import { describe, it, expect } from 'vitest';
import { stackTops } from '../../src/lib/utils/balloonStack';

describe('the margin balloon stack', () => {
  it('leaves a balloon at its anchor where there is room', () => {
    expect(stackTops([0, 200, 400], [50, 50, 50], 6)).toEqual([0, 200, 400]);
  });

  it('pushes an overlapping balloon below its predecessor', () => {
    expect(stackTops([0, 10, 20], [50, 50, 50], 6)).toEqual([0, 56, 112]);
  });

  it('never lifts one above the anchor it belongs to', () => {
    expect(stackTops([100, 0], [20, 20], 4)).toEqual([100, 124]);
  });

  it('pulls the column up so it ends inside the page', () => {
    expect(stackTops([0, 70], [40, 40], 6, 0, 100)).toEqual([0, 60]);
  });

  it('keeps the cards apart where the page cannot hold them all', () => {
    expect(stackTops([10, 20], [50, 50], 6, 0, 80)).toEqual([10, 66]);
  });

  it('holds an empty list', () => {
    expect(stackTops([], [], 6)).toEqual([]);
  });
});