from typing import Iterator
from simfile.types import Chart
from simfile.notes import Note, NoteData

def mirror_note(note: Note, columns: int) -> Note:
    # Make a new Note with all fields the same except for column
    return note._replace(
        # You could replace this expression with anything you want
        column=columns - note.column - 1
    )

def mirror_notes(notedata: NoteData) -> Iterator[Note]:
    columns = notedata.columns
    for note in notedata:
        yield mirror_note(note, columns)

def mirror_chart_in_place(chart: Chart) -> None:
    notedata = NoteData(chart)
    mirrored = NoteData.from_notes(
        mirror_notes(notedata),
        columns=notedata.columns,
    )
    # Assign str(NoteData) to Chart.notes to update the chart's notes
    chart.notes = str(mirrored)