replacenotes.py

replacenotes.py

'''
Replaces notes with flats with enharmonic sharps in SFZ and DSPRESET files.
'''

from pathlib import Path
from typing import Final
import re

DS_EXTS: Final = frozenset(['.dspreset'])
SFZ_EXTS: Final = frozenset(['.sfz'])

_NOTE_PATTERN: Final = r'''
    (?P<note> [A-Ga-g] b | [EeBb] \# )
    (?P<oct> -1 | [0-9] )'''
DS_PATTERN: Final = re.compile(fr'''(?x)
    (?P<pre> (root | hi | lo) Note = " )
    {_NOTE_PATTERN}
    (?P<post> " )''')
SFZ_PATTERN: Final = re.compile(fr'''(?x)
    (?P<pre> ((hi | lo |) key | pitch_keycenter) = )
    {_NOTE_PATTERN}
    (?P<post> )''')

OCT_SHIFT: Final = {'cb': -1, 'b#': +1}
REPL_UPPER: Final = {'Cb': 'B', 'Db': 'C#', 'Eb': 'D#', 'Fb': 'E', 'Gb': 'F#',
                     'Ab': 'G#', 'Bb': 'A#', 'E#': 'F', 'B#': 'C'}
REPL_LOWER: Final = {k.lower(): v.lower() for k, v in REPL_UPPER.items()}
REPL: Final = REPL_UPPER | REPL_LOWER

IDLE_RUN: Final[bool] = False

class NoteReplacer:
    def __init__(self) -> None:
        self.replaced: dict[str, str] = dict()

    def __call__(self, match: re.Match[str]) -> str:
        src_note = match['note']
        src_oct = match['oct']
        res = self.replaced.get(src_note + src_oct)

        if res is None:
            res_note = REPL.get(src_note, src_note)
            oct_shift = OCT_SHIFT.get(src_note.lower(), 0)
            res = f'{res_note}{int(src_oct) + oct_shift}'
            self.replaced[src_note + src_oct] = res

        return match['pre'] + res + match['post']

def main() -> None:
    print('HEYA. 🐙 I replace note names like Gb4 with names like F#4.')
    print('Type/paste .sfz/.dspreset files here; leave blank to exit:')
    while True:
        try:
            path = input('> ')
        except KeyboardInterrupt:
            print('\nRuude.')
            break
        except EOFError:
            print()
            break

        if not path.strip():
            break
        path = Path(path)

        if not path.is_file():
            print('That’s not a file!')
            continue

        suffixes = set(map(str.casefold, path.suffixes))
        for exts, pat in ((DS_EXTS, DS_PATTERN), (SFZ_EXTS, SFZ_PATTERN)):
            if not exts.isdisjoint(suffixes):
                pattern = pat
                break
        else:
            print('This file’s extension is not a known one.')
            continue

        with open(path, 'r', encoding='utf8') as f:
            source = f.read()
        note_replacer = NoteReplacer()
        new_source = pattern.sub(note_replacer, source)

        if new_source != source:
            print('Changes are made...')
            for from_, to in note_replacer.replaced.items():
                print(f'  {from_} -> {to}')
            if not IDLE_RUN:
                with open(path, 'w', encoding='utf8') as f:
                    f.write(new_source)
            print('OK')
        else:
            print('The file is left intact!')

    print('Later')

if __name__ == '__main__':
    main()