"""Unit tests for YamlPersistence file I/O."""
from __future__ import annotations

from pathlib import Path

import pytest
import yaml

from prometheus.infrastructure.file_io import YamlPersistence


class TestYamlPersistenceReadConfig:
    """Tests for read_config YAML loading."""

    def test_roundtrip_write_and_read(self, tmp_path: Path) -> None:
        persistence = YamlPersistence()
        data = {
            "seed_prompt": "You are helpful.",
            "task_description": "Answer questions.",
            "max_iterations": 30,
            "verbose": True,
        }
        config_file = tmp_path / "config.yaml"
        with open(config_file, "w") as f:
            yaml.dump(data, f)

        result = persistence.read_config(str(config_file))

        assert result == data

    def test_reads_nested_yaml(self, tmp_path: Path) -> None:
        persistence = YamlPersistence()
        data = {
            "model": {"name": "gpt-4o", "temperature": 0.7},
            "params": [1, 2, 3],
        }
        config_file = tmp_path / "nested.yaml"
        with open(config_file, "w") as f:
            yaml.dump(data, f)

        result = persistence.read_config(str(config_file))

        assert result["model"]["name"] == "gpt-4o"
        assert result["params"] == [1, 2, 3]

    def test_missing_file_raises_error(self, tmp_path: Path) -> None:
        persistence = YamlPersistence()
        missing = tmp_path / "nonexistent.yaml"

        with pytest.raises(FileNotFoundError):
            persistence.read_config(str(missing))

    def test_malformed_yaml_raises_error(self, tmp_path: Path) -> None:
        persistence = YamlPersistence()
        bad_file = tmp_path / "bad.yaml"
        bad_file.write_text(": [invalid: {yaml", encoding="utf-8")

        with pytest.raises(yaml.YAMLError):
            persistence.read_config(str(bad_file))


class TestYamlPersistenceWriteResult:
    """Tests for write_result YAML output."""

    def test_roundtrip_write_result(self, tmp_path: Path) -> None:
        persistence = YamlPersistence()
        data = {
            "optimized_prompt": "Improved prompt.",
            "initial_score": 0.4,
            "final_score": 0.85,
        }
        output_file = tmp_path / "result.yaml"
        persistence.write_result(str(output_file), data)

        with open(output_file) as f:
            loaded = yaml.safe_load(f)

        assert loaded == data

    def test_write_result_creates_valid_yaml(self, tmp_path: Path) -> None:
        persistence = YamlPersistence()
        data = {"key": "value", "number": 42}
        output_file = tmp_path / "out.yaml"
        persistence.write_result(str(output_file), data)

        content = output_file.read_text()
        assert "key: value" in content
        assert "number: 42" in content

    def test_write_result_handles_unicode(self, tmp_path: Path) -> None:
        persistence = YamlPersistence()
        data = {"prompt": "Répondez en français. 中文测试"}
        output_file = tmp_path / "unicode.yaml"
        persistence.write_result(str(output_file), data)

        with open(output_file, encoding="utf-8") as f:
            loaded = yaml.safe_load(f)

        assert loaded["prompt"] == "Répondez en français. 中文测试"