"""Tests for dataset loading and synthetic generation."""

from __future__ import annotations

import pytest

from data_cleaning_env.datasets import (
    TASK_CONFIGS,
    generate_synthetic_dataset,
    load_clean_dataset,
)


class TestDatasetLoading:
    def test_four_task_configs(self) -> None:
        assert len(TASK_CONFIGS) == 4
        assert "expert" in TASK_CONFIGS

    @pytest.mark.parametrize("task", ["easy", "medium", "hard", "expert"])
    def test_load_returns_nonempty(self, task: str) -> None:
        df, target = load_clean_dataset(task)
        assert len(df) > 0
        assert target in df.columns

    def test_unknown_task_raises(self) -> None:
        with pytest.raises(ValueError, match="Unknown task"):
            load_clean_dataset("nonexistent")


class TestSyntheticDataset:
    def test_default_shape(self) -> None:
        df, target = generate_synthetic_dataset()
        assert df.shape[0] == 5000
        assert target == "class"
        assert "class" in df.columns

    def test_deterministic(self) -> None:
        df1, _ = generate_synthetic_dataset(seed=99)
        df2, _ = generate_synthetic_dataset(seed=99)
        assert df1.equals(df2)