Parsing Latitude and Longitude Information

using System;
using System.Globalization;
using Geospatial;
using NUnit.Framework;

namespace UnitTests
{
    [TestFixture]
    class LongitudeTest
    {
        private const double Delta = 0.000001;

        [Test]
        public void TestCompareTo()
        {
            Assert.AreEqual(-1, Longitude.FromRadians(0).CompareTo(Longitude.FromRadians(1)));
            Assert.AreEqual(1, Longitude.FromRadians(0).CompareTo(Longitude.FromRadians(-1)));
            Assert.AreEqual(0, Longitude.FromRadians(0).CompareTo(Longitude.FromRadians(0)));
        }

        [Test]
        public void TestEquals()
        {
            Longitude zero = Longitude.FromRadians(0);
            Angle angle = Angle.FromRadians(0);
            object box = zero;

            Assert.IsTrue(zero == angle);
            Assert.IsTrue(zero == Longitude.FromRadians(0));
            Assert.IsTrue(zero.Equals(Longitude.FromRadians(0)));
            Assert.IsTrue(zero.Equals(angle));
            Assert.IsTrue(zero.Equals(box));
            Assert.IsTrue(zero.Equals((object)angle));

            Assert.IsFalse(zero == Latitude.FromRadians(0));

            Assert.AreEqual('E', Longitude.FromDegrees(0).Direction);
            Assert.AreEqual('E', Longitude.FromDegrees(1).Direction);
            Assert.AreEqual('W', Longitude.FromDegrees(-1).Direction);
            Assert.AreEqual('W', Longitude.FromDegrees(180).Direction); // This will be turned to negative
        }

        [Test]
        public void TestConstructors()
        {
            Assert.Throws<ArgumentNullException>(() => new Longitude(null));
            Assert.Throws<ArgumentOutOfRangeException>(() => new Longitude(Angle.FromRadians(double.MaxValue)));
            Assert.Throws<ArgumentOutOfRangeException>(() => new Longitude(Angle.FromRadians(double.NaN)));
            Assert.Throws<ArgumentOutOfRangeException>(() => new Longitude(Angle.FromRadians(double.NegativeInfinity)));
            Assert.DoesNotThrow(() => new Longitude(Angle.FromDegrees(-180)));

            // Special case for the 180th meridian, which should always be -180
            // degrees according to ISO 6709
            Assert.AreEqual(-180, Longitude.FromDegrees(180).Degrees);

            Assert.Throws<ArgumentOutOfRangeException>(() => Longitude.FromDegrees(180.1));
            Assert.Throws<ArgumentOutOfRangeException>(() => Longitude.FromRadians(-Math.PI - 0.01));

            Assert.Throws<ArgumentOutOfRangeException>(() => Longitude.FromDegrees(179, 61));
            Assert.Throws<ArgumentOutOfRangeException>(() => Longitude.FromDegrees(179, 59, 61));
            Assert.Throws<ArgumentOutOfRangeException>(() => Longitude.FromDegrees(-179, -61));
            Assert.Throws<ArgumentOutOfRangeException>(() => Longitude.FromDegrees(-179, -60, -61));

            // These should be ok
            Assert.DoesNotThrow(() => Longitude.FromDegrees(179, 60));
            Assert.DoesNotThrow(() => Longitude.FromDegrees(179, 59, 60));
            Assert.DoesNotThrow(() => Longitude.FromDegrees(-179, -60));
            Assert.DoesNotThrow(() => Longitude.FromDegrees(-179, -59, -60));

            Assert.AreEqual(Math.PI / 4.0, Longitude.FromDegrees(45).Radians, Delta);
            Assert.AreEqual(-45, Longitude.FromRadians(-Math.PI / 4.0).Degrees, Delta);
        }

        [Test]
        public void TestToString()
        {
            Longitude longitude = new Longitude(Angle.FromDegrees(-15.45));
            Assert.AreEqual("15\u00B0 27\u2032 W", longitude.ToString("DM", CultureInfo.InvariantCulture));

            longitude = new Longitude(Angle.FromDegrees(15.45));
            Assert.AreEqual("15\u00B0 27\u2032 E", longitude.ToString("DM", CultureInfo.InvariantCulture));

            longitude = new Longitude(Angle.FromDegrees(0, 45, 6));
            Assert.AreEqual("0\u00B0 45.1\u2032 E", longitude.ToString("DM", CultureInfo.InvariantCulture));
            Assert.AreEqual("+0004506", longitude.ToString("ISO", CultureInfo.InvariantCulture));

            longitude = new Longitude(Angle.FromDegrees(0, -45, -6));
            Assert.AreEqual("0\u00B0 45.1\u2032 W", longitude.ToString("DM", CultureInfo.InvariantCulture));
            Assert.AreEqual("-0004506", longitude.ToString("ISO", CultureInfo.InvariantCulture));
        }
    }
}