// Imported from:  https://github.com/airblade/stimulus-datepicker/blob/main/src/datepicker.js

import { Controller } from "@hotwired/stimulus";
import IsoDate from "utils/iso_date";
import { useClickOutside } from "stimulus-use";

// All dates are local, not UTC.
export default class UIDatePickerController extends Controller {
  static targets = [
    "input",
    "hidden",
    "toggle",
    "calendar",
    "month",
    "year",
    "prevMonth",
    "today",
    "nextMonth",
    "days",
  ];

  static values = {
    date: String,
    month: String,
    year: String,
    min: String,
    max: String,
    isCalendarOpen: { type: Boolean, default: false },
    isSelectOpen: { type: Boolean, default: false },
    format: { type: String, default: "%Y-%m-%d" },
    firstDayOfWeek: { type: Number, default: 1 },
    dayNameLength: { type: Number, default: 2 },
    allowWeekends: { type: Boolean, default: true },
    monthJump: { type: String, default: "dayOfMonth" },
    disallow: Array,
    text: Object,
    locales: { type: Array, default: ["default"] },
  };

  static defaultTextValue = {
    underflow: "",
    overflow: "",
    previousMonth: "Previous month",
    nextMonth: "Next month",
    today: "Today",
    chooseDate: "Choose Date",
    changeDate: "Change Date",
  };

  text(key) {
    return { ...this.constructor.defaultTextValue, ...this.textValue }[key];
  }

  connect() {
    useClickOutside(this);
    if (!this.hasHiddenTarget) this.addHiddenInput();
    this.addInputAction();
    this.addToggleAction();
    this.setToggleAriaLabel();
    this.dateValue = this.validate(this.inputTarget.textContent)
      ? ""
      : this.inputTarget.textContent;
  }

  disconnect() {
    this.isCalendarOpenValue = false;
  }

  dateValueChanged(value, previousValue) {
    if (!this.hasHiddenTarget) return;
    const dispatchChangeEvent = value != this.hiddenTarget.value;
    this.hiddenTarget.value = value;
    // this.inputTarget.value = this.format(value)
    this.inputTarget.textContent = value || "Pick a date";
    // Trigger change event on input when user selects date from picker.
    // http://developer.mozilla.org/en-US/docs/Web/API/HTMLElement/change_event
    if (dispatchChangeEvent) this.inputTarget.dispatchEvent(new Event("change"));
    this.validate(value);
  }

  validate(dateStr) {
    this.validationMessage(dateStr);
  }

  validationMessage(dateStr) {
    if (!dateStr) return "";
    const isoDate = new IsoDate(dateStr);
    return this.rangeUnderflow(isoDate)
      ? this.underflowMessage()
      : this.rangeOverflow(isoDate)
      ? this.overflowMessage()
      : "";
  }

  underflowMessage() {
    return this.text("underflow").replace("%s", this.format(this.minValue));
  }

  overflowMessage() {
    return this.text("overflow").replace("%s", this.format(this.maxValue));
  }

  addHiddenInput() {
    this.inputTarget.insertAdjacentHTML(
      "afterend",
      `
      <input type="hidden"
            name="${this.inputTarget.getAttribute("name")}"
            value="${this.inputTarget.textContent}"
            data-ui--date-picker-target="hidden"/>
    `,
    );
  }

  addInputAction() {
    this.addAction(this.inputTarget, "ui--date-picker#update");
  }

  addToggleAction() {
    if (!this.hasToggleTarget) return;

    let action = "click->ui--date-picker#toggle";
    if (!(this.toggleTarget instanceof HTMLButtonElement))
      action += " keydown->ui--date-picker#toggle";

    this.addAction(this.toggleTarget, action);
  }

  addAction(element, action) {
    if ("action" in element.dataset) {
      element.dataset.action += ` ${action}`;
    } else {
      element.dataset.action = action;
    }
  }

