Files
Gitea-Tools/role_session_router.py

247 lines
8.0 KiB
Python

"""Pre-task role/session router (#206).
Classifies a declared task type against the active MCP profile/session and
returns a route result before any downstream mutation tools run.
"""
from __future__ import annotations
import os
ROUTE_ALLOWED = "allowed_current_session"
ROUTE_WRONG_ROLE = "wrong_role_stop"
ROUTE_TO_AUTHOR = "route_to_author_session"
ROUTE_TO_REVIEWER = "route_to_reviewer_session"
ROUTE_AMBIGUOUS = "ambiguous_task_stop"
ROUTE_INFRA_STOP = "infra_stop"
REVIEWER_TASKS = frozenset({
"review_pr",
"merge_pr",
"blind_pr_queue_review",
"request_changes_pr",
"approve_pr",
})
AUTHOR_TASKS = frozenset({
"create_issue",
"comment_issue",
"close_issue",
"claim_issue",
"create_branch",
"push_branch",
"create_pr",
"comment_pr",
"address_pr_change_requests",
"delete_branch",
})
TASK_REQUIRED_ROLE = {
"create_issue": "author",
"comment_issue": "author",
"close_issue": "author",
"claim_issue": "author",
"create_branch": "author",
"push_branch": "author",
"create_pr": "author",
"comment_pr": "author",
"address_pr_change_requests": "author",
"delete_branch": "author",
"review_pr": "reviewer",
"merge_pr": "reviewer",
"blind_pr_queue_review": "reviewer",
"request_changes_pr": "reviewer",
"approve_pr": "reviewer",
}
WRONG_ROLE_REVIEWER_MSG = (
"Wrong role/session for reviewer task. Launch reviewer MCP namespace."
)
_session_last_route: dict | None = None
def required_role_for_task(task_type: str) -> str | None:
return TASK_REQUIRED_ROLE.get((task_type or "").strip())
def route_task_session(
task_type: str,
*,
active_profile: str,
active_role_kind: str,
allowed_in_current_session: bool,
runtime_switching_supported: bool = False,
) -> dict:
"""Return routing verdict for *task_type* under the active session."""
task_type = (task_type or "").strip()
required_role = required_role_for_task(task_type)
if required_role is None:
result = {
"task_type": task_type,
"required_role": None,
"active_role": active_role_kind,
"active_profile": active_profile,
"route_result": ROUTE_AMBIGUOUS,
"downstream_allowed": False,
"reasons": [
f"unknown task type '{task_type}'; cannot route session "
"(fail closed)"
],
"message": (
"Ambiguous task type; relaunch with an explicit task before "
"any tool use."
),
}
_record_route(result)
return result
if required_role == "reviewer" and check_mid_merge():
result = {
"task_type": task_type,
"required_role": required_role,
"active_role": active_role_kind,
"active_profile": active_profile,
"route_result": ROUTE_INFRA_STOP,
"downstream_allowed": False,
"reasons": [
"infra_stop: Unresolved merge conflict or mid-merge state detected in MCP runtime source.",
"Please resolve all conflicts manually, finish/abort the merge, restart the MCP server, and retry."
],
"message": "infra_stop: Unresolved merge conflict or mid-merge state detected in MCP runtime source.",
}
_record_route(result)
return result
if allowed_in_current_session:
result = {
"task_type": task_type,
"required_role": required_role,
"active_role": active_role_kind,
"active_profile": active_profile,
"route_result": ROUTE_ALLOWED,
"downstream_allowed": True,
"reasons": [],
"message": "Task role matches active session; proceed.",
}
_record_route(result)
return result
if required_role == "reviewer":
result = {
"task_type": task_type,
"required_role": required_role,
"active_role": active_role_kind,
"active_profile": active_profile,
"route_result": ROUTE_WRONG_ROLE,
"downstream_allowed": False,
"reasons": [
WRONG_ROLE_REVIEWER_MSG,
"Reviewer tasks cannot run in author-bound sessions.",
"Static-profile mode does not permit in-place role switching.",
],
"message": WRONG_ROLE_REVIEWER_MSG,
"runtime_switching_supported": runtime_switching_supported,
"profile_switch_blocked": not runtime_switching_supported,
}
_record_route(result)
return result
if required_role == "author":
route = ROUTE_TO_AUTHOR
message = (
"Wrong role/session for author task. Launch author MCP namespace."
)
result = {
"task_type": task_type,
"required_role": required_role,
"active_role": active_role_kind,
"active_profile": active_profile,
"route_result": route,
"downstream_allowed": False,
"reasons": [message],
"message": message,
"runtime_switching_supported": runtime_switching_supported,
"profile_switch_blocked": not runtime_switching_supported,
}
_record_route(result)
return result
result = {
"task_type": task_type,
"required_role": required_role,
"active_role": active_role_kind,
"active_profile": active_profile,
"route_result": ROUTE_AMBIGUOUS,
"downstream_allowed": False,
"reasons": ["unable to classify task role (fail closed)"],
"message": "Ambiguous task type; stop before any mutation.",
}
_record_route(result)
return result
def last_route() -> dict | None:
return _session_last_route
def clear_route_state():
global _session_last_route
_session_last_route = None
def _record_route(result: dict):
global _session_last_route
_session_last_route = dict(result)
def check_author_mutation_after_reviewer_stop(mutation_task: str) -> tuple[bool, list[str]]:
"""Block author-side fallback after a reviewer wrong_role_stop (#206)."""
last = _session_last_route
if not last:
return True, []
if last.get("route_result") != ROUTE_WRONG_ROLE:
return True, []
if last.get("required_role") != "reviewer":
return True, []
if mutation_task in AUTHOR_TASKS:
return False, [
WRONG_ROLE_REVIEWER_MSG,
"Author-side mutations are blocked after a reviewer-task "
"wrong_role_stop unless the operator explicitly changes the "
"task and relaunches an author MCP session.",
f"Attempted fallback mutation: {mutation_task}",
]
return True, []
def check_mid_merge() -> bool:
"""Return True if the repository is mid-merge, mid-rebase, or has conflict markers."""
project_root = os.path.dirname(os.path.abspath(__file__))
git_dir = os.path.join(project_root, ".git")
if os.path.exists(git_dir):
if (os.path.exists(os.path.join(git_dir, "MERGE_HEAD"))
or os.path.exists(os.path.join(git_dir, "rebase-merge"))
or os.path.exists(os.path.join(git_dir, "rebase-apply"))):
return True
# Scan python files for conflict markers
conflict_patterns = [
b"<" * 7 + b" ",
b"=" * 7 + b"\n",
b"=" * 7 + b"\r\n",
b">" * 7 + b" "
]
for root, dirs, files in os.walk(project_root):
if any(p in root for p in ("venv", ".git", ".pytest_cache", "branches")):
continue
for file in files:
if file.endswith(".py"):
file_path = os.path.join(root, file)
try:
with open(file_path, "rb") as f:
content = f.read()
if any(pattern in content for pattern in conflict_patterns):
return True
except Exception:
pass
return False