import { html } from 'lit';
import { getLocalizeManager } from '@lion/ui/localize-no-side-effects.js';
import { localizeTearDown } from '@lion/ui/localize-test-helpers.js';
import { expect, fixture as _fixture } from '@open-wc/testing';
import sinon from 'sinon';
import '@lion/ui/define/lion-calendar.js';
import { isSameDate } from '@lion/ui/calendar.js';
import { CalendarObject, DayObject } from '@lion/ui/calendar-test-helpers.js';

/**
 * @typedef {import('../src/LionCalendar.js').LionCalendar} LionCalendar
 * @typedef {import('lit').TemplateResult} TemplateResult
 */

const fixture = /** @type {(arg: TemplateResult) => Promise<LionCalendar>} */ (_fixture);

describe('<lion-calendar>', () => {
  const localizeManager = getLocalizeManager();

  beforeEach(() => {
    localizeTearDown();
  });

  describe('Structure', () => {
    it('implements BEM structure', async () => {
      const el = await fixture(html`<lion-calendar></lion-calendar>`);

      expect(el.shadowRoot?.querySelector('.calendar')).to.exist;
      expect(el.shadowRoot?.querySelector('.calendar__navigation')).to.exist;
      expect(el.shadowRoot?.querySelector('.calendar__previous-button')).to.exist;
      expect(el.shadowRoot?.querySelector('.calendar__next-button')).to.exist;
      expect(el.shadowRoot?.querySelector('.calendar__navigation-heading')).to.exist;
      expect(el.shadowRoot?.querySelector('.calendar__grid')).to.exist;
    });

    it('has heading with month and year', async () => {
      const clock = sinon.useFakeTimers({ now: new Date('2000/12/01').getTime() });

      const el = await fixture(html`<lion-calendar></lion-calendar>`);

      expect(el.shadowRoot?.querySelector('#year')).dom.to.equal(`
        <h2
          id="year"
          class="calendar__navigation-heading"
          aria-atomic="true"
        >
          2000
        </h2>
      `);
      expect(el.shadowRoot?.querySelector('#month')).dom.to.equal(`
      <h2
        id="month"
        class="calendar__navigation-heading"
        aria-atomic="true"
      >
        December
      </h2>
    `);

      clock.restore();
    });

    it('has previous year button', async () => {
      const el = await fixture(
        html`<lion-calendar .centralDate=${new Date('2019/11/20')}></lion-calendar>`,
      );
      expect(el.shadowRoot?.querySelectorAll('.calendar__previous-button')[0]).dom.to.equal(`
        <button class="calendar__previous-button" aria-label="Previous year, November 2018" title="Previous year, November 2018">&lt;</button>
      `);
    });

    it('has next year button', async () => {
      const el = await fixture(
        html`<lion-calendar .centralDate=${new Date('2019/11/20')}></lion-calendar>`,
      );
      expect(el.shadowRoot?.querySelectorAll('.calendar__next-button')[0]).dom.to.equal(`
        <button class="calendar__next-button" aria-label="Next year, November 2020" title="Next year, November 2020">&gt;</button>
      `);
    });

    it('has previous month button', async () => {
      const el = await fixture(
        html`<lion-calendar .centralDate=${new Date('2019/11/20')}></lion-calendar>`,
      );
      expect(el.shadowRoot?.querySelectorAll('.calendar__previous-button')[1]).dom.to.equal(`
        <button class="calendar__previous-button" aria-label="Previous month, October 2019" title="Previous month, October 2019">&lt;</button>
      `);
    });

    it('has next month button', async () => {
      const el = await fixture(
        html`<lion-calendar .centralDate=${new Date('2019/11/20')}></lion-calendar>`,
      );
      expect(el.shadowRoot?.querySelectorAll('.calendar__next-button')[1]).dom.to.equal(`
        <button class="calendar__next-button" aria-label="Next month, December 2019" title="Next month, December 2019">&gt;</button>
      `);
    });
  });

  describe('Public API', () => {
    it('has property "centralDate" that determines currently visible month', async () => {
      const elObj = new CalendarObject(
        await fixture(html`
          <lion-calendar .centralDate="${new Date('2014/05/15')}"></lion-calendar>
        `),
      );
      expect(elObj.activeMonth).to.equal('May');
      expect(elObj.activeYear).to.equal('2014');
    });

    it('sets "centralDate" to today by default', async () => {
      const clock = sinon.useFakeTimers({ now: new Date('2013/03/15').getTime() });

      const el = await fixture(html`<lion-calendar></lion-calendar>`);
      const elObj = new CalendarObject(el);
      expect(isSameDate(el.centralDate, new Date())).to.be.true;
      expect(elObj.activeMonth).to.equal('March');
      expect(elObj.activeYear).to.equal('2013');

      clock.restore();
    });

    it('determines the date focusable with keyboard from "centralDate"', async () => {
      const elObj = new CalendarObject(
        await fixture(html`
          <lion-calendar .centralDate="${new Date('2017/07/05')}"></lion-calendar>
        `),
      );
      expect(
        elObj.checkForAllDayObjs(
          /** @param {DayObject} o */ o => o.buttonEl.getAttribute('tabindex') === '0',
          /** @param {number} n */ n => n === 5,
        ),
      ).to.be.true;
      expect(
        elObj.checkForAllDayObjs(
          /** @param {DayObject} o */ o => o.buttonEl.getAttribute('tabindex') === '-1',
          /** @param {number} n */ n => n !== 5,
        ),
      ).to.be.true;
    });

    it('has property "selectedDate" for the selected date', async () => {
      const el = await fixture(html`
        <lion-calendar .selectedDate="${new Date('2019/06/15')}"></lion-calendar>
      `);
      const elObj = new CalendarObject(el);
      expect(elObj.getDayObj(15).isSelected).to.equal(true);
      expect(elObj.getDayObj(16).isSelected).to.equal(false);
      expect(elObj.getDayObj(14).isSelected).to.equal(false);
      el.selectedDate = new Date('2019/06/16');
      await el.updateComplete;
      expect(elObj.getDayObj(15).isSelected).to.equal(false);
    });

    it('gives priority to "centralDate" to display the month when "selectedDate" is also defined', async () => {
      const elObj = new CalendarObject(
        await fixture(html`
          <lion-calendar
            .centralDate="${new Date('2018/06/01')}"
            .selectedDate="${new Date('2018/07/15')}"
          ></lion-calendar>
        `),
      );
      expect(elObj.activeMonth).to.equal('June');
      expect(elObj.activeYear).to.equal('2018');
    });

    it('changes "centralDate" from default to "selectedDate" on first render if no other custom "centralDate" is provided', async () => {
      const clock = sinon.useFakeTimers({ now: new Date('2010/01/01').getTime() });

      const el = await fixture(html`
        <lion-calendar .selectedDate="${new Date('2016/10/20')}"></lion-calendar>
      `);
      const elObj = new CalendarObject(el);
      expect(isSameDate(el.centralDate, new Date('2016/10/20'))).to.be.true;
      expect(elObj.activeMonth).to.equal('October');
      expect(elObj.activeYear).to.equal('2016');
      clock.restore();
    });

