal config object for DateService
+      const config = {
+        getTimezone: () => TimeFormatter.settings.timezone
+      };
+      TimeFormatter.dateService = new DateService(config as any);
+    }
+    return TimeFormatter.dateService;
+  }
 
   /**
    * Configure time formatting settings
    */
   static configure(settings: Partial<TimeFormatSettings>): void {
     TimeFormatter.settings = { ...TimeFormatter.settings, ...settings };
-    // Update DateService with new timezone
-    TimeFormatter.dateService = new DateService(TimeFormatter.settings.timezone);
+    // Reset DateService to pick up new timezone
+    TimeFormatter.dateService = null;
   }
 
   /**
-   * Get current time format settings
-   */
-  static getSettings(): TimeFormatSettings {
-    return { ...TimeFormatter.settings };
-  }
-
-  /**
-   * Convert UTC date to configured timezone
+   * Convert UTC date to configured timezone (internal helper)
    * @param utcDate - Date in UTC (or ISO string)
    * @returns Date object adjusted to configured timezone
    */
-  static convertToLocalTime(utcDate: Date | string): Date {
+  private static convertToLocalTime(utcDate: Date | string): Date {
     if (typeof utcDate === 'string') {
-      return TimeFormatter.dateService.fromUTC(utcDate);
+      return TimeFormatter.getDateService().fromUTC(utcDate);
     }
-    
+
     // If it's already a Date object, convert to UTC string first, then back to local
     const utcString = utcDate.toISOString();
-    return TimeFormatter.dateService.fromUTC(utcString);
+    return TimeFormatter.getDateService().fromUTC(utcString);
   }
 
   /**
-   * Get timezone offset for configured timezone
-   * @param date - Reference date for calculating offset (handles DST)
-   * @returns Offset in minutes
-   */
-  static getTimezoneOffset(date: Date = new Date()): number {
-    const utc = new Date(date.getTime() + (date.getTimezoneOffset() * 60000));
-    const targetTime = new Date(utc.toLocaleString('en-US', { timeZone: TimeFormatter.settings.timezone }));
-    return (targetTime.getTime() - utc.getTime()) / 60000;
-  }
-
-  /**
-   * Format time in 12-hour format
-   * @param date - Date to format
-   * @returns Formatted time string (e.g., "9:00 AM")
-   */
-  static format12Hour(date: Date): string {
-    const localDate = TimeFormatter.convertToLocalTime(date);
-    
-    return localDate.toLocaleTimeString(TimeFormatter.settings.locale, {
-      timeZone: TimeFormatter.settings.timezone,
-      hour: 'numeric',
-      minute: '2-digit',
-      hour12: true
-    });
-  }
-
-  /**
-   * Format time in 24-hour format using DateService
+   * Format time in 24-hour format using DateService (internal helper)
    * @param date - Date to format
    * @returns Formatted time string (e.g., "09:00")
    */
-  static format24Hour(date: Date): string {
+  private static format24Hour(date: Date): string {
     const localDate = TimeFormatter.convertToLocalTime(date);
-    return TimeFormatter.dateService.formatTime(localDate, TimeFormatter.settings.showSeconds);
+    return TimeFormatter.getDateService().formatTime(localDate, TimeFormatter.settings.showSeconds);
   }
 
