// 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 System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using Microsoft.ML;
using Microsoft.ML.CommandLine;
using Microsoft.ML.EntryPoints;
using Microsoft.ML.Internal.Internallearn;
using Microsoft.ML.Runtime;
using Microsoft.ML.Trainers.Ensemble;
 
[assembly: LoadableClass(typeof(BestDiverseSelectorRegression), typeof(BestDiverseSelectorRegression.Arguments),
    typeof(SignatureEnsembleSubModelSelector), BestDiverseSelectorRegression.UserName, BestDiverseSelectorRegression.LoadName)]
 
namespace Microsoft.ML.Trainers.Ensemble
{
    internal sealed class BestDiverseSelectorRegression : BaseDiverseSelector<Single, RegressionDisagreementDiversityMeasure>, IRegressionSubModelSelector
    {
        public const string UserName = "Best Diverse Selector";
        public const string LoadName = "BestDiverseSelectorRegression";
 
        [TlcModule.Component(Name = LoadName, FriendlyName = UserName)]
        public sealed class Arguments : DiverseSelectorArguments, ISupportRegressionSubModelSelectorFactory
        {
            [Argument(ArgumentType.Multiple, HelpText = "The metric type to be used to find the diversity among base learners", ShortName = "dm", SortOrder = 50)]
            [TGUI(Label = "Diversity Measure Type")]
            public ISupportRegressionDiversityMeasureFactory DiversityMetricType = new RegressionDisagreementDiversityFactory();
            public IRegressionSubModelSelector CreateComponent(IHostEnvironment env) => new BestDiverseSelectorRegression(env, this);
        }
 
        public BestDiverseSelectorRegression(IHostEnvironment env, Arguments args)
            : base(env, args, LoadName, args.DiversityMetricType)
        {
        }
 
        public override List<ModelDiversityMetric<Single>> CalculateDiversityMeasure(IList<FeatureSubsetModel<float>> models,
            ConcurrentDictionary<FeatureSubsetModel<float>, Single[]> predictions)
        {
            var diversityMetric = CreateDiversityMetric();
            return diversityMetric.CalculateDiversityMeasure(models, predictions);
        }
 
        protected override PredictionKind PredictionKind => PredictionKind.Regression;
    }
}