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

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

  it('should calculate average SOF and round it', () => {
    const ratings = [
      { driverId: 'd1', rating: 1500 },
      { driverId: 'd2', rating: 2000 },
      { driverId: 'd3', rating: 1750 },
    ];

    const sof = calculator.calculate(ratings);

    expect(sof).toBe(1750);
  });

  it('should handle rounding correctly', () => {
    const ratings = [
      { driverId: 'd1', rating: 1000 },
      { driverId: 'd2', rating: 1001 },
    ];

    const sof = calculator.calculate(ratings);

    expect(sof).toBe(1001); // (1000 + 1001) / 2 = 1000.5 -> 1001
  });

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

  it('should filter out non-positive ratings', () => {
    const ratings = [
      { driverId: 'd1', rating: 1500 },
      { driverId: 'd2', rating: 0 },
      { driverId: 'd3', rating: -100 },
    ];

    const sof = calculator.calculate(ratings);

    expect(sof).toBe(1500);
  });

  it('should return null if all ratings are non-positive', () => {
    const ratings = [
      { driverId: 'd1', rating: 0 },
      { driverId: 'd2', rating: -500 },
    ];

    expect(calculator.calculate(ratings)).toBeNull();
  });
});