"""
Detects the submodules in the Git repositories via "git show HEAD:.gitmodules" and adds them to the list of
repositories to be checked out. Works on bare repositories.
"""

import json
import re
import os
import urllib
from utils import constants as c, utils as u, archive as a

if __name__ == '__main__':

    regex_submodules = re.compile(r"url = (\S*)", re.MULTILINE)

    # get this folder
    root_folder = os.path.realpath(os.path.dirname(__file__))
    archive_folder = c.get_config('archive-folder')
    base_folder = os.path.join(archive_folder, 'git')

    # read archives.json
    text = u.read_text(os.path.join(root_folder, 'archives.json'))
    archives = json.loads(text)

    # loop over all git archives
    submodules = []
    for repo in archives['git']:
        print('process {}'.format(repo))
        git_folder = a.git_folder_name(repo)
        folder = os.path.join(archive_folder, 'git', git_folder)
        if not os.path.isdir(folder):
            print('Warning: folder {} does not exist'.format(git_folder))
            continue
        os.chdir(folder)
        try:
            content = u.subprocess_run(['git', 'show', 'HEAD:.gitmodules'], False)
        except:
            continue
        matches = regex_submodules.findall(content)
        # resolve relative urls
        matches = [urllib.parse.urljoin(repo, x) if x.startswith('..') else x for x in matches]
        submodules.extend(matches)

    # transform git://github.com to https://github.com
    for a, b in (('git://github.com', 'https://github.com'), ('git@github.com:', 'https://github.com/'), ('git+ssh://git@github.com', 'https://github.com')):
        submodules = [b + x[len(a):] if x.startswith(a) else x for x in submodules]

    # let all github repos end on ".git"
    submodules = [x + '.git' if 'github.com' in x and not x.endswith('.git') else x for x in submodules]

    # eliminate those which are duplicates and those which are in archives already
    submodules = set(submodules) - set(archives['git'])
    submodules = sorted(list(submodules))

    # TODO single dots are not yet resolved correctly, for example in https://github.com/henkboom/pax-britannica.git
    submodules = [x for x in submodules if not any([x.startswith(y) for y in ('.', 'git@')])]

    # store them
    print('found {} submodules'.format(len(submodules)))
    u.write_text(os.path.join(root_folder, 'archives.git-submodules.json'), json.dumps(submodules, indent=1))