datetime.tsx

import type { ComponentInterface, EventEmitter } from '@stencil/core';
import { Component, Element, Event, Host, Method, Prop, State, Watch, h, writeTask } from '@stencil/core';
import { caretDownSharp, caretUpSharp, chevronBack, chevronDown, chevronForward } from 'ionicons/icons';

import { getIonMode } from '../../global/ionic-global';
import type {
  Color,
  DatetimePresentation,
  DatetimeChangeEventDetail,
  DatetimeParts,
  Mode,
  StyleEventDetail,
} from '../../interface';
import { startFocusVisible } from '../../utils/focus-visible';
import { getElementRoot, raf, renderHiddenInput } from '../../utils/helpers';
import { printIonError, printIonWarning } from '../../utils/logging';
import { isRTL } from '../../utils/rtl';
import { createColorClasses } from '../../utils/theme';
import type { PickerColumnItem } from '../picker-column-internal/picker-column-internal-interfaces';

import { isSameDay, warnIfValueOutOfBounds } from './utils/comparison';
import {
  generateMonths,
  getDaysOfMonth,
  getDaysOfWeek,
  getToday,
  getMonthColumnData,
  getDayColumnData,
  getYearColumnData,
  getTimeColumnsData,
  getCombinedDateColumnData,
} from './utils/data';
import { formatValue, getLocalizedTime, getMonthAndDay, getMonthAndYear } from './utils/format';
import { is24Hour, isLocaleDayPeriodRTL, isMonthFirstLocale } from './utils/helpers';
import {
  calculateHourFromAMPM,
  convertDataToISO,
  getEndOfWeek,
  getNextDay,
  getNextMonth,
  getNextWeek,
  getNextYear,
  getPreviousDay,
  getPreviousMonth,
  getPreviousWeek,
  getPreviousYear,
  getStartOfWeek,
} from './utils/manipulation';
import { clampDate, convertToArrayOfNumbers, getPartsFromCalendarDay, parseAmPm, parseDate } from './utils/parse';
import {
  getCalendarDayState,
  isDayDisabled,
  isMonthDisabled,
  isNextMonthDisabled,
  isPrevMonthDisabled,
} from './utils/state';

/**
 * @virtualProp {"ios" | "md"} mode - The mode determines which platform styles to use.
 *
 * @slot title - The title of the datetime.
 * @slot buttons - The buttons in the datetime.
 * @slot time-label - The label for the time selector in the datetime.
 */
@Component({
  tag: 'ion-datetime',
  styleUrls: {
    ios: 'datetime.ios.scss',
    md: 'datetime.md.scss',
  },
  shadow: true,
})
export class Datetime implements ComponentInterface {
  private inputId = `ion-dt-${datetimeIds++}`;
  private calendarBodyRef?: HTMLElement;
  private popoverRef?: HTMLIonPopoverElement;
  private clearFocusVisible?: () => void;

  /**
   * Whether to highlight the active day with a solid circle (as opposed
   * to the outline circle around today). If you don't specify an initial
   * value for the datetime, it doesn't automatically init to a default to
   * avoid unwanted change events firing. If the solid circle were still
   * shown then, it would look like a date had already been selected, which
   * is misleading UX.
   */
  private highlightActiveParts = false;

  private parsedMinuteValues?: number[];
  private parsedHourValues?: number[];
  private parsedMonthValues?: number[];
  private parsedYearValues?: number[];
  private parsedDayValues?: number[];

  private destroyCalendarListener?: () => void;
  private destroyKeyboardMO?: () => void;

  private minParts?: any;
  private maxParts?: any;
  private todayParts = parseDate(getToday());

  private prevPresentation: string | null = null;

  /**
   * Duplicate reference to `activeParts` that does not trigger a re-render of the component.
   * Allows caching an instance of the `activeParts` in between render cycles.
   */
  private activePartsClone!: DatetimeParts | DatetimeParts[];

  @State() showMonthAndYear = false;

  @State() activeParts: DatetimeParts | DatetimeParts[] = {
    month: 5,
    day: 28,
    year: 2021,
    hour: 13,
    minute: 52,
    ampm: 'pm',
  };

  @State() workingParts: DatetimeParts = {
    month: 5,
    day: 28,
    year: 2021,
    hour: 13,
    minute: 52,
    ampm: 'pm',
  };

  @Element() el!: HTMLIonDatetimeElement;

  @State() isPresented = false;
  @State() isTimePopoverOpen = false;

  /**
   * The color to use from your application's color palette.
   * Default options are: `"primary"`, `"secondary"`, `"tertiary"`, `"success"`, `"warning"`, `"danger"`, `"light"`, `"medium"`, and `"dark"`.
   * For more information on colors, see [theming](/docs/theming/basics).
   */
  @Prop() color?: Color = 'primary';

  /**
   * The name of the control, which is submitted with the form data.
   */
  @Prop() name: string = this.inputId;

  /**
   * If `true`, the user cannot interact with the datetime.
   */
  @Prop() disabled = false;

  /**
   * If `true`, the datetime appears normal but is not interactive.
   */
  @Prop() readonly = false;

  /**
   * Returns if an individual date (calendar day) is enabled or disabled.
   *
   * If `true`, the day will be enabled/interactive.
   * If `false`, the day will be disabled/non-interactive.
   *
   * The function accepts an ISO 8601 date string of a given day.
   * By default, all days are enabled. Developers can use this function
   * to write custom logic to disable certain days.
   *
   * The function is called for each rendered calendar day, for the previous, current and next month.
   * Custom implementations should be optimized for performance to avoid jank.
   */
  @Prop() isDateEnabled?: (dateIsoString: string) => boolean;

  @Watch('disabled')
  protected disabledChanged() {
    this.emitStyle();
  }

  /**
   * The minimum datetime allowed. Value must be a date string
   * following the
   * [ISO 8601 datetime format standard](https://www.w3.org/TR/NOTE-datetime),
   * such as `1996-12-19`. The format does not have to be specific to an exact
   * datetime. For example, the minimum could just be the year, such as `1994`.
   * Defaults to the beginning of the year, 100 years ago from today.
   */
  @Prop({ mutable: true }) min?: string;

  @Watch('min')
  protected minChanged() {
    this.processMinParts();
  }

  /**
   * The maximum datetime allowed. Value must be a date string
   * following the
   * [ISO 8601 datetime format standard](https://www.w3.org/TR/NOTE-datetime),
   * `1996-12-19`. The format does not have to be specific to an exact
   * datetime. For example, the maximum could just be the year, such as `1994`.
   * Defaults to the end of this year.
   */
  @Prop({ mutable: true }) max?: string;

  @Watch('max')
  protected maxChanged() {
    this.processMaxParts();
  }

  /**
   * Which values you want to select. `'date'` will show
   * a calendar picker to select the month, day, and year. `'time'`
   * will show a time picker to select the hour, minute, and (optionally)
   * AM/PM. `'date-time'` will show the date picker first and time picker second.
   * `'time-date'` will show the time picker first and date picker second.
   */
  @Prop() presentation: DatetimePresentation = 'date-time';

  /**
   * The text to display on the picker's cancel button.
   */
  @Prop() cancelText = 'Cancel';

  /**
   * The text to display on the picker's "Done" button.
   */
  @Prop() doneText = 'Done';

  /**
   * The text to display on the picker's "Clear" button.
   */
  @Prop() clearText = 'Clear';

  /**
   * Values used to create the list of selectable years. By default
   * the year values range between the `min` and `max` datetime inputs. However, to
   * control exactly which years to display, the `yearValues` input can take a number, an array
   * of numbers, or string of comma separated numbers. For example, to show upcoming and
   * recent leap years, then this input's value would be `yearValues="2024,2020,2016,2012,2008"`.
   */
  @Prop() yearValues?: number[] | number | string;
  @Watch('yearValues')
  protected yearValuesChanged() {
    this.parsedYearValues = convertToArrayOfNumbers(this.yearValues);
  }

