class Rota {
    LocalDate date;
    List<String> users;
    String week;
    String holidayType; // 0-普通 1-節(jié)假日 2-補班
    String remark;

    @Override
    public String toString() {
        return date + " " + week + " -> " + users + " [" + remark + "]";
    }
}

class Holidays {
    LocalDate date;
    String name;
    boolean offDay; // true=休息 false=補班

    Holidays(LocalDate date, String name, boolean offDay) {
        this.date = date;
        this.name = name;
        this.offDay = offDay;
    }
}

public static List<Rota> batchInsertRota(
        LocalDate startDate,
        LocalDate endDate,
        List<String> employees,
        boolean twoDutyAtMonthEnd,
        List<Holidays> holidaysList
) {

    Set<LocalDate> holidayDates = holidaysList.stream()
            .filter(h -> h.offDay)
            .map(h -> h.date)
            .collect(Collectors.toSet());

    Set<LocalDate> weekendWorkDates = holidaysList.stream()
            .filter(h -> !h.offDay)
            .map(h -> h.date)
            .collect(Collectors.toSet());

    Map<String, LocalDate> lastDuty = new HashMap<>();
    employees.forEach(e -> lastDuty.put(e, startDate.minusDays(1)));

    List<String> dutyQueue = new ArrayList<>(employees);
    List<Rota> result = new ArrayList<>();

    LocalDate current = startDate;

    while (!current.isAfter(endDate)) {

        LocalDate lastDayOfMonth = current.with(TemporalAdjusters.lastDayOfMonth());

        boolean isWeekend = current.getDayOfWeek() == DayOfWeek.SATURDAY
                || current.getDayOfWeek() == DayOfWeek.SUNDAY;

        boolean isHoliday = holidayDates.contains(current);
        boolean isWeekendWork = weekendWorkDates.contains(current);

        //  是否“本來就需要值班”
        boolean needDutyDay = (isWeekend || isHoliday) && !isWeekendWork;

        if (needDutyDay) {

            List<String> dutyUsers = new ArrayList<>();

            String user1 = Collections.min(dutyQueue, Comparator.comparing(lastDuty::get));
            dutyQueue.remove(user1);
            lastDuty.put(user1, current);
            dutyUsers.add(user1);

            //  月底雙人：僅在“已是值班日”的前提下
            if (twoDutyAtMonthEnd &&
                    ChronoUnit.DAYS.between(current, lastDayOfMonth) <= 1 &&
                    !dutyQueue.isEmpty()) {

                String user2 = Collections.min(dutyQueue, Comparator.comparing(lastDuty::get));
                dutyQueue.remove(user2);
                lastDuty.put(user2, current);
                dutyUsers.add(user2);
            }

            Rota rota = new Rota();
            rota.date = current;
            rota.users = dutyUsers;
            rota.week = "星期" + "一二三四五六日".charAt(current.getDayOfWeek().getValue() - 1);

            if (isHoliday) {
                rota.holidayType = "1";
                rota.remark = holidaysList.stream()
                        .filter(h -> h.date.equals(current))
                        .map(h -> h.name)
                        .findFirst().orElse("節(jié)假日");
            } else {
                rota.holidayType = "0";
                rota.remark = "周末";
            }

            result.add(rota);
            dutyQueue.addAll(dutyUsers);
        }

        current = current.plusDays(1);
    }

    return result;
}

public static void main(String[] args) {

    LocalDate start = LocalDate.of(2025, 1, 1);
    LocalDate end   = LocalDate.of(2025, 1, 31);

    List<String> employees = Arrays.asList(
            "張三", "李四", "王五", "趙六"
    );

    // 真實 2025 年 1 月節(jié)假日（示例）
    List<Holidays> holidays = Arrays.asList(
            new Holidays(LocalDate.of(2025, 1, 1), "元旦", true),

            new Holidays(LocalDate.of(2025, 1, 26), "春節(jié)調休補班", false),

            new Holidays(LocalDate.of(2025, 1, 28), "春節(jié)", true),
            new Holidays(LocalDate.of(2025, 1, 29), "春節(jié)", true),
            new Holidays(LocalDate.of(2025, 1, 30), "春節(jié)", true),
            new Holidays(LocalDate.of(2025, 1, 31), "春節(jié)", true)
    );

    List<Rota> rotaList = batchInsertRota(
            start,
            end,
            employees,
            true,
            holidays
    );

    rotaList.forEach(System.out::println);
}