    it('does not change "centralDate" to "selectedDate" when new date is provided programmatically', async () => {
      const el = await fixture(html`
        <lion-calendar
          .centralDate="${new Date('2018/06/01')}"
          .selectedDate="${new Date('2018/06/02')}"
        ></lion-calendar>
      `);
      expect(isSameDate(el.centralDate, new Date('2018/06/01'))).to.be.true;
      el.selectedDate = new Date('2018/06/03');
      await el.updateComplete;
      expect(isSameDate(el.centralDate, new Date('2018/06/01'))).to.be.true;
    });

    it('does not set "selectedDate" by default', async () => {
      const el = await fixture(html`<lion-calendar></lion-calendar>`);
      const elObj = new CalendarObject(el);
      const today = new Date();
      expect(el.selectedDate).to.equal(undefined);
      expect(elObj.getDayObj(today.getDate()).isSelected).to.equal(false);
    });

    it('allows to reset "selectedDate"', async () => {
      const el = await fixture(html`
        <lion-calendar .selectedDate="${new Date('2019/06/15')}"></lion-calendar>
      `);
      const elObj = new CalendarObject(el);
      el.selectedDate = undefined;
      await el.updateComplete;
      expect(elObj.selectedDayObj).to.be.undefined;
    });

    it('recalculates "centralDate" when "selectedDate" is reset', async () => {
      const el = await fixture(html`
        <lion-calendar .selectedDate="${new Date('2019/06/15')}"></lion-calendar>
      `);
      const elObj = new CalendarObject(el);
      el.selectedDate = undefined;
      await el.updateComplete;
      expect(elObj.selectedDayObj).to.be.undefined;
      expect(isSameDate(el.centralDate, new Date('2019/06/15'))).to.be.true;
    });

    it('sends event "user-selected-date-changed" when user selects a date', async () => {
      const dateChangedSpy = sinon.spy();
      const el = await fixture(html`
        <lion-calendar
          .selectedDate="${new Date('2000/12/12')}"
          @user-selected-date-changed="${dateChangedSpy}"
        ></lion-calendar>
      `);
      const elObj = new CalendarObject(el);
      expect(dateChangedSpy.called).to.equal(false);
      elObj.getDayEl(15).click();
      await el.updateComplete;
      expect(dateChangedSpy.calledOnce).to.equal(true);
      expect(
        isSameDate(dateChangedSpy.args[0][0].detail.selectedDate, new Date('2000/12/15')),
      ).to.equal(true);
    });

    it('doesn\'t send event "user-selected-date-changed" when user selects a disabled date', async () => {
      const dateChangedSpy = sinon.spy();
      const disable15th = /** @param {Date} d */ d => d.getDate() === 15;
      const el = await fixture(html`
        <lion-calendar
          .selectedDate="${new Date('2000/12/12')}"
          @user-selected-date-changed="${dateChangedSpy}"
          .disableDates=${disable15th}
        ></lion-calendar>
      `);
      const elObj = new CalendarObject(el);
      elObj.getDayEl(15).click();
      await el.updateComplete;
      expect(dateChangedSpy.called).to.equal(false);
    });

    it('exposes focusedDate getter', async () => {
      const el = await fixture(html`
        <lion-calendar .centralDate="${new Date('2019/06/01')}"></lion-calendar>
      `);
      const elObj = new CalendarObject(el);
      expect(el.focusedDate).to.be.null;
      elObj.getDayEl(15).click();
      expect(isSameDate(/** @type {Date} */ (el.focusedDate), new Date('2019/06/15'))).to.equal(
        true,
      );
    });

    it('has a focusDate() method to focus an arbitrary date', async () => {
      const el = await fixture(html`<lion-calendar></lion-calendar>`);
      const elObj = new CalendarObject(el);
      await el.focusDate(new Date('2016/06/10'));
      expect(isSameDate(/** @type {Date} */ (el.focusedDate), new Date('2016/06/10'))).to.be.true;
      expect(elObj.getDayObj(10).isFocused).to.be.true;
    });

    it('has a focusCentralDate() method to focus the central date', async () => {
      const el = await fixture(html`
        <lion-calendar
          .centralDate="${new Date('2015/12/02')}"
          .selectedDate="${new Date('2015/12/04')}"
        ></lion-calendar>
      `);
      const elObj = new CalendarObject(el);
      el.focusCentralDate();
      expect(isSameDate(/** @type {Date} */ (el.focusedDate), new Date('2015/12/02'))).to.be.true;
      expect(elObj.getDayObj(2).isFocused).to.be.true;
    });

    it('has a focusSelectedDate() method to focus the selected date', async () => {
      const el = await fixture(html`
        <lion-calendar
          .centralDate="${new Date('2014/07/05')}"
          .selectedDate="${new Date('2014/07/07')}"
        ></lion-calendar>
      `);
      const elObj = new CalendarObject(el);
      await el.focusSelectedDate();
      expect(isSameDate(/** @type {Date} */ (el.focusedDate), new Date('2014/07/07'))).to.be.true;
      expect(elObj.getDayObj(7).isFocused).to.be.true;
    });

    it('has a initCentralDate() method for external contexts like datepickers', async () => {
      const initialCentralDate = new Date('2014/07/05');
      const initialSelectedDate = new Date('2014/07/07');
      const el = await fixture(html`<lion-calendar
        .centralDate="${initialCentralDate}"
        .selectedDate="${initialSelectedDate}"
      ></lion-calendar>`);

      expect(el.selectedDate).to.equal(initialSelectedDate);
      expect(el.centralDate).to.equal(initialCentralDate);

      const newSelectedDate = new Date('2015/07/05');
      el.selectedDate = newSelectedDate;
      el.initCentralDate();
      expect(el.centralDate).to.equal(newSelectedDate);
      el.selectedDate = undefined;
      el.initCentralDate();
      expect(el.centralDate).to.equal(initialCentralDate);
    });

    describe('Enabled Dates', () => {
      it('disables all days before "minDate" property', async () => {
        const el = await fixture(html`
          <lion-calendar
            .selectedDate="${new Date('2000/12/31')}"
            .minDate="${new Date('2000/12/09')}"
          >
          </lion-calendar>
        `);
        const elObj = new CalendarObject(el);
        expect(elObj.getDayObj(15).isDisabled).to.equal(false);
        elObj.dayEls.forEach((d, i) => {
          const shouldBeDisabled = i < 8;
          expect(new DayObject(d).isDisabled).to.equal(shouldBeDisabled);
        });
      });

      it('disables all days after "maxDate" property', async () => {
        const el = await fixture(html`
          <lion-calendar
            .selectedDate="${new Date('2000/12/01')}"
            .maxDate="${new Date('2000/12/09')}"
          >
          </lion-calendar>
        `);
        const elObj = new CalendarObject(el);
        expect(elObj.getDayObj(5).isDisabled).to.equal(false);
        elObj.dayEls.forEach((d, i) => {
          const shouldBeDisabled = i > 8;
          expect(new DayObject(d).isDisabled).to.equal(shouldBeDisabled);
        });
      });

