import math
from datetime import date, timedelta

def calculate_end_date(start_date_str: str, work_days: float, works_on_saturday: bool, works_on_sunday: bool) -> str:
    """주말(토/일) 근무 여부 플래그를 고려하여 가동 후 실제 종료 날짜(YYYY-MM-DD)를 계산합니다."""
    start_date = date.fromisoformat(start_date_str)
    work_days_required = math.ceil(work_days)
    
    current_date = start_date
    days_counted = 0
    if work_days_required <= 0:
        return start_date.isoformat()

    while days_counted < work_days_required:
        weekday = current_date.weekday()  # 월요일 0, 일요일 6
        
        is_working_day = True
        if weekday == 5:  # 토요일
            if not works_on_saturday:
                is_working_day = False
        elif weekday == 6:  # 일요일
            if not works_on_sunday:
                is_working_day = False
        
        if is_working_day:
            days_counted += 1

        if days_counted < work_days_required:
            current_date += timedelta(days=1)

    return current_date.isoformat()