Auto install git-theta when doing a track as people often forget this step (#232)

* When someone runs git theta track or git theta add, make sure they have
git theta installed.

* move to loggers

Author: blester125

git_theta/git_utils.py

@@ -33,6 +33,13 @@
 # files. Defined as a variable in case extra functionality ever requires more
 # attributes.
 THETA_ATTRIBUTES = ("filter", "merge", "diff")
+THETA_CONFIG_KEYS = (
+    "filter.theta.clean=",
+    "filter.theta.smudge=",
+    "merge.theta.name=",
+    "merge.theta.driver=",
+    "diff.theta.command=",
+)
 
 
 def get_git_repo():
@@ -409,6 +416,26 @@ def is_git_lfs_installed():
         return False
 
 
+def is_git_theta_installed(
+    repo: Optional = None, git_theta_config_keys: Sequence[str] = THETA_CONFIG_KEYS
+) -> bool:
+    """Check if git-theta is installed.
+
+    By checking `git config --list` we see all configuration options reguardless
+    of if they setup git-theta up in ~/.gitconfig, ${repo}/.git/config, etc.
+
+    Note:
+      This check requires you to be in the repo, but this is fine for our use
+      cases.
+    """
+    repo = get_git_repo() if repo is None else repo
+    config = repo.git.config("--list")
+    for config_key in git_theta_config_keys:
+        if config_key not in config:
+            return False
+    return True
+
+
 def make_blob(repo, contents: str, path: str):
     contents = contents.encode("utf-8")
     mode = 33188  # The mode magic number used for blobs in git python

git_theta/scripts/git_theta.py

@@ -120,8 +120,9 @@ def install(args):
     """
     # check if git-lfs is installed and abort if not
     if not git_utils.is_git_lfs_installed():
-        print(
-            f"git-theta depends on git-lfs and it does not appear to be installed. See installation directions at https://github.com/r-three/git-theta/blob/main/README.md#git-lfs-installation"
+        logger = logging.getLogger("git_theta")
+        logger.error(
+            "git-theta depends on git-lfs and it does not appear to be installed. See installation directions at https://github.com/r-three/git-theta/blob/main/README.md#git-lfs-installation"
         )
         sys.exit(1)
 
@@ -142,6 +143,12 @@ def track(args):
     Track a particular model checkpoint file with git-theta
     """
     repo = git_utils.get_git_repo()
+    if not git_utils.is_git_theta_installed():
+        logger = logging.getLogger("git_theta")
+        logger.error(
+            "You are trying to track a file with git-theta, but git-theta is not installed, please run `git theta install`."
+        )
+        sys.exit(1)
     model_path = git_utils.get_relative_path_from_root(repo, args.file)
 
     gitattributes_file = git_utils.get_gitattributes_file(repo)
@@ -155,6 +162,12 @@ def track(args):
 
 def add(args, unparsed_args):
     repo = git_utils.get_git_repo()
+    if not git_utils.is_git_theta_installed():
+        logger = logging.getLogger("git_theta")
+        logger.error(
+            "You are trying to add a file using git-theta, but git-theta is not installed, please run `git theta install`."
+        )
+        sys.exit(1)
     env_vars = {
         "GIT_THETA_UPDATE_TYPE": args.update_type,
         "GIT_THETA_UPDATE_DATA_PATH": args.update_data,