export class RatingTrendDisplay {
  static getTrend(currentRating: number, previousRating: number | undefined): 'up' | 'down' | 'same' {
    if (!previousRating) return 'same';
    if (currentRating > previousRating) return 'up';
    if (currentRating < previousRating) return 'down';
    return 'same';
  }

  static getChangeIndicator(currentRating: number, previousRating: number | undefined): string {
    const change = previousRating ? currentRating - previousRating : 0;
    if (change > 0) return `+${change}`;
    if (change < 0) return `${change}`;
    return '0';
  }
}