import json
def login(name,password):
    with open('./namelist.txt','r',encoding='utf-8') as f:
        for item in json.load(f):
            if item.get('name') == name and item.get('password') == password:
                return True
        else:
            print('用戶名不存在或用戶名密碼錯(cuò)誤')
            return False

def signup(name):
    with open('./namelist.txt', 'r', encoding='utf-8') as f:
        flag = 1
        while flag:
            for item in json.load(f):
                if item.get('name') == name:
                    name = input('用戶名已存在請重新輸入：')
                    break
            else:
                flag = 0
        return True


with open('./namelist.txt','r+',encoding='utf-8') as f:
    if f.read() == '':
        f.write('[{}]')


while True:
    print("""
歡迎來到學(xué)生管理系統(tǒng)
1.登錄
2.注冊
3.退出
""")
    choice = input('請選擇：')
    if choice == '1':
        name = input('請輸入用戶名：')
        password = input('請輸入密碼：')
        if login(name,password) == True:
            print("""
 歡迎%s
 1.添加學(xué)生
 2.查看學(xué)生
 3.刪除學(xué)生
 4.返回           
            """ % name)
            choice1= input('請輸入：')
            continue
    elif choice == '2':
        while True:
            name = input('請輸入用戶名：')
            signup(name)
            password = input('請輸入密碼：')
            with open('./namelist.txt','r',encoding='utf-8') as f:
                former_members = json.load(f)
                new_member = {'name':name,'password':password}
                former_members.append(new_member)
            with open('./namelist.txt', 'w', encoding='utf-8') as f:
                json.dump(former_members,f)
            print("""
 注冊成功
 1.繼續(xù)注冊
 2.返回           
            """)
            choice2 = input('請輸入：')
            if choice2 == '1':

                continue
            else:
                break
    else:
        break