import re
import sqlite3

from PyQt5.QtCore import pyqtSignal
from PyQt5.QtWidgets import QApplication, QMainWindow, QPushButton, QLabel, QLineEdit, QMessageBox



class LoginWindow(QMainWindow):

    login_successful = pyqtSignal()  # 定义 login_successful 信号

    def __init__(self):
        super(LoginWindow, self).__init__()
        self.init_ui()

    def init_ui(self):
        self.setWindowTitle('登录/注册')
        self.resize(300, 200)

        self.label_username = QLabel('用户名:', self)
        self.label_username.move(50, 30)
        self.lineEdit_username = QLineEdit(self)
        self.lineEdit_username.move(110, 30)
        self.lineEdit_username.resize(150, 20)

        self.label_password = QLabel('密码:', self)
        self.label_password.move(50, 70)
        self.lineEdit_password = QLineEdit(self)
        self.lineEdit_password.move(110, 70)
        self.lineEdit_password.resize(150, 20)
        self.lineEdit_password.setEchoMode(QLineEdit.Password)

        self.btn_login = QPushButton('登录', self)
        self.btn_login.move(80, 120)
        self.btn_login.clicked.connect(self.login)

        self.btn_register = QPushButton('注册', self)
        self.btn_register.move(160, 120)
        self.btn_register.clicked.connect(self.register)

    def login(self):
        username = self.lineEdit_username.text()
        password = self.lineEdit_password.text()
        success, message = LoginSystem().login(username, password)
        if success:
            QMessageBox.information(self, '成功', '登录成功！')
            self.login_successful.emit()  # 发射登录成功信号
        else:
            QMessageBox.warning(self, '错误', message)

    def register(self):
        username = self.lineEdit_username.text()
        password = self.lineEdit_password.text()
        success, message = LoginSystem().register(username, password)
        if success:
            QMessageBox.information(self, '成功', '注册成功！')
        else:
            QMessageBox.warning(self, '错误', message)

class LoginSystem:
    def __init__(self, db_name='user.db'):
        self.conn = sqlite3.connect(db_name)
        self.cursor = self.conn.cursor()
        self.create_table()

    def create_table(self):
        self.cursor.execute('''CREATE TABLE IF NOT EXISTS users
                            (id INTEGER PRIMARY KEY AUTOINCREMENT,
                            username TEXT NOT NULL UNIQUE,
                            password TEXT NOT NULL)''')
        self.conn.commit()

    def register(self, username, password):
        if not re.match(r'^\d{5,12}$', username):
            return False, "用户名必须是5-12位纯数字。"

        if not re.match(r'^(?=.*[a-zA-Z])(?=.*\d|.*[\W_])[A-Za-z\d\W_]{8,12}$', password):
            return False, "密码必须是8-12个字符，并且包含以下至少两种类型的字符：字母、数字、特殊字符。"

        try:
            self.cursor.execute("INSERT INTO users (username, password) VALUES (?, ?)", (username, password))
            self.conn.commit()
            return True, "注册成功。"
        except sqlite3.IntegrityError:
            return False, "用户名已存在，请更改。"

    def login(self, username, password):
        self.cursor.execute("SELECT * FROM users WHERE username=? AND password=?", (username, password))
        user = self.cursor.fetchone()
        if user:
            return True, "登录成功。"
        else:
            return False, "用户名或密码无效。"