      it('disables a date with disableDates function', async () => {
        /** @param {Date} d */
        const disable15th = d => d.getDate() === 15;
        const el = await fixture(
          html`
            <lion-calendar
              .selectedDate="${new Date('2000/12/01')}"
              .disableDates=${disable15th}
            ></lion-calendar>
          `,
        );
        const elObj = new CalendarObject(el);
        elObj.dayEls.forEach((d, i) => {
          const shouldBeDisabled = i === 15 - 1;
          expect(new DayObject(d).isDisabled).to.equal(shouldBeDisabled);
        });

        el.selectedDate = new Date('2000/11/01'); // When month view updates, it should still work
        await el.updateComplete;
        elObj.dayEls.forEach((d, i) => {
          const shouldBeDisabled = i === 15 - 1;
          expect(new DayObject(d).isDisabled).to.equal(shouldBeDisabled);
        });
      });

      it('does not prevent initializing "centralDate" from "selectedDate" when today is disabled', async () => {
        const clock = sinon.useFakeTimers({ now: new Date('2019/06/03').getTime() });

        const el = await fixture(html`
          <lion-calendar
            .selectedDate="${new Date('2001/01/08')}"
            .disableDates=${/** @param {Date} date */ date => date.getDate() === 3}
          ></lion-calendar>
        `);
        const elObj = new CalendarObject(el);
        expect(isSameDate(el.centralDate, new Date('2001/01/08'))).to.be.true;
        expect(elObj.activeMonth).to.equal('January');
        expect(elObj.activeYear).to.equal('2001');

        clock.restore();
      });

      it('requires the user to set an appropriate centralDate even when minDate and maxDate are equal', async () => {
        const clock = sinon.useFakeTimers({ now: new Date('2019/06/03').getTime() });

        const el = await fixture(html`
          <lion-calendar
            .minDate="${new Date('2019/07/03')}"
            .maxDate="${new Date('2019/07/03')}"
          ></lion-calendar>
        `);
        const elSetting = await fixture(html`
          <lion-calendar
            .centralDate="${new Date('2019/07/03')}"
            .minDate="${new Date('2019/07/03')}"
            .maxDate="${new Date('2019/07/03')}"
          ></lion-calendar>
        `);

        clock.restore();
        expect(isSameDate(el.centralDate, new Date('2019/06/03')), 'central date').to.be.true;
        expect(isSameDate(elSetting.centralDate, new Date('2019/07/03')), 'central date').to.be
          .true;
      });

      describe('Normalization', () => {
        it('normalizes all generated dates', async () => {
          /** @param {Date} d */
          function isNormalizedDate(d) {
            return d.getHours() === 0 && d.getMinutes() === 0 && d.getSeconds() === 0;
          }

          const el = await fixture(html`<lion-calendar></lion-calendar>`);
          // The central date will be today's date: it's the date all other
          // dates in the month view will be derived from.
          expect(isNormalizedDate(el.centralDate)).to.be.true;
        });

        it('normalizes dates in date comparisons', async () => {
          const selectedDate = new Date('2000-11-04T03:00:00');
          // without normalization, selectedDate > maxDate would wrongfully be disabled
          const maxDate = new Date('2000-11-29T02:00:00');
          // without normalization, selectedDate < minDate would wrongfully be disabled
          const minDate = new Date('2000-11-02T04:00:00');

          const el = await fixture(
            html`
              <lion-calendar
                .selectedDate="${selectedDate}"
                .minDate="${minDate}"
                .maxDate="${maxDate}"
              ></lion-calendar>
            `,
          );
          const elObj = new CalendarObject(el);

          expect(elObj.getDayObj(29).isDisabled).to.equal(false);
          expect(elObj.getDayObj(30).isDisabled).to.equal(true);

          expect(elObj.getDayObj(2).isDisabled).to.equal(false);
          expect(elObj.getDayObj(1).isDisabled).to.equal(true);
        });
      });
    });
  });

  describe('Calendar navigation', () => {
    describe('Title', () => {
      it('contains secondary title displaying the current month and year in focus', async () => {
        const el = await fixture(
          html`<lion-calendar .selectedDate="${new Date('2000/12/12')}"></lion-calendar>`,
        );
        const elObj = new CalendarObject(el);
        expect(elObj.activeMonth).to.equal('December');
        expect(elObj.activeYear).to.equal('2000');
      });

      it('updates the secondary title when the displayed month/year changes', async () => {
        const el = await fixture(
          html`<lion-calendar .centralDate="${new Date('2000/12/12')}"></lion-calendar>`,
        );
        const elObj = new CalendarObject(el);
        el.centralDate = new Date('1999/10/12');
        await el.updateComplete;
        expect(elObj.activeMonth).to.equal('October');
        expect(elObj.activeYear).to.equal('1999');
      });

      describe('Accessibility', () => {
        it('has aria-atomic="true" set on the secondary title', async () => {
          const elObj = new CalendarObject(await fixture(html`<lion-calendar></lion-calendar>`));
          expect(elObj.monthHeadingEl?.getAttribute('aria-atomic')).to.equal('true');
        });
      });
    });

    describe('Navigation', () => {
      describe('finding enabled dates', () => {
        it('has helper for `findNextEnabledDate()`, `findPreviousEnabledDate()`, `findNearestEnabledDate()`', async () => {
          const el = await fixture(html`
            <lion-calendar
              .selectedDate="${new Date('2001/01/02')}"
              .disableDates=${
                /** @param {Date} date */ date => date.getDate() === 3 || date.getDate() === 4
              }
            ></lion-calendar>
          `);
          const elObj = new CalendarObject(el);

          el.focusDate(el.findNextEnabledDate());
          await el.updateComplete;
          expect(elObj.focusedDayObj?.monthday).to.equal(5);

          el.focusDate(el.findPreviousEnabledDate());
          await el.updateComplete;
          expect(elObj.focusedDayObj?.monthday).to.equal(2);

          el.focusDate(el.findNearestEnabledDate());
          await el.updateComplete;
          expect(elObj.focusedDayObj?.monthday).to.equal(1);
        });

        it('future dates take precedence over past dates when "distance" between dates is equal', async () => {
          const clock = sinon.useFakeTimers({ now: new Date('2000/12/15').getTime() });

          const el = await fixture(html`
            <lion-calendar
              .disableDates="${/** @param {Date} d */ d => d.getDate() === 15}"
            ></lion-calendar>
          `);
          el.focusDate(el.findNearestEnabledDate());
          await el.updateComplete;

          const elObj = new CalendarObject(el);
          expect(elObj.centralDayObj?.monthday).to.equal(16);

          clock.restore();
        });

        it('will search 750 days in the past', async () => {
          const clock = sinon.useFakeTimers({ now: new Date('2000/12/15').getTime() });

          const el = await fixture(html`
            <lion-calendar
              .disableDates="${/** @param {Date} d */ d => d.getFullYear() > 1998}"
            ></lion-calendar>
          `);
          el.focusDate(el.findNearestEnabledDate());
          await el.updateComplete;

          expect(el.centralDate.getFullYear()).to.equal(1998);
          expect(el.centralDate.getMonth()).to.equal(11);
          expect(el.centralDate.getDate()).to.equal(31);

          clock.restore();
        });

