import { describe, expect, it } from 'vitest';
import {
  toPreviewHTML,
  toggleLinePrefix,
  toggleMarker,
  stripFormatting,
  isMarkerActive,
  WHATSAPP_MARKERS,
} from './whatsapp-markup';

describe('toPreviewHTML — inline formatting', () => {
  it('renders bold', () => {
    expect(toPreviewHTML('*bold*')).toBe('<strong>bold</strong>');
  });

  it('renders italic', () => {
    expect(toPreviewHTML('_italic_')).toBe('<em>italic</em>');
  });

  it('renders strikethrough', () => {
    expect(toPreviewHTML('~strike~')).toBe('<del>strike</del>');
  });

  it('renders inline monospace', () => {
    expect(toPreviewHTML('`code`')).toBe('<code>code</code>');
  });

  it('renders a single-character marker', () => {
    expect(toPreviewHTML('*a*')).toBe('<strong>a</strong>');
  });

  it('formats markers mid-sentence', () => {
    expect(toPreviewHTML('this is *bold* text')).toBe('this is <strong>bold</strong> text');
  });

  it('nests bold + italic', () => {
    expect(toPreviewHTML('*_x_*')).toBe('<strong><em>x</em></strong>');
  });

  it('does not format markers padded with spaces', () => {
    // Mid-sentence so the leading "* " is not parsed as a bullet list.
    expect(toPreviewHTML('a * not bold * b')).toBe('a * not bold * b');
  });

  it('leaves unmatched markers literal', () => {
    expect(toPreviewHTML('a * b')).toBe('a * b');
  });
});

describe('toPreviewHTML — code spans are literal', () => {
  it('does not format markers inside inline code', () => {
    expect(toPreviewHTML('`*not bold*`')).toBe('<code>*not bold*</code>');
  });

  it('renders fenced code blocks', () => {
    expect(toPreviewHTML('```\nline1\nline2\n```')).toBe('<pre><code>line1\nline2</code></pre>');
  });

  it('escapes html inside code', () => {
    expect(toPreviewHTML('`<b>&</b>`')).toBe('<code>&lt;b&gt;&amp;&lt;/b&gt;</code>');
  });
});

describe('toPreviewHTML — blocks', () => {
  it('renders a blockquote', () => {
    expect(toPreviewHTML('> quoted')).toBe('<blockquote>quoted</blockquote>');
  });

  it('renders an unordered list', () => {
    expect(toPreviewHTML('- one\n- two')).toBe('<ul><li>one</li><li>two</li></ul>');
  });

  it('renders an ordered list', () => {
    expect(toPreviewHTML('1. one\n2. two')).toBe('<ol><li>one</li><li>two</li></ol>');
  });

  it('applies inline formatting within list items', () => {
    expect(toPreviewHTML('- *bold*')).toBe('<ul><li><strong>bold</strong></li></ul>');
  });

  it('joins plain lines with <br>', () => {
    expect(toPreviewHTML('a\nb')).toBe('a<br>b');
  });
});

describe('toPreviewHTML — safety', () => {
  it('escapes html in plain text', () => {
    expect(toPreviewHTML('<script>alert(1)</script>')).toBe(
      '&lt;script&gt;alert(1)&lt;/script&gt;',
    );
  });

  it('returns empty string for empty input', () => {
    expect(toPreviewHTML('')).toBe('');
  });
});

describe('toggleMarker', () => {
  const bold = WHATSAPP_MARKERS.bold;

  it('wraps a selection', () => {
    const r = toggleMarker('hello world', 6, 11, bold);
    expect(r.value).toBe('hello *world*');
    expect(r.value.slice(r.selectionStart, r.selectionEnd)).toBe('world');
  });

  it('wraps an empty selection and places caret between markers', () => {
    const r = toggleMarker('hi ', 3, 3, bold);
    expect(r.value).toBe('hi **');
    expect(r.selectionStart).toBe(4);
    expect(r.selectionEnd).toBe(4);
  });

  it('unwraps when the selection includes the markers', () => {
    const r = toggleMarker('*world*', 0, 7, bold);
    expect(r.value).toBe('world');
    expect(r.value.slice(r.selectionStart, r.selectionEnd)).toBe('world');
  });

