import copy

import pytest

from central.app.ai.fake_provider import DeterministicFakeSemanticProvider
from central.app.ai.llm_provider import LlmAnswerError, LlmEvalItem
from central.app.ai.provider import ProviderContractError, ProviderTransportError


def _item(work_item_id="w1"):
    return LlmEvalItem(
        work_item_id=work_item_id,
        description="AGUA MINERAL 500ML",
        normalized_description="AGUA MINERAL 500ML",
        brand=None,
        unit="ML",
        segment="mercado",
        candidates=[("22011000", "AGUAS MINERAIS", 0.9), ("22019000", "OUTRAS AGUAS", 0.4)],
    )


@pytest.mark.parametrize(
    ("scenario", "selected", "abstain"),
    [
        ("CORRECT", "22011000", False),
        ("WRONG", "22019000", False),
        ("ABSTAIN", None, True),
    ],
)
def test_fake_provider_returns_deterministic_valid_answers(scenario, selected, abstain):
    provider = DeterministicFakeSemanticProvider()

    answers = provider.select_batch([_item()], scenario=scenario)

    assert answers == provider.select_batch([_item()], scenario=scenario)
    assert answers[0]["work_item_id"] == "w1"
    assert answers[0]["selected_ncm"] == selected
    assert answers[0]["abstain"] is abstain
    assert provider.calls == 2


@pytest.mark.parametrize("scenario", ["INVALID_JSON", "MISSING_ITEM", "DUPLICATE_ITEM", "OUT_OF_CANDIDATE"])
def test_fake_provider_rejects_contract_scenarios_without_mutating_items(scenario):
    provider = DeterministicFakeSemanticProvider()
    items = [_item("w1"), _item("w2")]
    original = copy.deepcopy(items)

    with pytest.raises((LlmAnswerError, ProviderContractError)):
        provider.select_batch(items, scenario=scenario)

    assert items == original
    assert provider.calls == 1


@pytest.mark.parametrize("scenario", ["TIMEOUT", "429", "500"])
def test_fake_provider_raises_typed_transport_errors(scenario):
    provider = DeterministicFakeSemanticProvider()

    with pytest.raises(ProviderTransportError):
        provider.select_batch([_item()], scenario=scenario)

    assert provider.calls == 1


def test_fake_provider_rejects_unknown_scenarios():
    with pytest.raises(ValueError):
        DeterministicFakeSemanticProvider().select_batch([_item()], scenario="UNKNOWN")