  setToggleAriaLabel(value = this.text("chooseDate")) {
    if (!this.hasToggleTarget) return;
    this.toggleTarget.setAttribute("aria-label", value);
  }

  update() {
    const dateStr = this.parse(this.inputTarget.value);
    if (dateStr != "") this.dateValue = dateStr;
  }

  toggle(event) {
    event.preventDefault();
    event.stopPropagation();
    if (event.type == "keydown" && ![" ", "Enter"].includes(event.key)) return;
    this.hasCalendarTarget ? this.close(true) : this.open(true);
  }

  close(animate) {
    if (animate) {
      this.calendarTarget.classList.add("fade-out");
      if (this.hasCssAnimation(this.calendarTarget)) {
        this.calendarTarget.onanimationend = (e) => e.target.remove();
      } else {
        this.calendarTarget.remove();
      }
    } else {
      this.calendarTarget.remove();
    }
    this.isCalendarOpenValue = false;
    this.toggleTarget.focus();
  }

  open(animate, isoDate = this.initialIsoDate()) {
    this.isCalendarOpenValue = true;
    this.render(isoDate, animate);
    this.focusDate(isoDate);
  }

  // Returns the date to focus on initially.  This is `dateValue` if given
  // or today.  Whichever is used, it is clamped to `minValue` and/or `maxValue`
  // dates if given.
  initialIsoDate() {
    return this.clamp(new IsoDate(this.dateValue));
  }

  clamp(isoDate) {
    return this.rangeUnderflow(isoDate)
      ? new IsoDate(this.minValue)
      : this.rangeOverflow(isoDate)
      ? new IsoDate(this.maxValue)
      : isoDate;
  }

  rangeUnderflow(isoDate) {
    return this.hasMinValue && isoDate.before(new IsoDate(this.minValue));
  }

  rangeOverflow(isoDate) {
    return this.hasMaxValue && isoDate.after(new IsoDate(this.maxValue));
  }

  isOutOfRange(isoDate) {
    return this.rangeUnderflow(isoDate) || this.rangeOverflow(isoDate);
  }

  clickOutside(event) {
    if (this.isCalendarOpenValue) event.preventDefault();
    if (!this.isCalendarOpenValue) return;
    if (event.target.closest('[data-ui--date-picker-target="calendar"]')) return;
    if (this.isSelectOpenValue) return;
    this.close(true);
  }

  // To track option is clicked
  clickOption() {
    this.isSelectOpenValue = true;
  }

  monthSelect(event) {
    this.monthValue = event.target.textContent;
    this.redraw();
    setTimeout(() => {
      this.isSelectOpenValue = false;
    }, 500);
  }

  yearSelect(event) {
    this.yearValue = event.target.textContent;
    this.redraw();
    setTimeout(() => {
      this.isSelectOpenValue = false;
    }, 500);
  }

  redraw() {
    const isoDate = this.dateFromMonthYearSelectsAndDayGrid();
    this.close(false);
    this.open(false, isoDate);
  }

  gotoPrevMonth() {
    const isoDate = this.dateFromMonthYearSelectsAndDayGrid();
    const previousMonthDate = isoDate.previousMonth(this.monthJumpValue == "dayOfMonth");
    this.monthValue = previousMonthDate.mm;
    this.yearValue = previousMonthDate.yyyy;
    this.close(false);
    this.open(false, previousMonthDate);
    this.prevMonthTarget.focus();
  }

  gotoNextMonth() {
    const isoDate = this.dateFromMonthYearSelectsAndDayGrid();
    const nextMonthDate = isoDate.nextMonth(this.monthJumpValue == "dayOfMonth");
    this.monthValue = nextMonthDate.mm;
    this.yearValue = nextMonthDate.yyyy;
    this.close(false);
    this.open(false, nextMonthDate);
    this.nextMonthTarget.focus();
  }

  gotoToday() {
    this.close(false);
    this.open(false, new IsoDate());
    this.todayTarget.focus();
  }

