// 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.Collections;
using System.Collections.Generic;
using System.Collections.Immutable;
using System.Runtime.Serialization;
 
namespace Microsoft.CodeAnalysis.SolutionCrawler;
 
[DataContract]
internal partial struct InvocationReasons(ImmutableHashSet<string> reasons) : IEnumerable<string>
{
    public static readonly InvocationReasons Empty = new(ImmutableHashSet<string>.Empty);
 
    [DataMember(Order = 0)]
    private readonly ImmutableHashSet<string> _reasons = reasons ?? [];
 
    public InvocationReasons(string reason)
        : this(ImmutableHashSet.Create(reason))
    {
    }
 
    public bool IsEmpty => _reasons.IsEmpty;
 
    public bool Contains(string reason)
        => _reasons.Contains(reason);
 
    public InvocationReasons With(InvocationReasons invocationReasons)
        => new(_reasons.Union(invocationReasons._reasons));
 
    public InvocationReasons With(string reason)
        => new(_reasons.Add(reason));
 
    public ImmutableHashSet<string>.Enumerator GetEnumerator()
        => _reasons.GetEnumerator();
 
    IEnumerator<string> IEnumerable<string>.GetEnumerator()
        => _reasons.GetEnumerator();
 
    IEnumerator IEnumerable.GetEnumerator()
        => _reasons.GetEnumerator();
 
    public override string ToString()
        => string.Join("|", _reasons ?? []);
}