"""Section-refinement eval (`make eval`).

Runs against the CONFIGURED chat endpoint — it must be live. Proves the core
of writing-first capture on a real model: a rough section becomes mature
prose, its heading is kept, ONLY that section comes back (FIM), the language
is preserved, and no load-bearing fact is dropped.
"""

import pytest

from app.authoring.prompts import render_refine_prompt
from app.llm.client import chat_stream

pytestmark = pytest.mark.eval

# Same flag the /refine endpoint uses: turn off the reasoning channel so the
# call is fast and the eval measures the answer, not the thinking.
_NO_THINKING = {"chat_template_kwargs": {"enable_thinking": False}}

PREFIX = "## Zweck\nDieser Ablauf beschreibt die monatliche Rechnungsstellung."
SECTION = (
    "## Ablauf\n"
    "also man macht das am monatsanfang. erst die stunden exportieren, dann in "
    "die vorlage kopieren und per mail raus. bei einer PO muss die nummer drauf."
)
SUFFIX = "## Fallstricke"


async def _refine(
    section: str,
    prefix: str,
    suffix: str,
    knowledge: list[str] | None = None,
) -> str:
    messages = render_refine_prompt(
        section,
        prefix=prefix,
        suffix=suffix,
        persona="Du bist ein präziser Fachredakteur, der Abläufe dokumentiert.",
        hint="Die Schritte in Reihenfolge, als Liste.",
        knowledge=knowledge,
    )
    parts: list[str] = []
    async for token in chat_stream(
        messages, role="chat", temperature=0.4, extra_body=_NO_THINKING
    ):
        parts.append(token)
    return "".join(parts).strip()


async def test_refinement_matures_only_the_active_section() -> None:
    out = await _refine(SECTION, PREFIX, SUFFIX)

    assert out, "refinement returned nothing"
    # Kept the section's own heading.
    assert out.lstrip().startswith("## Ablauf")
    # ONLY this section: the surrounding headings must not be re-emitted.
    assert "## Zweck" not in out
    assert "## Fallstricke" not in out
    # Used the input and kept the load-bearing PO fact.
    assert any(token in out for token in ("PO", "Purchase", "Bestell"))
    # Language preserved (German): a switch to English would be a regression.
    lowered = out.lower()
    assert any(word in lowered for word in (" der ", " die ", " und ", " wird "))


# A related document the company already has. It shares the topic but carries a
# distinctive fact the section itself never mentions.
GROUNDING = [
    'From "Zahlungsbedingungen" (Fristen): Rechnungen sind binnen 14 Tagen '
    "fällig, mit zwei Prozent Skonto bei Zahlung binnen sieben Tagen."
]


async def test_grounding_informs_without_being_copied_in() -> None:
    out = await _refine(SECTION, PREFIX, SUFFIX, knowledge=GROUNDING)

    assert out, "refinement returned nothing"
    # Grounding does not break the one-section contract.
    assert out.lstrip().startswith("## Ablauf")
    assert "## Zweck" not in out and "## Fallstricke" not in out
    # The section keeps its own load-bearing fact.
    assert any(token in out for token in ("PO", "Purchase", "Bestell"))
    # Grounding is a reference, not a fact source: the related document's own
    # detail must not be imported into this section, and the reference framing
    # must not be echoed back.
    assert "Skonto" not in out
    assert "Zahlungsbedingungen" not in out