from git import Repo, Remote

from app.config import get_settings


class GitService:
  def __init__(self):
    self._settings = get_settings()
    self._repo = Repo(self._settings.git.directory)
    self._origin: Remote = self._repo.remotes.origin

  def get_modified_compose(self) -> str | None:
    self._update()
    return self._diff()

  def _update(self):
    self._origin.pull()

  def _diff(self) -> str | None:
    diff = self._repo.head.commit.diff("HEAD~1")
    composes = [f for f in diff if f.a_path.endswith("docker-compose.yml")]
    match len(composes):
      case 0:
        return None
      case 1:
        return composes[0].a_path
      case _:
        raise Exception("Multiple compose files modified")