import os


#用户注册函数
def sign_in():
    print("欢迎来到用户注册界面")
    username = input("请输入你的用户名：")
    password = input('请输入你的密码：')
    repassword = input("请再次输入你的密码：")
    if password==repassword:
        with open(r"D:\p1\user.txt", "rb") as rstream:
            while True:
                filelist = rstream.readline()

                if not filelist:
                    break
                users = '{} {}\n'.format(username, password)

                if users == filelist:
                    print("对不起该用户已经注册过了")
                    break
            with open(r"D:\p1\user.txt", 'a') as wstream:
                wstream.write('{} {}\n'.format(username, password))
            print("注册成功")



    else:
        print("两次密码不一致，请重新输入")
# 用户登入界面
def login():
    print("欢迎来到用户登入界面！")
    username = input("请输入你的用户名：")
    password = input("请输入你的密码：")
    with open(r"D:\p1\user.txt") as stream:
        while True:
            filelist = stream.readline()

            if not filelist:
                print("用户登入有错误！")
                break
            users = '{} {}\n'.format(username, password)

            if users == filelist:
                print("用户登入成功！")
                return 1
                break
#显示所有图书
def show_books():
    print("******图书馆含有的图书**************")
    with open( r'D:\p1\books.txt',"r",encoding='utf-8') as stream:
        books = stream.readlines()
        for book in books:
            print(book,end="")
#借书
def borrow_book(book1):
    transit = ""  # 创立空的字符串用于储存文件
    with open(r'D:\p1\books.txt', "r", encoding='utf-8') as stream:
        books = stream.readlines()
        for book in books:
            if book1 not in book:
                print("对不起，没有该书")
            elif book1 in book:
                continue
            else:
                transit += book  # 将数据写入过渡的字符串中
    with open(r'D:\p1\books.txt', "w", encoding='utf-8') as wstream:
        wstream.write(transit)
#还书
def  return_book(book1):
    with open(r'D:\p1\books.txt', "a", encoding='utf-8') as stream:
        stream.write('\n{}\n'.format(book1))
#查书
def  look_book(book1):
    with open(r'D:\p1\books.txt', "r", encoding='utf-8') as stream:
        books = stream.readlines()
        for book in books:
            if book1 in book:
                print("该书在图书馆内")
                break
        else:
            print("对不起查无此书")




print("*******欢迎来到图书馆登入系统******")
while True:
    print('功能：1，登入   2.注册    ')
    str = input('请输入你要做的事情：')
    if str == "1":
        a=login()
        while True:
            print("***********************")
            print('''功能：
1,借书   2，还书    3，查书   4，显示所有图书  5，退出登入
                    ''')
            key = input("请输入你要做的事情：")
            if key == '1':
                book1 = input("请输入你要借的书的书名：")
                borrow_book(book1)
                print("借书成功！")
            if key == '2':
                book1 = input("请输入你要还的书的书名")
                return_book(book1)
                print("还书成功！")
            if key == '3':
                book1 = input("请输入你要查的书的书名")
                look_book(book1)
            if key == '4':
                show_books()
            else:
                print("成功退出界面")
                print(key)
    if str == "2":
        sign_in()
    else:
        print("对不起，小图还没有学会该功能呢！")
        print(str)