"""IMP-47B u5 — PARTIAL_OVERRIDES apply tests.

Scope (this slice):
  Helper ``_apply_ai_repair_proposals_to_zones`` (src/phase_z2_pipeline.py)
  merges ``proposal.payload.slots`` into ``zones_data[k]["slot_payload"]``
  for PARTIAL_OVERRIDES proposals only, and loud-fails out-of-scope
  proposal kinds (builder_options_patch, slot_mapping_proposal) with an
  explicit ``apply_status`` marker.

The IMP-33 u5 validator inside ``route_ai_fallback`` already enforces
declared-slot completeness — the apply helper is therefore a structural
merge over the validator's contract, not a per-slot guard re-implementation.

u6 (step12_ai_repair.json audit), u7 (coverage invariant), and u8
(slide_status surfacing) are out of scope for this unit.
"""
from __future__ import annotations

from src.phase_z2_pipeline import _apply_ai_repair_proposals_to_zones


def _record(
    *,
    unit_index: int,
    proposal: dict | None,
    source_section_ids: list[str] | None = None,
) -> dict:
    """Synthetic gather_step12_ai_repair_proposals record."""
    return {
        "unit_index": unit_index,
        "source_section_ids": source_section_ids or [f"MOCK_S{unit_index}"],
        "frame_template_id": "MOCK_T",
        "label": "reject",
        "route_hint": "ai_adaptation_required",
        "provisional": True,
        "ai_called": proposal is not None,
        "skip_reason": None,
        "proposal": proposal,
        "error": None,
        "cache_key": "MOCK_F::abc" if proposal is not None else None,
        "fingerprints": {"contract_sha": "x", "partial_sha": "y", "catalog_sha": ""}
        if proposal is not None
        else None,
    }


def _zone(*, position: str, slot_payload: dict | None = None) -> dict:
    """Synthetic zones_data entry — only fields the apply helper touches."""
    return {
        "position": position,
        "template_id": "MOCK_T",
        "slot_payload": slot_payload if slot_payload is not None else {},
    }


# ─── Case 1 : PARTIAL_OVERRIDES → merged + applied marker ──────────


def test_partial_overrides_merges_slots_into_zone_slot_payload():
    """The validator already guarantees declared-slot completeness, so
    apply is a structural ``dict.update``. Pre-existing meta keys
    (``_truncated_count``) survive; declared slot values are replaced
    by the AI proposal values."""
    proposal = {
        "proposal_kind": "partial_overrides",
        "payload": {
            "slots": {
                "title": "AI title",
                "bullets": ["AI bullet 1", "AI bullet 2"],
            }
        },
        "rationale": "MOCK",
    }
    records = [_record(unit_index=0, proposal=proposal)]
    zones = [
        _zone(
            position="top",
            slot_payload={
                "title": "deterministic title",
                "bullets": ["det bullet"],
                "_truncated_count": 0,
            },
        )
    ]

    _apply_ai_repair_proposals_to_zones(records, ["top"], zones)

    assert records[0]["apply_status"] == "applied:partial_overrides"
    assert zones[0]["slot_payload"]["title"] == "AI title"
    assert zones[0]["slot_payload"]["bullets"] == ["AI bullet 1", "AI bullet 2"]
    # meta keys not in proposal must survive the merge
    assert zones[0]["slot_payload"]["_truncated_count"] == 0


# ─── Case 2 : BUILDER_OPTIONS_PATCH → loud-fail unsupported_kind ───


def test_builder_options_patch_is_unsupported_for_reject_route():
    """Builder-options application is out-of-scope for IMP-47B reject
    route (see Stage 2 plan). u5 must mark, not apply — the zone
    slot_payload stays byte-identical and the record carries the
    ``unsupported_kind_for_reject_route:<kind>`` marker so u8 can
    surface human_review downstream."""
    proposal = {
        "proposal_kind": "builder_options_patch",
        "payload": {"font_size_px": 14},
        "rationale": "MOCK",
    }
    records = [_record(unit_index=0, proposal=proposal)]
    original_slot_payload = {"title": "deterministic"}
    zones = [_zone(position="top", slot_payload=dict(original_slot_payload))]