  // Returns a date where the month and year come from the dropdowns
  // and the day of the month from the grid.
  // @return [IsoDate]
  dateFromMonthYearSelectsAndDayGrid() {
    const isoDate = this.initialIsoDate();
    this.yearValue ||= isoDate.yyyy;
    this.monthValue ||= isoDate.mm;

    let day = this.daysTarget.querySelector('button[tabindex="0"] time').textContent;

    const daysInMonth = IsoDate.daysInMonth(+this.monthValue, +this.yearValue);
    if (day > daysInMonth) day = daysInMonth;

    return new IsoDate(this.yearValue, this.monthValue, day);
  }

  // Generates the HTML for the calendar and inserts it into the DOM.
  //
  // Does not focus the given date.
  //
  // @param isoDate [IsoDate] the date of interest
  render(isoDate, animate) {
    const cal = `<div class="absolute z-10 p-3 rounded-md border bg-white" data-ui--date-picker-target="calendar" data-action="keydown->ui--date-picker#key" role="dialog" aria-modal="true" aria-label="${this.text(
      "chooseDate",
    )}">
      <div class="flex flex-col sm:flex-row space-y-4 sm:space-x-4 sm:space-y-0 overscroll-contain">
        <div class="space-y-4">
          <div class="flex justify-center relative items-center">
            <div class="flex items-center">
              <button data-ui--date-picker-target="prevMonth" data-action="ui--date-picker#gotoPrevMonth" title="${this.text(
                "previousMonth",
              )}" aria-label="${this.text("previousMonth")}"
                class="inline-flex items-center justify-center whitespace-nowrap rounded-md text-sm font-medium ring-offset-background transition-colors focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring focus-visible:ring-offset-2 disabled:pointer-events-none disabled:opacity-50 border border-input hover:bg-accent hover:text-accent-foreground h-7 w-7 bg-transparent p-0 opacity-50 hover:opacity-100 absolute left-1" type="button">
                <svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="lucide lucide-chevron-left h-4 w-4"><path d="m15 18-6-6 6-6"></path></svg>
              </button>
            </div>
            <div class="flex">
              <div data-controller="ui--select" data-ui--select-target="wrapper" data-action="keydown->ui--select#key keydown.enter->ui--date-picker#clickOption click->ui--date-picker#clickOption change->ui--date-picker#monthSelect">
                <div class="relative">
                  <button data-action="ui--select#toggle" data-ui--date-picker-target="month" class="py-2 px-3 rounded-md flex items-center justify-between w-full text-sm focus:outline-none focus:ring-2 focus:ring-ring focus:ring-offset-2">
                    <span data-ui--select-target="value">${isoDate.getMonthName()}</span>
                    <svg class="w-4 h-4 mt-1 stroke-slate-400" fill="none"  viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M19 9l-7 7-7-7"></path></svg>
                  </button>
                  <div data-ui--select-target="menu" data-action="click->ui--select#select"
                    class="absolute z-10 bg-white rounded-md shadow-lg mt-2 w-30 py-1 hidden overflow-auto overscroll-contain max-h-60">
                    ${this.monthOptions(+isoDate.mm)}
                  </div>
                </div>
              </div>
            </div>
            <div class="flex">
