import { ContainerFocusHandler } from 'src/utils/accessibility/FocusHandling/FocusContainer';

const createFocusContainer = (
  { itemsCount, setFocusAtFn }: { itemsCount: number; setFocusAtFn?: () => void } = {
    itemsCount: 0,
  },
) => new ContainerFocusHandler(() => itemsCount, setFocusAtFn || (() => {}));

describe('Focus Container', () => {
  test('inits with focused item index 0', () => {
    const focusContainer = createFocusContainer();

    expect(focusContainer).toBeDefined();
    expect(focusContainer.getFocusedIndex()).toBe(0);
  });

  describe('sync item index', () => {
    test('should set focus item index', () => {
      const focusContainer = createFocusContainer({ itemsCount: 5 });
      focusContainer.syncFocusedIndex(4);

      expect(focusContainer.getFocusedIndex()).toBe(4);
    });

    test('should not set focus index function', () => {
      const setFocusAt = jest.fn();
      const focusContainer = createFocusContainer({ itemsCount: 5, setFocusAtFn: setFocusAt });

      focusContainer.syncFocusedIndex(4);
      expect(setFocusAt).not.toBeCalled();
    });
  });

  describe('move previous', () => {
    test('should decrement index of focused item', () => {
      const focusContainer = createFocusContainer({ itemsCount: 5 });
      focusContainer.syncFocusedIndex(4);

      focusContainer.movePrevious();
      expect(focusContainer.getFocusedIndex()).toBe(3);
    });

    test('should call set focus index function if there are any items', () => {
      const setFocusAt = jest.fn();
      const focusContainer = createFocusContainer({ itemsCount: 5, setFocusAtFn: setFocusAt });

      focusContainer.movePrevious();
      expect(setFocusAt).toBeCalled();
    });

    test('should skip call to set focus index function if there are no items', () => {
      const setFocusAt = jest.fn();
      const focusContainer = createFocusContainer({ itemsCount: 0, setFocusAtFn: setFocusAt });

      focusContainer.movePrevious();
      expect(setFocusAt).not.toBeCalled();
    });

    test('focused item index should not ever become less than 0', () => {
      const focusContainer = createFocusContainer({ itemsCount: 5 });
      focusContainer.syncFocusedIndex(0);

      focusContainer.movePrevious();

      expect(focusContainer.getFocusedIndex()).toBe(0);
    });
  });

  describe('move next', () => {
    test('should increment index of focused item', () => {
      const focusContainer = createFocusContainer({ itemsCount: 5 });
      focusContainer.syncFocusedIndex(3);

      focusContainer.moveNext();
      expect(focusContainer.getFocusedIndex()).toBe(4);
    });

    test('should call set focus index function if there are any items', () => {
      const setFocusAt = jest.fn();
      const focusContainer = createFocusContainer({ itemsCount: 5, setFocusAtFn: setFocusAt });

      focusContainer.moveNext();
      expect(setFocusAt).toBeCalled();
    });

    test('should skip call to set focus index function if there are no items', () => {
      const setFocusAt = jest.fn();
      const focusContainer = createFocusContainer({ itemsCount: 0, setFocusAtFn: setFocusAt });

      focusContainer.moveNext();
      expect(setFocusAt).not.toBeCalled();
    });

    test('focused item index should not exceed range of valid indexes', () => {
      const focusContainer = createFocusContainer({ itemsCount: 5 });
      focusContainer.syncFocusedIndex(4);

      focusContainer.moveNext();

      expect(focusContainer.getFocusedIndex()).toBe(4);
    });
  });

  describe('move first', () => {
    test('should set focused item index to 0', () => {
      const focusContainer = createFocusContainer({ itemsCount: 5 });
      focusContainer.syncFocusedIndex(3);

      focusContainer.moveFirst();
      expect(focusContainer.getFocusedIndex()).toBe(0);
    });

    test('should call set focus index function if there are any items', () => {
      const setFocusAt = jest.fn();
      const focusContainer = createFocusContainer({ itemsCount: 5, setFocusAtFn: setFocusAt });

      focusContainer.moveFirst();
      expect(setFocusAt).toBeCalled();
    });

    test('should skip call to set focus index function if there are no items', () => {
      const setFocusAt = jest.fn();
      const focusContainer = createFocusContainer({ itemsCount: 0, setFocusAtFn: setFocusAt });

      focusContainer.moveFirst();
      expect(setFocusAt).not.toBeCalled();
    });
  });

  describe('move last', () => {
    test('should set focused item index to last index of valid range', () => {
      const focusContainer = createFocusContainer({ itemsCount: 5 });
      focusContainer.syncFocusedIndex(2);

      focusContainer.moveLast();
      expect(focusContainer.getFocusedIndex()).toBe(4);
    });

    test('should call set focus index function if there are any items', () => {
      const setFocusAt = jest.fn();
      const focusContainer = createFocusContainer({ itemsCount: 5, setFocusAtFn: setFocusAt });

      focusContainer.moveLast();
      expect(setFocusAt).toBeCalled();
    });

    test('should skip call to set focus index function if there are no items', () => {
      const setFocusAt = jest.fn();
      const focusContainer = createFocusContainer({ itemsCount: 0, setFocusAtFn: setFocusAt });

      focusContainer.moveLast();
      expect(setFocusAt).not.toBeCalled();
    });
  });
});