import { addDaysIso, pad2 } from "@/domain/work-orders/utils/wizard-date-utils";

export const WEEKDAY_LABELS = ["SUN", "MON", "TUE", "WED", "THU", "FRI", "SAT"] as const;

export function deriveDayFields(rawDate: string): {
  dayGroup: string;
  dayLabel: string;
} {
  const dayGroup = rawDate ? rawDate.replace(/^\d{4}-(\d{2})-(\d{2})$/, "$1/$2") : "";
  const dayLabel = rawDate
    ? (() => {
        const d = new Date(`${rawDate}T12:00:00`);
        return `${WEEKDAY_LABELS[d.getDay()]} · ${dayGroup}`;
      })()
    : "";
  return { dayGroup, dayLabel };
}

export function buildWeekSkeleton(weekMonday: string): {
  key: string;
  label: string;
  date: string;
  items: never[];
}[] {
  const base = new Date(`${weekMonday}T12:00:00`);
  return Array.from({ length: 5 }, (_, i) => {
    const d = new Date(base);
    d.setDate(base.getDate() + i);
    const key = `${pad2(d.getMonth() + 1)}/${pad2(d.getDate())}`;
    const iso = `${d.getFullYear()}-${pad2(d.getMonth() + 1)}-${pad2(d.getDate())}`;
    return {
      key,
      label: `${WEEKDAY_LABELS[d.getDay()]} · ${key}`,
      date: iso,
      items: [],
    };
  });
}

export function isDateInWeek(iso: string, weekMonday: string): boolean {
  if (!iso || !/^\d{4}-\d{2}-\d{2}$/.test(iso)) {
    return false;
  }
  const friday = addDaysIso(weekMonday, 4);
  return iso >= weekMonday && iso <= friday;
}