import { describe, expect, test } from 'bun:test';
import { wrapText } from './wrap';

describe('wrapText', () => {
  test('preserves short lines unchanged', () => {
    expect(wrapText('hello world', 80)).toEqual(['hello world']);
  });

  test('preserves existing newlines as line breaks', () => {
    expect(wrapText('a\nb\nc', 80)).toEqual(['a', 'b', 'c']);
  });

  test('empty input lines render as single space (visible blank row)', () => {
    expect(wrapText('a\n\nb', 80)).toEqual(['a', ' ', 'b']);
  });

  test('word-wraps long lines on whitespace', () => {
    const result = wrapText('the quick brown fox jumps over the lazy dog', 15);
    expect(result.every((line) => line.length <= 15)).toBe(true);
    expect(result.join(' ').replace(/\s+/g, ' ')).toBe(
      'the quick brown fox jumps over the lazy dog',
    );
  });

  test('hard-breaks words longer than the width', () => {
    const result = wrapText('xxxxxxxxxxxxxxxxxxxx', 5);
    expect(result.every((line) => line.length <= 5)).toBe(true);
    expect(result.join('')).toBe('xxxxxxxxxxxxxxxxxxxx');
  });

  test('mix of short, long, and blank lines', () => {
    const text = ['short', '', 'a much longer sentence that needs to wrap'].join('\n');
    const result = wrapText(text, 20);
    // First line: short stays as-is
    expect(result[0]).toBe('short');
    // Second line: blank → space
    expect(result[1]).toBe(' ');
    // Subsequent lines: each <= 20
    for (const line of result.slice(2)) {
      expect(line.length).toBeLessThanOrEqual(20);
    }
  });
});