  /**
   * Values used to create the list of selectable months. By default
   * the month values range from `1` to `12`. However, to control exactly which months to
   * display, the `monthValues` input can take a number, an array of numbers, or a string of
   * comma separated numbers. For example, if only summer months should be shown, then this
   * input value would be `monthValues="6,7,8"`. Note that month numbers do *not* have a
   * zero-based index, meaning January's value is `1`, and December's is `12`.
   */
  @Prop() monthValues?: number[] | number | string;
  @Watch('monthValues')
  protected monthValuesChanged() {
    this.parsedMonthValues = convertToArrayOfNumbers(this.monthValues);
  }

  /**
   * Values used to create the list of selectable days. By default
   * every day is shown for the given month. However, to control exactly which days of
   * the month to display, the `dayValues` input can take a number, an array of numbers, or
   * a string of comma separated numbers. Note that even if the array days have an invalid
   * number for the selected month, like `31` in February, it will correctly not show
   * days which are not valid for the selected month.
   */
  @Prop() dayValues?: number[] | number | string;
  @Watch('dayValues')
  protected dayValuesChanged() {
    this.parsedDayValues = convertToArrayOfNumbers(this.dayValues);
  }

  /**
   * Values used to create the list of selectable hours. By default
   * the hour values range from `0` to `23` for 24-hour, or `1` to `12` for 12-hour. However,
   * to control exactly which hours to display, the `hourValues` input can take a number, an
   * array of numbers, or a string of comma separated numbers.
   */
  @Prop() hourValues?: number[] | number | string;
  @Watch('hourValues')
  protected hourValuesChanged() {
    this.parsedHourValues = convertToArrayOfNumbers(this.hourValues);
  }

  /**
   * Values used to create the list of selectable minutes. By default
   * the minutes range from `0` to `59`. However, to control exactly which minutes to display,
   * the `minuteValues` input can take a number, an array of numbers, or a string of comma
   * separated numbers. For example, if the minute selections should only be every 15 minutes,
   * then this input value would be `minuteValues="0,15,30,45"`.
   */
  @Prop() minuteValues?: number[] | number | string;
  @Watch('minuteValues')
  protected minuteValuesChanged() {
    this.parsedMinuteValues = convertToArrayOfNumbers(this.minuteValues);
  }

  @Watch('activeParts')
  protected activePartsChanged() {
    this.activePartsClone = this.activeParts;
  }

  /**
   * The locale to use for `ion-datetime`. This
   * impacts month and day name formatting.
   * The `'default'` value refers to the default
   * locale set by your device.
   */
  @Prop() locale = 'default';

  /**
   * The first day of the week to use for `ion-datetime`. The
   * default value is `0` and represents Sunday.
   */
  @Prop() firstDayOfWeek = 0;

  /**
   * If `true`, multiple dates can be selected at once. Only
   * applies to `presentation="date"` and `preferWheel="false"`.
   */
  @Prop() multiple = false;

  /**
   * The value of the datetime as a valid ISO 8601 datetime string.
   * Should be an array of strings if `multiple="true"`.
   */
  @Prop({ mutable: true }) value?: string | string[] | null;

  /**
   * Update the datetime value when the value changes
   */
  @Watch('value')
  protected valueChanged() {
    const { value, minParts, maxParts, workingParts, multiple } = this;

    if (this.hasValue()) {
      if (!multiple && Array.isArray(value)) {
        this.value = value[0];
        return; // setting this.value will trigger re-run of this function
      }

      /**
       * Clones the value of the `activeParts` to the private clone, to update
       * the date display on the current render cycle without causing another render.
       *
       * This allows us to update the current value's date/time display without
       * refocusing or shifting the user's display (leaves the user in place).
       */
      const valueDateParts = parseDate(value);
      if (valueDateParts) {
        warnIfValueOutOfBounds(valueDateParts, minParts, maxParts);

        if (Array.isArray(valueDateParts)) {
          this.activePartsClone = [...valueDateParts];
        } else {
          const { month, day, year, hour, minute } = valueDateParts;
          const ampm = hour != null ? (hour >= 12 ? 'pm' : 'am') : undefined;

          this.activePartsClone = {
            ...this.activeParts,
            month,
            day,
            year,
            hour,
            minute,
            ampm,
          };

          /**
           * The working parts am/pm value must be updated when the value changes, to
           * ensure the time picker hour column values are generated correctly.
           *
           * Note that we don't need to do this if valueDateParts is an array, since
           * multiple="true" does not apply to time pickers.
           */
          this.setWorkingParts({
            ...workingParts,
            ampm,
          });
        }
      } else {
        printIonWarning(`Unable to parse date string: ${value}. Please provide a valid ISO 8601 datetime string.`);
      }
    }

    this.emitStyle();
    this.ionChange.emit({ value });
  }

  /**
   * If `true`, a header will be shown above the calendar
   * picker. On `ios` mode this will include the
   * slotted title, and on `md` mode this will include
   * the slotted title and the selected date.
   */
  @Prop() showDefaultTitle = false;

  /**
   * If `true`, the default "Cancel" and "OK" buttons
   * will be rendered at the bottom of the `ion-datetime`
   * component. Developers can also use the `button` slot
   * if they want to customize these buttons. If custom
   * buttons are set in the `button` slot then the
   * default buttons will not be rendered.
   */
  @Prop() showDefaultButtons = false;

  /**
   * If `true`, a "Clear" button will be rendered alongside
   * the default "Cancel" and "OK" buttons at the bottom of the `ion-datetime`
   * component. Developers can also use the `button` slot
   * if they want to customize these buttons. If custom
   * buttons are set in the `button` slot then the
   * default buttons will not be rendered.
   */
  @Prop() showClearButton = false;

  /**
   * If `true`, the default "Time" label will be rendered
   * for the time selector of the `ion-datetime` component.
   * Developers can also use the `time-label` slot
   * if they want to customize this label. If a custom
   * label is set in the `time-label` slot then the
   * default label will not be rendered.
   */
  @Prop() showDefaultTimeLabel = true;

  /**
   * The hour cycle of the `ion-datetime`. If no value is set, this is
   * specified by the current locale.
   */
  @Prop() hourCycle?: 'h23' | 'h12';

  /**
   * If `cover`, the `ion-datetime` will expand to cover the full width of its container.
   * If `fixed`, the `ion-datetime` will have a fixed width.
   */
  @Prop() size: 'cover' | 'fixed' = 'fixed';

  /**
   * If `true`, a wheel picker will be rendered instead of a calendar grid
   * where possible. If `false`, a calendar grid will be rendered instead of
   * a wheel picker where possible.
   *
   * A wheel picker can be rendered instead of a grid when `presentation` is
   * one of the following values: `'date'`, `'date-time'`, or `'time-date'`.
   *
   * A wheel picker will always be rendered regardless of
   * the `preferWheel` value when `presentation` is one of the following values:
   * `'time'`, `'month'`, `'month-year'`, or `'year'`.
   */
  @Prop() preferWheel = false;

  /**
   * Emitted when the datetime selection was cancelled.
   */
  @Event() ionCancel!: EventEmitter<void>;

  /**
   * Emitted when the value (selected date) has changed.
   */
  @Event() ionChange!: EventEmitter<DatetimeChangeEventDetail>;

  /**
   * Emitted when the datetime has focus.
   */
  @Event() ionFocus!: EventEmitter<void>;

  /**
   * Emitted when the datetime loses focus.
   */
  @Event() ionBlur!: EventEmitter<void>;

  /**
   * Emitted when the styles change.
   * @internal
   */
  @Event() ionStyle!: EventEmitter<StyleEventDetail>;

  /**
   * Emitted when componentDidRender is fired.
   * @internal
   */
  @Event() ionRender!: EventEmitter<void>;

  /**
   * Confirms the selected datetime value, updates the
   * `value` property, and optionally closes the popover
   * or modal that the datetime was presented in.
   */
  @Method()
  async confirm(closeOverlay = false) {
    const { highlightActiveParts, isCalendarPicker, activeParts } = this;

