fix_file_links.py

#!/usr/bin/env python3

import argparse
import os
import shutil
import sys
import traceback
import unicodedata

from _utils import get_artisttitle, get_attribute, set_attribute

HELP = """
Try to fix file links in #COVER, #MP3, #VIDEO and #BACKGROUND, which do not
resolve correctly, due to differing encodings of filenames on the disk and in
the attributes. Once the correct files have been found, rename them to
"<artist> - <song>.<extension>", update the attributes and rewrite the file
in-place. Remove any attributes, which cannot be resolved. Expects the text
files to be in the same directory as the media files. Only accepts UTF-8 encoded
text files.
"""


def force_ascii(text):
    text = unicodedata.normalize("NFC", text)  # combine decomposed characters
    return text.encode("ascii", errors="ignore").decode()


def fix_file_links(path, keep_missing_files, dry_run=False, verbose=False):
    print(path)

    song_dir = os.path.dirname(path)
    song_files = os.listdir(song_dir)
    song_files = {force_ascii(s): s for s in song_files}

    renamed = {}

    with open(path) as f:
        text = f.read()

    try:
        artisttitle = get_artisttitle(text)
        artisttitle = artisttitle.replace("/", " ")
    except KeyError:
        return

    new_path = song_dir + "/" + artisttitle + ".txt"
    if new_path != path:
        print(f"rename {new_path}")

        if not dry_run:
            os.rename(path, new_path)

    lines = text.splitlines(True)

    for attr in ("MP3", "VIDEO", "COVER", "BACKGROUND"):
        try:
            attr_path = get_attribute(text, attr)
            attr_path_ascii = force_ascii(attr_path)
        except KeyError:
            continue

        if verbose:
            print(f"processing {attr}: {attr_path_ascii}")
            print(f"candiates: " + " ".join(f[0] for f in song_files.items()))

        candidates = [
            original
            for ascii, original in song_files.items()
            if ascii.lower() == attr_path_ascii.lower()
        ]

        if not candidates:
            if keep_missing_files:
                print(f"keep {attr}, no file found")
            else:
                print(f"remove {attr}, no file found")
                lines = set_attribute(lines, attr, None)
            continue

        if attr_path == attr_path_ascii:
            print(f"ignore {attr}, ascii")
            continue

        old_attr_name = candidates[0]
        attr_ext = os.path.splitext(old_attr_name)[1]
        new_attr_name = artisttitle + " " + attr + attr_ext

        if old_attr_name == new_attr_name:
            print(f"ignore {attr}, no change")
            continue

        if old_attr_name not in renamed:
            print(f"rewrite {attr}: {old_attr_name} => {new_attr_name}")
            if not dry_run:
                os.rename(
                    song_dir + "/" + old_attr_name, song_dir + "/" + new_attr_name
                )
            renamed[old_attr_name] = new_attr_name
        else:
            new_attr_name = renamed[old_attr_name]
            print(f"rewrite {attr} (double-ref): {old_attr_name} => {new_attr_name}")

        lines = set_attribute(lines, attr, new_attr_name)

    if not dry_run:
        with open(new_path, "w") as f:
            f.writelines(lines)


def main(argv):
    parser = argparse.ArgumentParser(description=HELP)
    parser.add_argument("files", nargs="+")
    parser.add_argument(
        "--keep-nullpointer-lines",
        action="store_true",
        help="do not delete attributes, which reference non-existing files",
    )
    parser.add_argument("--dry-run", action="store_true")
    parser.add_argument("--verbose", action="store_true")
    args = parser.parse_args(argv)

    for path in args.files:
        try:
            fix_file_links(
                path, args.keep_nullpointer_lines, args.dry_run, args.verbose
            )
        except Exception as ex:
            traceback.print_exc()


if __name__ == "__main__":
    main(sys.argv[1:])