        it('will search 750 days in the future', async () => {
          const clock = sinon.useFakeTimers({ now: new Date('2000/12/15').getTime() });

          const el = await fixture(html`
            <lion-calendar
              .disableDates="${/** @param {Date} d */ d => d.getFullYear() < 2002}"
            ></lion-calendar>
          `);

          el.focusDate(el.findNearestEnabledDate());
          await el.updateComplete;

          expect(el.centralDate.getFullYear()).to.equal(2002);
          expect(el.centralDate.getMonth()).to.equal(0);
          expect(el.centralDate.getDate()).to.equal(1);

          clock.restore();
        });

        it('throws if no available date can be found within +/- 750 days', async () => {
          const el = await fixture(html`
            <lion-calendar
              .disableDates="${/** @param {Date} d */ d => d.getFullYear() < 2002}"
            ></lion-calendar>
          `);

          expect(() => {
            el.findNextEnabledDate(new Date('1900/01/01'));
          }).to.throw(Error, 'Could not find a selectable date within +/- 750 day for 1900/1/1');
        });
      });

      describe('Year', () => {
        it('has a button for navigation to previous year', async () => {
          const el = await fixture(
            html`<lion-calendar .selectedDate="${new Date('2001/01/01')}"></lion-calendar>`,
          );
          const elObj = new CalendarObject(el);
          expect(elObj.previousYearButtonEl).not.to.equal(null);
          expect(elObj.activeMonth).to.equal('January');
          expect(elObj.activeYear).to.equal('2001');

          /** @type {HTMLElement} */ (elObj.previousYearButtonEl).click();
          await el.updateComplete;
          expect(elObj.activeMonth).to.equal('January');
          expect(elObj.activeYear).to.equal('2000');

          /** @type {HTMLElement} */ (elObj.previousYearButtonEl).click();
          await el.updateComplete;
          expect(elObj.activeMonth).to.equal('January');
          expect(elObj.activeYear).to.equal('1999');
        });

        it('has a button for navigation to next year', async () => {
          const el = await fixture(
            html`<lion-calendar .selectedDate="${new Date('2000/12/12')}"></lion-calendar>`,
          );
          const elObj = new CalendarObject(el);
          expect(elObj.nextYearButtonEl).not.to.equal(null);
          expect(elObj.activeMonth).to.equal('December');
          expect(elObj.activeYear).to.equal('2000');

          /** @type {HTMLElement} */ (elObj.nextYearButtonEl).click();
          await el.updateComplete;
          expect(elObj.activeMonth).to.equal('December');
          expect(elObj.activeYear).to.equal('2001');

          /** @type {HTMLElement} */ (elObj.nextYearButtonEl).click();
          await el.updateComplete;
          expect(elObj.activeMonth).to.equal('December');
          expect(elObj.activeYear).to.equal('2002');
        });

        it('disables previousYearButton and nextYearButton based on disabled days accordingly', async () => {
          const el = await fixture(html`
            <lion-calendar .selectedDate="${new Date('2000/06/12')}"></lion-calendar>
          `);
          const elObj = new CalendarObject(el);
          expect(elObj.activeMonth).to.equal('June');
          expect(elObj.activeYear).to.equal('2000');
          expect(elObj.previousYearButtonEl?.hasAttribute('disabled')).to.equal(false);
          expect(elObj.nextYearButtonEl?.hasAttribute('disabled')).to.equal(false);

          el.minDate = new Date('2000/01/01');
          el.maxDate = new Date('2000/12/31');
          await el.updateComplete;

          expect(elObj.previousYearButtonEl?.hasAttribute('disabled')).to.equal(true);
          expect(elObj.nextYearButtonEl?.hasAttribute('disabled')).to.equal(true);

          /** @type {HTMLElement} */ (elObj.previousYearButtonEl).click();
          await el.updateComplete;
          expect(elObj.activeMonth).to.equal('June');
          expect(elObj.activeYear).to.equal('2000');

          el.minDate = new Date('1999/12/31');
          el.maxDate = new Date('2001/01/01');
          await el.updateComplete;

          expect(elObj.previousYearButtonEl?.hasAttribute('disabled')).to.equal(false);
          expect(elObj.nextYearButtonEl?.hasAttribute('disabled')).to.equal(false);
        });

        it('sets label to correct month previousYearButton and nextYearButton based on disabled days accordingly', async () => {
          const el = await fixture(html`
            <lion-calendar .selectedDate="${new Date('2000/06/12')}"></lion-calendar>
          `);
          const elObj = new CalendarObject(el);
          el.minDate = new Date('1999/07/12');
          el.maxDate = new Date('2001/05/12');
          await el.updateComplete;

          expect(elObj.previousYearButtonEl?.hasAttribute('disabled')).to.equal(false);
          expect(elObj.previousYearButtonEl.getAttribute('aria-label')).to.equal(
            'Previous year, July 1999',
          );
          expect(elObj.nextYearButtonEl?.hasAttribute('disabled')).to.equal(false);
          expect(elObj.nextYearButtonEl.getAttribute('aria-label')).to.equal('Next year, May 2001');
        });
      });

      describe('Month', () => {
        it('has a button for navigation to previous month', async () => {
          const el = await fixture(
            html`<lion-calendar .selectedDate="${new Date('2001/01/01')}"></lion-calendar>`,
          );
          const elObj = new CalendarObject(el);
          expect(elObj.previousMonthButtonEl).not.to.equal(null);
          expect(elObj.activeMonth).to.equal('January');
          expect(elObj.activeYear).to.equal('2001');

          /** @type {HTMLElement} */ (elObj.previousMonthButtonEl).click();
          await el.updateComplete;
          expect(elObj.activeMonth).to.equal('December');
          expect(elObj.activeYear).to.equal('2000');

          /** @type {HTMLElement} */ (elObj.previousMonthButtonEl).click();
          await el.updateComplete;
          expect(elObj.activeMonth).to.equal('November');
          expect(elObj.activeYear).to.equal('2000');
        });

        it('has a button for navigation to next month', async () => {
          const el = await fixture(
            html`<lion-calendar .selectedDate="${new Date('2000/12/12')}"></lion-calendar>`,
          );
          const elObj = new CalendarObject(el);
          expect(elObj.nextMonthButtonEl).not.to.equal(null);
          expect(elObj.activeMonth).to.equal('December');
          expect(elObj.activeYear).to.equal('2000');
          /** @type {HTMLElement} */ (elObj.nextMonthButtonEl).click();
          await el.updateComplete;
          expect(elObj.activeMonth).to.equal('January');
          expect(elObj.activeYear).to.equal('2001');

