import { describe, expect, it } from 'vitest';
import { MoneyError, formatCents, parseAmountToCents, platformFee, proPayout, splitCharge } from '../src/money';

describe('platformFee', () => {
  it('takes the stated percentage', () => {
    expect(platformFee(10_000, 1500)).toBe(1500);
    expect(platformFee(15_000, 1200)).toBe(1800);
  });

  it('rounds half-up to whole cents', () => {
    expect(platformFee(333, 1500)).toBe(50); // 49.95 -> 50
    expect(platformFee(1, 1500)).toBe(0); // 0.15 -> 0
  });

  it('handles the boundaries', () => {
    expect(platformFee(10_000, 0)).toBe(0);
    expect(platformFee(10_000, 10_000)).toBe(10_000);
  });

  it('rejects nonsense rates', () => {
    expect(() => platformFee(10_000, -1)).toThrow(MoneyError);
    expect(() => platformFee(10_000, 10_001)).toThrow(MoneyError);
    expect(() => platformFee(10_000, 12.5)).toThrow(MoneyError);
  });

  it('rejects non-integer amounts — floats never reach Stripe', () => {
    expect(() => platformFee(99.99, 1500)).toThrow(MoneyError);
    expect(() => platformFee(-100, 1500)).toThrow(MoneyError);
  });
});

describe('splitCharge', () => {
  it('always sums back to the original amount', () => {
    for (const amount of [1, 7, 333, 999, 10_000, 123_457]) {
      const { fee, payout } = splitCharge(amount, 1500);
      expect(fee + payout).toBe(amount);
    }
  });

  it('agrees with proPayout', () => {
    expect(splitCharge(20_000, 1500).payout).toBe(proPayout(20_000, 1500));
  });
});

describe('parseAmountToCents', () => {
  it('parses the shapes a human types', () => {
    expect(parseAmountToCents('150')).toBe(15_000);
    expect(parseAmountToCents('150.50')).toBe(15_050);
    expect(parseAmountToCents('150,50')).toBe(15_050);
    expect(parseAmountToCents('$150.50')).toBe(15_050);
  });

  it('rounds to the nearest cent rather than truncating', () => {
    expect(parseAmountToCents('10.999')).toBe(1100);
  });

  it('throws on junk', () => {
    expect(() => parseAmountToCents('abc')).toThrow(MoneyError);
  });
});

describe('formatCents', () => {
  it('renders whole currency units', () => {
    expect(formatCents(15_000)).toContain('150');
  });
});