"""
工具函数模块
"""
from datetime import datetime
from typing import Optional


def get_current_period() -> tuple[int, int]:
    """获取当前考核周期（年、月）"""
    now = datetime.now()
    return now.year, now.month


def format_period(year: int, month: int) -> str:
    """格式化考核周期"""
    return f"{year}年{month:02d}月"


def calculate_score_level(score: float) -> str:
    """计算绩效等级"""
    if score >= 90:
        return "优秀"
    elif score >= 80:
        return "良好"
    elif score >= 60:
        return "合格"
    else:
        return "不合格"


def generate_employee_id(department_code: str, sequence: int) -> str:
    """生成员工工号"""
    return f"{department_code}{sequence:04d}"