    /**
     * We only update the value if the presentation is not a calendar picker,
     * or if `highlightActiveParts` is true; indicating that the user
     * has selected a date from the calendar picker.
     *
     * Otherwise "today" would accidentally be set as the value.
     */
    if (highlightActiveParts || !isCalendarPicker) {
      const activePartsIsArray = Array.isArray(activeParts);
      if (activePartsIsArray && activeParts.length === 0) {
        this.value = undefined;
      } else {
        /**
         * Prevent convertDataToISO from doing any
         * kind of transformation based on timezone
         * This cancels out any change it attempts to make
         *
         * Important: Take the timezone offset based on
         * the date that is currently selected, otherwise
         * there can be 1 hr difference when dealing w/ DST
         */
        if (activePartsIsArray) {
          const dates = convertDataToISO(activeParts).map((str) => new Date(str));
          for (let i = 0; i < dates.length; i++) {
            activeParts[i].tzOffset = dates[i].getTimezoneOffset() * -1;
          }
        } else {
          const date = new Date(convertDataToISO(activeParts));
          activeParts.tzOffset = date.getTimezoneOffset() * -1;
        }

        this.value = convertDataToISO(activeParts);
      }
    }

    if (closeOverlay) {
      this.closeParentOverlay();
    }
  }

  /**
   * Resets the internal state of the datetime but does not update the value.
   * Passing a valid ISO-8601 string will reset the state of the component to the provided date.
   * If no value is provided, the internal state will be reset to the clamped value of the min, max and today.
   */
  @Method()
  async reset(startDate?: string) {
    this.processValue(startDate);
  }

  /**
   * Emits the ionCancel event and
   * optionally closes the popover
   * or modal that the datetime was
   * presented in.
   */
  @Method()
  async cancel(closeOverlay = false) {
    this.ionCancel.emit();

    if (closeOverlay) {
      this.closeParentOverlay();
    }
  }

  private closeParentOverlay = () => {
    const popoverOrModal = this.el.closest('ion-modal, ion-popover') as
      | HTMLIonModalElement
      | HTMLIonPopoverElement
      | null;
    if (popoverOrModal) {
      popoverOrModal.dismiss();
    }
  };

  private setWorkingParts = (parts: DatetimeParts) => {
    this.workingParts = {
      ...parts,
    };
  };

  private setActiveParts = (parts: DatetimeParts, removeDate = false) => {
    const { multiple, activePartsClone, highlightActiveParts } = this;

    if (multiple) {
      /**
       * We read from activePartsClone here because valueChanged() only updates that,
       * so it's the more reliable source of truth. If we read from activeParts, then
       * if you click July 1, manually set the value to July 2, and then click July 3,
       * the new value would be [July 1, July 3], ignoring the value set.
       *
       * We can then pass the new value to activeParts (rather than activePartsClone)
       * since the clone will be updated automatically by activePartsChanged().
       */
      const activePartsArray = Array.isArray(activePartsClone) ? activePartsClone : [activePartsClone];
      if (removeDate) {
        this.activeParts = activePartsArray.filter((p) => !isSameDay(p, parts));
      } else if (highlightActiveParts) {
        this.activeParts = [...activePartsArray, parts];
      } else {
        /**
         * If highlightActiveParts is false, that means we just have a
         * default value of today in activeParts; we need to replace that
         * rather than adding to it since it's just a placeholder.
         */
        this.activeParts = [parts];
      }
    } else {
      this.activeParts = {
        ...parts,
      };
    }

    /**
     * Now that the user has interacted somehow to select something, we can
     * show the solid highlight. This needs to be done after checking it above,
     * but before the confirm call below.
     *
     * Note that for datetimes with confirm/cancel buttons, the value
     * isn't updated until you call confirm(). We need to bring the
     * solid circle back on day click for UX reasons, rather than only
     * show the circle if `value` is truthy.
     */
    this.highlightActiveParts = true;

    const hasSlottedButtons = this.el.querySelector('[slot="buttons"]') !== null;
    if (hasSlottedButtons || this.showDefaultButtons) {
      return;
    }

    this.confirm();
  };

  private get isCalendarPicker() {
    const { presentation } = this;
    return presentation === 'date' || presentation === 'date-time' || presentation === 'time-date';
  }

  /**
   * Stencil sometimes sets calendarBodyRef to null on rerender, even though
   * the element is present. Query for it manually as a fallback.
   *
   * TODO(FW-901) Remove when issue is resolved: https://github.com/ionic-team/stencil/issues/3253
   */
  private getCalendarBodyEl = () => {
    return this.calendarBodyRef || this.el.shadowRoot?.querySelector('.calendar-body');
  };

  private initializeKeyboardListeners = () => {
    const calendarBodyRef = this.getCalendarBodyEl();
    if (!calendarBodyRef) {
      return;
    }

    const root = this.el!.shadowRoot!;

    /**
     * Get a reference to the month
     * element we are currently viewing.
     */
    const currentMonth = calendarBodyRef.querySelector('.calendar-month:nth-of-type(2)')!;

    /**
     * When focusing the calendar body, we want to pass focus
     * to the working day, but other days should
     * only be accessible using the arrow keys. Pressing
     * Tab should jump between bodies of selectable content.
     */
    const checkCalendarBodyFocus = (ev: MutationRecord[]) => {
      const record = ev[0];

      /**
       * If calendar body was already focused
       * when this fired or if the calendar body
       * if not currently focused, we should not re-focus
       * the inner day.
       */
      if (record.oldValue?.includes('ion-focused') || !calendarBodyRef.classList.contains('ion-focused')) {
        return;
      }

      this.focusWorkingDay(currentMonth);
    };
    const mo = new MutationObserver(checkCalendarBodyFocus);
    mo.observe(calendarBodyRef, { attributeFilter: ['class'], attributeOldValue: true });

    this.destroyKeyboardMO = () => {
      mo?.disconnect();
    };

    /**
     * We must use keydown not keyup as we want
     * to prevent scrolling when using the arrow keys.
     */
    calendarBodyRef.addEventListener('keydown', (ev: KeyboardEvent) => {
      const activeElement = root.activeElement;
      if (!activeElement || !activeElement.classList.contains('calendar-day')) {
        return;
      }

      const parts = getPartsFromCalendarDay(activeElement as HTMLElement);

      let partsToFocus: DatetimeParts | undefined;
      switch (ev.key) {
        case 'ArrowDown':
          ev.preventDefault();
          partsToFocus = getNextWeek(parts);
          break;
        case 'ArrowUp':
          ev.preventDefault();
          partsToFocus = getPreviousWeek(parts);
          break;
        case 'ArrowRight':
          ev.preventDefault();
          partsToFocus = getNextDay(parts);
          break;
        case 'ArrowLeft':
          ev.preventDefault();
          partsToFocus = getPreviousDay(parts);
          break;
        case 'Home':
          ev.preventDefault();
          partsToFocus = getStartOfWeek(parts);
          break;
        case 'End':
          ev.preventDefault();
          partsToFocus = getEndOfWeek(parts);
          break;
        case 'PageUp':
          ev.preventDefault();
          partsToFocus = ev.shiftKey ? getPreviousYear(parts) : getPreviousMonth(parts);
          break;
        case 'PageDown':
          ev.preventDefault();
          partsToFocus = ev.shiftKey ? getNextYear(parts) : getNextMonth(parts);
          break;
        /**
         * Do not preventDefault here
         * as we do not want to override other
         * browser defaults such as pressing Enter/Space
         * to select a day.
         */
        default:
          return;
      }

      /**
       * If the day we want to move focus to is
       * disabled, do not do anything.
       */
      if (isDayDisabled(partsToFocus, this.minParts, this.maxParts)) {
        return;
      }

      this.setWorkingParts({
        ...this.workingParts,
        ...partsToFocus,
      });

