// Copyright (c) Meta Platforms, Inc. and affiliates.

import {describe, expect, it} from 'vitest';
import {parseOutlineFromMarkdown} from './parseOutlineFromMarkdown';

describe('parseOutlineFromMarkdown', () => {
  it('returns an empty outline for content with no headings', () => {
    expect(parseOutlineFromMarkdown('just a paragraph of text')).toEqual([]);
    expect(parseOutlineFromMarkdown('')).toEqual([]);
  });

  it('extracts headings with their level and slugified id', () => {
    const outline = parseOutlineFromMarkdown('# Getting Started');
    expect(outline).toEqual([
      {id: 'getting-started', label: 'Getting Started', level: 1},
    ]);
  });

  it('captures heading levels distinctly', () => {
    const outline = parseOutlineFromMarkdown(
      ['# One', '## Two', '### Three'].join('\n\n'),
    );
    expect(outline.map(i => i.level)).toEqual([1, 2, 3]);
    expect(outline.map(i => i.label)).toEqual(['One', 'Two', 'Three']);
  });

  it('slugifies punctuation and spaces into single hyphens', () => {
    const outline = parseOutlineFromMarkdown('# Hello, World!  Again');
    expect(outline[0].id).toBe('hello-world-again');
  });

  it('strips quotes rather than converting them to hyphens', () => {
    const outline = parseOutlineFromMarkdown(`# The "Best" Way`);
    expect(outline[0].id).toBe('the-best-way');
  });

  it('trims leading and trailing hyphens from the slug', () => {
    const outline = parseOutlineFromMarkdown('# ...leading and trailing...');
    expect(outline[0].id).not.toMatch(/^-/);
    expect(outline[0].id).not.toMatch(/-$/);
  });

  it('deduplicates repeated slugs with a numeric suffix', () => {
    const outline = parseOutlineFromMarkdown(
      ['# Setup', '# Setup', '# Setup'].join('\n\n'),
    );
    expect(outline.map(i => i.id)).toEqual(['setup', 'setup-1', 'setup-2']);
    // labels stay unchanged even as ids are disambiguated
    expect(outline.every(i => i.label === 'Setup')).toBe(true);
  });

  it('falls back to "section" when a heading slugifies to empty', () => {
    const outline = parseOutlineFromMarkdown(['# !!!', '# @@@'].join('\n\n'));
    expect(outline.map(i => i.id)).toEqual(['section', 'section-1']);
  });

  it('flattens inline formatting into the label text', () => {
    const outline = parseOutlineFromMarkdown('# **Bold** and _italic_ text');
    expect(outline[0].label).toBe('Bold and italic text');
    expect(outline[0].id).toBe('bold-and-italic-text');
  });

  it('includes inline code content in the label', () => {
    const outline = parseOutlineFromMarkdown('# The `useState` hook');
    expect(outline[0].label).toBe('The useState hook');
  });

  it('does not treat fenced code block content as headings', () => {
    const md = ['# Real Heading', '', '```', '# not a heading', '```'].join(
      '\n',
    );
    const outline = parseOutlineFromMarkdown(md);
    expect(outline.map(i => i.label)).toEqual(['Real Heading']);
  });

  it('trims surrounding whitespace from labels', () => {
    const outline = parseOutlineFromMarkdown('#    Spaced Out   ');
    expect(outline[0].label).toBe('Spaced Out');
  });
});