import { describe, it, expect } from 'vitest';
import { AverageStrengthOfFieldCalculator, DriverRating } from './StrengthOfFieldCalculator';

describe('AverageStrengthOfFieldCalculator', () => {
  const calculator = new AverageStrengthOfFieldCalculator();

  it('should return null for empty list', () => {
    expect(calculator.calculate([])).toBeNull();
  });

  it('should return null if no valid ratings (>0)', () => {
    const ratings: DriverRating[] = [
      { driverId: '1', rating: 0 },
      { driverId: '2', rating: -100 },
    ];
    expect(calculator.calculate(ratings)).toBeNull();
  });

  it('should calculate average of valid ratings', () => {
    const ratings: DriverRating[] = [
      { driverId: '1', rating: 1000 },
      { driverId: '2', rating: 2000 },
      { driverId: '3', rating: 0 }, // Should be ignored
    ];
    expect(calculator.calculate(ratings)).toBe(1500);
  });

  it('should round the result', () => {
    const ratings: DriverRating[] = [
      { driverId: '1', rating: 1000 },
      { driverId: '2', rating: 1001 },
    ];
    expect(calculator.calculate(ratings)).toBe(1001); // (1000+1001)/2 = 1000.5 -> 1001
  });
});