      /**
       * Give view a chance to re-render
       * then move focus to the new working day
       */
      requestAnimationFrame(() => this.focusWorkingDay(currentMonth));
    });
  };

  private focusWorkingDay = (currentMonth: Element) => {
    /**
     * Get the number of padding days so
     * we know how much to offset our next selector by
     * to grab the correct calenday-day element.
     */
    const padding = currentMonth.querySelectorAll('.calendar-day-padding');
    const { day } = this.workingParts;

    if (day === null) {
      return;
    }

    /**
     * Get the calendar day element
     * and focus it.
     */
    const dayEl = currentMonth.querySelector(
      `.calendar-day:nth-of-type(${padding.length + day})`
    ) as HTMLElement | null;
    if (dayEl) {
      dayEl.focus();
    }
  };

  private processMinParts = () => {
    if (this.min === undefined) {
      this.minParts = undefined;
      return;
    }

    const { month, day, year, hour, minute } = parseDate(this.min);

    this.minParts = {
      month,
      day,
      year,
      hour,
      minute,
    };
  };

  private processMaxParts = () => {
    if (this.max === undefined) {
      this.maxParts = undefined;
      return;
    }

    const { month, day, year, hour, minute } = parseDate(this.max);

    this.maxParts = {
      month,
      day,
      year,
      hour,
      minute,
    };
  };

  private initializeCalendarListener = () => {
    const calendarBodyRef = this.getCalendarBodyEl();
    if (!calendarBodyRef) {
      return;
    }

    /**
     * For performance reasons, we only render 3
     * months at a time: The current month, the previous
     * month, and the next month. We have a scroll listener
     * on the calendar body to append/prepend new months.
     *
     * We can do this because Stencil is smart enough to not
     * re-create the .calendar-month containers, but rather
     * update the content within those containers.
     *
     * As an added bonus, WebKit has some troubles with
     * scroll-snap-stop: always, so not rendering all of
     * the months in a row allows us to mostly sidestep
     * that issue.
     */
    const months = calendarBodyRef.querySelectorAll('.calendar-month');

    const startMonth = months[0] as HTMLElement;
    const workingMonth = months[1] as HTMLElement;
    const endMonth = months[2] as HTMLElement;
    const mode = getIonMode(this);
    const needsiOSRubberBandFix = mode === 'ios' && typeof navigator !== 'undefined' && navigator.maxTouchPoints > 1;

    /**
     * Before setting up the scroll listener,
     * scroll the middle month into view.
     * scrollIntoView() will scroll entire page
     * if element is not in viewport. Use scrollLeft instead.
     */
    writeTask(() => {
      calendarBodyRef.scrollLeft = startMonth.clientWidth * (isRTL(this.el) ? -1 : 1);

      const getChangedMonth = (parts: DatetimeParts): DatetimeParts | undefined => {
        const box = calendarBodyRef.getBoundingClientRect();
        const root = this.el!.shadowRoot!;

        /**
         * Get the element that is in the center of the calendar body.
         * This will be an element inside of the active month.
         */
        const elementAtCenter = root.elementFromPoint(box.x + box.width / 2, box.y + box.height / 2);
        /**
         * If there is no element then the
         * component may be re-rendering on a slow device.
         */
        if (!elementAtCenter) return;

        const month = elementAtCenter.closest('.calendar-month');
        if (!month) return;

        /**
         * The edge of the month must be lined up with
         * the edge of the calendar body in order for
         * the component to update. Otherwise, it
         * may be the case that the user has paused their
         * swipe or the browser has not finished snapping yet.
         * Rather than check if the x values are equal,
         * we give it a tolerance of 2px to account for
         * sub pixel rendering.
         */
        const monthBox = month.getBoundingClientRect();
        if (Math.abs(monthBox.x - box.x) > 2) return;

        /**
         * From here, we can determine if the start
         * month or the end month was scrolled into view.
         * If no month was changed, then we can return from
         * the scroll callback early.
         */
        if (month === startMonth) {
          return getPreviousMonth(parts);
        } else if (month === endMonth) {
          return getNextMonth(parts);
        } else {
          return;
        }
      };

      const updateActiveMonth = () => {
        if (needsiOSRubberBandFix) {
          calendarBodyRef.style.removeProperty('pointer-events');
          appliediOSRubberBandFix = false;
        }

        /**
         * If the month did not change
         * then we can return early.
         */
        const newDate = getChangedMonth(this.workingParts);
        if (!newDate) return;

        const { month, day, year } = newDate;

        if (
          isMonthDisabled(
            { month, year, day: null },
            {
              minParts: { ...this.minParts, day: null },
              maxParts: { ...this.maxParts, day: null },
            }
          )
        ) {
          return;
        }

        /**
         * Prevent scrolling for other browsers
         * to give the DOM time to update and the container
         * time to properly snap.
         */
        calendarBodyRef.style.setProperty('overflow', 'hidden');

        /**
         * Use a writeTask here to ensure
         * that the state is updated and the
         * correct month is scrolled into view
         * in the same frame. This is not
         * typically a problem on newer devices
         * but older/slower device may have a flicker
         * if we did not do this.
         */
        writeTask(() => {
          this.setWorkingParts({
            ...this.workingParts,
            month,
            day: day!,
            year,
          });

          calendarBodyRef.scrollLeft = workingMonth.clientWidth * (isRTL(this.el) ? -1 : 1);
          calendarBodyRef.style.removeProperty('overflow');
        });
      };

      /**
       * When the container finishes scrolling we
       * need to update the DOM with the selected month.
       */
      let scrollTimeout: ReturnType<typeof setTimeout> | undefined;

      /**
       * We do not want to attempt to set pointer-events
       * multiple times within a single swipe gesture as
       * that adds unnecessary work to the main thread.
       */
      let appliediOSRubberBandFix = false;
      const scrollCallback = () => {
        if (scrollTimeout) {
          clearTimeout(scrollTimeout);
        }

        /**
         * On iOS it is possible to quickly rubber band
         * the scroll area before the scroll timeout has fired.
         * This results in users reaching the end of the scrollable
         * container before the DOM has updated.
         * By setting `pointer-events: none` we can ensure that
         * subsequent swipes do not happen while the container
         * is snapping.
         */
        if (!appliediOSRubberBandFix && needsiOSRubberBandFix) {
          calendarBodyRef.style.setProperty('pointer-events', 'none');
          appliediOSRubberBandFix = true;
        }

        // Wait ~3 frames
        scrollTimeout = setTimeout(updateActiveMonth, 50);
      };

      calendarBodyRef.addEventListener('scroll', scrollCallback);

      this.destroyCalendarListener = () => {
        calendarBodyRef.removeEventListener('scroll', scrollCallback);
      };
    });
  };

  connectedCallback() {
    this.clearFocusVisible = startFocusVisible(this.el).destroy;
  }

  disconnectedCallback() {
    if (this.clearFocusVisible) {
      this.clearFocusVisible();
      this.clearFocusVisible = undefined;
    }
  }

  /**
   * Clean up all listeners except for the overlay
   * listener. This is so that we can re-create the listeners
   * if the datetime has been hidden/presented by a modal or popover.
   */
  private destroyInteractionListeners = () => {
    const { destroyCalendarListener, destroyKeyboardMO } = this;

    if (destroyCalendarListener !== undefined) {
      destroyCalendarListener();
    }

    if (destroyKeyboardMO !== undefined) {
      destroyKeyboardMO();
    }
  };

  private initializeListeners() {
    this.initializeCalendarListener();
    this.initializeKeyboardListeners();
  }

  componentDidLoad() {
    /**
     * If a scrollable element is hidden using `display: none`,
     * it will not have a scroll height meaning we cannot scroll elements
     * into view. As a result, we will need to wait for the datetime to become
     * visible if used inside of a modal or a popover otherwise the scrollable
     * areas will not have the correct values snapped into place.
     */
    const visibleCallback = (entries: IntersectionObserverEntry[]) => {
      const ev = entries[0];
      if (!ev.isIntersecting) {
        return;
      }

      this.initializeListeners();

      /**
       * TODO: Datetime needs a frame to ensure that it
       * can properly scroll contents into view. As a result
       * we hide the scrollable content until after that frame
       * so users do not see the content quickly shifting. The downside
       * is that the content will pop into view a frame after. Maybe there
       * is a better way to handle this?
       */
      writeTask(() => {
        this.el.classList.add('datetime-ready');
      });
    };
    const visibleIO = new IntersectionObserver(visibleCallback, { threshold: 0.01 });

