"""S5.2 — Varsling: unit/contract tests for ``notify.py`` (Notifier protocol + notifiers).

Detach-seam (RED-when-detached) twins live in ``tests/test_notify_loadbearing.py``. Tests may
import MAF-tainted modules freely (``verdicts``) — only ``notify.py`` itself must stay MAF-free.
"""

from __future__ import annotations

import io
import json

from portfolio_optimiser.notify import ConsoleNotifier, FileNotifier, Notifier, _verdict_payload
from portfolio_optimiser.verdicts import ProposalFeatures, Verdict, capture_verdict, verdict_to_dict


def _verdict() -> Verdict:
    return capture_verdict(
        ProposalFeatures(
            affected_codes=frozenset({"05.2", "03.1"}),
            measure_type="scope_reduction",
            claimed_saving_nok=200_000.0,
            description="LED retrofit",
        ),
        "approved",
        "feasible within range",
    )


def test_plain_callable_satisfies_notifier() -> None:
    """The seam promise: any plain callable satisfies the runtime-checkable ``Notifier`` protocol,
    so ``run_project(notify=lambda v: ...)`` stays valid — a structural superset of
    ``Callable[[Verdict], None]``, not a new ABC (needs ``@runtime_checkable``)."""
    assert isinstance(lambda v: None, Notifier)


def test_console_emits_id_and_decision() -> None:
    """ConsoleNotifier writes the verdict id + decision to the injected stream (never a URL)."""
    stream = io.StringIO()
    verdict = _verdict()
    ConsoleNotifier(stream=stream)(verdict)
    out = stream.getvalue()
    assert verdict.id in out
    assert verdict.decision in out


def test_payload_matches_verdict_to_dict_oracle() -> None:
    """DRIFT-ORACLE: the duck-typed ``_verdict_payload`` reproduces ``verdict_to_dict``'s exact
    NESTED shape (verdicts.py:124-139) without importing it at runtime — the test imports both
    (tests may pull MAF freely) and pins them equal, so a ``Verdict`` shape change goes RED here
    instead of silently diverging the notified payload."""
    verdict = _verdict()
    assert _verdict_payload(verdict) == verdict_to_dict(verdict)


def test_file_notifier_byte_deterministic(tmp_path) -> None:
    """FileNotifier appends one JSONL line per verdict — two writes of the same verdict are
    byte-identical, LF-terminated, nested per the oracle shape, and carry no wall-clock key."""
    path = tmp_path / "sub" / "notify.jsonl"
    verdict = _verdict()
    notifier = FileNotifier(str(path))
    notifier(verdict)
    first = path.read_bytes()
    notifier(verdict)
    second = path.read_bytes()
    assert second == first * 2  # identical appended line bytes
    line = first.decode("utf-8")
    assert line.endswith("\n")
    payload = json.loads(line)
    assert payload["id"] == verdict.id
    assert payload["proposal_features"]["affected_codes"] == ["03.1", "05.2"]
    assert not any(k in payload for k in ("date", "timestamp", "created", "ts"))