"""IMP-33 u3 — fallback prompt builder tests.

Scope (Stage 2 plan, u3):
  - Prompt is built only when V4 route == 'ai_adaptation_required'.
  - System prompt declares MDX READ-ONLY and pins the u2 whitelist.
  - System prompt forbids the u2 forbidden kinds + frame_id swap.
  - User payload carries all 6 declared inputs and labels MDX READ_ONLY.
"""
from __future__ import annotations

import json

import pytest

from src.phase_z2_ai_fallback.prompts import (
    SYSTEM_PROMPT,
    V4_ROUTE_AI_ADAPTATION,
    build_ai_fallback_prompt,
)
from src.phase_z2_ai_fallback.schema import FORBIDDEN_KINDS, ProposalKind


def _v4(route: str = V4_ROUTE_AI_ADAPTATION) -> dict:
    return {
        "route": route,
        "cardinality": {"strict": 3},
        "label": "restructure",
        "frame_id": 1171281190,
        "rank": 1,
    }


def _inputs(route: str = V4_ROUTE_AI_ADAPTATION) -> dict:
    return {
        "v4_result": _v4(route),
        "frame_contract": {"template_id": "three_parallel_requirements"},
        "frame_visual_html": "<section class='f13b'/>",
        "figma_partial_json": {"nodes": []},
        "internal_region": {"id": "region_top", "bbox": [0, 0, 1200, 320]},
        "mdx_text": "# 대목차\n- 항목 1\n- 항목 2\n- 항목 3",
    }


def test_system_prompt_declares_mdx_read_only() -> None:
    assert "READ-ONLY" in SYSTEM_PROMPT


def test_system_prompt_lists_all_whitelisted_kinds() -> None:
    for kind in ProposalKind:
        assert kind.value in SYSTEM_PROMPT


def test_system_prompt_forbids_all_forbidden_kinds() -> None:
    for forbidden in FORBIDDEN_KINDS:
        assert forbidden in SYSTEM_PROMPT


def test_system_prompt_locks_frame_id_swap() -> None:
    assert "frame_id" in SYSTEM_PROMPT


def test_build_prompt_returns_system_and_user() -> None:
    prompt = build_ai_fallback_prompt(**_inputs())
    assert set(prompt.keys()) == {"system", "user"}
    assert prompt["system"] == SYSTEM_PROMPT


def test_user_payload_carries_all_inputs_and_marks_mdx_read_only() -> None:
    prompt = build_ai_fallback_prompt(**_inputs())
    payload = json.loads(prompt["user"])
    assert payload["v4"]["route"] == V4_ROUTE_AI_ADAPTATION
    assert payload["v4"]["cardinality"] == {"strict": 3}
    assert payload["v4"]["frame_id"] == 1171281190
    assert payload["frame_contract"]["template_id"] == "three_parallel_requirements"
    assert payload["frame_visual_html"] == "<section class='f13b'/>"
    assert payload["figma_partial_json"] == {"nodes": []}
    assert payload["internal_region"]["id"] == "region_top"
    assert "mdx_text_READ_ONLY" in payload
    assert payload["mdx_text_READ_ONLY"].startswith("# 대목차")
    assert "mdx_text" not in payload  # only the READ_ONLY key, not a writable alias


@pytest.mark.parametrize(
    "route", ["direct_render", "deterministic_minor_adjustment", "design_reference_only", None]
)
def test_non_ai_route_rejected(route) -> None:
    inputs = _inputs(route=route) if route is not None else _inputs()
    if route is None:
        inputs["v4_result"].pop("route")
    with pytest.raises(ValueError, match=V4_ROUTE_AI_ADAPTATION):
        build_ai_fallback_prompt(**inputs)


def test_cardinality_signature_alias_accepted() -> None:
    """Some V4 callers expose ``cardinality_signature``; both keys must resolve."""
    inputs = _inputs()
    inputs["v4_result"].pop("cardinality")
    inputs["v4_result"]["cardinality_signature"] = {"strict": 4}
    payload = json.loads(build_ai_fallback_prompt(**inputs)["user"])
    assert payload["v4"]["cardinality"] == {"strict": 4}