    /**
     * Use raf to avoid a race condition between the component loading and
     * its display animation starting (such as when shown in a modal). This
     * could cause the datetime to start at a visibility of 0, erroneously
     * triggering the `hiddenIO` observer below.
     */
    raf(() => visibleIO?.observe(this.el));

    /**
     * We need to clean up listeners when the datetime is hidden
     * in a popover/modal so that we can properly scroll containers
     * back into view if they are re-presented. When the datetime is hidden
     * the scroll areas have scroll widths/heights of 0px, so any snapping
     * we did originally has been lost.
     */
    const hiddenCallback = (entries: IntersectionObserverEntry[]) => {
      const ev = entries[0];
      if (ev.isIntersecting) {
        return;
      }

      this.destroyInteractionListeners();

      writeTask(() => {
        this.el.classList.remove('datetime-ready');
      });
    };
    const hiddenIO = new IntersectionObserver(hiddenCallback, { threshold: 0 });
    raf(() => hiddenIO?.observe(this.el));

    /**
     * Datetime uses Ionic components that emit
     * ionFocus and ionBlur. These events are
     * composed meaning they will cross
     * the shadow dom boundary. We need to
     * stop propagation on these events otherwise
     * developers will see 2 ionFocus or 2 ionBlur
     * events at a time.
     */
    const root = getElementRoot(this.el);
    root.addEventListener('ionFocus', (ev: Event) => ev.stopPropagation());
    root.addEventListener('ionBlur', (ev: Event) => ev.stopPropagation());
  }

  /**
   * When the presentation is changed, all calendar content is recreated,
   * so we need to re-init behavior with the new elements.
   */
  componentDidRender() {
    const { presentation, prevPresentation } = this;

    if (prevPresentation === null) {
      this.prevPresentation = presentation;
      return;
    }

    if (presentation === prevPresentation) {
      return;
    }
    this.prevPresentation = presentation;

    this.destroyInteractionListeners();

    this.initializeListeners();

    /**
     * The month/year picker from the date interface
     * should be closed as it is not available in non-date
     * interfaces.
     */
    this.showMonthAndYear = false;

    raf(() => {
      this.ionRender.emit();
    });
  }

  private processValue = (value?: string | string[] | null) => {
    this.highlightActiveParts = !!value;
    let valueToProcess = parseDate(value || getToday());

    const { minParts, maxParts, multiple } = this;
    if (!multiple && Array.isArray(value)) {
      this.value = value[0];
      valueToProcess = (valueToProcess as DatetimeParts[])[0];
    }

    warnIfValueOutOfBounds(valueToProcess, minParts, maxParts);

    /**
     * If there are multiple values, pick an arbitrary one to clamp to. This way,
     * if the values are across months, we always show at least one of them. Note
     * that the values don't necessarily have to be in order.
     */
    const singleValue = Array.isArray(valueToProcess) ? valueToProcess[0] : valueToProcess;

    const { month, day, year, hour, minute, tzOffset } = clampDate(singleValue, minParts, maxParts);
    const ampm = parseAmPm(hour!);

    this.setWorkingParts({
      month,
      day,
      year,
      hour,
      minute,
      tzOffset,
      ampm,
    });

    if (Array.isArray(valueToProcess)) {
      this.activeParts = [...valueToProcess];
    } else {
      this.activeParts = {
        month,
        day,
        year,
        hour,
        minute,
        tzOffset,
        ampm,
      };
    }
  };

  componentWillLoad() {
    const { el, multiple, presentation, preferWheel } = this;

    if (multiple) {
      if (presentation !== 'date') {
        printIonWarning('Multiple date selection is only supported for presentation="date".', el);
      }

      if (preferWheel) {
        printIonWarning('Multiple date selection is not supported with preferWheel="true".', el);
      }
    }

    this.processMinParts();
    this.processMaxParts();
    this.processValue(this.value);
    this.parsedHourValues = convertToArrayOfNumbers(this.hourValues);
    this.parsedMinuteValues = convertToArrayOfNumbers(this.minuteValues);
    this.parsedMonthValues = convertToArrayOfNumbers(this.monthValues);
    this.parsedYearValues = convertToArrayOfNumbers(this.yearValues);
    this.parsedDayValues = convertToArrayOfNumbers(this.dayValues);
    this.emitStyle();
  }

  private emitStyle() {
    this.ionStyle.emit({
      interactive: true,
      datetime: true,
      'interactive-disabled': this.disabled,
    });
  }

  private onFocus = () => {
    this.ionFocus.emit();
  };

  private onBlur = () => {
    this.ionBlur.emit();
  };

  private hasValue = () => {
    return this.value != null && this.value !== '';
  };

  private nextMonth = () => {
    const calendarBodyRef = this.getCalendarBodyEl();
    if (!calendarBodyRef) {
      return;
    }

    const nextMonth = calendarBodyRef.querySelector('.calendar-month:last-of-type');
    if (!nextMonth) {
      return;
    }

    const left = (nextMonth as HTMLElement).offsetWidth * 2;

    calendarBodyRef.scrollTo({
      top: 0,
      left: left * (isRTL(this.el) ? -1 : 1),
      behavior: 'smooth',
    });
  };

  private prevMonth = () => {
    const calendarBodyRef = this.getCalendarBodyEl();
    if (!calendarBodyRef) {
      return;
    }

    const prevMonth = calendarBodyRef.querySelector('.calendar-month:first-of-type');
    if (!prevMonth) {
      return;
    }

    calendarBodyRef.scrollTo({
      top: 0,
      left: 0,
      behavior: 'smooth',
    });
  };

  private toggleMonthAndYearView = () => {
    this.showMonthAndYear = !this.showMonthAndYear;
  };

  /**
   * Universal render methods
   * These are pieces of datetime that
   * are rendered independently of presentation.
   */

  private renderFooter() {
    const { showDefaultButtons, showClearButton } = this;
    const hasSlottedButtons = this.el.querySelector('[slot="buttons"]') !== null;
    if (!hasSlottedButtons && !showDefaultButtons && !showClearButton) {
      return;
    }

    const clearButtonClick = () => {
      this.reset();
      this.value = undefined;
    };

    /**
     * By default we render two buttons:
     * Cancel - Dismisses the datetime and
     * does not update the `value` prop.
     * OK - Dismisses the datetime and
     * updates the `value` prop.
     */
    return (
      <div class="datetime-footer">
        <div class="datetime-buttons">
          <div
            class={{
              ['datetime-action-buttons']: true,
              ['has-clear-button']: this.showClearButton,
            }}
          >
            <slot name="buttons">
              <ion-buttons>
                {showDefaultButtons && (
                  <ion-button id="cancel-button" color={this.color} onClick={() => this.cancel(true)}>
                    {this.cancelText}
                  </ion-button>
                )}
                <div>
                  {showClearButton && (
                    <ion-button id="clear-button" color={this.color} onClick={() => clearButtonClick()}>
                      {this.clearText}
                    </ion-button>
                  )}
                  {showDefaultButtons && (
                    <ion-button id="confirm-button" color={this.color} onClick={() => this.confirm(true)}>
                      {this.doneText}
                    </ion-button>
                  )}
                </div>
              </ion-buttons>
            </slot>
          </div>
        </div>
      </div>
    );
  }

  /**
   * Wheel picker render methods
   */

  private renderWheelPicker(forcePresentation: string = this.presentation) {
    /**
     * If presentation="time-date" we switch the
     * order of the render array here instead of
     * manually reordering each date/time picker
     * column with CSS. This allows for additional
     * flexibility if we need to render subsets
     * of the date/time data or do additional ordering
     * within the child render functions.
     */
    const renderArray =
      forcePresentation === 'time-date'
        ? [this.renderTimePickerColumns(forcePresentation), this.renderDatePickerColumns(forcePresentation)]
        : [this.renderDatePickerColumns(forcePresentation), this.renderTimePickerColumns(forcePresentation)];
    return <ion-picker-internal>{renderArray}</ion-picker-internal>;
  }

  private renderDatePickerColumns(forcePresentation: string) {
    return forcePresentation === 'date-time' || forcePresentation === 'time-date'
      ? this.renderCombinedDatePickerColumn()
      : this.renderIndividualDatePickerColumns(forcePresentation);
  }

  private renderCombinedDatePickerColumn() {
    const { activeParts, workingParts, locale, minParts, maxParts, todayParts, isDateEnabled } = this;

