"""Test homeassistant distance utility functions."""

import unittest
import homeassistant.util.distance as distance_util
from homeassistant.const import (LENGTH_KILOMETERS, LENGTH_METERS, LENGTH_FEET,
                                 LENGTH_MILES)
import pytest

INVALID_SYMBOL = 'bob'
VALID_SYMBOL = LENGTH_KILOMETERS


class TestDistanceUtil(unittest.TestCase):
    """Test the distance utility functions."""

    def test_convert_same_unit(self):
        """Test conversion from any unit to same unit."""
        assert 5 == distance_util.convert(5, LENGTH_KILOMETERS,
                                          LENGTH_KILOMETERS)
        assert 2 == distance_util.convert(2, LENGTH_METERS,
                                          LENGTH_METERS)
        assert 10 == distance_util.convert(10, LENGTH_MILES, LENGTH_MILES)
        assert 9 == distance_util.convert(9, LENGTH_FEET, LENGTH_FEET)

    def test_convert_invalid_unit(self):
        """Test exception is thrown for invalid units."""
        with pytest.raises(ValueError):
            distance_util.convert(5, INVALID_SYMBOL,
                                  VALID_SYMBOL)

        with pytest.raises(ValueError):
            distance_util.convert(5, VALID_SYMBOL,
                                  INVALID_SYMBOL)

    def test_convert_nonnumeric_value(self):
        """Test exception is thrown for nonnumeric type."""
        with pytest.raises(TypeError):
            distance_util.convert('a', LENGTH_KILOMETERS, LENGTH_METERS)

    def test_convert_from_miles(self):
        """Test conversion from miles to other units."""
        miles = 5
        assert distance_util.convert(
            miles, LENGTH_MILES, LENGTH_KILOMETERS
        ) == 8.04672
        assert distance_util.convert(miles, LENGTH_MILES, LENGTH_METERS) == \
            8046.72
        assert distance_util.convert(miles, LENGTH_MILES, LENGTH_FEET) == \
            26400.0008448

    def test_convert_from_feet(self):
        """Test conversion from feet to other units."""
        feet = 5000
        assert distance_util.convert(feet, LENGTH_FEET, LENGTH_KILOMETERS) == \
            1.524
        assert distance_util.convert(feet, LENGTH_FEET, LENGTH_METERS) == \
            1524
        assert distance_util.convert(feet, LENGTH_FEET, LENGTH_MILES) == \
            0.9469694040000001

    def test_convert_from_kilometers(self):
        """Test conversion from kilometers to other units."""
        km = 5
        assert distance_util.convert(km, LENGTH_KILOMETERS, LENGTH_FEET) == \
            16404.2
        assert distance_util.convert(km, LENGTH_KILOMETERS, LENGTH_METERS) == \
            5000
        assert distance_util.convert(km, LENGTH_KILOMETERS, LENGTH_MILES) == \
            3.106855

    def test_convert_from_meters(self):
        """Test conversion from meters to other units."""
        m = 5000
        assert distance_util.convert(m, LENGTH_METERS, LENGTH_FEET) == \
            16404.2
        assert distance_util.convert(m, LENGTH_METERS, LENGTH_KILOMETERS) == \
            5
        assert distance_util.convert(m, LENGTH_METERS, LENGTH_MILES) == \
            3.106855