"""
Autopsy API — post-hoc root cause analysis for failed actions.
"""

from fastapi import APIRouter

from backend.analysis.failure_autopsy import FailureAutopsy
from backend.analysis.timeline_store import STORE as TIMELINE_STORE
from backend.api.replay import SESSION_DB

router = APIRouter(prefix="/autopsy", tags=["autopsy"])


# -----------------------------
# RUN AUTOPSY
# -----------------------------
@router.get("/{session_id}/{action}")
def run_autopsy(session_id: str, action: str):
    """Run a failure autopsy for `action` against the replay session `session_id`."""

    # Try to fetch events for this session from SessionDB
    events = SESSION_DB.get_replay_stream(session_id)

    if not events:
        # Fallback: use the live timeline store
        journal = TIMELINE_STORE
    else:
        # Wrap the session's event list in a tiny shim that quacks like
        # the TimelineStore API the FailureAutopsy expects.
        journal = _JournalShim(events)

    autopsy = FailureAutopsy(journal)
    return autopsy.report(action)


# -----------------------------
# Legacy wrapper for api.py facade
# -----------------------------
def autopsy_endpoint(session_id, action=None):
    """Legacy entrypoint — caller passed only session_id; we look up
    failures across all known sessions."""
    events = SESSION_DB.get_replay_stream(session_id)
    if not events:
        return {"error": "session not found"}
    journal = _JournalShim(events)
    autopsy = FailureAutopsy(journal)
    # If no action given, report on the first failure we find
    if action is None:
        failures = autopsy.find_failures()
        if not failures:
            return {"status": "no_failures_in_session", "session_id": session_id}
        action = failures[0].get("data", failures[0]).get("action")
        if not action:
            return {"status": "no_actionable_failure", "session_id": session_id}
    return autopsy.report(action)


class _JournalShim:
    """Minimal adapter that lets FailureAutopsy work against a plain list
    of events (from a replay session) instead of a full TimelineStore."""

    def __init__(self, events):
        self.events = events

    def find_failures(self):
        return [
            e for e in self.events
            if e.get("type") in ("failure", "task_update", "pipeline_update")
            and (e.get("state") == "failed" or e.get("data", {}).get("state") == "failed")
        ]

    def trace_action(self, action_name):
        return [
            e for e in self.events
            if (e.get("action") == action_name) or (e.get("data", {}).get("action") == action_name)
        ]