// Small time/date helpers shared by popup, dashboard and planner.
// Times of day are handled as "minutes since midnight", durations as minutes.
var U = (() => {
  const pad = (n) => String(n).padStart(2, '0');

  const toMin = (hhmm) => {
    const m = /^(\d{1,2})[:.h](\d{2})$/.exec(String(hhmm || '').trim());
    return m ? +m[1] * 60 + +m[2] : null;
  };

  const fmtTime = (min) => `${pad(Math.floor(min / 60))}:${pad(min % 60)}`;

  const fmtDur = (min) => {
    const sign = min < 0 ? '-' : '';
    min = Math.abs(Math.round(min));
    return `${sign}${Math.floor(min / 60)}:${pad(min % 60)}`;
  };

  // "1", "1.5", "1,5", "1:30", "90m", "1h30" -> minutes. Empty -> null.
  const parseHours = (s) => {
    s = String(s ?? '').trim().toLowerCase();
    if (!s) return null;
    let m;
    if ((m = /^(\d+)\s*m(in)?$/.exec(s))) return +m[1];
    if ((m = /^(\d+)\s*[:h]\s*(\d{1,2})?\s*m?(in)?$/.exec(s))) return +m[1] * 60 + +(m[2] || 0);
    if ((m = /^(\d+(?:[.,]\d+)?)$/.exec(s))) return Math.round(parseFloat(m[1].replace(',', '.')) * 60);
    return null;
  };

  const parseDate = (iso) => {
    const [y, m, d] = iso.split('-').map(Number);
    return new Date(y, m - 1, d);
  };

  const isoDate = (dt) => `${dt.getFullYear()}-${pad(dt.getMonth() + 1)}-${pad(dt.getDate())}`;

  const addDays = (iso, n) => {
    const dt = parseDate(iso);
    dt.setDate(dt.getDate() + n);
    return isoDate(dt);
  };

  // ISO weekday: 1 = Monday ... 7 = Sunday
  const weekday = (iso) => parseDate(iso).getDay() || 7;

  const WEEKDAYS = ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun'];
  const weekdayName = (iso) => WEEKDAYS[weekday(iso) - 1];

  // Monday of the week containing iso
  const monday = (iso) => addDays(iso, 1 - weekday(iso));

  const weeksBetween = (a, b) =>
    Math.round((parseDate(monday(b)) - parseDate(monday(a))) / (7 * 864e5));

  // Kimai wants HTML5 local datetime: 2026-10-07T08:00:00
  const kimaiDateTime = (iso, min) => `${iso}T${fmtTime(min)}:00`;

  const uid = () => Math.random().toString(36).slice(2, 10);

  /* Swiss display: 01/09/2026, 13:30. Internally always ISO dates + HH:MM. */
  const fmtDate = (iso) => (iso ? `${iso.slice(8, 10)}/${iso.slice(5, 7)}/${iso.slice(0, 4)}` : '');

  // "1/9/2026", "01.09.2026", "01-09-26", "2026-09-01" -> "2026-09-01" (null if invalid)
  const parseUserDate = (s) => {
    s = String(s || '').trim();
    let m, y, mo, d;
    if ((m = /^(\d{4})-(\d{1,2})-(\d{1,2})$/.exec(s))) [, y, mo, d] = m;
    else if ((m = /^(\d{1,2})[./-](\d{1,2})[./-](\d{4}|\d{2})$/.exec(s))) [, d, mo, y] = m;
    else return null;
    if (y.length === 2) y = '20' + y;
    const dt = new Date(+y, +mo - 1, +d);
    return dt.getMonth() === +mo - 1 && dt.getDate() === +d ? isoDate(dt) : null;
  };

  const fmtDateTime = (dt) => `${fmtDate(isoDate(dt))} ${fmtTime(dt.getHours() * 60 + dt.getMinutes())}`;

  // "930", "9:30", "9.30", "9h30", "9" -> "09:30" (null if invalid)
  const parseUserTime = (s) => {
    s = String(s || '').trim();
    let m;
    if ((m = /^(\d{1,2})$/.exec(s))) m = [s, m[1], '0'];
    else if (!(m = /^(\d{1,2})[:.h]?(\d{2})$/.exec(s))) return null;
    const min = +m[1] * 60 + +m[2];
    return +m[1] < 24 && +m[2] < 60 ? fmtTime(min) : null;
  };

  // Text inputs with data-kind="date" | "time": read/write ISO / HH:MM, show Swiss format
  const getField = (el) => (el.dataset.kind === 'date' ? parseUserDate(el.value) : parseUserTime(el.value)) || '';
  const setField = (el, v) => { el.value = el.dataset.kind === 'date' ? fmtDate(v) : v || ''; };
  const setupFields = (root = document) => {
    root.querySelectorAll('input[data-kind]').forEach((el) => {
      el.placeholder ||= el.dataset.kind === 'date' ? 'dd/mm/yyyy' : 'hh:mm';
      el.size = el.dataset.kind === 'date' ? 10 : 5;
      el.addEventListener('blur', () => {
        const v = getField(el);
        el.classList.toggle('invalid', !!el.value.trim() && !v);
        if (v) setField(el, v);
      });
    });
  };

  return {
    pad, toMin, fmtTime, fmtDur, parseHours, parseDate, isoDate, addDays,
    weekday, weekdayName, WEEKDAYS, monday, weeksBetween, kimaiDateTime, uid,
    fmtDate, parseUserDate, fmtDateTime, parseUserTime, getField, setField, setupFields,
  };
})();