import { describe, it, expect } from 'vitest';
import { opponentStartPosition, deserializePhantoms } from '../src/phantoms.js';

describe('opponentStartPosition', () => {
  it('seeds 16 black pieces on ranks 7-8', () => {
    const p = opponentStartPosition('b');
    expect(Object.keys(p).length).toBe(16);
    expect(p.e8).toEqual({ color: 'b', type: 'k' });
    expect(p.d8).toEqual({ color: 'b', type: 'q' });
    expect(p.a8).toEqual({ color: 'b', type: 'r' });
    expect(p.h7).toEqual({ color: 'b', type: 'p' });
  });

  it('seeds 16 white pieces on ranks 1-2', () => {
    const p = opponentStartPosition('w');
    expect(Object.keys(p).length).toBe(16);
    expect(p.e1).toEqual({ color: 'w', type: 'k' });
    expect(p.a2).toEqual({ color: 'w', type: 'p' });
  });
});

describe('deserializePhantoms', () => {
  it('returns {} for null or invalid JSON', () => {
    expect(deserializePhantoms(null)).toEqual({});
    expect(deserializePhantoms('not json')).toEqual({});
    expect(deserializePhantoms('[]')).toEqual({});
  });

  it('keeps valid entries and drops invalid ones', () => {
    const raw = JSON.stringify({
      e5: { color: 'b', type: 'n' },
      zz: { color: 'b', type: 'p' },  // invalid square
      a1: { color: 'x', type: 'p' },  // invalid colour
      b2: { color: 'b', type: 'z' },  // invalid type
    });
    expect(deserializePhantoms(raw)).toEqual({ e5: { color: 'b', type: 'n' } });
  });
});