#!/usr/bin/env python3

import sys
import hashlib

from PyQt5.QtWidgets import QApplication
from PyQt5.QtWidgets import QMainWindow
from PyQt5.QtWidgets import QLineEdit
from PyQt5.QtWidgets import QVBoxLayout
from PyQt5.QtWidgets import QWidget
from PyQt5.QtGui import QCursor
from PyQt5.QtCore import Qt
from PyQt5.QtCore import QTimer


CORRECT_PASSWORD_HASH = '1d2e2b10cf9a5474612138ac00bc8b1e8fe895822ddc1e77e0edd023fcff4565'

class FullScreenWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        self.title = 'plock'
        self.initUI()

    def initUI(self):
        self.setWindowTitle(self.title)

        self.central_widget = QWidget()
        self.setCentralWidget(self.central_widget)

        layout = QVBoxLayout()

        self.password_field = QLineEdit()
        self.password_field.setEchoMode(QLineEdit.Password)
        self.password_field.returnPressed.connect(self.check_password)
        self.password_field.setFixedWidth(200)

        layout.addWidget(self.password_field, 0, Qt.AlignCenter)

        self.central_widget.setLayout(layout)

        self.showFullScreen()

    def check_password(self):
        entered_password_hash = hashlib.sha256(self.password_field.text().encode('utf-8')).hexdigest()
        if entered_password_hash == CORRECT_PASSWORD_HASH:
            self.close()

    def showEvent(self, event):
        super().showEvent(event)
        QTimer.singleShot(100, self.grabKeyboardAndMouse)

    def grabKeyboardAndMouse(self):
        super().showFullScreen()
        self.grabMouse()
        self.grabKeyboard()
        self.setCursor(QCursor(Qt.BlankCursor))
        self.password_field.setFocus()

    def keyPressEvent(self, event):
        self.grabMouse()
        self.grabKeyboard()
        if event.key() == Qt.Key_Escape:
            if event.modifiers() & Qt.ControlModifier:
                print("Secure exit requested")
                self.close()
        else:
            self.password_field.keyPressEvent(event)

def main() -> int:
    app = QApplication(sys.argv)
    ex = FullScreenWindow()
    return app.exec_()

if __name__ == '__main__':
    raise SystemExit(main())