              <div data-controller="ui--select" data-ui--select-target="wrapper" data-action="keydown->ui--select#key keydown.enter->ui--date-picker#clickOption click->ui--date-picker#clickOption change->ui--date-picker#yearSelect">
                <div class="relative">
                  <button data-action="ui--select#toggle" data-ui--date-picker-target="year" class="py-2 px-3 rounded-md flex items-center justify-between w-full text-sm focus:outline-none focus:ring-2 focus:ring-ring focus:ring-offset-2">
                    <span data-ui--select-target="value">${isoDate.yyyy}</span>
                    <svg class="w-4 h-4 mt-1 stroke-slate-400" fill="none"  viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M19 9l-7 7-7-7"></path></svg>
                  </button>
                  <div data-ui--select-target="menu" data-action="click->ui--select#select"
                    class="absolute z-10 bg-white rounded-md shadow-lg mt-2 w-20 py-1 hidden overflow-auto overscroll-contain max-h-60 scrollbar:!h-1.5 scrollbar:bg-transparent scrollbar-track:!bg-slate-100 scrollbar-thumb:!rounded scrollbar-thumb:!bg-slate-300 scrollbar-track:!rounded">
                    ${this.yearOptions(+isoDate.yyyy)}
                  </div>
                </div>
              </div>
            </div>
            <div class="flex items-center">
              <button data-ui--date-picker-target="nextMonth" data-action="ui--date-picker#gotoNextMonth" title="${this.text(
                "nextMonth",
              )}" aria-label="${this.text("nextMonth")}"
                class="inline-flex items-center justify-center whitespace-nowrap rounded-md text-sm font-medium ring-offset-background transition-colors focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring focus-visible:ring-offset-2 disabled:pointer-events-none disabled:opacity-50 border border-input hover:bg-accent hover:text-accent-foreground h-7 w-7 bg-transparent p-0 opacity-50 hover:opacity-100 absolute right-1" type="button">
                <svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="lucide lucide-chevron-right h-4 w-4"><path d="m9 18 6-6-6-6"></path></svg>
              </button>
            </div>
          </div>
          <div class="sdp-days-of-week grid grid-cols-7 text-center">
            ${this.daysOfWeek()}
          </div>
          <div class="sdp-days grid grid-cols-7 text-center" role="grid" data-ui--date-picker-target="days" data-action="click->ui--date-picker#pick">
            ${this.days(isoDate)}
          </div>
          <div class="flex items-center justify-center">
            <button data-ui--date-picker-target="today" data-action="ui--date-picker#gotoToday"
              class="inline-flex items-center justify-center whitespace-nowrap rounded-md text-sm font-medium ring-offset-background transition-colors focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring focus-visible:ring-offset-2 disabled:pointer-events-none disabled:opacity-50 border border-input hover:bg-accent hover:text-accent-foreground bg-transparent opacity-50 hover:opacity-100 py-1 px-2"
              title="${this.text("today")}" aria-label="${this.text("today")}">
              Today
            </button>
          </div>
        </div>
      </div>
    </div>`;
    this.element.insertAdjacentHTML("beforeend", cal);
  }