          /** @type {HTMLElement} */ (elObj.nextMonthButtonEl).click();
          await el.updateComplete;
          expect(elObj.activeMonth).to.equal('February');
          expect(elObj.activeYear).to.equal('2001');
        });

        it('disables previousMonthButton and nextMonthButton based on disabled days accordingly', async () => {
          const el = await fixture(html`
            <lion-calendar .selectedDate="${new Date('2000/12/12')}"></lion-calendar>
          `);
          const elObj = new CalendarObject(el);
          expect(elObj.activeMonth).to.equal('December');
          expect(elObj.activeYear).to.equal('2000');
          expect(elObj.previousMonthButtonEl?.hasAttribute('disabled')).to.equal(false);
          expect(elObj.nextMonthButtonEl?.hasAttribute('disabled')).to.equal(false);

          el.minDate = new Date('2000/12/01');
          el.maxDate = new Date('2000/12/31');
          await el.updateComplete;

          expect(elObj.previousMonthButtonEl?.hasAttribute('disabled')).to.equal(true);
          expect(elObj.nextMonthButtonEl?.hasAttribute('disabled')).to.equal(true);
          /** @type {HTMLElement} */ (elObj.previousMonthButtonEl).click();
          await el.updateComplete;
          expect(elObj.activeMonth).to.equal('December');
          expect(elObj.activeYear).to.equal('2000');
          /** @type {HTMLElement} */ (elObj.previousMonthButtonEl).click();
          await el.updateComplete;
          expect(elObj.activeMonth).to.equal('December');
          expect(elObj.activeYear).to.equal('2000');
        });

        it('handles switch to previous month when dates are disabled', async () => {
          const clock = sinon.useFakeTimers({ now: new Date('2000/12/15').getTime() });

          const el = await fixture(html`<lion-calendar></lion-calendar>`);
          const elObj = new CalendarObject(el);
          expect(elObj.activeMonth).to.equal('December');
          expect(elObj.activeYear).to.equal('2000');

          el.minDate = new Date('2000/11/20');
          await el.updateComplete;

          expect(elObj.previousMonthButtonEl?.hasAttribute('disabled')).to.equal(false);
          expect(isSameDate(el.centralDate, new Date('2000/12/15'))).to.be.true;

          /** @type {HTMLElement} */ (elObj.previousMonthButtonEl).click();
          await el.updateComplete;
          expect(elObj.activeMonth).to.equal('November');
          expect(elObj.activeYear).to.equal('2000');
          expect(isSameDate(el.centralDate, new Date('2000/11/15'))).to.be.true;

          clock.restore();
        });

        it('handles switch to next month when dates are disabled', async () => {
          const clock = sinon.useFakeTimers({ now: new Date('2000/12/15').getTime() });

          const el = await fixture(html`<lion-calendar></lion-calendar>`);
          const elObj = new CalendarObject(el);
          expect(elObj.activeMonth).to.equal('December');
          expect(elObj.activeYear).to.equal('2000');

          el.maxDate = new Date('2001/01/10');
          await el.updateComplete;

          expect(elObj.nextMonthButtonEl?.hasAttribute('disabled')).to.equal(false);
          expect(isSameDate(el.centralDate, new Date('2000/12/15'))).to.be.true;
          /** @type {HTMLElement} */ (elObj.nextMonthButtonEl).click();
          await el.updateComplete;
          expect(elObj.activeMonth).to.equal('January');
          expect(elObj.activeYear).to.equal('2001');
          expect(isSameDate(el.centralDate, new Date('2001/01/15'))).to.be.true;

          clock.restore();
        });

        it('supports navigating from larger months to smaller ones (day counts)', async () => {
          // given
          const inputDate = new Date('2019/08/31');
          const element = await fixture(html`
            <lion-calendar .centralDate="${inputDate}"> </lion-calendar>
          `);
          // when
          const remote = new CalendarObject(element);
          /** @type {HTMLElement} */ (remote.nextMonthButtonEl).click();
          await element.updateComplete;
          // then
          expect(remote.activeMonth).to.equal('September');
          expect(remote.activeYear).to.equal('2019');
          expect(remote.centralDayObj?.el).dom.to.equal(`
            <div
              class="calendar__day-button"
              aria-disabled="false"
              role="button"
              tabindex="0"
              aria-pressed="false"
              past=""
              current-month="">
              <span class="calendar__day-button__text">
                30
              </span>
              <span class="u-sr-only">
                September 2019 Monday
              </span>
            </div>
          `);
        });
      });

      describe('Accessibility', () => {
        it('navigate buttons have a aria-label and title attribute with accessible label', async () => {
          const el = await fixture(html`
            <lion-calendar .selectedDate="${new Date('2000/12/12')}"></lion-calendar>
          `);
          const elObj = new CalendarObject(el);
          // month
          expect(elObj.previousMonthButtonEl?.getAttribute('title')).to.equal(
            'Previous month, November 2000',
          );
          expect(elObj.previousMonthButtonEl?.getAttribute('aria-label')).to.equal(
            'Previous month, November 2000',
          );
          expect(elObj.nextMonthButtonEl?.getAttribute('title')).to.equal(
            'Next month, January 2001',
          );
          expect(elObj.nextMonthButtonEl?.getAttribute('aria-label')).to.equal(
            'Next month, January 2001',
          );

          // year
          expect(elObj.previousYearButtonEl.getAttribute('title')).to.equal(
            'Previous year, December 1999',
          );
          expect(elObj.previousYearButtonEl.getAttribute('aria-label')).to.equal(
            'Previous year, December 1999',
          );
          expect(elObj.nextYearButtonEl.getAttribute('title')).to.equal('Next year, December 2001');
          expect(elObj.nextYearButtonEl.getAttribute('aria-label')).to.equal(
            'Next year, December 2001',
          );
        });
      });
    });
  });

  describe('Calendar body (months view)', () => {
    it('renders the days of the week as table headers', async () => {
      const el = await fixture(
        html`<lion-calendar .selectedDate="${new Date('2000/12/12')}"></lion-calendar>`,
      );
      const elObj = new CalendarObject(el);
      expect(elObj.weekdayHeaderEls.map(h => h.textContent?.trim())).to.deep.equal([
        'Sun',
        'Mon',
        'Tue',
        'Wed',
        'Thu',
        'Fri',
        'Sat',
      ]);
    });

    describe('Day view', () => {
      it('adds "today" attribute if date is today', async () => {
        const clock = sinon.useFakeTimers({ now: new Date('2000/12/15').getTime() });

        const el = await fixture(html`<lion-calendar></lion-calendar>`);
        const elObj = new CalendarObject(el);
        expect(elObj.getDayEl(15).hasAttribute('today')).to.be.true;

        expect(elObj.checkForAllDayObjs(/** @param {DayObject} d */ d => d.isToday, [15])).to.equal(
          true,
        );

        clock.restore();
      });

      it('adds "selected" attribute to the selected date', async () => {
        const el = await fixture(
          html`<lion-calendar .selectedDate="${new Date('2000/12/12')}"></lion-calendar>`,
        );
        const elObj = new CalendarObject(el);
        expect(
          elObj.checkForAllDayObjs(
            /** @param {DayObject} obj */ obj => obj.el.hasAttribute('selected'),
            [12],
          ),
        ).to.equal(true);

        el.selectedDate = new Date('2000/12/15');
        await el.updateComplete;
        expect(
          elObj.checkForAllDayObjs(
            /** @param {DayObject} obj */ obj => obj.el.hasAttribute('selected'),
            [15],
          ),
        ).to.equal(true);
      });

      it('adds aria-disabled="true" attribute to disabled dates', async () => {
        const clock = sinon.useFakeTimers({ now: new Date('2000/12/15').getTime() });

