hs-backup.py

# Author: Areeb Beigh
# Created: 28th July 2016

"""
Automatically creates a backup of all the files in the backup location. Both,
the files and the backup location are specified in the configuration
"""

#############################################################################
#    Copyright (C) 2016  Areeb Beigh <areebbeigh@gmail.com>                 #
#                                                                           #
#    This program is free software: you can redistribute it and/or modify   #
#    it under the terms of the GNU General Public License as published by   #
#    the Free Software Foundation, either version 3 of the License, or      #
#    (at your option) any later version.                                    #
#                                                                           #
#    This program is distributed in the hope that it will be useful,        #
#    but WITHOUT ANY WARRANTY; without even the implied warranty of         #
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the          #
#    GNU General Public License for more details.                           #
#                                                                           #
#    You should have received a copy of the GNU General Public License      #
#    along with this program.  If not, see <http://www.gnu.org/licenses/>.  #
#############################################################################

# Python imports
import argparse
import os
import sys

# Local imports
from src import help
from src.errors import *
from src.initialize import Initialize
from src.configreader import ConfigReader

initializer = Initialize()
config_file = initializer.config_file
config_reader = ConfigReader(config_file)


def main():
    parser = argparse.ArgumentParser(add_help=True, allow_abbrev=False)
    group = parser.add_mutually_exclusive_group()
    group.add_argument('-d',
                       '--directory',
                       metavar='DIR',
                       nargs=1,
                       help='backup location')
    group.add_argument('-dh',
                       '--dhelp',
                       action='store_true',
                       help='displays detailed help for this hacker-script')
    args = parser.parse_args()

    if args.dhelp:
        cmd = sys.argv[0].partition(".")[0]
        help.display_help(cmd)
        return

    if args.directory:
        execute(args.directory[0])
    else:
        execute()


def is_valid_config(purge, retries, backup_location, files):
    """Takes all options in the "hs-backup" section as parameters and returns
    True if they are valid, else raises a ConfigError"""

    try:
        purge = int(purge)
        if not (purge == 0 or purge == 1):
            raise ValueError
    except ValueError:
        raise ConfigError("Value of purge must be either 0 or 1")

    try:
        retries = int(retries)
        if not (retries > 0):
            raise ValueError
    except ValueError:
        raise ConfigError("Value of retries must be an integer greater than 0")

    if not os.path.isdir(backup_location):
        raise ConfigError("Value of backup_location must be a valid directory)")

    for file in files:
        if not os.path.isdir(file):
            raise ConfigError("{} is not a directory".format(file))

    return True


def execute(backup_location=None):
    if not backup_location:
        purge, retries, backup_location, directories = config_reader.read_config("hs-backup")
    else:
        purge, retries, dummy, directories = config_reader.read_config("hs-backup")

    print(" Backing up all files to", backup_location)
    log_file = "backup_log.txt"
    max_log_size = 1 * 1024 * 1024  # Default 1 MB

    if is_valid_config(purge, retries, backup_location, directories):
        purge = int(purge)
        retries = int(retries)

        for file in directories:
            backup = os.path.join(backup_location, os.path.basename(file))
            if not os.path.exists(backup):
                os.makedirs(backup)
            src = file
            dst = backup
            print(" " + file, backup, sep=" -> ", end="")
            # Removes the log file if it gets larger than max_log_size (default 1 MB)
            try:
                if os.path.getsize(log_file) > max_log_size:
                    os.remove(log_file)
            except FileNotFoundError:
                pass

            if purge == 0:
                command = "ROBOCOPY /LOG+:\"{0}\" /V /E /R:{1} \"{2}\" \"{3}\"".format(
                    log_file,
                    retries,
                    src,
                    dst)
            else:
                command = "ROBOCOPY /LOG+:\"{0}\" /V /E /PURGE /R:{1} \"{2}\" \"{3}\"".format(
                    log_file,
                    retries,
                    src,
                    dst)

            os.system(command)
            print()

if __name__ == "__main__":
    main()