from git import Repo, Remote
from injectable import injectable

from app.config import GitConfig, get_settings


@injectable(singleton=True)
class GitService:
  def __init__(self):
    self._settings = get_settings()
    self._repo = self._check_preconditions(self._settings.git)
    if self._repo.head.ref.name != self._settings.git.branch:
      self._repo.git.checkout(self._settings.git.branch)
    self._origin: Remote = self._repo.remotes.origin

  @staticmethod
  def _check_preconditions(config: GitConfig) -> Repo:
    def clone():
      return Repo.clone_from(config.url, config.path, branch=config.branch)

    import os
    if not config.path.exists():
      return clone()
    if not (config.path / ".git").exists():
      os.rmdir(config.path)
      return clone()
    return Repo(config.path)

  def checkout(self, sha: str):
    self._origin.fetch()
    self._repo.git.checkout(sha)