qBittorrent FastResume Migration Script

fastresume-migrate.py

import argparse
import os
import pprint
import shutil
from typing import Dict, List, Optional

import bencodepy

BENCODE_TYPE = bytes | List['BENCODE_TYPE']


class FastResume:
    info: Dict[str, str]

    def __init__(self, data: Dict[bytes, BENCODE_TYPE]) -> None:
        self.info = {}
        for key, value in data.items():
            self.info[key.decode()] = value

    def __repr__(self) -> str:
        return pprint.pformat(self.__dict__)

    def __str__(self) -> str:
        return pprint.pformat(self.__dict__)

    def export(self, encoding: str = 'utf-8', path: Optional[str] = None) -> bytes:
        """
        Export FastResume.
        :param path str: Optional argument to export FastResume to file.
        :returns str: Encoded data.
        """
        encoded = bencodepy.encode(self.info, encoding)
        
        if path is not None:
            with open(path, 'wb') as f:
                f.write(encoded)

        return encoded

    # "from" functions.
    @staticmethod
    def from_bytes(data: bytes) -> 'FastResume':
        return FastResume(bencodepy.decode(data))
    
    @staticmethod
    def from_file(path: str) -> 'FastResume':
        return FastResume(bencodepy.decode_from_file(path))


def change_save_path(fastresume: FastResume, new_save_path: str) -> None:
    """
    Change the save path of a FastResume object.

    Args:
    fastresume: The FastResume object to change the save path of.
    new_save_path: The new save path.
    """
    fastresume.info['qBt-savePath'] = new_save_path
    fastresume.info['save_path'] = new_save_path

def backup_file(file_path: str, backup_directory: str) -> None:
    """
    Backup a file to a given directory.

    Args:
    file_path: The path of the file to backup.
    backup_directory: The path of the directory to backup the file to.
    """
    backup_file_path = os.path.join(backup_directory, os.path.basename(file_path))
    shutil.copyfile(file_path, backup_file_path)

def process_files(files_path: str, new_save_path: str) -> None:
    """
    Process all files in a directory, changing the save path of any `fastresume` files to a new save path and backing up the original files.

    Args:
    files_path: The directory path to process.
    new_save_path: The new save path.
    """
    backup_directory = os.path.join(files_path, 'fastresume-migrate-backup')
    os.makedirs(backup_directory, exist_ok=True)

    for root, directories, files in os.walk(files_path):
        for filename in files:
            if (file_path := os.path.join(root, filename)).endswith('.fastresume'):
                print(f'Processing {file_path}.')
                backup_file(file_path, backup_directory)
                fastresume = FastResume.from_file(file_path)
                change_save_path(fastresume, new_save_path)
                fastresume.export(path=file_path)
        break


def main():
    parser = argparse.ArgumentParser(description='Change the save path of all qBittorrent `fastresume` files in a given directory to a new save path.')
    parser.add_argument('--files-path', required=True, help='The path of the directory containing the `fastresume` files to modify.')
    parser.add_argument('--new-save-path', required=True, help='The new save path to set.')

    args = parser.parse_args()

    process_files(args.files_path, args.new_save_path)

    print('The save paths of all `fastresume` files have been changed.')


if __name__ == '__main__':
    main()