"""
03 函数版本：学生增删改查

相比列表版本：
    1. 数据仍然用列表和字典保存。
    2. 每个功能拆成一个函数。
    3. 主流程只负责显示菜单和分发任务。
"""

students = []
next_id = 1


def show_menu():
    print("\n====== 学生管理系统：函数版本 ======")
    print("1. 添加学生")
    print("2. 查看所有学生")
    print("3. 查询学生")
    print("4. 修改学生")
    print("5. 删除学生")
    print("0. 退出")


def add_student():
    global next_id
    name = input("姓名：").strip()
    age = input("年龄：").strip()
    phone = input("电话：").strip()

    student = {
        "id": next_id,
        "name": name,
        "age": age,
        "phone": phone,
    }
    students.append(student)
    next_id += 1
    print("添加成功")


def list_students():
    if not students:
        print("暂无学生")
        return

    for student in students:
        print(student)


def find_student_by_id(student_id):
    for student in students:
        if str(student["id"]) == str(student_id):
            return student
    return None


def search_student():
    keyword = input("请输入要查询的姓名：").strip()
    result = []

    for student in students:
        if student["name"] == keyword:
            result.append(student)

    if not result:
        print("没有找到该学生")
        return

    for student in result:
        print(student)


def update_student():
    student_id = input("请输入要修改的学生 ID：").strip()
    student = find_student_by_id(student_id)

    if student is None:
        print("没有找到该学生")
        return

    student["name"] = input("新姓名：").strip()
    student["age"] = input("新年龄：").strip()
    student["phone"] = input("新电话：").strip()
    print("修改成功")


def delete_student():
    student_id = input("请输入要删除的学生 ID：").strip()
    student = find_student_by_id(student_id)

    if student is None:
        print("没有找到该学生")
        return

    students.remove(student)
    print("删除成功")


def main():
    while True:
        show_menu()
        choice = input("请输入操作编号：").strip()

        if choice == "1":
            add_student()
        elif choice == "2":
            list_students()
        elif choice == "3":
            search_student()
        elif choice == "4":
            update_student()
        elif choice == "5":
            delete_student()
        elif choice == "0":
            print("程序结束")
            break
        else:
            print("输入有误，请重新输入")


if __name__ == "__main__":
    main()