        const el = await fixture(html`
          <lion-calendar
            .selectedDate="${new Date('2000/12/10')}"
            .minDate="${new Date('2000/12/03')}"
            .maxDate="${new Date('2000/12/29')}"
          >
          </lion-calendar>
        `);
        const elObj = new CalendarObject(el);
        expect(
          elObj.checkForAllDayObjs(
            /** @param {DayObject} d */ d => d.el.getAttribute('aria-disabled') === 'true',
            [1, 2, 30, 31],
          ),
        ).to.equal(true);

        clock.restore();
      });
    });

    describe('User Interaction', () => {
      // For implementation, base on: https://www.w3.org/TR/2017/NOTE-wai-aria-practices-1.1-20171214/examples/grid/js/dataGrid.js

      describe('Keyboard Navigation', () => {
        it('focused day is reachable via tab (tabindex="0")', async () => {
          const el = await fixture(html`
            <lion-calendar .selectedDate="${new Date('2000/12/12')}"></lion-calendar>
          `);
          const elObj = new CalendarObject(el);
          expect(
            elObj.checkForAllDayObjs(
              /** @param {DayObject} d */ d => d.buttonEl.getAttribute('tabindex') === '0',
              [12],
            ),
          ).to.equal(true);
        });

        it('non focused days are not reachable via tab (have tabindex="-1")', async () => {
          const el = await fixture(html`
            <lion-calendar .selectedDate="${new Date('2000/12/12')}"></lion-calendar>
          `);
          const elObj = new CalendarObject(el);
          expect(
            elObj.checkForAllDayObjs(
              /** @param {DayObject} d */ d => d.buttonEl.getAttribute('tabindex') === '-1',
              /** @param {number} dayNumber */ dayNumber => dayNumber !== 12,
            ),
          ).to.equal(true);
        });

        it('blocks navigation to disabled days', async () => {
          const el = await fixture(html`
            <lion-calendar
              .selectedDate="${new Date('2000/12/31')}"
              .minDate="${new Date('2000/12/09')}"
            >
            </lion-calendar>
          `);
          const elObj = new CalendarObject(el);
          expect(
            elObj.checkForAllDayObjs(
              /** @param {DayObject} d */ d => d.buttonEl.getAttribute('tabindex') === '-1',
              /** @param {number} dayNumber */ dayNumber => dayNumber < 9,
            ),
          ).to.equal(true);
        });

        it('navigates through months with [pageup] [pagedown] keys', async () => {
          const el = await fixture(html`
            <lion-calendar .selectedDate="${new Date('2001/01/02')}"></lion-calendar>
          `);
          const elObj = new CalendarObject(el);
          expect(elObj.activeMonth).to.equal('January');
          expect(elObj.activeYear).to.equal('2001');

          el.__contentWrapperElement?.dispatchEvent(
            new KeyboardEvent('keydown', { key: 'PageUp' }),
          );
          await el.updateComplete;
          expect(elObj.activeMonth).to.equal('December');
          expect(elObj.activeYear).to.equal('2000');

          el.__contentWrapperElement?.dispatchEvent(
            new KeyboardEvent('keydown', { key: 'PageDown' }),
          );
          await el.updateComplete;
          expect(elObj.activeMonth).to.equal('January');
          expect(elObj.activeYear).to.equal('2001');
        });

        it('navigates through years with [alt + pageup] [alt + pagedown] keys', async () => {
          const el = await fixture(html`
            <lion-calendar .selectedDate="${new Date('2001/01/02')}"></lion-calendar>
          `);
          const elObj = new CalendarObject(el);
          expect(elObj.activeMonth).to.equal('January');
          expect(elObj.activeYear).to.equal('2001');

          el.__contentWrapperElement?.dispatchEvent(
            new KeyboardEvent('keydown', { key: 'PageDown', altKey: true }),
          );
          await el.updateComplete;
          expect(elObj.activeMonth).to.equal('January');
          expect(elObj.activeYear).to.equal('2002');

          el.__contentWrapperElement?.dispatchEvent(
            new KeyboardEvent('keydown', { key: 'PageUp', altKey: true }),
          );
          await el.updateComplete;
          expect(elObj.activeMonth).to.equal('January');
          expect(elObj.activeYear).to.equal('2001');
        });

        describe('Arrow keys', () => {
          it('navigates (sets focus) to next row item via [arrow down] key', async () => {
            const el = await fixture(html`
              <lion-calendar .selectedDate="${new Date('2001/01/02')}"></lion-calendar>
            `);
            const elObj = new CalendarObject(el);

            el.__contentWrapperElement?.dispatchEvent(
              new KeyboardEvent('keydown', { key: 'ArrowDown' }),
            );
            await el.updateComplete;
            expect(elObj.focusedDayObj?.monthday).to.equal(2 + 7);
          });

          it('navigates (sets focus) to previous row item via [arrow up] key', async () => {
            const el = await fixture(html`
              <lion-calendar .selectedDate="${new Date('2001/01/02')}"></lion-calendar>
            `);
            const elObj = new CalendarObject(el);

            el.__contentWrapperElement?.dispatchEvent(
              new KeyboardEvent('keydown', { key: 'ArrowUp' }),
            );
            await el.updateComplete;
            expect(elObj.focusedDayObj?.monthday).to.equal(26); // of month before
          });

          it('navigates (sets focus) to previous column item via [arrow left] key', async () => {
            // 2000-12-12 is Tuesday; at 2nd of row
            const el = await fixture(html`
              <lion-calendar .selectedDate="${new Date('2000/12/12')}"></lion-calendar>
            `);
            const elObj = new CalendarObject(el);

            el.__contentWrapperElement?.dispatchEvent(
              new KeyboardEvent('keydown', { key: 'ArrowLeft' }),
            );
            await el.updateComplete;
            expect(elObj.focusedDayObj?.monthday).to.equal(12 - 1);
          });

          it('navigates (sets focus) to next column item via [arrow right] key', async () => {
            // 2000-12-12 is Tuesday; at 2nd of row
            const el = await fixture(html`
              <lion-calendar .selectedDate="${new Date('2000/12/12')}"></lion-calendar>
            `);
            const elObj = new CalendarObject(el);

            el.__contentWrapperElement?.dispatchEvent(
              new KeyboardEvent('keydown', { key: 'ArrowRight' }),
            );
            await el.updateComplete;
            expect(elObj.focusedDayObj?.monthday).to.equal(12 + 1);
          });

          it('navigates (sets focus) to next column item via [arrow right] key', async () => {
            const el = await fixture(html`
              <lion-calendar
                .selectedDate="${new Date('2001/01/02')}"
                .disableDates=${
                  /** @param {Date} date */ date => date.getDate() === 3 || date.getDate() === 4
                }
              ></lion-calendar>
            `);
            const elObj = new CalendarObject(el);

            el.__contentWrapperElement?.dispatchEvent(
              new KeyboardEvent('keydown', { key: 'ArrowRight' }),
            );
            await el.updateComplete;
            expect(elObj.focusedDayObj?.monthday).to.equal(3);
          });

