"""Transport-neutral plan-decision normalizer (the ONE safe mapping).

THE LOAD-BEARING B3 SAFETY MAPPING, in a single transport-neutral home so BOTH
the graph (:func:`agent_team.graph._parse_decision`) and the transports (the
Slack listener / adapter) call ONE function rather than each re-deriving the
allowlist. Keeping it here avoids a graph→transport import: the graph is the
universal chokepoint and depends only on this leaf module, and the Slack adapter
keeps a thin :func:`~agent_team.transport.slack_adapter.map_plan_decision`
wrapper that delegates here.

A plan-gate decision can be WRITTEN by several paths — the Slack listener (which
pre-maps), but ALSO the operator CLI (``answer_on_behalf`` → ``answer_question``,
RAW) and ``Coordinator.submit_answer`` (RAW). On resume, whatever was stored
reaches the graph's decision parser. Previously the graph mapped any UNRECOGNIZED
verb to ``abandon`` → terminal FAILED, so an operator (or any non-listener
writer) answering change-request prose silently FAILED the task. Centralizing the
safe mapping here and calling it AT THE GRAPH makes every writer safe.

``allow_abandon`` is the LOGIC-05 distinction. A destructive verb
(``cancel``/``stop``/``kill``/``reject``/``abandon``) is honoured as an abandon
ONLY when the caller vouches that the input is a *confirmed* destructive intent
— i.e. the Slack Block Kit "Abandon" button, which is guarded by a confirm
dialog. A bare destructive verb typed as FREE TEXT in a thread (``allow_abandon
=False``) must NOT terminally fail the task with no confirmation; it normalizes
to ``request_changes`` carrying the full reply as notes.
"""

from __future__ import annotations

from typing import Any

__all__ = [
    "ABANDON_VERBS",
    "APPROVE_VERBS",
    "VALID_DECISIONS",
    "normalize_decision",
]

# Approve-allowlist: a reply that is exactly one of these (case/whitespace
# insensitive) is an approval; anything else is never an accidental approve.
APPROVE_VERBS: frozenset[str] = frozenset(
    {"approve", "approved", "yes", "ok", "lgtm", "ship"}
)

# Abandon-allowlist (DESTRUCTIVE). A bare verb here abandons the task →
# terminal FAILED, BUT ONLY when ``allow_abandon=True`` — i.e. the input is a
# CONFIRMED destructive intent (the confirm-dialog-guarded Block Kit Abandon
# button, or the graph chokepoint honouring an explicit prior decision). The
# SAME verbs typed as FREE TEXT (``allow_abandon=False``) are NOT honoured as a
# destructive abandon (LOGIC-05): they fall through to ``request_changes`` so a
# casually-typed "cancel" never terminally fails a task with no confirmation.
ABANDON_VERBS: frozenset[str] = frozenset(
    {"abandon", "reject", "cancel", "stop", "kill"}
)

# The three valid structured decisions a normalized result can carry.
VALID_DECISIONS: frozenset[str] = frozenset({"approve", "request_changes", "abandon"})


def normalize_decision(raw: Any, *, allow_abandon: bool) -> dict[str, str]:
    """Map a raw plan-gate reply to a structured ``{"decision","notes"}`` dict.

    The single transport-neutral normalizer. Behavior:

    * **Idempotent** — if ``raw`` is already a dict carrying a valid
      ``"decision"`` in :data:`VALID_DECISIONS`, return it normalized (decision
      lowercased/stripped, notes coerced to ``str``) WITHOUT re-mapping. This
      lets the graph chokepoint accept an already-decided value (e.g. the
      listener's pre-mapped ``request_changes`` with notes) unchanged, while a
      RAW string from another writer is mapped below. An ``abandon`` dict is
      honoured here regardless of ``allow_abandon`` because it is an explicit,
      already-formed decision, not raw free text.
    * **String** — normalize (``str`` → strip → lowercase):
        * in :data:`APPROVE_VERBS` → ``approve`` (notes ``""``);
        * if ``allow_abandon`` AND in :data:`ABANDON_VERBS` → ``abandon``
          (notes ``""``);
        * **everything else** — prose, empty/whitespace, AND abandon-verbs when
          ``allow_abandon=False`` — → ``request_changes`` carrying the FULL
          ORIGINAL reply (original casing preserved) as ``notes``. This is the
          safe default: arbitrary input is a change request, never an accidental
          approve or (unconfirmed) abandon.

    The reply is opaque DATA throughout — never executed or interpreted beyond
    this verb match.
    """
    # Idempotency: an already-formed decision dict passes through normalized.
    if isinstance(raw, dict):
        decision = str(raw.get("decision", "") or "").strip().lower()
        if decision in VALID_DECISIONS:
            return {
                "decision": decision,
                "notes": str(raw.get("notes", "") or ""),
            }
        # A dict WITHOUT a recognized decision falls through to the string path
        # using its stringified form (defensive; should not occur in practice).

    original = "" if raw is None else str(raw)
    verb = original.strip().lower()
    if verb in APPROVE_VERBS:
        return {"decision": "approve", "notes": ""}
    if allow_abandon and verb in ABANDON_VERBS:
        return {"decision": "abandon", "notes": ""}
    # Everything else → request_changes, carrying the full ORIGINAL reply (not
    # the lowercased form) so the notes preserve the human's exact wording. A
    # bare destructive verb typed as free text lands here when allow_abandon is
    # False (LOGIC-05): it requests changes, never a silent terminal abandon.
    return {"decision": "request_changes", "notes": original.strip()}