// 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.
 
#nullable disable
 
using Microsoft.VisualStudio.Debugger.Evaluation;
using Microsoft.VisualStudio.Debugger.Evaluation.ClrCompilation;
 
namespace Microsoft.CodeAnalysis.ExpressionEvaluator
{
    internal sealed class AggregateExpansion : Expansion
    {
        private readonly bool _containsFavorites;
        private readonly Expansion[] _expansions;
 
        internal static Expansion CreateExpansion(ArrayBuilder<Expansion> expansions)
        {
            switch (expansions.Count)
            {
                case 0:
                    return null;
                case 1:
                    return expansions[0];
                default:
                    return new AggregateExpansion(expansions.ToArray());
            }
        }
 
        internal AggregateExpansion(Expansion[] expansions)
        {
            _expansions = expansions;
 
            if (expansions != null)
            {
                foreach (var expansion in expansions)
                {
                    if (expansion.ContainsFavorites)
                    {
                        _containsFavorites = true;
                        break;
                    }
                }
            }
        }
 
        internal override bool ContainsFavorites => _containsFavorites;
 
        internal override void GetRows(
            ResultProvider resultProvider,
            ArrayBuilder<EvalResult> rows,
            DkmInspectionContext inspectionContext,
            EvalResultDataItem parent,
            DkmClrValue value,
            int startIndex,
            int count,
            bool visitAll,
            ref int index)
        {
            foreach (var expansion in _expansions)
            {
                expansion.GetRows(resultProvider, rows, inspectionContext, parent, value, startIndex, count, visitAll, ref index);
                if (!visitAll && (index >= startIndex + count))
                {
                    return;
                }
            }
        }
    }
}