  pick(event) {
    event.preventDefault();

    let button, time;
    switch (event.target.constructor) {
      case HTMLTimeElement:
        time = event.target;
        button = time.parentElement;
        break;
      case HTMLButtonElement:
        button = event.target;
        time = button.children[0];
        break;
      default:
        return;
    }

    if (button.hasAttribute("aria-disabled")) return;
    const dateStr = time.getAttribute("datetime");
    this.selectDate(new IsoDate(dateStr));
  }

  key(event) {
    // if(this.isSelectOpenValue){return}
    switch (event.key) {
      case "Escape":
        this.close(true);
        return;
      case "Tab":
        if (event.shiftKey) {
          if (document.activeElement == this.firstTabStop()) {
            event.preventDefault();
            this.lastTabStop().focus();
          }
        } else {
          if (document.activeElement == this.lastTabStop()) {
            event.preventDefault();
            this.firstTabStop().focus();
          }
        }
        return;
    }

    const button = event.target;
    if (!this.daysTarget.contains(button)) return;

    const dateStr = button.children[0].getAttribute("datetime");
    const isoDate = new IsoDate(dateStr);

    switch (event.key) {
      case "Enter":
      case " ":
        event.preventDefault();
        if (!button.hasAttribute("aria-disabled")) this.selectDate(isoDate);
        break;
      case "ArrowUp":
      case "k":
        this.focusDate(isoDate.previousWeek());
        break;
      case "ArrowDown":
      case "j":
        this.focusDate(isoDate.nextWeek());
        break;
      case "ArrowLeft":
      case "h":
        this.focusDate(isoDate.previousDay());
        break;
      case "ArrowRight":
      case "l":
        this.focusDate(isoDate.nextDay());
        break;
      case "Home":
      case "0":
      case "^":
        this.focusDate(isoDate.firstDayOfWeek(this.firstDayOfWeekValue));
        break;
      case "End":
      case "$":
        this.focusDate(isoDate.lastDayOfWeek(this.firstDayOfWeekValue));
        break;
      case "PageUp":
        event.shiftKey
          ? this.focusDate(isoDate.previousYear())
          : this.focusDate(isoDate.previousMonth(this.monthJumpIsDayOfMonth()));
        break;
      case "PageDown":
        event.shiftKey
          ? this.focusDate(isoDate.nextYear())
          : this.focusDate(isoDate.nextMonth(this.monthJumpIsDayOfMonth()));
        break;
      case "b":
        this.focusDate(isoDate.previousMonth(this.monthJumpIsDayOfMonth()));
        break;
      case "B":
        this.focusDate(isoDate.previousYear());
        break;
      case "w":
        this.focusDate(isoDate.nextMonth(this.monthJumpIsDayOfMonth()));
        break;
      case "W":
        this.focusDate(isoDate.nextYear());
        break;
    }
  }

  firstTabStop() {
    return this.prevMonthTarget;
  }

  lastTabStop() {
    return this.todayTarget;
  }

  monthJumpIsDayOfMonth() {
    return this.monthJumpValue == "dayOfMonth";
  }

  // @param isoDate [isoDate] the date to select
  selectDate(isoDate) {
    if (this.isSelectOpenValue) return;

    this.close(true);
    this.toggleTarget.focus();
    this.dateValue = isoDate.toString();
  }

  // Focuses the given date in the calendar.
  // If the date is not visible because it is in the hidden part of the previous or
  // next month, the calendar is updated to show the corresponding month.
  //
  // @param isoDate [IsoDate] the date to focus on in the calendar
  focusDate(isoDate) {
    const time = this.daysTarget.querySelectorAll(`time[datetime="${isoDate.toString()}"]`)[0];

    if (!time) {
      const leadingDatetime = this.daysTarget.querySelectorAll("time")[0].getAttribute("datetime");
      if (isoDate.before(new IsoDate(leadingDatetime))) {
        this.gotoPrevMonth();
      } else {
        this.gotoNextMonth();
      }
      this.focusDate(isoDate);
      return;
    }

    const currentFocus = this.daysTarget.querySelectorAll('button[tabindex="0"]')[0];
    if (currentFocus) currentFocus.setAttribute("tabindex", -1);

    const button = time.parentElement;
    button.setAttribute("tabindex", 0);
    button.focus();

    if (!button.hasAttribute("aria-disabled")) {
      this.setToggleAriaLabel(`${this.text("changeDate")}, ${this.format(isoDate.toString())}`);
    }
  }

  // @param selected [Number] the selected month (January is 1)
  monthOptions(selected) {
    const klass = "hover:bg-gray-100 cursor-pointer py-2 px-4";
    return this.monthNames("long")
      .map(
        (name, i) =>
          `<div class="${klass}" value="${i + 1}" ${
            i + 1 == selected ? "selected" : ""
          }>${name}</div>`,
      )
      .join("");
  }

  // @param selected [Number] the selected year
  yearOptions(selected) {
    const years = [];
    const extent = 10;
    const klass = "hover:bg-gray-100 cursor-pointer py-2 px-4";

    for (let y = selected - extent; y <= selected + extent; y++) years.push(y);
    return years
      .map(
        (year) =>
          `<div class="${klass}" value=${year} ${year == selected ? "selected" : ""}>${year}</div>`,
      )
      .join("");
  }

  daysOfWeek() {
    return this.dayNames("long")
      .map(
        (
          name,
        ) => `<div scope="col" class="text-muted-foreground rounded-md w-9 font-normal text-[0.8rem]" aria-label="${name}">
            ${name.slice(0, this.dayNameLengthValue)} </div>`,
      )
      .join("");
  }