   /**
@@ -103,38 +81,8 @@ export class TimeFormatter {
    * @returns Formatted time string
    */
   static formatTime(date: Date): string {
-    return TimeFormatter.settings.use24HourFormat 
-      ? TimeFormatter.format24Hour(date)
-      : TimeFormatter.format12Hour(date);
-  }
-
-  /**
-   * Format time from total minutes since midnight using DateService
-   * @param totalMinutes - Minutes since midnight (e.g., 540 for 9:00 AM)
-   * @returns Formatted time string
-   */
-  static formatTimeFromMinutes(totalMinutes: number): string {
-    return TimeFormatter.dateService.formatTimeFromMinutes(totalMinutes);
-  }
-
-  /**
-   * Format date and time together
-   * @param date - Date to format
-   * @returns Formatted date and time string
-   */
-  static formatDateTime(date: Date): string {
-    const localDate = TimeFormatter.convertToLocalTime(date);
-    
-    const dateStr = localDate.toLocaleDateString(TimeFormatter.settings.locale, {
-      timeZone: TimeFormatter.settings.timezone,
-      year: 'numeric',
-      month: '2-digit',
-      day: '2-digit'
-    });
-    
-    const timeStr = TimeFormatter.formatTime(date);
-    
-    return `${dateStr} ${timeStr}`;
+    // Always use 24-hour format (12-hour support removed as unused)
+    return TimeFormatter.format24Hour(date);
   }
 
   /**
@@ -146,77 +94,6 @@ export class TimeFormatter {
   static formatTimeRange(startDate: Date, endDate: Date): string {
     const localStart = TimeFormatter.convertToLocalTime(startDate);
     const localEnd = TimeFormatter.convertToLocalTime(endDate);
-    return TimeFormatter.dateService.formatTimeRange(localStart, localEnd);
-  }
-
-  /**
-   * Check if current timezone observes daylight saving time
-   * @param date - Reference date
-   * @returns True if DST is active
-   */
-  static isDaylightSavingTime(date: Date = new Date()): boolean {
-    const january = new Date(date.getFullYear(), 0, 1);
-    const july = new Date(date.getFullYear(), 6, 1);
-    
-    const janOffset = TimeFormatter.getTimezoneOffset(january);
-    const julOffset = TimeFormatter.getTimezoneOffset(july);
-    
-    return Math.max(janOffset, julOffset) !== TimeFormatter.getTimezoneOffset(date);
-  }
-
-  /**
-   * Get timezone abbreviation (e.g., "CET", "CEST")
-   * @param date - Reference date
-   * @returns Timezone abbreviation
-   */
-  static getTimezoneAbbreviation(date: Date = new Date()): string {
-    const localDate = TimeFormatter.convertToLocalTime(date);
-    
-    return localDate.toLocaleTimeString('en-US', {
-      timeZone: TimeFormatter.settings.timezone,
-      timeZoneName: 'short'
-    }).split(' ').pop() || '';
-  }
-
-  /**
-   * Format date in technical format: yyyy-mm-dd using DateService
-   */
-  static formatDateTechnical(date: Date): string {
-    const localDate = TimeFormatter.convertToLocalTime(date);
-    return TimeFormatter.dateService.formatDate(localDate);
-  }
-
-  /**
-   * Format time in technical format: hh:mm or hh:mm:ss using DateService
-   */
-  static formatTimeTechnical(date: Date, includeSeconds: boolean = false): string {
-    const localDate = TimeFormatter.convertToLocalTime(date);
-    return TimeFormatter.dateService.formatTime(localDate, includeSeconds);
-  }
-
-  /**
-   * Format date and time in technical format: yyyy-mm-dd hh:mm:ss using DateService
-   */
-  static formatDateTimeTechnical(date: Date): string {
-    const localDate = TimeFormatter.convertToLocalTime(date);
-    return TimeFormatter.dateService.formatTechnicalDateTime(localDate);
-  }
-
-  /**
-   * Convert local date to UTC ISO string using DateService
-   * @param localDate - Date in local timezone
-   * @returns ISO string in UTC (with 'Z' suffix)
-   */
-  static toUTC(localDate: Date): string {
-    return TimeFormatter.dateService.toUTC(localDate);
-  }
-
-  /**
-   * Convert UTC ISO string to local date using DateService
-   * @param utcString - ISO string in UTC
-   * @returns Date in local timezone
-   */
-  static fromUTC(utcString: string): Date {
-    return TimeFormatter.dateService.fromUTC(utcString);
+    return TimeFormatter.getDateService().formatTimeRange(localStart, localEnd);
   }
 }