    _apply_ai_repair_proposals_to_zones(records, ["top"], zones)

    assert (
        records[0]["apply_status"]
        == "unsupported_kind_for_reject_route:builder_options_patch"
    )
    assert zones[0]["slot_payload"] == original_slot_payload


# ─── Case 3 : SLOT_MAPPING_PROPOSAL → loud-fail unsupported_kind ───


def test_slot_mapping_proposal_is_unsupported_for_reject_route():
    """Slot-mapping (restructuring) application is also out-of-scope —
    builder-options + slot-mapping share the same marker path."""
    proposal = {
        "proposal_kind": "slot_mapping_proposal",
        "payload": {"slots": {"title": "x"}},
        "rationale": "MOCK",
    }
    records = [_record(unit_index=0, proposal=proposal)]
    zones = [_zone(position="top", slot_payload={"title": "deterministic"})]

    _apply_ai_repair_proposals_to_zones(records, ["top"], zones)

    assert (
        records[0]["apply_status"]
        == "unsupported_kind_for_reject_route:slot_mapping_proposal"
    )
    assert zones[0]["slot_payload"] == {"title": "deterministic"}


# ─── Case 4 : no proposal (router short-circuit / not_provisional) ──


def test_record_without_proposal_marked_no_proposal_and_zone_untouched():
    """Flag-off short-circuit and non-AI-route units carry
    ``proposal=None``. apply_status must distinguish "no proposal to
    apply" from real apply outcomes so u8 can categorise the per-unit
    status without re-reading skip_reason."""
    records = [_record(unit_index=0, proposal=None)]
    zones = [_zone(position="top", slot_payload={"title": "deterministic"})]

    _apply_ai_repair_proposals_to_zones(records, ["top"], zones)

    assert records[0]["apply_status"] == "no_proposal"
    assert zones[0]["slot_payload"] == {"title": "deterministic"}


# ─── Case 5 : proposal exists but no matching zone (B4 mismatch) ────


def test_proposal_for_unit_without_zone_match_marked_no_zone_match():
    """When a unit is dropped from zones_data (B4 mismatch or FitError
    in the Step 12 render loop) but still gathered an AI proposal,
    apply must surface the mismatch via ``no_zone_match`` rather than
    silently dropping the proposal or writing into a wrong zone."""
    proposal = {
        "proposal_kind": "partial_overrides",
        "payload": {"slots": {"title": "AI title"}},
        "rationale": "MOCK",
    }
    records = [_record(unit_index=0, proposal=proposal)]
    # unit_positions[0]="top" but zones_data has only the bottom zone
    # → no match for the dropped unit's position.
    zones = [_zone(position="bottom", slot_payload={"title": "other zone"})]

    _apply_ai_repair_proposals_to_zones(records, ["top"], zones)

    assert records[0]["apply_status"] == "no_zone_match"
    # untouched zone — apply must not bleed into a different position
    assert zones[0]["slot_payload"] == {"title": "other zone"}


# ─── Case 6 : mixed records — independent per-record classification ──


def test_mixed_records_classified_independently():
    """All five apply_status branches coexist in one batch — confirms
    the helper does not short-circuit on the first non-applied record."""
    records = [
        _record(unit_index=0, proposal={
            "proposal_kind": "partial_overrides",
            "payload": {"slots": {"title": "AI"}},
            "rationale": "",
        }),
        _record(unit_index=1, proposal={
            "proposal_kind": "builder_options_patch",
            "payload": {"font_size_px": 14},
            "rationale": "",
        }),
        _record(unit_index=2, proposal=None),
    ]
    zones = [
        _zone(position="top", slot_payload={"title": "det"}),
        _zone(position="middle", slot_payload={"title": "det"}),
        _zone(position="bottom", slot_payload={"title": "det"}),
    ]

    _apply_ai_repair_proposals_to_zones(
        records, ["top", "middle", "bottom"], zones,
    )

    assert [r["apply_status"] for r in records] == [
        "applied:partial_overrides",
        "unsupported_kind_for_reject_route:builder_options_patch",
        "no_proposal",
    ]
    assert zones[0]["slot_payload"]["title"] == "AI"
    assert zones[1]["slot_payload"]["title"] == "det"
    assert zones[2]["slot_payload"]["title"] == "det"