Create convention_service.py

app/services/convention_service.py

@@ -0,0 +1,108 @@
+import logging
+import re
+import json
+from typing import Dict, Any, Optional
+import httpx
+from app.core.model_loader import llm_engine
+
+logger = logging.getLogger(__name__)
+
+class ConventionService:
+    def __init__(self):
+        self.cache: Dict[str, Dict[str, Any]] = {}
+
+    async def get_conventions(self, owner: str, repo: str) -> Dict[str, Any]:
+        key = f"{owner}/{repo}"
+        if key in self.cache:
+            return self.cache[key]
+
+        # 1. Fetch recent commits from GitHub
+        commits = await self._fetch_recent_commits(owner, repo, limit=40)
+        if not commits:
+            return self._default_conventions()
+
+        commit_text = "\n".join([c.get("message", "")[:200] for c in commits[:30]])
+
+        # 2. Ask the LLM to infer conventions
+        prompt = f"""Analyze these recent commit messages and return ONLY a valid JSON object with these keys:
+- "commit_style": either "conventional_commits" or "plain"
+- "branch_naming_pattern": a short regex or example pattern (e.g. "feat/.*", "feature/*")
+- "merge_policy": "squash", "merge", "rebase" or "unknown"
+- "exampleGoodCommit": one good example from the history
+
+Commit history:
+{commit_text}
+"""
+
+        try:
+            raw = llm_engine.generate(prompt, max_tokens=250)
+            conventions = self._parse_json(raw)
+        except Exception as e:
+            logger.warning(f"LLM convention inference failed: {e}")
+            conventions = self._default_conventions()
+
+        # Enrich
+        if commits:
+            conventions["exampleGoodCommit"] = commits[0].get("message", "")[:120]
+        conventions.setdefault("commit_style", "plain")
+        conventions.setdefault("branch_naming_pattern", "feature/*")
+        conventions.setdefault("merge_policy", "unknown")
+
+        self.cache[key] = conventions
+        return conventions
+
+    async def _fetch_recent_commits(self, owner: str, repo: str, limit: int = 30) -> list:
+        url = f"https://api.github.com/repos/{owner}/{repo}/commits"
+        params = {"per_page": min(limit, 100)}
+        headers = {"Accept": "application/vnd.github.v3+json"}
+
+        # Optional: add a GitHub token if you have one in env for higher rate limits
+        token = None  # os.getenv("GITHUB_TOKEN")
+        if token:
+            headers["Authorization"] = f"token {token}"
+
+        try:
+            async with httpx.AsyncClient(timeout=15.0) as client:
+                resp = await client.get(url, params=params, headers=headers)
+                if resp.status_code != 200:
+                    logger.warning(f"GitHub commits API {resp.status_code}")
+                    return []
+                data = resp.json()
+                return [
+                    {
+                        "message": c.get("commit", {}).get("message", ""),
+                        "sha": c.get("sha", ""),
+                        "author": c.get("commit", {}).get("author", {}).get("name", ""),
+                    }
+                    for c in data
+                ]
+        except Exception as e:
+            logger.error(f"Failed to fetch commits: {e}")
+            return []
+
+    def _parse_json(self, text: str) -> dict:
+        text = text.strip()
+        text = re.sub(r"```(?:json)?", "", text, flags=re.IGNORECASE).strip()
+        try:
+            return json.loads(text)
+        except json.JSONDecodeError:
+            start = text.find("{")
+            end = text.rfind("}")
+            if start != -1 and end > start:
+                try:
+                    return json.loads(text[start : end + 1])
+                except Exception:
+                    pass
+        return self._default_conventions()
+
+    def _default_conventions(self) -> dict:
+        return {
+            "commit_style": "plain",
+            "branch_naming_pattern": "feature/*",
+            "merge_policy": "unknown",
+            "exampleGoodCommit": "Update something",
+        }
+
+
+# Singleton-style instance
+convention_service = ConventionService()