"""IMP-38 U2 — dynamic effective max_rank + trace 8-field + 3-tier usable predicate.

Verify:
  - max_rank=None (default) → policy applied (usable_count + effective_max_rank 결정)
  - max_rank=int (caller override) → that value used as-is (backward compat)
  - trace contains 8 IMP-38 fields + legacy "max_rank" alias
  - usable_count >= threshold → default_max_rank (mdx03 정상 case)
  - usable_count < threshold → effective_extended_ceiling (mdx05-2 확장 case)
  - effective_extended_ceiling = min(configured, len(judgments_full32)) (Codex #2)
  - IMP-30 allow_provisional byte-identical (chain_exhausted 후 provisional 합성)

4 round 합의 (#67):
  - Codex #1: 별 yaml (catalog 오염 방지)
  - Codex #2: min(configured, len(judgments)) 정정
  - Codex #3: load_frame_contracts() shape 무변
"""
from __future__ import annotations

import pytest


@pytest.fixture(autouse=True)
def _reset_policy_cache():
    """Reset module-level _V4_FALLBACK_POLICY_CACHE for test isolation."""
    import src.phase_z2_mapper as mapper
    mapper._V4_FALLBACK_POLICY_CACHE = None
    yield
    mapper._V4_FALLBACK_POLICY_CACHE = None


def _make_v4_section(judgments: list[dict]) -> dict:
    """Helper — V4 fixture with mdx_sections[section_id].judgments_full32."""
    return {
        "mdx_sections": {
            "sec-1": {
                "judgments_full32": judgments,
            }
        }
    }


def _judgment(template_id: str, label: str, confidence: float = 0.5, frame_id: int = 0) -> dict:
    """Helper — V4 judgment entry shape."""
    return {
        "template_id": template_id,
        "frame_id": frame_id or hash(template_id) % 10000,
        "frame_number": 0,
        "confidence": confidence,
        "label": label,
    }


# ─── U2 Test: caller override (backward compat) ────────────────────


def test_caller_override_uses_explicit_max_rank():
    """max_rank=3 explicit → effective_max_rank=3, policy_applied=caller_override."""
    from src.phase_z2_pipeline import lookup_v4_match_with_fallback
    judgments = [_judgment(f"t{i}", "reject") for i in range(5)]
    v4 = _make_v4_section(judgments)
    _match, trace = lookup_v4_match_with_fallback(v4, "sec-1", max_rank=3)
    assert trace["policy_applied"] == "caller_override"
    assert trace["effective_max_rank"] == 3
    assert trace["max_rank"] == 3  # legacy alias


def test_caller_override_max_rank_5_used_directly():
    """max_rank=5 explicit → effective_max_rank=5 (policy 무시)."""
    from src.phase_z2_pipeline import lookup_v4_match_with_fallback
    judgments = [_judgment(f"t{i}", "reject") for i in range(10)]
    v4 = _make_v4_section(judgments)
    _match, trace = lookup_v4_match_with_fallback(v4, "sec-1", max_rank=5)
    assert trace["policy_applied"] == "caller_override"
    assert trace["effective_max_rank"] == 5


# ─── U2 Test: 8 trace fields presence ──────────────────────────────


def test_trace_contains_8_imp38_fields():
    """trace dict must contain all 8 IMP-38 fields + legacy max_rank alias."""
    from src.phase_z2_pipeline import lookup_v4_match_with_fallback
    judgments = [_judgment(f"t{i}", "reject") for i in range(3)]
    v4 = _make_v4_section(judgments)
    _match, trace = lookup_v4_match_with_fallback(v4, "sec-1")
    expected = {
        "requested_max_rank",
        "default_max_rank",
        "configured_extended_max_rank",
        "judgments_count",
        "effective_extended_ceiling",
        "effective_max_rank",
        "usable_count",
        "policy_applied",
        "max_rank",  # legacy alias
    }
    missing = expected - set(trace.keys())
    assert not missing, f"missing IMP-38 trace fields: {missing}"


# ─── U2 Test: Codex #2 정정 — min(configured, len(judgments_full32)) ──


def test_effective_extended_ceiling_is_min_of_configured_and_judgments_count():
    """Codex #2 LOCK — judgments_count < configured 일 때 ceiling = judgments_count."""
    from src.phase_z2_pipeline import lookup_v4_match_with_fallback
    # 5 judgments only — configured extended (32) 보다 작음
    judgments = [_judgment(f"t{i}", "reject") for i in range(5)]
    v4 = _make_v4_section(judgments)
    _match, trace = lookup_v4_match_with_fallback(v4, "sec-1")
    assert trace["judgments_count"] == 5
    assert trace["effective_extended_ceiling"] == 5  # min(32, 5) = 5


# ─── U2 Test: no_judgments path ──────────────────────────────────


def test_no_judgments_path():
    """judgments_count=0 → policy_applied=no_judgments, effective_max_rank=default."""
    from src.phase_z2_pipeline import lookup_v4_match_with_fallback
    v4 = _make_v4_section([])
    _match, trace = lookup_v4_match_with_fallback(v4, "sec-1")
    assert trace["policy_applied"] == "no_judgments"
    assert trace["judgments_count"] == 0
    assert trace["effective_max_rank"] == trace["default_max_rank"]
    assert trace["fallback_reason"] == "empty_v4_judgments"


# ─── U2 Test: no_v4_section ─────────────────────────────────────


def test_no_v4_section_path():
    """unknown section_id → fallback_reason=no_v4_section + trace still has 8 IMP-38 fields."""
    from src.phase_z2_pipeline import lookup_v4_match_with_fallback
    v4 = {"mdx_sections": {}}
    _match, trace = lookup_v4_match_with_fallback(v4, "unknown-sec")
    assert trace["fallback_reason"] == "no_v4_section"
    # 8 fields still present even when no section found
    assert "policy_applied" in trace
    assert "effective_max_rank" in trace


# ─── U2 Test: chain_exhausted message reflects effective_max_rank ──


def test_chain_exhausted_message_includes_effective_max_rank():
    """fallback_reason 메시지가 동적 effective_max_rank 반영 (hardcoded "1_to_3" X)."""
    from src.phase_z2_pipeline import lookup_v4_match_with_fallback
    # 3 judgments all reject (catalog 등록 X 가정 — t1/t2/t3 는 catalog 에 없음)
    judgments = [_judgment(f"unregistered_t{i}", "reject") for i in range(3)]
    v4 = _make_v4_section(judgments)
    _match, trace = lookup_v4_match_with_fallback(v4, "sec-1", max_rank=3)
    # chain exhausted — 메시지 가 effective_max_rank=3 반영
    if trace["selection_path"] == "chain_exhausted":
        # first_skip_reason 가 있으면 그게 우선, 없으면 default 메시지
        assert (
            trace["fallback_reason"] is not None
            and ("no_auto_renderable" in trace["fallback_reason"] or "phase_z_status" in trace["fallback_reason"] or "no_contract" in trace["fallback_reason"])
        )