"""Decision outcome read for a submitter's own memos (INFD-WP-0010-T04, founder decision 2026-11-01).

State Hub's dispatch worker (STATE-WP-0096) pulls the human's answer to a memo it posed and
carries it to the hub; informed-decision holds no hub credential. This module builds the
``informed-decision.decision-outcome`` v1 record (state-hub
``docs/decision-services-alignment-answer.md`` section 5.2) from evidence already recorded here.

Read-only. Value-free: identifiers, digests, the verb, the deciding subject and its assurance.
No packet content, brief, note, reasons, display name or token ever leaves through this record.
It is a projection of evidence; nothing may execute on the strength of it.
"""
from datetime import datetime, timezone
import json

from .evidence import EventClass
from .store import EvidenceUnavailable

DISPOSITION = EventClass.DISPOSITION.value

KIND = "informed-decision.decision-outcome"
VERSION = 1
TERMINAL = ("accept", "decline")
MAX_RECORD = 8 * 1024


class OutcomeError(Exception):
    def __init__(self, status, code):
        self.status, self.code = status, code
        super().__init__(code)


def _assurance(db, disposition_id):
    """The assurance the PDP evaluated for this act, from its recorded policy observation."""
    row = db.execute("SELECT content FROM evidence WHERE class=? "
                     "AND json_extract(envelope,'$.data.disposition_id')=? ORDER BY rowid LIMIT 1",
                     (DISPOSITION, disposition_id)).fetchone()
    policy_id = json.loads(row["content"]).get("policy_observation_id") if row else None
    observation = db.execute("SELECT request,outcome FROM policy_observations WHERE id=?",
                             (policy_id,)).fetchone() if policy_id else None
    if observation is None or observation["outcome"] != "allow":
        return None
    attributes = json.loads(observation["request"]).get("subject", {}).get("attributes", {})
    assurance = attributes.get("assurance")
    if (not isinstance(assurance, dict) or not isinstance(assurance.get("level"), str)
            or type(assurance.get("at")) is not int or assurance["at"] <= 0):
        return None
    auth_time = datetime.fromtimestamp(assurance["at"], timezone.utc).isoformat(timespec="seconds")
    return {"aal": assurance["level"], "auth_time": auth_time.replace("+00:00", "Z")}


def outcome_for(store, submitter_id, memo_id, *, issuer):
    """(status, body) for one memo. 404 hides memos this submitter did not pose."""
    with store._connection() as db:
        intake = db.execute("SELECT metadata FROM intake_ledger WHERE submitter=? AND memo_id=? AND state='ready'",
                            (submitter_id, memo_id)).fetchone()
        if intake is None:
            raise OutcomeError(404, "memo_not_found")
        metadata = json.loads(intake["metadata"])
        serves = metadata.get("serves")
        if metadata.get("profile") == "present_existing" or not serves or serves.get("resolves") != "on-answer":
            raise OutcomeError(409, "memo_does_not_resolve")
        # The first terminal human answer on any revision is the answer (resolves: on-answer).
        rows = db.execute("SELECT d.id,d.body FROM dispositions d JOIN presentations p ON p.id=d.presentation_id "
                          "WHERE p.memo_id=? ORDER BY d.rowid", (memo_id,)).fetchall()
        answer = None
        for row in rows:
            body = json.loads(row["body"])
            if body["verb"] in TERMINAL and body["actor"]["kind"] == "person":
                answer = body
                break
        if answer is None:
            return 202, {"kind": KIND, "version": VERSION, "memo_id": memo_id, "status": "pending"}
        presentation = json.loads(db.execute("SELECT body FROM presentations WHERE id=?",
                                             (answer["presentation_id"],)).fetchone()["body"])
        assurance = _assurance(db, answer["id"])
        if assurance is None:
            raise OutcomeError(409, "assurance_unrecorded")
        record = {"kind": KIND, "version": VERSION, "status": "decided",
                  "hub_decision_id": serves["hub_decision_id"],
                  "memo_id": memo_id, "memo_revision": answer["memo_version"],
                  "verb": answer["verb"],
                  "subject": {"issuer": issuer, "sub": answer["actor"]["sub"]},
                  "assurance": assurance, "decided_at": answer["at"],
                  "view_hash": presentation["view_hash"], "presentation_id": answer["presentation_id"],
                  "approval_id": answer.get("approval_id")}
        if answer["verb"] == "accept":
            submission = db.execute("SELECT state,approved_at FROM submissions WHERE disposition_id=?",
                                    (answer["id"],)).fetchone()
            if submission is None or submission["state"] in ("prepared", "in_flight"):
                # The human accepted; the approval entry is not yet confirmed. Not an answer yet.
                return 202, {"kind": KIND, "version": VERSION, "memo_id": memo_id, "status": "pending"}
            if submission["state"] != "confirmed":
                raise OutcomeError(409, "approval_entry_unresolved")
            # approval-engine entries carry no id; (approval_id, subject, approved_at) is the correlation.
            record["approval_entry"] = {"approved_at": submission["approved_at"]}
        audit = db.execute("SELECT o.receiver_reference FROM evidence e JOIN outbox o ON o.id=e.id "
                           "WHERE e.class=? AND json_extract(e.envelope,'$.data.disposition_id')=? "
                           "AND o.state='delivered' ORDER BY e.rowid LIMIT 1", (DISPOSITION, answer["id"])).fetchone()
        if audit is not None and audit["receiver_reference"]:
            record["audit_ref"] = audit["receiver_reference"]
    if len(json.dumps(record).encode()) > MAX_RECORD:
        raise EvidenceUnavailable("outcome record exceeds its bound")
    return 200, record