#!/usr/bin/python3

import os
import sys
import re
import shutil
from git import Repo
from zipfile import ZipFile

def create_backup_zip(directory_to_backup):
    parent_directory, directory_name = os.path.split(directory_to_backup)
    repository = Repo(directory_to_backup)
    git_handle = repository.git
    git_bundle_file_name = os.path.join(parent_directory, (directory_name + '.bundle'))
    git_handle.bundle('create', git_bundle_file_name, '--all')
    
    pattern_for_untracked_files_flag = re.compile(r'^\?+$')
    non_staged_files_raw_output = git_handle.status('--porcelain')
    if len(non_staged_files_raw_output.strip()) > 0:
        non_staged_files = list(filter(
            lambda x: pattern_for_untracked_files_flag.match(x[0]) is None,
            list(map(lambda _: _.strip().split(), non_staged_files_raw_output.split(os.linesep)))
        ))
    else:
        non_staged_files = []

    if len(non_staged_files) > 0:
        git_handle.stash('push', '-m', 'git-backup-stash')
    
    stashes = git_handle.stash('list').strip()
    stash_list = stashes.split(os.linesep)
    patch_files = []
    if (len(stashes) > 0) and (len(stash_list) > 0):
        patch_files_directory = os.path.join(parent_directory, 'patch-files')
        os.makedirs(patch_files_directory, exist_ok=True)
        for stash in stash_list:
            stash_name = stash.split(': ')[0]
            stash_branch_name = stash.split(': ')[1].split()[1]
            stash_message = ': '.join(stash.split(': ')[2:])
            
            patch_file_name = ':'.join([stash_name, stash_branch_name, stash_message]) + '.txt'
            patch_file_path = os.path.join(patch_files_directory, patch_file_name)
            patch_contents = git_handle.stash('show', '-p', stash_name)
            with open(patch_file_path, 'x') as f:
                f.write(patch_contents)
            patch_files.append(patch_file_path)
    
    zip_file_name = directory_name + '.zip'
    zip_file_path = os.path.join(parent_directory, zip_file_name)
    with ZipFile(zip_file_path, 'x') as z:
        z.write(git_bundle_file_name, arcname=os.path.split(git_bundle_file_name)[1])
        for patch_file in patch_files:
            z.write(patch_file, arcname=os.path.join('patch-files', os.path.split(patch_file)[1]))
    
    os.remove(git_bundle_file_name)
    if len(patch_files) > 0:
        shutil.rmtree(patch_files_directory)
    print(zip_file_name + ' created')

if __name__ == "__main__":
    arguments = sys.argv[1:]
    if len(arguments) == 0:
        directory_to_backup = os.getcwd()
    else:
        directory_to_backup = arguments[0]

    directory_to_backup = os.path.abspath(directory_to_backup)

    git_directory = os.path.join(directory_to_backup, '.git')
    if os.path.exists(git_directory) and os.path.isdir(git_directory):
        create_backup_zip(directory_to_backup)
    else:
        print(directory_to_backup + ' is not a git repository')