  it('unwraps when markers sit just outside the selection', () => {
    const r = toggleMarker('*world*', 1, 6, bold);
    expect(r.value).toBe('world');
    expect(r.value.slice(r.selectionStart, r.selectionEnd)).toBe('world');
  });

  it('round-trips wrap then unwrap', () => {
    const wrapped = toggleMarker('abc', 0, 3, bold);
    expect(wrapped.value).toBe('*abc*');
    const unwrapped = toggleMarker(
      wrapped.value,
      wrapped.selectionStart,
      wrapped.selectionEnd,
      bold,
    );
    expect(unwrapped.value).toBe('abc');
  });
});

describe('toggleLinePrefix', () => {
  it('adds a blockquote prefix to a single line', () => {
    const r = toggleLinePrefix('hello', 0, 0, 'blockquote');
    expect(r.value).toBe('> hello');
  });

  it('removes the blockquote prefix when toggled again', () => {
    const r = toggleLinePrefix('> hello', 0, 0, 'blockquote');
    expect(r.value).toBe('hello');
  });

  it('adds a bullet prefix', () => {
    const r = toggleLinePrefix('milk', 0, 0, 'bullet');
    expect(r.value).toBe('- milk');
  });

  it('numbers an ordered list across multiple selected lines', () => {
    const text = 'one\ntwo\nthree';
    const r = toggleLinePrefix(text, 0, text.length, 'ordered');
    expect(r.value).toBe('1. one\n2. two\n3. three');
  });

  it('toggles an ordered list off', () => {
    const text = '1. one\n2. two';
    const r = toggleLinePrefix(text, 0, text.length, 'ordered');
    expect(r.value).toBe('one\ntwo');
  });

  it('applies bullets to every line spanned by the selection', () => {
    const text = 'a\nb';
    const r = toggleLinePrefix(text, 0, text.length, 'bullet');
    expect(r.value).toBe('- a\n- b');
  });

  it('only affects the line under the caret, not the whole text', () => {
    const text = 'first\nsecond';
    // caret inside "second" (index 8)
    const r = toggleLinePrefix(text, 8, 8, 'blockquote');
    expect(r.value).toBe('first\n> second');
  });

  it('switches family from bullet to ordered without stacking', () => {
    const r = toggleLinePrefix('- a', 0, 3, 'ordered');
    expect(r.value).toBe('1. a');
  });
});

describe('stripFormatting', () => {
  it('removes inline markers', () => {
    expect(stripFormatting('*bold* _italic_ ~strike~ `mono`')).toBe('bold italic strike mono');
  });

  it('removes nested markers', () => {
    expect(stripFormatting('*_x_*')).toBe('x');
  });

  it('unwraps fenced code blocks', () => {
    expect(stripFormatting('```\ncode\n```')).toBe('code');
  });

  it('strips line-prefix blocks', () => {
    expect(stripFormatting('> quote\n- item\n1. first')).toBe('quote\nitem\nfirst');
  });

  it('leaves plain text untouched', () => {
    expect(stripFormatting('nothing here')).toBe('nothing here');
  });

  it('is idempotent', () => {
    const once = stripFormatting('*a* _b_');
    expect(stripFormatting(once)).toBe(once);
  });
});

describe('isMarkerActive', () => {
  const BOLD = WHATSAPP_MARKERS.bold;
  const ITALIC = WHATSAPP_MARKERS.italic;

  it('is false for a collapsed selection', () => {
    expect(isMarkerActive('*hi*', 2, 2, BOLD)).toBe(false);
  });

  it('detects when the selection itself is wrapped (case A)', () => {
    expect(isMarkerActive('*hi*', 0, 4, BOLD)).toBe(true);
  });

  it('detects when markers sit just outside the selection (case B)', () => {
    // "hi" selected inside *hi*
    expect(isMarkerActive('*hi*', 1, 3, BOLD)).toBe(true);
  });

  it('is false for an unformatted selection', () => {
    expect(isMarkerActive('hi there', 0, 2, BOLD)).toBe(false);
  });

  it('is marker-specific', () => {
    expect(isMarkerActive('_hi_', 0, 4, BOLD)).toBe(false);
    expect(isMarkerActive('_hi_', 0, 4, ITALIC)).toBe(true);
  });
});