Bold Toggling Bug

ovid.py

"""
This is a minimum test case for a bug in some code I'm writing. It's for a custom text editor (hobby
project).

The intent is that if I select some text and apply Bold formatting (for example, by hitting "ctrl-b"),
it will toggle the formatting. Specifically, it should remove the bold formatting if all of the selected
text is bold. Otherwise, it will apply the bold formatting.

However, it won't remove the bold formatting.

For example, in the sentence "this is a test", if I select "is a" and apply the bold formatting, I get 
"this is a test", with the "is a" properly bold. However, with the selection in place, it still remains
bold if I hit "ctrl-b". If I deselect either the first or last character, the toggling of bold works as
expected. (I've tried reversing the if/else logic, but that fails, too).

In the example below, you can also click the "B" button on the menu bar to apply bold.
"""

import sys
from PyQt6.QtWidgets import (
    QTextEdit,
    QToolButton,
    QApplication,
    QMainWindow,
    QToolBar,
)
from PyQt6.QtGui import (
    QFont,
    QShortcut,
    QKeySequence,
    QTextCharFormat
)

class OvidFont:
    def __init__(self, ovid) -> None:
        self.textEditor = ovid.textEditor

    def setBoldText(self):
        fmt = QTextCharFormat()
        print(f"charFormat: {self.textEditor.textCursor().charFormat()}")
        weight = self.textEditor.currentCharFormat().fontWeight()
        print(f"weight: {weight} QFont.Weight.Bold: {QFont.Weight.Bold}")
        if self.textEditor.currentCharFormat().fontWeight() == QFont.Weight.Bold:
            print("    setting normal")
            fmt.setFontWeight(QFont.Weight.Normal)
        else:
            print("    setting bold")
            fmt.setFontWeight(QFont.Weight.Bold)
        cursor = self.textEditor.textCursor()
        cursor.setCharFormat(fmt)
        self.textEditor.setTextCursor(cursor)

class Ovid(QMainWindow):
    def __init__(self):
        super().__init__()
        self.initUI()

    def initUI(self):
        self.setWindowTitle("Ovid")
        self.setGeometry(100, 100, 1200, 800)
        # Create the text editor area
        self.textEditor = QTextEdit()
        self.setCentralWidget(self.textEditor)
        self.fonts = OvidFont(self)

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

        # Add actions for text formatting
        bold_button = QToolButton()
        bold_button.setText("B")
        bold_button.setFont(QFont("Arial", 16, QFont.Weight.Bold))
        bold_button.setToolTip("Bold")
        bold_button.clicked.connect(self.fonts.setBoldText)
        self.toolbar.addWidget(bold_button)

        # Shortcuts for text formatting
        QShortcut(QKeySequence("Ctrl+B"), self, self.fonts.setBoldText)

def main():
    app = QApplication(sys.argv)
    ex = Ovid()
    ex.show()
    sys.exit(app.exec())


if __name__ == "__main__":
    main()