import { describe, expect, test } from 'bun:test';
import { bodyOf, frontmatter, patchFrontmatter } from './tree';

const FILE = `---
id: fleet/an-item
title: "An item, with: punctuation"
theme: fleet
status: open
created: 2026-08-21
order: 2
---

**The body.** Hand-written prose with --- inside it.

- a list
`;

describe('frontmatter', () => {
  test('reads plain and JSON-quoted values', () => {
    const fm = frontmatter(FILE);
    expect(fm.id).toBe('fleet/an-item');
    expect(fm.title).toBe('An item, with: punctuation');
    expect(fm.order).toBe('2');
  });

  test('accepts prettier-style single quotes', () => {
    expect(frontmatter(`---\ntitle: 'A quoted title'\n---\n`).title).toBe('A quoted title');
  });

  test('no frontmatter → empty', () => {
    expect(frontmatter('just prose')).toEqual({});
  });
});

describe('bodyOf', () => {
  test('returns everything after the fence, trimmed of leading blank lines', () => {
    expect(bodyOf(FILE).startsWith('**The body.**')).toBe(true);
  });
});

describe('patchFrontmatter', () => {
  test('replaces an existing key in place', () => {
    const out = patchFrontmatter(FILE, { status: 'done' });
    expect(frontmatter(out).status).toBe('done');
    expect(out.match(/^status:/gm)).toHaveLength(1);
  });

  test('appends a key that was absent', () => {
    const out = patchFrontmatter(FILE, { priority: 'urgent' });
    expect(frontmatter(out).priority).toBe('urgent');
  });

  test('never touches the body — byte for byte', () => {
    const out = patchFrontmatter(FILE, { status: 'doing', order: '9' });
    expect(bodyOf(out)).toBe(bodyOf(FILE));
  });

  test('a --- inside the body is not mistaken for the fence', () => {
    const out = patchFrontmatter(FILE, { status: 'done' });
    expect(out).toContain('with --- inside it');
  });
});