          it('navigates (sets focus) to next row via [arrow right] key if last item in row', async () => {
            const el = await fixture(html`
              <lion-calendar .selectedDate="${new Date('2019/01/05')}"></lion-calendar>
            `);
            const elObj = new CalendarObject(el);
            expect(elObj.centralDayObj?.weekdayNameShort).to.equal('Sat');

            el.__contentWrapperElement?.dispatchEvent(
              new KeyboardEvent('keydown', { key: 'ArrowRight' }),
            );
            await el.updateComplete;
            expect(elObj.focusedDayObj?.monthday).to.equal(6);
            expect(elObj.focusedDayObj?.weekdayNameShort).to.equal('Sun');
          });

          it('navigates (sets focus) to previous row via [arrow left] key if first item in row', async () => {
            const el = await fixture(html`
              <lion-calendar .selectedDate="${new Date('2019/01/06')}"></lion-calendar>
            `);
            const elObj = new CalendarObject(el);
            expect(elObj.centralDayObj?.weekdayNameShort).to.equal('Sun');

            el.__contentWrapperElement?.dispatchEvent(
              new KeyboardEvent('keydown', { key: 'ArrowLeft' }),
            );
            await el.updateComplete;
            expect(elObj.focusedDayObj?.monthday).to.equal(5);
            expect(elObj.focusedDayObj?.weekdayNameShort).to.equal('Sat');
          });

          it('navigates to next month via [arrow right] key if last day of month', async () => {
            const el = await fixture(html`
              <lion-calendar .selectedDate="${new Date('2000/12/31')}"></lion-calendar>
            `);
            const elObj = new CalendarObject(el);
            expect(elObj.activeMonth).to.equal('December');
            expect(elObj.activeYear).to.equal('2000');

            el.__contentWrapperElement?.dispatchEvent(
              new KeyboardEvent('keydown', { key: 'ArrowRight' }),
            );
            await el.updateComplete;
            expect(elObj.activeMonth).to.equal('January');
            expect(elObj.activeYear).to.equal('2001');
            expect(elObj.focusedDayObj?.monthday).to.equal(1);
          });

          it('navigates to previous month via [arrow left] key if first day of month', async () => {
            const el = await fixture(html`
              <lion-calendar .selectedDate="${new Date('2001/01/01')}"></lion-calendar>
            `);
            const elObj = new CalendarObject(el);
            expect(elObj.activeMonth).to.equal('January');
            expect(elObj.activeYear).to.equal('2001');

            el.__contentWrapperElement?.dispatchEvent(
              new KeyboardEvent('keydown', { key: 'ArrowLeft' }),
            );
            await el.updateComplete;
            expect(elObj.activeMonth).to.equal('December');
            expect(elObj.activeYear).to.equal('2000');
            expect(elObj.focusedDayObj?.monthday).to.equal(31);
          });

          it('navigates to next month via [arrow down] key if last row of month', async () => {
            const el = await fixture(html`
              <lion-calendar .selectedDate="${new Date('2000/12/30')}"></lion-calendar>
            `);
            const elObj = new CalendarObject(el);
            expect(elObj.activeMonth).to.equal('December');
            expect(elObj.activeYear).to.equal('2000');

            el.__contentWrapperElement?.dispatchEvent(
              new KeyboardEvent('keydown', { key: 'ArrowDown' }),
            );
            await el.updateComplete;
            expect(elObj.activeMonth).to.equal('January');
            expect(elObj.activeYear).to.equal('2001');
            expect(elObj.focusedDayObj?.monthday).to.equal(6);
          });

          it('navigates to previous month via [arrow up] key if first row of month', async () => {
            const el = await fixture(html`
              <lion-calendar .selectedDate="${new Date('2001/01/02')}"></lion-calendar>
            `);
            const elObj = new CalendarObject(el);
            expect(elObj.activeMonth).to.equal('January');
            expect(elObj.activeYear).to.equal('2001');

            el.__contentWrapperElement?.dispatchEvent(
              new KeyboardEvent('keydown', { key: 'ArrowUp' }),
            );
            await el.updateComplete;
            expect(elObj.activeMonth).to.equal('December');
            expect(elObj.activeYear).to.equal('2000');
            expect(elObj.focusedDayObj?.monthday).to.equal(26);
          });
        });
      });

      describe('Initial central', () => {
        it('is based on "selectedDate"', async () => {
          const el = await fixture(html`
            <lion-calendar .selectedDate=${new Date('2019/06/15')}></lion-calendar>
          `);
          const elObj = new CalendarObject(el);
          expect(elObj.centralDayObj?.monthday).to.equal(15);
        });

        it('is today if no selected date is available', async () => {
          const clock = sinon.useFakeTimers({ now: new Date('2000/12/15').getTime() });

          const el = await fixture(html`<lion-calendar></lion-calendar>`);
          const elObj = new CalendarObject(el);
          expect(elObj.centralDayObj?.monthday).to.equal(15);

          clock.restore();
        });
      });

      /**
       * Not in scope:
       * - (virtual) scrolling: still under discussion. Wait for UX
       */
    });

    describe('Accessibility', () => {
      // Based on:
      // - https://codepen.io/erikkroes/pen/jJEWpR

      // Navigation and day labels based on:
      // - https://dequeuniversity.com/library/aria/date-pickers/sf-date-picker
      //   (recommended in W3C Editors Draft)

      // For implementation, base on:
      // https://www.w3.org/TR/2017/NOTE-wai-aria-practices-1.1-20171214/examples/grid/js/dataGrid.js
      // As an enhancement, we detect when grid boundaries day are exceeded, so we move to
      // next/previous month.
      it('has role="application" to activate keyboard navigation', async () => {
        const elObj = new CalendarObject(await fixture(html`<lion-calendar></lion-calendar>`));
        expect(elObj.rootEl?.getAttribute('role')).to.equal('application');
      });

      it(`renders the calendar as a table element with role="grid", aria-readonly="true" and
        a caption (month + year)`, async () => {
        const elObj = new CalendarObject(await fixture(html`<lion-calendar></lion-calendar>`));
        expect(elObj.gridEl?.getAttribute('role')).to.equal('grid');
        expect(elObj.gridEl?.getAttribute('aria-readonly')).to.equal('true');
      });

      it('adds aria-labels to the weekday table headers', async () => {
        const elObj = new CalendarObject(await fixture(html`<lion-calendar></lion-calendar>`));
        expect(elObj.weekdayHeaderEls.map(h => h.getAttribute('aria-label'))).to.eql([
          'Sunday',
          'Monday',
          'Tuesday',
          'Wednesday',
          'Thursday',
          'Friday',
          'Saturday',
        ]);
      });

      it('renders each day as a button inside a table cell', async () => {
        const elObj = new CalendarObject(await fixture(html`<lion-calendar></lion-calendar>`));
        const hasBtn = /** @param {DayObject} d */ d =>
          d.el.tagName === 'DIV' && d.el.getAttribute('role') === 'button';
        expect(elObj.checkForAllDayObjs(hasBtn)).to.equal(true);
      });

