using Nonemm.Core;

namespace Nonemm.Core.Tests;

public class GridSquareTests
{
    [Fact]
    public void FourCharacterSquareCentresOnTheSquare()
    {
        Assert.True(GridSquare.TryParse("JN88", out GridSquare grid));
        Assert.Equal(48.5, grid.Latitude, 3);
        Assert.Equal(17.0, grid.Longitude, 3);
    }

    [Fact]
    public void SixCharacterSquareIsMorePrecise()
    {
        Assert.True(GridSquare.TryParse("FN31pr", out GridSquare grid));
        Assert.Equal(41.7, grid.Latitude, 1);
        Assert.Equal(-72.7, grid.Longitude, 1);
    }

    [Theory]
    [InlineData("")]
    [InlineData("JN8")]
    [InlineData("SN89")]
    [InlineData("JNXY")]
    public void MalformedLocatorIsRejected(string text) =>
        Assert.False(GridSquare.TryParse(text, out _));

    [Fact]
    public void DistanceIsTheGreatCircleBetweenSquareCentres()
    {
        Assert.True(GridSquare.TryParse("JO99", out GridSquare jo99));
        Assert.True(GridSquare.TryParse("IO91", out GridSquare io91));
        Assert.InRange(jo99.DistanceTo(io91), 1525, 1540);
    }

    [Fact]
    public void BearingIsZeroDueNorth()
    {
        Assert.True(GridSquare.TryParse("JO99", out GridSquare south));
        Assert.True(GridSquare.TryParse("JP90", out GridSquare north));
        Assert.Equal(0, south.BearingTo(north), 6);
    }

    [Theory]
    [InlineData("JN88md")]
    [InlineData("FN31pr")]
    [InlineData("AA00aa")]
    [InlineData("RR99xx")]
    public void LocatorOfASquareCentreIsThatSquare(string locator)
    {
        Assert.True(GridSquare.TryParse(locator, out GridSquare grid));
        Assert.Equal(locator, GridSquare.From(grid.Latitude, grid.Longitude));
    }
}