import { describe, expect, it } from 'vitest';
import { buildSeats, commitName, rosterReady, shuffleSeeded, type RosterRow } from './roster';

describe('commitName (keep-last-valid)', () => {
  it('commits a valid, trimmed name', () => {
    expect(commitName('Ann', '')).toBe('Ann');
    expect(commitName('  Ann  ', '')).toBe('Ann');
  });

  it('keeps the previous valid name when the input goes invalid', () => {
    expect(commitName('', 'Ann')).toBe('Ann');
    expect(commitName('   ', 'Ann')).toBe('Ann');
    expect(commitName('a'.repeat(33), 'Ann')).toBe('Ann'); // over the 32-rune cap
    expect(commitName('_bad', 'Ann')).toBe('Ann'); // leading separator
  });

  it('replaces the committed name with a newer valid one', () => {
    expect(commitName('Bob', 'Ann')).toBe('Bob');
  });
});

describe('rosterReady', () => {
  const row = (committed: string): RosterRow => ({ name: committed, committed });

  it('needs 2-4 rows, each with a committed name', () => {
    expect(rosterReady([row('A'), row('B')])).toBe(true);
    expect(rosterReady([row('A'), row('B'), row('C'), row('D')])).toBe(true);
  });

  it('rejects fewer than 2, more than 4, or an empty row', () => {
    expect(rosterReady([row('A')])).toBe(false);
    expect(rosterReady([row('A'), row('B'), row('C'), row('D'), row('E')])).toBe(false);
    expect(rosterReady([row('A'), row('')])).toBe(false);
  });
});

describe('buildSeats', () => {
  it('maps committed rows to account-less human seats, carrying the PIN', () => {
    const lock = { hash: 'h', salt: 's' };
    const seats = buildSeats([
      { name: 'Ann', committed: 'Ann', pin: lock },
      { name: 'x', committed: 'Bob' },
    ]);
    expect(seats).toEqual([
      { kind: 'human', name: 'Ann', pin: lock },
      { kind: 'human', name: 'Bob', pin: undefined },
    ]);
    expect(seats.every((s) => !('accountId' in s) || s.accountId === undefined)).toBe(true);
  });
});

describe('shuffleSeeded', () => {
  it('is deterministic for the same seed', () => {
    expect(shuffleSeeded([0, 1, 2, 3], 42n)).toEqual(shuffleSeeded([0, 1, 2, 3], 42n));
  });

  it('keeps every element (a permutation) and does not mutate the input', () => {
    const input = [0, 1, 2, 3];
    const out = shuffleSeeded(input, 7n);
    expect([...out].sort((a, b) => a - b)).toEqual([0, 1, 2, 3]);
    expect(input).toEqual([0, 1, 2, 3]); // input untouched
  });

  it('varies the order across seeds (not always the identity)', () => {
    const orders = new Set([1n, 2n, 3n, 4n, 5n, 6n, 7n, 8n].map((s) => shuffleSeeded([0, 1, 2, 3], s).join('')));
    expect(orders.size).toBeGreaterThan(1);
  });
});