import sys
from PyQt6.QtWidgets import (
    QApplication,
    QMainWindow,
    QWidget,
    QPlainTextEdit,
    QVBoxLayout,
    QFileDialog,
    QMessageBox,
    QMenuBar,
    QMenu,
    QToolBar
)
from PyQt6.QtGui import QAction, QKeySequence
from PyQt6.QtCore import Qt

class TextViewer(QMainWindow):
    def __init__(self):
        super().__init__()
        self.initializeUI()

    def initializeUI(self):
        # Set window properties
        self.setGeometry(100, 100, 600, 400)  # Position and size
        self.setWindowTitle("Accessible Text Viewer")

        # Create the menu bar
        self.menu_bar = self.menuBar()
        self.menu = QMenu("Menu", self)
        self.menu.setTitle("Menu (&M)")
        self.menu_bar.addMenu(self.menu)

        # Create actions for the menu
        self.open_file_action = QAction("Open File", self)
        self.open_file_action.setShortcut(QKeySequence("Alt+O"))
        self.open_file_action.triggered.connect(self.open_file)
        self.menu.addAction(self.open_file_action)

        # Create the toolbar
        self.toolbar = QToolBar("Main Toolbar", self)
        self.addToolBar(self.toolbar)

        # Add actions to the toolbar
        self.toolbar.addAction(self.open_file_action)

        # Create the plain text editor
        self.text_viewer = QPlainTextEdit(self)
        self.text_viewer.setReadOnly(True)  # Make the text editor read-only
        self.text_viewer.setTextInteractionFlags(Qt.TextInteractionFlag.TextSelectableByKeyboard | Qt.TextInteractionFlag.TextSelectableByMouse)
        self.text_viewer.setAccessibleName("Text Viewer")

        # Set up the layout
        central_widget = QWidget()
        layout = QVBoxLayout(central_widget)
        layout.setMenuBar(self.menu_bar)
        layout.addWidget(self.text_viewer)
        self.setCentralWidget(central_widget)

        # Show the window
        self.show()

    def open_file(self):
        # Open file dialog to select a file
        file_name, _ = QFileDialog.getOpenFileName(
            self,
            "Open Text File",
            "",
            "Text Files (*.txt);;All Files (*)"
        )

        if file_name:
            try:
                with open(file_name, 'r', encoding='utf-8') as file:
                    content = file.read()
                    self.text_viewer.setPlainText(content)  # Display file content in plain text editor
                    self.text_viewer.setFocus()
            except Exception as e:
                # Display error message if file reading fails
                error_message = f"Error reading file:\n{e}"
                self.text_viewer.setPlainText(error_message)
                QMessageBox.critical(self, "File Read Error", error_message)


if __name__ == "__main__":
    app = QApplication(sys.argv)
    window = TextViewer()
    sys.exit(app.exec())