    /**
     * By default, generate a range of 3 months:
     * Previous month, current month, and next month
     */
    const monthsToRender = generateMonths(workingParts);

    /**
     * generateMonths returns the day data as well,
     * but we do not want the day value to act as a max/min
     * on the data we are going to generate.
     */
    for (let i = 0; i <= monthsToRender.length - 1; i++) {
      monthsToRender[i].day = null;
    }

    /**
     * If developers have provided their own
     * min/max values, use that instead. Otherwise,
     * fallback to the default range of 3 months.
     */
    const min = minParts || monthsToRender[0];
    const max = maxParts || monthsToRender[monthsToRender.length - 1];

    const result = getCombinedDateColumnData(
      locale,
      workingParts,
      todayParts,
      min,
      max,
      this.parsedDayValues,
      this.parsedMonthValues
    );
    let items = result.items;
    const parts = result.parts;

    if (isDateEnabled) {
      items = items.map((itemObject, index) => {
        const referenceParts = parts[index];

        let disabled;
        try {
          /**
           * The `isDateEnabled` implementation is try-catch wrapped
           * to prevent exceptions in the user's function from
           * interrupting the calendar rendering.
           */
          disabled = !isDateEnabled(convertDataToISO(referenceParts));
        } catch (e) {
          printIonError(
            'Exception thrown from provided `isDateEnabled` function. Please check your function and try again.',
            e
          );
        }

        return {
          ...itemObject,
          disabled,
        };
      });
    }

    /**
     * If we have selected a day already, then default the column
     * to that value. Otherwise, default it to today.
     */
    const todayString = workingParts.day
      ? `${workingParts.year}-${workingParts.month}-${workingParts.day}`
      : `${todayParts.year}-${todayParts.month}-${todayParts.day}`;

    return (
      <ion-picker-column-internal
        class="date-column"
        color={this.color}
        items={items}
        value={todayString}
        onIonChange={(ev: CustomEvent) => {
          // TODO(FW-1823) Remove this when iOS 14 support is dropped.
          // Due to a Safari 14 issue we need to destroy
          // the scroll listener before we update state
          // and trigger a re-render.
          if (this.destroyCalendarListener) {
            this.destroyCalendarListener();
          }

          const { value } = ev.detail;
          const findPart = parts.find(({ month, day, year }) => value === `${year}-${month}-${day}`);

          this.setWorkingParts({
            ...workingParts,
            ...findPart,
          });

          if (!Array.isArray(activeParts)) {
            this.setActiveParts({
              ...activeParts,
              ...findPart,
            });
          }

          // We can re-attach the scroll listener after
          // the working parts have been updated.
          this.initializeCalendarListener();

          ev.stopPropagation();
        }}
      ></ion-picker-column-internal>
    );
  }

  private renderIndividualDatePickerColumns(forcePresentation: string) {
    const { workingParts, isDateEnabled } = this;
    const shouldRenderMonths = forcePresentation !== 'year' && forcePresentation !== 'time';
    const months = shouldRenderMonths
      ? getMonthColumnData(this.locale, workingParts, this.minParts, this.maxParts, this.parsedMonthValues)
      : [];

    const shouldRenderDays = forcePresentation === 'date';
    let days = shouldRenderDays
      ? getDayColumnData(this.locale, workingParts, this.minParts, this.maxParts, this.parsedDayValues)
      : [];

    if (isDateEnabled) {
      days = days.map((dayObject) => {
        const { value } = dayObject;
        const valueNum = typeof value === 'string' ? parseInt(value) : value;
        const referenceParts: DatetimeParts = {
          month: workingParts.month,
          day: valueNum,
          year: workingParts.year,
        };

        let disabled;
        try {
          /**
           * The `isDateEnabled` implementation is try-catch wrapped
           * to prevent exceptions in the user's function from
           * interrupting the calendar rendering.
           */
          disabled = !isDateEnabled(convertDataToISO(referenceParts));
        } catch (e) {
          printIonError(
            'Exception thrown from provided `isDateEnabled` function. Please check your function and try again.',
            e
          );
        }

        return {
          ...dayObject,
          disabled,
        };
      });
    }

    const shouldRenderYears = forcePresentation !== 'month' && forcePresentation !== 'time';
    const years = shouldRenderYears
      ? getYearColumnData(this.todayParts, this.minParts, this.maxParts, this.parsedYearValues)
      : [];

    /**
     * Certain locales show the day before the month.
     */
    const showMonthFirst = isMonthFirstLocale(this.locale, { month: 'numeric', day: 'numeric' });

    let renderArray = [];
    if (showMonthFirst) {
      renderArray = [
        this.renderMonthPickerColumn(months),
        this.renderDayPickerColumn(days),
        this.renderYearPickerColumn(years),
      ];
    } else {
      renderArray = [
        this.renderDayPickerColumn(days),
        this.renderMonthPickerColumn(months),
        this.renderYearPickerColumn(years),
      ];
    }

    return renderArray;
  }

  private renderDayPickerColumn(days: PickerColumnItem[]) {
    if (days.length === 0) {
      return [];
    }

    const { activeParts, workingParts } = this;

    return (
      <ion-picker-column-internal
        class="day-column"
        color={this.color}
        items={days}
        value={(workingParts.day || this.todayParts.day) ?? undefined}
        onIonChange={(ev: CustomEvent) => {
          // TODO(FW-1823) Remove this when iOS 14 support is dropped.
          // Due to a Safari 14 issue we need to destroy
          // the scroll listener before we update state
          // and trigger a re-render.
          if (this.destroyCalendarListener) {
            this.destroyCalendarListener();
          }

          this.setWorkingParts({
            ...workingParts,
            day: ev.detail.value,
          });

          if (!Array.isArray(activeParts)) {
            this.setActiveParts({
              ...activeParts,
              day: ev.detail.value,
            });
          }

          // We can re-attach the scroll listener after
          // the working parts have been updated.
          this.initializeCalendarListener();

          ev.stopPropagation();
        }}
      ></ion-picker-column-internal>
    );
  }

  private renderMonthPickerColumn(months: PickerColumnItem[]) {
    if (months.length === 0) {
      return [];
    }

    const { activeParts, workingParts } = this;

    return (
      <ion-picker-column-internal
        class="month-column"
        color={this.color}
        items={months}
        value={workingParts.month}
        onIonChange={(ev: CustomEvent) => {
          // TODO(FW-1823) Remove this when iOS 14 support is dropped.
          // Due to a Safari 14 issue we need to destroy
          // the scroll listener before we update state
          // and trigger a re-render.
          if (this.destroyCalendarListener) {
            this.destroyCalendarListener();
          }

          this.setWorkingParts({
            ...workingParts,
            month: ev.detail.value,
          });

          if (!Array.isArray(activeParts)) {
            this.setActiveParts({
              ...activeParts,
              month: ev.detail.value,
            });
          }

          // We can re-attach the scroll listener after
          // the working parts have been updated.
          this.initializeCalendarListener();

          ev.stopPropagation();
        }}
      ></ion-picker-column-internal>
    );
  }
  private renderYearPickerColumn(years: PickerColumnItem[]) {
    if (years.length === 0) {
      return [];
    }

    const { activeParts, workingParts } = this;

    return (
      <ion-picker-column-internal
        class="year-column"
        color={this.color}
        items={years}
        value={workingParts.year}
        onIonChange={(ev: CustomEvent) => {
          // TODO(FW-1823) Remove this when iOS 14 support is dropped.
          // Due to a Safari 14 issue we need to destroy
          // the scroll listener before we update state
          // and trigger a re-render.
          if (this.destroyCalendarListener) {
            this.destroyCalendarListener();
          }

          this.setWorkingParts({
            ...workingParts,
            year: ev.detail.value,
          });

          if (!Array.isArray(activeParts)) {
            this.setActiveParts({
              ...activeParts,
              year: ev.detail.value,
            });
          }