      it('renders days for previous and next months', async () => {
        const elObj = new CalendarObject(
          await fixture(html`
            <lion-calendar .selectedDate="${new Date('2000/11/12')}"></lion-calendar>
          `),
        );
        const { previousMonthDayObjs, nextMonthDayObjs } = elObj;
        expect(previousMonthDayObjs.length).to.equal(3);
        expect(previousMonthDayObjs[0].cellIndex).to.equal(0);
        expect(previousMonthDayObjs[0].monthday).to.equal(29);
        expect(previousMonthDayObjs[1].cellIndex).to.equal(1);
        expect(previousMonthDayObjs[1].monthday).to.equal(30);
        expect(previousMonthDayObjs[2].cellIndex).to.equal(2);
        expect(previousMonthDayObjs[2].monthday).to.equal(31);

        expect(nextMonthDayObjs.length).to.equal(2);
        expect(nextMonthDayObjs[0].cellIndex).to.equal(5);
        expect(nextMonthDayObjs[0].monthday).to.equal(1);
        expect(nextMonthDayObjs[1].cellIndex).to.equal(6);
        expect(nextMonthDayObjs[1].monthday).to.equal(2);
      });

      it('renders days for next months in the last month of the year', async () => {
        const elObj = new CalendarObject(
          await fixture(html`
            <lion-calendar .selectedDate="${new Date('2020/12/12')}"></lion-calendar>
          `),
        );
        const { nextMonthDayObjs } = elObj;
        expect(nextMonthDayObjs.length).to.equal(2);
        expect(nextMonthDayObjs[0].cellIndex).to.equal(5);
        expect(nextMonthDayObjs[0].monthday).to.equal(1);
        expect(nextMonthDayObjs[1].cellIndex).to.equal(6);
        expect(nextMonthDayObjs[1].monthday).to.equal(2);
      });

      it('renders days for previous months in the first month of the year', async () => {
        const elObj = new CalendarObject(
          await fixture(html`
            <lion-calendar .selectedDate="${new Date('2020/01/12')}"></lion-calendar>
          `),
        );
        const { previousMonthDayObjs } = elObj;
        expect(previousMonthDayObjs.length).to.equal(3);
        expect(previousMonthDayObjs[0].cellIndex).to.equal(0);
        expect(previousMonthDayObjs[0].monthday).to.equal(29);
        expect(previousMonthDayObjs[1].cellIndex).to.equal(1);
        expect(previousMonthDayObjs[1].monthday).to.equal(30);
        expect(previousMonthDayObjs[2].cellIndex).to.equal(2);
        expect(previousMonthDayObjs[2].monthday).to.equal(31);
      });

      it('sets aria-current="date" to todays button', async () => {
        const elObj = new CalendarObject(await fixture(html`<lion-calendar></lion-calendar>`));
        const hasAriaCurrent = /** @param {DayObject} d */ d =>
          d.buttonEl.getAttribute('aria-current') === 'date';
        const monthday = new Date().getDate();
        expect(elObj.checkForAllDayObjs(hasAriaCurrent, [monthday])).to.equal(true);
      });

      it('sets aria-pressed="true" on selected date button', async () => {
        const elObj = new CalendarObject(
          await fixture(html`
            <lion-calendar .selectedDate="${new Date('2000/11/12')}"></lion-calendar>
          `),
        );
        const hasAriaPressed = /** @param {DayObject} d */ d =>
          d.buttonEl.getAttribute('aria-pressed') === 'true';
        expect(elObj.checkForAllDayObjs(hasAriaPressed, [12])).to.equal(true);
      });

      /**
       * Not in scope:
       * - reads the new focused day on month navigation"
       */
    });

    /**
     * Not in scope:
     * - show week numbers
     */
  });

  describe('Localization', () => {
    it('supports custom locale with a fallback to a global locale', async () => {
      const el = await fixture(html`
        <lion-calendar .selectedDate="${new Date('2019/12/20')}"></lion-calendar>
      `);
      const elObj = new CalendarObject(el);
      expect(elObj.activeMonth).to.equal('December');

      el.locale = 'fr-FR';
      await el.updateComplete;
      expect(elObj.activeMonth).to.equal('décembre');

      localizeManager.locale = 'cs-CZ';
      await el.updateComplete;
      expect(elObj.activeMonth).to.equal('décembre');

      el.locale = '';
      await el.updateComplete;
      expect(elObj.activeMonth).to.equal('prosinec');
    });

    it('displays the right translations according to locale', async () => {
      const el = await fixture(html`
        <lion-calendar .centralDate=${new Date('2019/11/20')}></lion-calendar>
      `);

      const elObj = new CalendarObject(el);
      expect(elObj.nextMonthButtonEl?.getAttribute('aria-label')).to.equal(
        'Next month, December 2019',
      );

      expect(elObj.previousMonthButtonEl?.getAttribute('aria-label')).to.equal(
        'Previous month, October 2019',
      );

      expect(elObj.weekdayHeaderEls.map(h => h.getAttribute('aria-label'))).to.eql([
        'Sunday',
        'Monday',
        'Tuesday',
        'Wednesday',
        'Thursday',
        'Friday',
        'Saturday',
      ]);

      expect(elObj.weekdayHeaderEls.map(h => h.textContent?.trim())).to.deep.equal([
        'Sun',
        'Mon',
        'Tue',
        'Wed',
        'Thu',
        'Fri',
        'Sat',
      ]);

      localizeManager.locale = 'nl-NL';
      await el.localizeNamespacesLoaded;
      await el.updateComplete;
      expect(elObj.nextMonthButtonEl?.getAttribute('aria-label')).to.equal(
        'Volgende maand, december 2019',
      );

      expect(elObj.previousMonthButtonEl?.getAttribute('aria-label')).to.equal(
        'Vorige maand, oktober 2019',
      );

      expect(elObj.weekdayHeaderEls.map(h => h.getAttribute('aria-label'))).to.eql([
        'zondag',
        'maandag',
        'dinsdag',
        'woensdag',
        'donderdag',
        'vrijdag',
        'zaterdag',
      ]);

      expect(elObj.weekdayHeaderEls.map(h => h.textContent?.trim())).to.deep.equal([
        'zo',
        'ma',
        'di',
        'wo',
        'do',
        'vr',
        'za',
      ]);
    });
  });

  describe('Accessibility', () => {
    it('is accessible', async () => {
      const el = await fixture(html`<lion-calendar></lion-calendar>`);
      await expect(el).to.be.accessible();
    });

    it('is accessible with a date selected', async () => {
      const today = new Date();
      const selectedDate = new Date(today.getFullYear(), today.getMonth(), today.getDate() + 1);
      const el = await fixture(
        html`<lion-calendar .selectedDate="${selectedDate}"></lion-calendar>`,
      );
      await expect(el).to.be.accessible();
    });

    it('is accessible with disabled dates', async () => {
      const el = await fixture(
        html`
          <lion-calendar
            .disableDates=${
              /** @param {Date} date */ date => date.getDay() === 6 || date.getDay() === 0
            }
          ></lion-calendar>
        `,
      );
      await expect(el).to.be.accessible();
    });

    it('is hidden when attribute hidden is true', async () => {
      const el = await fixture(html`<lion-calendar hidden></lion-calendar>`);
      expect(el).not.to.be.displayed;
    });
  });
});