from    QT              import QtWidgets, QT
from    User            import User
import  yaml

class Login_Dialog (QtWidgets.QDialog) :

    def __init__ (self, config_file, username = "") :
        super ().__init__ ()
        cfg = User.Load_Yaml (config_file)
        self.users = User (cfg.users)
        self.setWindowTitle ("Login")
        self.layout = L     = QtWidgets.QFormLayout (self)
        self.user_name      = QtWidgets.QLineEdit ()
        self.password       = QtWidgets.QLineEdit ()
        self.password.setEchoMode (QtWidgets.QLineEdit.Password)
        L.addRow ("Benutzername", self.user_name)
        L.addRow ("Passwort",     self.password)
        layout  = QtWidgets.QHBoxLayout  ()
        login   = QtWidgets.QPushButton  ("Login")
        login.setEnabled                 (False)
        self.error = QtWidgets.QLabel    ("")
        layout.addWidget                 (self.error)
        login.clicked.connect            (self._login)
        layout.addStretch                (10)
        layout.addWidget                 (login)
        login.setDefault                 (True)
        L.addRow                         (layout)
        self.login = login
        self.password.editingFinished.connect (self._login)
        self.user_name.editingFinished.connect(self._check_login_possible)
        self.user_name.setText (username)
        if username :
            self.password.setFocus ()
    # end def __init__
    
    def _check_login_possible (self) :
        un = self.user_name.text ()
        pw = self.password.text ()
        self.login.setEnabled ((len (un) >= 3) and (len (pw) >= 3))
    # end def _check_login_possible
    
    def _login (self) :
        un      = self.user_name.text ()
        pw      = self.password.text ()
        pw_ok   = self.users.check_password (un, pw, True)
        self.login.setEnabled (pw_ok)
        if not pw_ok :
            self.error.setText ("Passwort falsch")        
        else :
            self.accept ()
    # end def _login
    
# end class Login_Dialog