from datetime import datetime, timedelta

team_members = ["Yiannis", "Anastasia", "Bulat", "Thomas", "Sanika"]

def count_weekdays(start_date, end_date, target_weekdays):
    total_days = (end_date - start_date).days + 1
    count = 0
    
    for day in range(total_days):
        current_day = start_date + timedelta(days=day)
        if current_day.weekday() in target_weekdays:
            count += 1
            
    return count

def get_next_standup_taker(last_standup_taker, last_date_str, force_standup_taker=None, current_date=None):
    today = current_date if current_date else datetime.now().date()
    today_str = today.strftime("%Y-%m-%d")
    weekday = today.weekday()

    if weekday not in [1, 3]:
        return "Today is not a stand-up day.", today_str
    
    if force_standup_taker:
        return force_standup_taker, today_str
    
    last_date = datetime.strptime(last_date_str, "%Y-%m-%d").date()
    elapsed_days = count_weekdays(last_date, today, [1, 3])
    last_index = team_members.index(last_standup_taker)
    next_index = (last_index + elapsed_days - 1) % len(team_members)
    next_standup_taker = team_members[next_index]
    
    return next_standup_taker, today_str