          // We can re-attach the scroll listener after
          // the working parts have been updated.
          this.initializeCalendarListener();

          ev.stopPropagation();
        }}
      ></ion-picker-column-internal>
    );
  }
  private renderTimePickerColumns(forcePresentation: string) {
    if (['date', 'month', 'month-year', 'year'].includes(forcePresentation)) {
      return [];
    }

    const { hoursData, minutesData, dayPeriodData } = getTimeColumnsData(
      this.locale,
      this.workingParts,
      this.hourCycle,
      this.value ? this.minParts : undefined,
      this.value ? this.maxParts : undefined,
      this.parsedHourValues,
      this.parsedMinuteValues
    );

    return [
      this.renderHourPickerColumn(hoursData),
      this.renderMinutePickerColumn(minutesData),
      this.renderDayPeriodPickerColumn(dayPeriodData),
    ];
  }

  private renderHourPickerColumn(hoursData: PickerColumnItem[]) {
    const { workingParts, activePartsClone } = this;
    if (hoursData.length === 0) return [];

    return (
      <ion-picker-column-internal
        color={this.color}
        value={(activePartsClone as DatetimeParts).hour}
        items={hoursData}
        numericInput
        onIonChange={(ev: CustomEvent) => {
          this.setWorkingParts({
            ...workingParts,
            hour: ev.detail.value,
          });

          if (!Array.isArray(activePartsClone)) {
            this.setActiveParts({
              ...activePartsClone,
              hour: ev.detail.value,
            });
          }

          ev.stopPropagation();
        }}
      ></ion-picker-column-internal>
    );
  }
  private renderMinutePickerColumn(minutesData: PickerColumnItem[]) {
    const { workingParts, activePartsClone } = this;
    if (minutesData.length === 0) return [];

    return (
      <ion-picker-column-internal
        color={this.color}
        value={(activePartsClone as DatetimeParts).minute}
        items={minutesData}
        numericInput
        onIonChange={(ev: CustomEvent) => {
          this.setWorkingParts({
            ...workingParts,
            minute: ev.detail.value,
          });

          if (!Array.isArray(activePartsClone)) {
            this.setActiveParts({
              ...activePartsClone,
              minute: ev.detail.value,
            });
          }

          ev.stopPropagation();
        }}
      ></ion-picker-column-internal>
    );
  }
  private renderDayPeriodPickerColumn(dayPeriodData: PickerColumnItem[]) {
    const { workingParts, activePartsClone } = this;
    if (dayPeriodData.length === 0) {
      return [];
    }

    const isDayPeriodRTL = isLocaleDayPeriodRTL(this.locale);

    return (
      <ion-picker-column-internal
        style={isDayPeriodRTL ? { order: '-1' } : {}}
        color={this.color}
        value={(activePartsClone as DatetimeParts).ampm}
        items={dayPeriodData}
        onIonChange={(ev: CustomEvent) => {
          const hour = calculateHourFromAMPM(workingParts, ev.detail.value);

          this.setWorkingParts({
            ...workingParts,
            ampm: ev.detail.value,
            hour,
          });

          if (!Array.isArray(activePartsClone)) {
            this.setActiveParts({
              ...activePartsClone,
              ampm: ev.detail.value,
              hour,
            });
          }

          ev.stopPropagation();
        }}
      ></ion-picker-column-internal>
    );
  }

  private renderWheelView(forcePresentation?: string) {
    const { locale } = this;
    const showMonthFirst = isMonthFirstLocale(locale);
    const columnOrder = showMonthFirst ? 'month-first' : 'year-first';
    return (
      <div
        class={{
          [`wheel-order-${columnOrder}`]: true,
        }}
      >
        {this.renderWheelPicker(forcePresentation)}
      </div>
    );
  }

  /**
   * Grid Render Methods
   */

  private renderCalendarHeader(mode: Mode) {
    const expandedIcon = mode === 'ios' ? chevronDown : caretUpSharp;
    const collapsedIcon = mode === 'ios' ? chevronForward : caretDownSharp;

    const prevMonthDisabled = isPrevMonthDisabled(this.workingParts, this.minParts, this.maxParts);
    const nextMonthDisabled = isNextMonthDisabled(this.workingParts, this.maxParts);

    return (
      <div class="calendar-header">
        <div class="calendar-action-buttons">
          <div class="calendar-month-year">
            <ion-item button detail={false} lines="none" onClick={() => this.toggleMonthAndYearView()}>
              <ion-label>
                {getMonthAndYear(this.locale, this.workingParts)}{' '}
                <ion-icon icon={this.showMonthAndYear ? expandedIcon : collapsedIcon} lazy={false}></ion-icon>
              </ion-label>
            </ion-item>
          </div>

          <div class="calendar-next-prev">
            <ion-buttons>
              <ion-button disabled={prevMonthDisabled} onClick={() => this.prevMonth()}>
                <ion-icon slot="icon-only" icon={chevronBack} lazy={false} flipRtl></ion-icon>
              </ion-button>
              <ion-button disabled={nextMonthDisabled} onClick={() => this.nextMonth()}>
                <ion-icon slot="icon-only" icon={chevronForward} lazy={false} flipRtl></ion-icon>
              </ion-button>
            </ion-buttons>
          </div>
        </div>
        <div class="calendar-days-of-week">
          {getDaysOfWeek(this.locale, mode, this.firstDayOfWeek % 7).map((d) => {
            return <div class="day-of-week">{d}</div>;
          })}
        </div>
      </div>
    );
  }
  private renderMonth(month: number, year: number) {
    const { highlightActiveParts } = this;
    const yearAllowed = this.parsedYearValues === undefined || this.parsedYearValues.includes(year);
    const monthAllowed = this.parsedMonthValues === undefined || this.parsedMonthValues.includes(month);
    const isCalMonthDisabled = !yearAllowed || !monthAllowed;
    const swipeDisabled = isMonthDisabled(
      {
        month,
        year,
        day: null,
      },
      {
        // The day is not used when checking if a month is disabled.
        // Users should be able to access the min or max month, even if the
        // min/max date is out of bounds (e.g. min is set to Feb 15, Feb should not be disabled).
        minParts: { ...this.minParts, day: null },
        maxParts: { ...this.maxParts, day: null },
      }
    );
    // The working month should never have swipe disabled.
    // Otherwise the CSS scroll snap will not work and the user
    // can free-scroll the calendar.
    const isWorkingMonth = this.workingParts.month === month && this.workingParts.year === year;

    return (
      <div
        class={{
          'calendar-month': true,
          // Prevents scroll snap swipe gestures for months outside of the min/max bounds
          'calendar-month-disabled': !isWorkingMonth && swipeDisabled,
        }}
      >
        <div class="calendar-month-grid">
          {getDaysOfMonth(month, year, this.firstDayOfWeek % 7).map((dateObject, index) => {
            const { day, dayOfWeek } = dateObject;
            const { isDateEnabled, multiple } = this;
            const referenceParts = { month, day, year };
            const { isActive, isToday, ariaLabel, ariaSelected, disabled } = getCalendarDayState(
              this.locale,
              referenceParts,
              this.activePartsClone,
              this.todayParts,
              this.minParts,
              this.maxParts,
              this.parsedDayValues
            );

            let isCalDayDisabled = isCalMonthDisabled || disabled;

            if (!isCalDayDisabled && isDateEnabled !== undefined) {
              try {
                /**
                 * The `isDateEnabled` implementation is try-catch wrapped
                 * to prevent exceptions in the user's function from
                 * interrupting the calendar rendering.
                 */
                isCalDayDisabled = !isDateEnabled(convertDataToISO(referenceParts));
              } catch (e) {
                printIonError(
                  'Exception thrown from provided `isDateEnabled` function. Please check your function and try again.',
                  e
                );
              }
            }

            return (
              <button
                tabindex="-1"
                data-day={day}
                data-month={month}
                data-year={year}
                data-index={index}
                data-day-of-week={dayOfWeek}
                disabled={isCalDayDisabled}
                class={{
                  'calendar-day-padding': day === null,
                  'calendar-day': true,
                  'calendar-day-active': isActive && highlightActiveParts,
                  'calendar-day-today': isToday,
                }}
                aria-selected={ariaSelected}
                aria-label={ariaLabel}
                onClick={() => {
                  if (day === null) {
                    return;
                  }

                  this.setWorkingParts({
                    ...this.workingParts,
                    month,
                    day,
                    year,
                  });

