import { describe, expect, it } from 'vitest';
import { closeDocument, neighbourOf, openDocument, replaceDocument } from '../../src/editor/documents';
import { MIN_WINDOW_HEIGHT, MIN_WINDOW_WIDTH, onScreen, openingBox, sized } from '../../src/editor/floating';
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('what shows when a document goes to a window (#371)', () => {
  const all = () => true;

  it('picks the left neighbour, else the right one, else none', () => {
    expect(neighbourOf(['a', 'c'], 1, all)).toBe('a');
    expect(neighbourOf(['b', 'c'], 0, all)).toBe('b');
    expect(neighbourOf([], 0, all)).toBeNull();
  });

  it('passes over documents whose kind is in a window', () => {
    const tabs = (doc: string) => !doc.startsWith('fx');
    expect(neighbourOf(['a', 'fx1', 'fx2', 'b'], 3, tabs)).toBe('a');
    expect(neighbourOf(['fx1', 'fx2', 'b'], 1, tabs)).toBe('b');
    expect(neighbourOf(['fx1', 'fx2'], 1, tabs)).toBeNull();
  });
});

describe('a tab in a window (#371)', () => {
  it('opens in the middle of the screen, every further window a step lower right', () => {
    expect(openingBox(1280, 800, 0)).toEqual({ x: 320, y: 160, w: 640, h: 480 });
    expect(openingBox(1280, 800, 2)).toEqual({ x: 368, y: 208, w: 640, h: 480 });
  });

  it('is held whole on the screen when it is moved past an edge', () => {
    expect(onScreen({ x: 900, y: -40, w: 640, h: 480 }, 1280, 800)).toEqual({ x: 640, y: 0, w: 640, h: 480 });
    expect(onScreen({ x: 100, y: 100, w: 640, h: 480 }, 500, 400)).toEqual({ x: 0, y: 0, w: 500, h: 400 });
  });

  it('is sized from its lower right corner, down to a floor and out to the screen’s edge', () => {
    const box = { x: 600, y: 300, w: 400, h: 300 };
    expect(sized(box, 100, 50, 1280, 800)).toEqual({ ...box, w: 500, h: 350 });
    expect(sized(box, -500, -500, 1280, 800)).toEqual({ ...box, w: MIN_WINDOW_WIDTH, h: MIN_WINDOW_HEIGHT });
    expect(sized(box, 900, 900, 1280, 800)).toEqual({ ...box, w: 680, h: 500 });
  });
});

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'] });
  });
});