Auto Backup

""" Simple backup script which just creates the root structure in an other
folder and syncs everything which recursively lies within one of the source
folders. For files bigger than a threshold they are first gziped."""
# pillalamarri.in - Python Projects
import argparse
import gzip
import os
import shutil
import sys
import threading


def parse_input():
    """
    Argument Parser function, for parsing CLI.
    Returns: parse_args()

    """
    parser = argparse.ArgumentParser()
    parser.add_argument('-t',
                        '--target',
                        nargs=1,
                        required=True,
                        help='Target Backup folder')
    parser.add_argument('-s',
                        '--source',
                        nargs='+',
                        required=True,
                        help='Source Files to be added')
    parser.add_argument('-c',
                        '--compress',
                        nargs=1,
                        type=int,
                        help='Gzip threshold in bytes, Deafault 1024KB',
                        default=[1024000])
    # Default Threshold is 1024KB

    # Help is triggered when there is no Input Provided
    if len(sys.argv) == 1:
        parser.print_help()
        sys.exit()

    return parser.parse_args()


def size_if_newer(source, target):
    """
    If there is a difference in file size, this function reports the difference.
    Args:
        source: Source Path
        target: Target for ZIP file

    Returns: The Size difference

    """
    src_stat = os.stat(source)
    try:
        target_ts = os.stat(target).st_mtime
    except FileNotFoundError:
        try:
            target_ts = os.stat(target + '.gz').st_mtime
        except FileNotFoundError:
            target_ts = 0

    # The time difference of one second is necessary since subsecond accuracy
    # of os.st_mtime is striped by copy2
    return src_stat.st_size if (src_stat.st_mtime - target_ts > 1) else False


def threaded_sync_file(source, target, compress):
    """
    Multithreading for Synced files.
    Args:
        source: Source Path
        target: Target for ZIP file
        compress: The compression threshold

    Returns: The threads

    """
    size = size_if_newer(source, target)

    if size:
        thread = threading.Thread(target=transfer_file,
                                  args=(source, target, size > compress))
        thread.start()
        return thread


def sync_file(source, target, compress):
    """
    Synchronizing  files
    Args:
        source: Source Path
        target: Target for ZIP file
        compress: The compression threshold
    """
    size = size_if_newer(source, target)

    if size:
        transfer_file(source, target, size > compress)


def transfer_file(source, target, compress):
    """
    Transferring  files
    Args:
        source: Source Path
        target: Target for ZIP file
        compress: The compression threshold
    """
    try:
        if compress:
            with gzip.open(target + '.gz', 'wb') as target_fid:
                with open(source, 'rb') as source_fid:
                    target_fid.writelines(source_fid)
            print('Compress {}'.format(source))
        else:
            shutil.copy2(source, target)
            print('Copy {}'.format(source))
    except FileNotFoundError:
        os.makedirs(os.path.dirname(target))
        transfer_file(source, target, compress)


def sync_root(root, arg):
    """
    Synchronize Root with Target

    """
    target = arg.target[0]
    compress = arg.compress[0]
    threads = []

    for path, _, files in os.walk(root):
        for source in files:
            source = path + '/' + source
            threads.append(
                threaded_sync_file(source, target + source, compress))
    #            sync_file(source, target + source, compress)
    for thread in threads:
        thread.join()


if __name__ == '__main__':
    arg = parse_input()
    print('------------------------- Start copy -------------------------')
    print('______________________________________________________________')
    for root in arg.source:
        sync_root(root, arg)
    print('______________________________________________________________')
    print('------------------------- Done Done! -------------------------')
"""
Example Usage-
> python Auto_Backup.py --target ./Backup_Folder --source ./Source_Folder
"""
# pillalamarri.in - Python Projects