"""Tests that EvaluationResult.token_usage is persisted into metadata.json."""
from __future__ import annotations

import json
from pathlib import Path

from rag_eval.reporting.writers import write_run_artifacts
from rag_eval.shared.models import DatasetConfig, EvaluationResult, RuntimeConfig, Scenario


def _scenario(tmp_path: Path) -> Scenario:
    return Scenario(
        scenario_name="token-persist-test",
        mode="offline",
        dataset=DatasetConfig(path=tmp_path / "dataset.csv"),
        judge_model="gpt-5",
        embedding_model="embedding-model",
        metrics=["faithfulness"],
        output_dir=tmp_path / "outputs",
        runtime=RuntimeConfig(batch_size=1),
    )


def test_evaluation_result_defaults_token_usage_to_empty_dict(tmp_path: Path) -> None:
    result = EvaluationResult(
        scenario=_scenario(tmp_path),
        run_id="run-1",
        started_at="t0",
        finished_at="t1",
        valid_samples=[],
        invalid_samples=[],
        score_rows=[],
    )
    assert result.token_usage == {}


def test_write_run_artifacts_persists_token_usage(tmp_path: Path) -> None:
    scenario = _scenario(tmp_path)
    result = EvaluationResult(
        scenario=scenario,
        run_id="run-2",
        started_at="t0",
        finished_at="t1",
        valid_samples=[],
        invalid_samples=[],
        score_rows=[],
        token_usage={"gpt-5": {"input_tokens": 100, "output_tokens": 40, "calls": 2}},
    )

    write_run_artifacts(result)

    metadata_path = scenario.output_dir / "run-2" / "metadata.json"
    metadata = json.loads(metadata_path.read_text(encoding="utf-8"))
    assert metadata["token_usage"] == {
        "gpt-5": {"input_tokens": 100, "output_tokens": 40, "calls": 2}
    }


def test_write_run_artifacts_writes_empty_token_usage_when_unset(tmp_path: Path) -> None:
    scenario = _scenario(tmp_path)
    result = EvaluationResult(
        scenario=scenario,
        run_id="run-3",
        started_at="t0",
        finished_at="t1",
        valid_samples=[],
        invalid_samples=[],
        score_rows=[],
    )

    write_run_artifacts(result)

    metadata_path = scenario.output_dir / "run-3" / "metadata.json"
    metadata = json.loads(metadata_path.read_text(encoding="utf-8"))
    assert metadata["token_usage"] == {}