import { describe, expect, it } from 'vitest';
import { closeDocument, openDocument, replaceDocument } from '../../src/editor/documents';
import { tabRowLayout } from '../../src/editor/tabRow';

const row = (docs: string[], active: string | null) => ({ docs, active });

describe('open documents', () => {
  it('puts a new document right of the one showing', () => {
    expect(openDocument(row(['a', 'b', 'c'], 'a'), 'x')).toEqual(row(['a', 'x', 'b', 'c'], 'x'));
  });

  it('puts it last while a fixed tab is showing', () => {
    expect(openDocument(row(['a', 'b'], null), 'x')).toEqual(row(['a', 'b', 'x'], 'x'));
    expect(openDocument(row([], null), 'x')).toEqual(row(['x'], 'x'));
  });

  it('only brings an open document up – one tab per document', () => {
    expect(openDocument(row(['a', 'b', 'c'], 'c'), 'a')).toEqual(row(['a', 'b', 'c'], 'a'));
  });

  it('shows the left neighbour after the one showing closes', () => {
    expect(closeDocument(row(['a', 'b', 'c'], 'b'), 'b')).toEqual(row(['a', 'c'], 'a'));
  });

  it('shows the right one when the first closes, and nothing when the last goes', () => {
    expect(closeDocument(row(['a', 'b'], 'a'), 'a')).toEqual(row(['b'], 'b'));
    expect(closeDocument(row(['a'], 'a'), 'a')).toEqual(row([], null));
  });

  it('keeps what is showing when another tab closes', () => {
    expect(closeDocument(row(['a', 'b', 'c'], 'c'), 'a')).toEqual(row(['b', 'c'], 'c'));
    expect(closeDocument(row(['a', 'b'], null), 'b')).toEqual(row(['a'], null));
  });

  it('ignores a document that is not open', () => {
    const before = row(['a'], 'a');
    expect(closeDocument(before, 'x')).toBe(before);
  });

  it('lets a tab go on to another document in its place', () => {
    expect(replaceDocument(row(['a', 'b', 'c'], 'b'), 'b', 'x')).toEqual(row(['a', 'x', 'c'], 'x'));
  });

  it('drops the other tab of a document it goes on to', () => {
    expect(replaceDocument(row(['a', 'b', 'c'], 'a'), 'a', 'c')).toEqual(row(['c', 'b'], 'c'));
  });

  it('leaves the row alone for a tab that is not open', () => {
    const before = row(['a'], 'a');
    expect(replaceDocument(before, 'x', 'y')).toBe(before);
    expect(replaceDocument(before, 'a', 'a')).toBe(before);
  });
});

describe('tab row without an active tab', () => {
  it('fills the row in order when a kind with no document is showing', () => {
    const tabs = [
      { key: 'a', width: 50 },
      { key: 'b', width: 50 },
      { key: 'c', width: 50 },
    ];
    const layout = tabRowLayout({ tabs, available: 132, gap: 2, overflowWidth: 28, active: null });
    expect(layout).toEqual({ shown: ['a', 'b'], hidden: ['c'] });
  });
});