// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
 
using FluentAssertions;
using Microsoft.ML.SearchSpace.Option;
using Xunit;
using Xunit.Abstractions;
 
namespace Microsoft.ML.SearchSpace.Tests
{
    public class ChoiceOptionTest : TestBase
    {
        public ChoiceOptionTest(ITestOutputHelper output) : base(output)
        {
        }
 
        [Fact]
        public void Choice_option_sampling_from_uniform_space_test()
        {
            var option = new ChoiceOption("a", "b", "c");
            option.SampleFromFeatureSpace(new[] { 0.0 }).AsType<string>().Should().Be("a");
            option.SampleFromFeatureSpace(new[] { 0.33 }).AsType<string>().Should().Be("a");
            option.SampleFromFeatureSpace(new[] { 0.34 }).AsType<string>().Should().Be("b");
            option.SampleFromFeatureSpace(new[] { 0.66 }).AsType<string>().Should().Be("b");
            option.SampleFromFeatureSpace(new[] { 0.67 }).AsType<string>().Should().Be("c");
            option.SampleFromFeatureSpace(new[] { 0.97 }).AsType<string>().Should().Be("c");
            option.SampleFromFeatureSpace(new[] { 0.999999999 }).AsType<string>().Should().Be("c");
            option.SampleFromFeatureSpace(new[] { 1.0 }).AsType<string>().Should().Be("c");
        }
 
        [Fact]
        public void Choice_option_with_one_value_sampling_from_uniform_space_test()
        {
            var option = new ChoiceOption("a");
            option.SampleFromFeatureSpace(new[] { 0.0 }).AsType<string>().Should().Be("a");
            option.SampleFromFeatureSpace(new[] { 0.99 }).AsType<string>().Should().Be("a");
        }
 
        [Fact]
        public void Choice_option_mapping_to_uniform_space_test()
        {
            var option = new ChoiceOption("a", "b", "c");
            option.MappingToFeatureSpace(Parameter.FromString("a"))[0].Should().BeApproximately(0, 1e-5);
            option.MappingToFeatureSpace(Parameter.FromString("b"))[0].Should().BeApproximately(0.333333, 1e-5);
            option.MappingToFeatureSpace(Parameter.FromString("c"))[0].Should().BeApproximately(0.666666, 1e-5);
 
            option = new ChoiceOption("a", "b", "c", "d");
            var parameter = option.SampleFromFeatureSpace(new[] { 0.5 });
            parameter.AsType<string>().Should().Be("c");
            option.MappingToFeatureSpace(parameter).Should().Equal(0.5);
        }
 
        [Fact]
        public void Choice_option_dimension_should_be_0_if_contains_only_one_value()
        {
            var option = new ChoiceOption("b");
            option.FeatureSpaceDim.Should().Be(0);
            option.Default.Should().BeEquivalentTo(System.Array.Empty<double>());
            option.SampleFromFeatureSpace(new double[0]).AsType<string>().Should().Be("b");
            option.MappingToFeatureSpace(Parameter.FromString("b")).Should().BeEmpty();
        }
 
        [Fact]
        public void Choice_int_option_test()
        {
            var searchSpace = new SearchSpace();
            searchSpace["choice"] = new ChoiceOption(1, 2, 3);
            var parameter = searchSpace.SampleFromFeatureSpace(new[] { 0.5 });
            parameter["choice"].AsType<int>().Should().Be(2);
        }
    }
}