# analysis/failure_autopsy.py

class FailureAutopsy:

    def __init__(self, journal, critical_path=None):
        self.journal = journal
        self.critical_path = critical_path

    # -----------------------------
    # FIND FAILURE EVENTS
    # -----------------------------
    def find_failures(self):

        return [
            e for e in self.journal.events
            if e["type"] == "execution_result"
            and e["data"].get("state") == "failed"
        ]

    # -----------------------------
    # TRACE BACKWARD DEPENDENCY CHAIN
    # -----------------------------
    def trace_dependencies(self, action_name):

        trace = []
        visited = set()

        def walk(name):
            if name in visited:
                return
            visited.add(name)

            events = self.journal.trace_action(name)

            trace.append({
                "action": name,
                "events": events
            })

            for e in events:
                deps = e["data"].get("deps", [])
                for d in deps:
                    walk(d)

        walk(action_name)

        return trace

    # -----------------------------
    # GET LAST SCHEDULER DECISION
    # -----------------------------
    def last_decision(self, action_name):

        events = self.journal.trace_action(action_name)

        for e in reversed(events):
            if e["type"] == "schedule_decision":
                return e["data"]

        return None

    # -----------------------------
    # FULL AUTOPSY REPORT
    # -----------------------------
    def report(self, action_name):

        failures = self.find_failures()

        target_failure = None

        for f in failures:
            if f["data"].get("action") == action_name:
                target_failure = f
                break

        if not target_failure:
            return {
                "status": "no_failure_found",
                "action": action_name
            }

        deps_trace = self.trace_dependencies(action_name)
        last_sched = self.last_decision(action_name)

        return {
            "status": "failure_detected",
            "action": action_name,

            "failure_event": target_failure,

            "last_scheduler_decision": last_sched,

            "dependency_trace": deps_trace,

            "on_critical_path": (
                action_name in (self.critical_path or {}).get("score_map", {})
            )
        }