  // Generates the day grid for the given date's month.
  // The end of the previous month and the start of the next month
  // are shown if there is space in the grid.
  //
  // Does not focus on the given date.
  //
  // @param isoDate [IsoDate] the month of interest
  // @return [String] HTML for the day grid
  days(isoDate) {
    let days = [];
    const selected = new IsoDate(this.dateValue);
    let date = isoDate.setDayOfMonth(1).firstDayOfWeek(this.firstDayOfWeekValue);

    while (true) {
      const isPreviousMonth = date.mm != isoDate.mm && date.before(isoDate);
      const isNextMonth = date.mm != isoDate.mm && date.after(isoDate);

      if (isNextMonth && date.isFirstDayOfWeek(this.firstDayOfWeekValue)) break;

      const outsideMonthClass =
        "day-outside text-muted-foreground opacity-50 aria-selected:bg-accent/50 aria-selected:text-muted-foreground aria-selected:opacity-30";
      const klass = this.classAttribute(
        "sdp-day inline-flex items-center justify-center whitespace-nowrap rounded-md text-sm ring-offset-background transition-colors focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring focus-visible:ring-offset-2 disabled:pointer-events-none disabled:opacity-50 hover:bg-accent hover:text-accent-foreground h-9 w-9 p-0 font-normal aria-selected:opacity-100 text-accent-foreground",
        isPreviousMonth ? outsideMonthClass : "text-accent-foreground",
        isNextMonth ? outsideMonthClass : "text-accent-foreground",
        date.isToday() ? "sdp-today bg-accent" : "",
        date.isWeekend() ? "sdp-weekend" : "",
        date.equals(selected)
          ? "sdp-selected bg-primary text-primary-foreground hover:bg-primary hover:text-primary-foreground focus:bg-primary focus:text-primary-foreground"
          : "",
      );

      days.push(`
          <button type="button"
                  tabindex="-1"
                  ${klass}
                  ${date.equals(selected) ? 'aria-selected="true"' : ""}
                  ${this.isDisabled(date) ? 'aria-disabled="true"' : ""}
          >
            <time datetime="${date.toString()}">${+date.dd}</time>
          </button>
      `);
      date = date.nextDay();
    }

    return days.join("");
  }

  classAttribute(...classes) {
    const presentClasses = classes.filter((c) => c);
    if (presentClasses.length == 0) return "";
    return `class="${presentClasses.join(" ")}"`;
  }

  isDisabled(isoDate) {
    return (
      this.isOutOfRange(isoDate) ||
      (isoDate.isWeekend() && !this.allowWeekendsValue) ||
      this.disallowValue.includes(isoDate.toString())
    );
  }

  // Formats an ISO8601 date, using the `format` value, for display to the user.
  // Returns an empty string if `str` cannot be formatted.
  //
  // @param str [String] a date in YYYY-MM-DD format
  // @return [String] the date in a user-facing format, or an empty string if the
  //   given date cannot be formatted
  format(str) {
    if (!IsoDate.isValidStr(str)) return "";

    const [yyyy, mm, dd] = str.split("-");

    return this.formatValue
      .replace("%d", dd)
      .replace("%-d", +dd)
      .replace("%m", this.zeroPad(mm))
      .replace("%-m", +mm)
      .replace("%B", this.localisedMonth(mm, "long"))
      .replace("%b", this.localisedMonth(mm, "short"))
      .replace("%Y", yyyy)
      .replace("%y", +yyyy % 100);
  }

  // Returns a two-digit zero-padded string.
  zeroPad(num) {
    return num.toString().padStart(2, "0");
  }

