import { describe, it, expect } from 'vitest';
import { EditorState, type StateCommand } from '@codemirror/state';

import { sinkListItem, liftListItem, continueListItem } from './listKeymap';

/** Run a list-indent command headlessly and return the resulting doc + caret. */
function run(cmd: StateCommand, doc: string, cursor: number) {
  const state = EditorState.create({ doc, selection: { anchor: cursor } });
  let tr: ReturnType<EditorState['update']> | undefined;
  const ok = cmd({ state, dispatch: (t) => (tr = t) });
  return {
    ok,
    doc: tr ? tr.newDoc.toString() : doc,
    head: tr ? tr.newSelection.main.head : cursor,
  };
}

describe('continueListItem (Enter)', () => {
  it('continues a bullet marker with a trailing space, tightly', () => {
    const r = run(continueListItem, '- a', 3);
    expect(r.ok).toBe(true);
    expect(r.doc).toBe('- a\n- '); // no blank line between items
  });

  it('auto-increments an ordered list, tightly', () => {
    const r = run(continueListItem, '1. a', 4);
    expect(r.doc).toBe('1. a\n2. ');
  });

  it('continues at the same nested indent and increments', () => {
    const r = run(continueListItem, '1. a\n   1. b', 12);
    expect(r.doc).toBe('1. a\n   1. b\n   2. ');
  });

  it('keeps a multi-item list tight (no blank line inserted)', () => {
    // The bug: the old library command inserted a blank line here.
    const r = run(continueListItem, '1. a\n2. b', 9);
    expect(r.doc).toBe('1. a\n2. b\n3. ');
  });

  it('splits content after the cursor onto the continued line', () => {
    const r = run(continueListItem, '1. hello world', 9); // after "hello "
    expect(r.doc).toBe('1. hello \n2. world');
  });

  it('exits the list on an empty item', () => {
    expect(run(continueListItem, '- ', 2).doc).toBe('');
    expect(run(continueListItem, '1. ', 3).doc).toBe('');
  });

  it('falls through (returns false) outside a list item', () => {
    expect(run(continueListItem, 'plain', 5).ok).toBe(false);
  });
});

describe('sinkListItem (Tab)', () => {
  it('nests an ordered item under its sibling and resets it to 1', () => {
    // cursor at end of "2. b"
    const r = run(sinkListItem, '1. a\n2. b', 9);
    expect(r.ok).toBe(true);
    expect(r.doc).toBe('1. a\n   1. b');
  });

  it('closes the gap it leaves in the parent list', () => {
    const r = run(sinkListItem, '1. a\n2. b\n3. c', 9); // sink "b"
    expect(r.doc).toBe('1. a\n   1. b\n2. c');
  });

  it('nests a bullet item without touching a marker number', () => {
    const r = run(sinkListItem, '- a\n- b', 7); // end of "- b"
    expect(r.doc).toBe('- a\n  - b');
  });

  it('falls through on the first item of a list (nothing to nest under)', () => {
    const r = run(sinkListItem, '1. a', 4);
    expect(r.ok).toBe(false); // default Tab handles it
    expect(r.doc).toBe('1. a');
  });

  it('falls through (returns false) outside a list item', () => {
    const r = run(sinkListItem, 'plain text', 5);
    expect(r.ok).toBe(false);
  });
});

describe('liftListItem (Shift-Tab)', () => {
  it('outdents a nested ordered item and continues the parent numbering', () => {
    const r = run(liftListItem, '1. a\n   1. b', 12); // end of nested "1. b"
    expect(r.ok).toBe(true);
    expect(r.doc).toBe('1. a\n2. b');
  });

  it('increments following parent siblings when an item rejoins', () => {
    const r = run(liftListItem, '1. a\n   1. b\n2. c', 12); // lift "b"
    expect(r.doc).toBe('1. a\n2. b\n3. c');
  });

  it('restarts the siblings left behind in the nested list', () => {
    const r = run(liftListItem, '1. a\n   1. b\n   2. c', 12); // lift "b"
    expect(r.doc).toBe('1. a\n2. b\n   1. c');
  });

  it('falls through (returns false) at top level', () => {
    const r = run(liftListItem, '1. a', 4);
    expect(r.ok).toBe(false);
  });
});