"""
登录对话框模块 - 处理用户登录和密码管理
"""

from PyQt5.QtWidgets import (
    QDialog, QVBoxLayout, QHBoxLayout, QLabel, QLineEdit, 
    QPushButton, QMessageBox, QInputDialog
)
from PyQt5.QtCore import Qt
from database import get_db_connection


class LoginDialog(QDialog):
    def __init__(self, db_path):
        super().__init__()
        self.db_path = db_path
        self.is_admin = False
        self.setWindowTitle("选择模式并登录")
        self.resize(450, 350)
        self.setModal(True)
        
        self.setup_ui()
    
    def setup_ui(self):
        """设置用户界面"""
        layout = QVBoxLayout(self)
        layout.addWidget(QLabel("<b>请选择登录模式（默认密码均为 123456）</b>"))

        # 管理员登录区域
        admin_layout = QHBoxLayout()
        admin_layout.addWidget(QLabel("管理员模式密码:"))
        self.admin_input = QLineEdit()
        self.admin_input.setEchoMode(QLineEdit.Password)
        self.admin_input.setPlaceholderText("默认 123456")
        admin_layout.addWidget(self.admin_input)

        admin_login = QPushButton("登录管理员模式")
        admin_login.clicked.connect(lambda: self.login_mode(True))
        admin_layout.addWidget(admin_login)

        admin_change = QPushButton("修改管理员密码")
        admin_change.clicked.connect(self.change_admin_password)
        admin_layout.addWidget(admin_change)

        layout.addLayout(admin_layout)

        # 普通用户登录区域
        user_layout = QHBoxLayout()
        user_layout.addWidget(QLabel("普通用户模式密码:"))
        self.user_input = QLineEdit()
        self.user_input.setEchoMode(QLineEdit.Password)
        self.user_input.setPlaceholderText("默认 123456")
        user_layout.addWidget(self.user_input)

        user_login = QPushButton("登录普通用户模式")
        user_login.clicked.connect(lambda: self.login_mode(False))
        user_layout.addWidget(user_login)

        user_change = QPushButton("修改普通用户密码")
        user_change.clicked.connect(self.change_user_password)
        user_layout.addWidget(user_change)

        layout.addLayout(user_layout)

        layout.addStretch()

        # 退出按钮
        exit_btn = QPushButton("退出程序")
        exit_btn.clicked.connect(self.reject)
        layout.addWidget(exit_btn)

    def get_conn(self):
        """获取数据库连接"""
        return get_db_connection(self.db_path)

    def get_stored_password(self, password_type):
        """获取存储的密码"""
        try:
            with self.get_conn() as conn:
                cursor = conn.execute("SELECT value FROM admin_settings WHERE key = ?", (f"{password_type}_password",))
                row = cursor.fetchone()
                return row[0] if row else "123456"
        except:
            return "123456"

    def set_password(self, password_type, new_password):
        """设置新密码"""
        try:
            with self.get_conn() as conn:
                conn.execute("INSERT OR REPLACE INTO admin_settings (key, value) VALUES (?, ?)", 
                           (f"{password_type}_password", new_password))
                conn.commit()
                return True
        except Exception as e:
            QMessageBox.critical(self, "错误", f"密码保存失败: {str(e)}")
            return False

    def change_admin_password(self):
        """修改管理员密码"""
        old_pwd = self.get_stored_password("admin")
        old_input, ok1 = QInputDialog.getText(
            self, "修改管理员密码", "请输入当前管理员密码:", QLineEdit.Password
        )
        if not ok1 or old_input != old_pwd:
            QMessageBox.warning(self, "错误", "当前密码错误！")
            return
            
        new_pwd1, ok2 = QInputDialog.getText(
            self, "新密码", "请输入新管理员密码:", QLineEdit.Password
        )
        if not ok2 or len(new_pwd1) < 4:
            QMessageBox.warning(self, "错误", "新密码至少4位！")
            return
            
        new_pwd2, ok3 = QInputDialog.getText(
            self, "确认新密码", "请再次输入新管理员密码:", QLineEdit.Password
        )
        if not ok3 or new_pwd1 != new_pwd2:
            QMessageBox.warning(self, "错误", "两次输入的密码不一致！")
            return
            
        if self.set_password("admin", new_pwd1):
            QMessageBox.information(self, "成功", "管理员密码修改成功！")

    def change_user_password(self):
        """修改普通用户密码"""
        old_pwd = self.get_stored_password("user")
        old_input, ok1 = QInputDialog.getText(
            self, "修改普通用户密码", "请输入当前普通用户密码:", QLineEdit.Password
        )
        if not ok1 or old_input != old_pwd:
            QMessageBox.warning(self, "错误", "当前密码错误！")
            return
            
        new_pwd1, ok2 = QInputDialog.getText(
            self, "新密码", "请输入新普通用户密码:", QLineEdit.Password
        )
        if not ok2 or len(new_pwd1) < 4:
            QMessageBox.warning(self, "错误", "新密码至少4位！")
            return
            
        new_pwd2, ok3 = QInputDialog.getText(
            self, "确认新密码", "请再次输入新普通用户密码:", QLineEdit.Password
        )
        if not ok3 or new_pwd1 != new_pwd2:
            QMessageBox.warning(self, "错误", "两次输入的密码不一致！")
            return
            
        if self.set_password("user", new_pwd1):
            QMessageBox.information(self, "成功", "普通用户密码修改成功！")

    def login_mode(self, is_admin):
        """登录验证"""
        password_type = "admin" if is_admin else "user"
        input_pwd = self.admin_input.text().strip() if is_admin else self.user_input.text().strip()
        correct_pwd = self.get_stored_password(password_type)
        
        if input_pwd == correct_pwd:
            self.is_admin = is_admin
            self.accept()
        else:
            QMessageBox.warning(self, "错误", "密码错误，请重试！")