import { describe, it, expect } from 'vitest';
import { isPromotionMove } from '../src/promotion.js';
import type { Piece } from '../src/types.js';

const wp: Piece = { color: 'w', type: 'p' };
const bp: Piece = { color: 'b', type: 'p' };
const wn: Piece = { color: 'w', type: 'n' };

describe('isPromotionMove', () => {
  it('white pawn from the 7th rank to the 8th is a promotion', () => {
    expect(isPromotionMove(wp, 'e7', 'e8')).toBe(true);
    expect(isPromotionMove(wp, 'd7', 'e8')).toBe(true); // capture-promotion
  });

  it('black pawn from the 2nd rank to the 1st is a promotion', () => {
    expect(isPromotionMove(bp, 'e2', 'e1')).toBe(true);
    expect(isPromotionMove(bp, 'd2', 'c1')).toBe(true);
  });

  it('a pawn NOT on the rank adjacent to promotion is not a promotion', () => {
    expect(isPromotionMove(wp, 'e2', 'e8')).toBe(false); // the reported bug
    expect(isPromotionMove(wp, 'e5', 'e8')).toBe(false);
    expect(isPromotionMove(bp, 'e7', 'e1')).toBe(false);
  });

  it('an ordinary pawn move is not a promotion', () => {
    expect(isPromotionMove(wp, 'e2', 'e4')).toBe(false);
    expect(isPromotionMove(bp, 'e7', 'e5')).toBe(false);
  });

  it('a non-pawn reaching the last rank is not a promotion', () => {
    expect(isPromotionMove(wn, 'g6', 'e8')).toBe(false);
  });

  it('a pawn move spanning more than one file is not a promotion', () => {
    expect(isPromotionMove(wp, 'a7', 'h8')).toBe(false);
  });

  it('an undefined piece is not a promotion', () => {
    expect(isPromotionMove(undefined, 'e7', 'e8')).toBe(false);
  });
});