import pytest
from random import Random
from reasoning_gym.arithmetic.basic_arithmetic import ArithmeticDataset, ArithmeticDatasetConfig


def test_arithmetic_dataset_config_validation():
    """Test that invalid configs raise appropriate errors"""
    with pytest.raises(AssertionError):
        config = ArithmeticDatasetConfig(min_terms=0)
        config.validate()
    
    with pytest.raises(AssertionError):
        config = ArithmeticDatasetConfig(min_terms=3, max_terms=2)
        config.validate()
    
    with pytest.raises(AssertionError):
        config = ArithmeticDatasetConfig(operators=["^"])  # Invalid operator
        config.validate()


def test_arithmetic_dataset_deterministic():
    """Test that dataset generates same items with same seed"""
    config = ArithmeticDatasetConfig(seed=42, size=10)
    dataset1 = ArithmeticDataset(config)
    dataset2 = ArithmeticDataset(config)
    
    for i in range(len(dataset1)):
        assert dataset1[i] == dataset2[i]


def test_arithmetic_dataset_items():
    """Test basic properties of generated items"""
    config = ArithmeticDatasetConfig(
        min_terms=2,
        max_terms=4,
        min_digits=1,
        max_digits=2,
        size=100,
        seed=42
    )
    dataset = ArithmeticDataset(config)
    
    for i in range(len(dataset)):
        item = dataset[i]
        assert isinstance(item, dict)
        assert "question" in item
        assert "answer" in item
        assert "metadata" in item
        
        # Verify the answer matches the expression
        expression = item["metadata"]["expression"]
        answer = eval(expression)  # Safe here as we control the expression
        assert str(answer) == item["answer"]


def test_arithmetic_dataset_format_styles():
    """Test different question format styles"""
    config = ArithmeticDatasetConfig(
        size=10,
        seed=42,
        format_style="simple",
        min_terms=2,
        max_terms=3,  # Keep expressions simple for testing
        min_digits=1,
        max_digits=2
    )
    dataset = ArithmeticDataset(config)
    assert all(item["question"].endswith("=") for item in dataset)
    
    config.format_style = "natural"
    dataset = ArithmeticDataset(config)
    assert all("=" not in item["question"] for item in dataset)


def test_arithmetic_dataset_iteration():
    """Test that iteration respects dataset size"""
    config = ArithmeticDatasetConfig(
        min_terms=2,
        max_terms=2,
        size=5,  # Small size for testing
        seed=42
    )
    dataset = ArithmeticDataset(config)
    
    # Test manual iteration
    items = []
    for item in dataset:
        items.append(item)
    assert len(items) == config.size, "Iterator should yield exactly size items"
    
    # Test list conversion
    items = list(dataset)
    assert len(items) == config.size, "Iterator should yield exactly size items"
    
    # Test multiple iterations
    first_items = list(dataset)
    second_items = list(dataset)
    assert first_items == second_items, "Multiple iterations should yield same items"