feat(P5): sync batch transition with P5.3-P5.6 guards — auth, assignee, comment, permission, deps, auto-complete

app/api/routers/tasks.py

@@ -451,17 +451,24 @@ def list_all_tags(project_id: int = None, db: Session = Depends(get_db)):
 
 # ---- Batch ----
 
-class BatchTransition(BaseModel):
-    task_ids: List[int]
-    new_status: str
-
 class BatchAssign(BaseModel):
     task_ids: List[int]
     assignee_id: int
 
 
+class BatchTransitionBody(BaseModel):
+    task_ids: List[int]
+    new_status: str
+    comment: Optional[str] = None
+
+
 @router.post("/tasks/batch/transition")
-def batch_transition(data: BatchTransition, bg: BackgroundTasks, db: Session = Depends(get_db)):
+def batch_transition(
+    data: BatchTransitionBody,
+    bg: BackgroundTasks,
+    db: Session = Depends(get_db),
+    current_user: models.User = Depends(get_current_user_or_apikey),
+):
     valid_statuses = [s.value for s in TaskStatus]
     if data.new_status not in valid_statuses:
         raise HTTPException(status_code=400, detail="Invalid status")
@@ -469,22 +476,106 @@ def batch_transition(data: BatchTransition, bg: BackgroundTasks, db: Session = D
     skipped = []
     for task_id in data.task_ids:
         task = db.query(Task).filter(Task.id == task_id).first()
-        if task:
-            old_status = task.status.value if hasattr(task.status, 'value') else task.status
-            allowed = VALID_TRANSITIONS.get(old_status, set())
-            if data.new_status not in allowed:
+        if not task:
+            skipped.append({"id": task_id, "title": None, "old": None,
+                            "reason": "Task not found"})
+            continue
+        old_status = task.status.value if hasattr(task.status, 'value') else task.status
+        # P5.1: state-machine check
+        allowed = VALID_TRANSITIONS.get(old_status, set())
+        if data.new_status not in allowed:
+            skipped.append({"id": task.id, "title": task.title, "old": old_status,
+                            "reason": f"Cannot transition from '{old_status}' to '{data.new_status}'"})
+            continue
+
+        # P5.2: pending → open requires milestone undergoing + task deps
+        if old_status == "pending" and data.new_status == "open":
+            milestone = db.query(Milestone).filter(Milestone.id == task.milestone_id).first()
+            if milestone:
+                ms_status = milestone.status.value if hasattr(milestone.status, 'value') else milestone.status
+                if ms_status != "undergoing":
+                    skipped.append({"id": task.id, "title": task.title, "old": old_status,
+                                    "reason": f"Milestone is '{ms_status}', must be 'undergoing'"})
+                    continue
+            dep_result = check_task_deps(db, task.depend_on)
+            if not dep_result.ok:
                 skipped.append({"id": task.id, "title": task.title, "old": old_status,
-                                "reason": f"Cannot transition from '{old_status}' to '{data.new_status}'"})
+                                "reason": dep_result.reason})
                 continue
-            if data.new_status == "undergoing" and not task.started_on:
-                task.started_on = datetime.utcnow()
-            if data.new_status in ("closed", "completed") and not task.finished_on:
-                task.finished_on = datetime.utcnow()
-            if data.new_status == "open" and old_status in ("completed", "closed"):
-                task.finished_on = None
-            task.status = data.new_status
-            updated.append({"id": task.id, "title": task.title, "old": old_status, "new": data.new_status})
+
+        # P5.3: open → undergoing requires assignee == current_user
+        if old_status == "open" and data.new_status == "undergoing":
+            if not task.assignee_id:
+                skipped.append({"id": task.id, "title": task.title, "old": old_status,
+                                "reason": "Assignee must be set before starting"})
+                continue
+            if current_user.id != task.assignee_id:
+                skipped.append({"id": task.id, "title": task.title, "old": old_status,
+                                "reason": "Only the assigned user can start this task"})
+                continue
+
+        # P5.4: undergoing → completed requires comment + assignee check
+        if old_status == "undergoing" and data.new_status == "completed":
+            comment_text = data.comment
+            if not comment_text or not comment_text.strip():
+                skipped.append({"id": task.id, "title": task.title, "old": old_status,
+                                "reason": "A completion comment is required"})
+                continue
+            if task.assignee_id and current_user.id != task.assignee_id:
+                skipped.append({"id": task.id, "title": task.title, "old": old_status,
+                                "reason": "Only the assigned user can complete this task"})
+                continue
+
+        # P5.5: close requires permission
+        if data.new_status == "closed":
+            try:
+                check_permission(db, current_user.id, task.project_id, "task.close")
+            except HTTPException:
+                skipped.append({"id": task.id, "title": task.title, "old": old_status,
+                                "reason": "Missing 'task.close' permission"})
+                continue
+
+        # P5.6: reopen requires permission
+        if data.new_status == "open" and old_status in ("completed", "closed"):
+            perm = "task.reopen_completed" if old_status == "completed" else "task.reopen_closed"
+            try:
+                check_permission(db, current_user.id, task.project_id, perm)
+            except HTTPException:
+                skipped.append({"id": task.id, "title": task.title, "old": old_status,
+                                "reason": f"Missing '{perm}' permission"})
+                continue
+            task.finished_on = None
+
+        if data.new_status == "undergoing" and not task.started_on:
+            task.started_on = datetime.utcnow()
+        if data.new_status in ("closed", "completed") and not task.finished_on:
+            task.finished_on = datetime.utcnow()
+        task.status = data.new_status
+        updated.append({"id": task.id, "title": task.title, "old": old_status, "new": data.new_status})
+
+        # Activity log per task
+        log_activity(db, f"task.transition.{data.new_status}", "task", task.id, current_user.id,
+                     {"old_status": old_status, "new_status": data.new_status})
+
+        # P5.4: auto-create completion comment
+        if old_status == "undergoing" and data.new_status == "completed" and data.comment:
+            db_comment = models.Comment(
+                content=data.comment.strip(),
+                task_id=task.id,
+                author_id=current_user.id,
+            )
+            db.add(db_comment)
+
     db.commit()
+
+    # P3.5: auto-complete milestone for any completed task
+    for u in updated:
+        if u["new"] == "completed":
+            t = db.query(Task).filter(Task.id == u["id"]).first()
+            if t:
+                from app.api.routers.milestone_actions import try_auto_complete_milestone
+                try_auto_complete_milestone(db, t, user_id=current_user.id)
+
     for u in updated:
         event = "task.closed" if data.new_status == "closed" else "task.updated"
         bg.add_task(fire_webhooks_sync, event, u, None, db)