// 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.Linq;
 
namespace Microsoft.ML.SearchSpace.Tuner
{
    internal sealed class RandomTuner
    {
        private readonly Random _rnd;
 
        public RandomTuner(int? seed = null)
        {
            if (seed is int)
            {
                _rnd = new Random(seed.Value);
            }
            else
            {
                _rnd = new Random();
            }
        }
 
        public RandomTuner(int seed)
        {
            _rnd = new Random(seed);
        }
 
        public Parameter Propose(SearchSpace searchSpace)
        {
            var d = searchSpace.FeatureSpaceDim;
            var featureVec = Enumerable.Repeat(0, d).Select(i => _rnd.NextDouble()).ToArray();
            return searchSpace.SampleFromFeatureSpace(featureVec);
        }
 
        public void Update(Parameter param, double metric, bool isMaximize)
        {
            // do nothing
        }
    }
}