                  // multiple only needs date info, so we can wipe out other fields like time
                  if (multiple) {
                    this.setActiveParts(
                      {
                        month,
                        day,
                        year,
                      },
                      isActive && highlightActiveParts
                    );
                  } else {
                    this.setActiveParts({
                      ...this.activeParts,
                      month,
                      day,
                      year,
                    });
                  }
                }}
              >
                {day}
              </button>
            );
          })}
        </div>
      </div>
    );
  }
  private renderCalendarBody() {
    return (
      <div class="calendar-body ion-focusable" ref={(el) => (this.calendarBodyRef = el)} tabindex="0">
        {generateMonths(this.workingParts).map(({ month, year }) => {
          return this.renderMonth(month, year);
        })}
      </div>
    );
  }
  private renderCalendar(mode: Mode) {
    return (
      <div class="datetime-calendar">
        {this.renderCalendarHeader(mode)}
        {this.renderCalendarBody()}
      </div>
    );
  }
  private renderTimeLabel() {
    const hasSlottedTimeLabel = this.el.querySelector('[slot="time-label"]') !== null;
    if (!hasSlottedTimeLabel && !this.showDefaultTimeLabel) {
      return;
    }

    return <slot name="time-label">Time</slot>;
  }

  private renderTimeOverlay() {
    const use24Hour = is24Hour(this.locale, this.hourCycle);
    return [
      <div class="time-header">{this.renderTimeLabel()}</div>,
      <button
        class={{
          'time-body': true,
          'time-body-active': this.isTimePopoverOpen,
        }}
        aria-expanded="false"
        aria-haspopup="true"
        onClick={async (ev) => {
          const { popoverRef } = this;

          if (popoverRef) {
            this.isTimePopoverOpen = true;

            popoverRef.present(
              new CustomEvent('ionShadowTarget', {
                detail: {
                  ionShadowTarget: ev.target,
                },
              })
            );

            await popoverRef.onWillDismiss();

            this.isTimePopoverOpen = false;
          }
        }}
      >
        {getLocalizedTime(this.locale, this.activePartsClone as DatetimeParts, use24Hour)}
      </button>,
      <ion-popover
        alignment="center"
        translucent
        overlayIndex={1}
        arrow={false}
        onWillPresent={(ev) => {
          /**
           * Intersection Observers do not consistently fire between Blink and Webkit
           * when toggling the visibility of the popover and trying to scroll the picker
           * column to the correct time value.
           *
           * This will correctly scroll the element position to the correct time value,
           * before the popover is fully presented.
           */
          const cols = (ev.target! as HTMLElement).querySelectorAll('ion-picker-column-internal');
          // TODO (FW-615): Potentially remove this when intersection observers are fixed in picker column
          cols.forEach((col) => col.scrollActiveItemIntoView());
        }}
        style={{
          '--offset-y': '-10px',
          '--min-width': 'fit-content',
        }}
        // Allow native browser keyboard events to support up/down/home/end key
        // navigation within the time picker.
        keyboardEvents
        ref={(el) => (this.popoverRef = el)}
      >
        {this.renderWheelPicker('time')}
      </ion-popover>,
    ];
  }
  private renderCalendarViewHeader(mode: Mode) {
    const hasSlottedTitle = this.el.querySelector('[slot="title"]') !== null;
    if (!hasSlottedTitle && !this.showDefaultTitle) {
      return;
    }

    return (
      <div class="datetime-header">
        <div class="datetime-title">
          <slot name="title">Select Date</slot>
        </div>
        {mode === 'md' && !this.multiple && (
          <div class="datetime-selected-date">{getMonthAndDay(this.locale, this.activeParts as DatetimeParts)}</div>
        )}
      </div>
    );
  }

  /**
   * Render time picker inside of datetime.
   * Do not pass color prop to segment on
   * iOS mode. MD segment has been customized and
   * should take on the color prop, but iOS
   * should just be the default segment.
   */
  private renderTime() {
    const { presentation } = this;
    const timeOnlyPresentation = presentation === 'time';

    return (
      <div class="datetime-time">{timeOnlyPresentation ? this.renderWheelPicker() : this.renderTimeOverlay()}</div>
    );
  }

  /**
   * Renders the month/year picker that is
   * displayed on the calendar grid.
   * The .datetime-year class has additional
   * styles that let us show/hide the
   * picker when the user clicks on the
   * toggle in the calendar header.
   */
  private renderCalendarViewMonthYearPicker() {
    return <div class="datetime-year">{this.renderWheelView('month-year')}</div>;
  }

  /**
   * Render entry point
   * All presentation types are rendered from here.
   */

  private renderDatetime(mode: Mode) {
    const { presentation, preferWheel } = this;

    /**
     * Certain presentation types have separate grid and wheel displays.
     * If preferWheel is true then we should show a wheel picker instead.
     */
    const hasWheelVariant = presentation === 'date' || presentation === 'date-time' || presentation === 'time-date';
    if (preferWheel && hasWheelVariant) {
      return [this.renderWheelView(), this.renderFooter()];
    }

    switch (presentation) {
      case 'date-time':
        return [
          this.renderCalendarViewHeader(mode),
          this.renderCalendar(mode),
          this.renderCalendarViewMonthYearPicker(),
          this.renderTime(),
          this.renderFooter(),
        ];
      case 'time-date':
        return [
          this.renderCalendarViewHeader(mode),
          this.renderTime(),
          this.renderCalendar(mode),
          this.renderCalendarViewMonthYearPicker(),
          this.renderFooter(),
        ];
      case 'time':
        return [this.renderTime(), this.renderFooter()];
      case 'month':
      case 'month-year':
      case 'year':
        return [this.renderWheelView(), this.renderFooter()];
      default:
        return [
          this.renderCalendarViewHeader(mode),
          this.renderCalendar(mode),
          this.renderCalendarViewMonthYearPicker(),
          this.renderFooter(),
        ];
    }
  }

  render() {
    const {
      name,
      value,
      disabled,
      el,
      color,
      isPresented,
      readonly,
      showMonthAndYear,
      preferWheel,
      presentation,
      size,
    } = this;
    const mode = getIonMode(this);
    const isMonthAndYearPresentation =
      presentation === 'year' || presentation === 'month' || presentation === 'month-year';
    const shouldShowMonthAndYear = showMonthAndYear || isMonthAndYearPresentation;
    const monthYearPickerOpen = showMonthAndYear && !isMonthAndYearPresentation;
    const hasDatePresentation = presentation === 'date' || presentation === 'date-time' || presentation === 'time-date';
    const hasWheelVariant = hasDatePresentation && preferWheel;
    const hasGrid = hasDatePresentation && !preferWheel;

    renderHiddenInput(true, el, name, formatValue(value), disabled);

    return (
      <Host
        aria-disabled={disabled ? 'true' : null}
        onFocus={this.onFocus}
        onBlur={this.onBlur}
        class={{
          ...createColorClasses(color, {
            [mode]: true,
            ['datetime-presented']: isPresented,
            ['datetime-readonly']: readonly,
            ['datetime-disabled']: disabled,
            'show-month-and-year': shouldShowMonthAndYear,
            'month-year-picker-open': monthYearPickerOpen,
            [`datetime-presentation-${presentation}`]: true,
            [`datetime-size-${size}`]: true,
            [`datetime-prefer-wheel`]: hasWheelVariant,
            [`datetime-grid`]: hasGrid,
          }),
        }}
      >
        {this.renderDatetime(mode)}
      </Host>
    );
  }
}

let datetimeIds = 0;