Update app/services/danger_zone_service.py

app/services/danger_zone_service.py

@@ -2,10 +2,10 @@ import tempfile
 import shutil
 import logging
 from typing import List, Dict, Any
-from git import Repo
 
 logger = logging.getLogger(__name__)
 
+
 class DangerZoneService:
     @staticmethod
     def simulate_destructive_action(
@@ -19,21 +19,31 @@ class DangerZoneService:
         Clones the repo into an ephemeral temp directory, performs the action,
         and returns what would be lost. The temp dir is always cleaned up.
         """
+        # Lazy import so the whole app can still start even if git binary is missing
+        try:
+            from git import Repo
+        except ImportError as e:
+            logger.error(f"GitPython / git binary not available: {e}")
+            return {
+                "wouldLose": [],
+                "wouldRewrite": [],
+                "conflicts": [],
+                "summary": "Simulation unavailable: git binary is missing on the server.",
+                "error": "GIT_BINARY_MISSING"
+            }
+
         temp_dir = tempfile.mkdtemp(prefix="gitgud_danger_")
         repo_url = f"https://github.com/{owner}/{repo_name}.git"
 
         try:
             logger.info(f"Cloning {repo_url} into isolation dir for simulation...")
-            repo = Repo.clone_from(repo_url, temp_dir, depth=100)  # shallow is enough
+            repo = Repo.clone_from(repo_url, temp_dir, depth=100)
 
-            # Record reachable commits before the action
             before_shas = {c.hexsha for c in repo.iter_commits()}
 
-            # Apply the simulated operation
             if action in ("hard_reset", "force_push"):
                 repo.git.reset("--hard", target_ref)
             else:
-                # Future-proof: you can add rebase/squash later
                 repo.git.reset("--hard", target_ref)
 
             after_shas = {c.hexsha for c in repo.iter_commits()}
@@ -52,10 +62,12 @@ class DangerZoneService:
                 except Exception:
                     continue
 
-            # Optional: filter only commits that the client currently has locally
             if current_local_shas:
                 local_set = set(current_local_shas)
-                would_lose = [c for c in would_lose if any(c["id"] in s or s.startswith(c["id"]) for s in local_set)]
+                would_lose = [
+                    c for c in would_lose
+                    if any(c["id"] in s or s.startswith(c["id"]) for s in local_set)
+                ]
 
             summary = (
                 f"This {action.replace('_', ' ')} will eliminate "
@@ -64,7 +76,7 @@ class DangerZoneService:
 
             return {
                 "wouldLose": would_lose,
-                "wouldRewrite": [],          # extend later for rebase/squash
+                "wouldRewrite": [],
                 "conflicts": [],
                 "summary": summary,
             }
@@ -79,7 +91,6 @@ class DangerZoneService:
                 "error": str(e),
             }
         finally:
-            # Always clean the isolation directory
             try:
                 shutil.rmtree(temp_dir, ignore_errors=True)
             except Exception: