// "Занятия в Полоцке": Word marks the days a group spends in another town over the day's first
// row; the parser keeps them as notes of the day (server/places.js). The notes of a day for one
// group, shared by the server's timetable and the browser.

/**
 * The notes on a weekday (or a date) of the group: `{place, text, subgroup}`, the subgroup null
 * for the whole group. The same note in every subgroup (`labels`) is the whole group's.
 */
export function placesOn(places, group, labels, day, date = null) {
  const on = (places || [])
    .filter((p) => p.groups.includes(group) && p.day === day && (!p.date || p.date === date))
    .map((p) => ({ place: p.place, text: p.text, subgroup: p.subgroups.find((s) => s.group === group)?.label || null }));
  const whole = on.filter((p) => !p.subgroup);
  for (const p of on)
    if (
      p.subgroup &&
      !whole.some((w) => w.text === p.text) &&
      labels.length &&
      labels.every((label) => on.some((o) => o.subgroup === label && o.text === p.text))
    )
      whole.push({ ...p, subgroup: null });
  const parts = on.filter((p) => p.subgroup && !whole.some((w) => w.text === p.text));
  return [...whole, ...parts].filter(
    (p, i, all) => all.findIndex((o) => o.text === p.text && o.subgroup === p.subgroup) === i,
  );
}

/** The notes for the student's subgroup; a note for their own subgroup reads as the whole day's. */
export function placesFor(list, subgroup) {
  return list
    .filter((p) => !subgroup || !p.subgroup || p.subgroup === subgroup)
    .map((p) => (subgroup ? { ...p, subgroup: null } : p))
    .filter((p, i, all) => all.findIndex((o) => o.text === p.text && o.subgroup === p.subgroup) === i);
}