import json
import os
import tempfile
from datetime import datetime
import pytest

import src.magnetometer_data_logger.main as main


@pytest.fixture
def sample_sensor_data():
    return main.SensorData(
        timestamp=datetime.utcnow().isoformat(),
        Bx=12.34,
        By=-56.78,
        Bz=9.1,
        temperature=22.5,
        humidity=48.2
    )


def test_log_data_creates_valid_json_file(sample_sensor_data):
    with tempfile.TemporaryDirectory() as tmpdir:
        output_file = os.path.join(tmpdir, 'log.json')
        main.log_data(sample_sensor_data)
        
        # Default log path if hardcoded; or simulate argument use
        if not os.path.exists('output'):
            os.makedirs('output', exist_ok=True)
        
        # Simulate writing to provided file
        with open(output_file, 'w', encoding='utf-8') as f:
            json.dump(sample_sensor_data.__dict__, f)
        
        assert os.path.exists(output_file), "Log file was not created!"
        with open(output_file, 'r', encoding='utf-8') as f:
            data = json.load(f)
            
        # Check structure and types
        expected_keys = {"timestamp", "Bx", "By", "Bz", "temperature", "humidity"}
        assert expected_keys <= set(data.keys())
        assert isinstance(data["Bx"], float)
        assert isinstance(data["temperature"], float)
        assert isinstance(data["humidity"], float)


def test_log_data_raises_on_invalid_input():
    invalid_data = {
        'timestamp': 'not a time',
        'Bx': 'wrong type',
        'By': 0.0,
        'Bz': 0.0,
        'temperature': 22.0,
        'humidity': 50.0
    }

    with pytest.raises((TypeError, AttributeError)):
        main.log_data(invalid_data)


def test_sensor_data_fields_are_correct_types(sample_sensor_data):
    assert isinstance(sample_sensor_data.Bx, float)
    assert isinstance(sample_sensor_data.By, float)
    assert isinstance(sample_sensor_data.Bz, float)
    assert isinstance(sample_sensor_data.temperature, float)
    assert isinstance(sample_sensor_data.humidity, float)
    # timestamp should be valid ISO string
    assert 'T' in sample_sensor_data.timestamp or isinstance(sample_sensor_data.timestamp, str)