  // Parses a date from the user, using the `format` value, into an ISO8601 date.
  // Returns an empty string if `str` cannot be parsed.
  //
  // @param str [String] a user-facing date, e.g. 19/03/2022
  // @return [String] the date in ISO8601 format, e.g. 2022-03-19; or an empty string
  //   if the given date cannot be parsed
  parse(str) {
    const directives = {
      d: [
        "\\d{2}",
        function (match) {
          this.day = +match;
        },
      ],
      "-d": [
        "\\d{1,2}",
        function (match) {
          this.day = +match;
        },
      ],
      m: [
        "\\d{2}",
        function (match) {
          this.month = +match;
        },
      ],
      "-m": [
        "\\d{1,2}",
        function (match) {
          this.month = +match;
        },
      ],
      B: [
        "\\w+",
        function (match, controller) {
          this.month = controller.monthNumber(match, "long");
        },
      ],
      b: [
        "\\w{3}",
        function (match, controller) {
          this.month = controller.monthNumber(match, "short");
        },
      ],
      Y: [
        "\\d{4}",
        function (match) {
          this.year = +match;
        },
      ],
      y: [
        "\\d{2}",
        function (match) {
          this.year = 2000 + +match;
        },
      ],
    };
    const funcs = [];
    const re = new RegExp(
      this.formatValue.replace(/%(d|-d|m|-m|B|b|Y|y)/g, function (_, p) {
        const directive = directives[p];
        funcs.push(directive[1]);
        return `(${directive[0]})`;
      }),
    );
    const matches = str.match(re);
    if (!matches) return "";

    const parts = {};
    for (let i = 0, len = funcs.length; i < len; i++) {
      funcs[i].call(parts, matches[i + 1], this);
    }

    if (!IsoDate.isValidDate(parts.year, parts.month, parts.day)) return "";
    return new IsoDate(parts.year, parts.month, parts.day).toString();
  }

  // Returns the name of the month in the configured locale.
  //
  // @param month [Number] the month number (January is 1)
  // @param monthFormat [String] "long" (January) | "short" (Jan)
  // @return [String] the localised month name
  localisedMonth(month, monthFormat) {
    // Use the middle of the month to avoid timezone edge cases
    return new Date(`2022-${month}-15`).toLocaleString(this.localesValue, { month: monthFormat });
  }

  // Returns the number of the month (January is 1).
  //
  // @param name [String] the name of the month in the current locale (e.g. January or Jan)
  // @param monthFormat [String] "long" (January) | "short" (Jan)
  // @return [Number] the number of the month, or 0 if name is not recognised
  monthNumber(name, monthFormat) {
    return this.monthNames(monthFormat).findIndex((m) => name.includes(m)) + 1;
  }

  // Returns the month names in the configured locale.
  //
  // @param format [String] "long" (January) | "short" (Jan)
  // @return [Array] localised month names
  monthNames(format) {
    const formatter = new Intl.DateTimeFormat(this.localesValue, { month: format });
    return ["01", "02", "03", "04", "05", "06", "07", "08", "09", "10", "11", "12"].map((mm) =>
      // Use the middle of the month to avoid timezone edge cases
      formatter.format(new Date(`2022-${mm}-15`)),
    );
  }

  // Returns the day names in the configured locale, starting with the
  // firstDayOfTheWeekValue.
  //
  // @param format [String] "long" (Monday) | "short" (Mon) | "narrow" (M)
  // @return [Array] localised day names
  dayNames(format) {
    const formatter = new Intl.DateTimeFormat(this.localesValue, { weekday: format });
    const names = [];
    // Ensure date in month is two digits. 2022-04-10 is a Sunday
    for (let i = this.firstDayOfWeekValue + 10, n = i + 7; i < n; i++) {
      names.push(formatter.format(new Date(`2022-04-${i}T00:00:00`)));
    }
    return names;
  }

  hasCssAnimation(el) {
    return window.getComputedStyle(el).getPropertyValue("animation-name") !== "none";
  }
}