// 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.
 
namespace Roslyn.LanguageServer.Protocol
{
    using System.Text.Json.Serialization;
 
    /// <summary>
    /// Class representing a single signature of a callable item.
    /// <para>
    /// See the <see href="https://microsoft.github.io/language-server-protocol/specifications/specification-current/#signatureInformation">Language Server Protocol specification</see> for additional information.
    /// </para>
    /// </summary>
    internal class SignatureInformation
    {
        /// <summary>
        /// The label of this signature. Will be shown in the UI.
        /// </summary>
        [JsonPropertyName("label")]
        public string Label
        {
            get;
            set;
        }
 
        /// <summary>
        /// The human-readable documentation of this signature.
        /// Will be shown in the UI but can be omitted.
        /// </summary>
        [JsonPropertyName("documentation")]
        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
        public SumType<string, MarkupContent>? Documentation
        {
            get;
            set;
        }
 
        /// <summary>
        /// Gets or sets the parameters of this signature.
        /// </summary>
        [JsonPropertyName("parameters")]
        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
        public ParameterInformation[]? Parameters
        {
            get;
            set;
        }
 
        /// <summary>
        /// The index of the active parameter.
        /// <para>
        /// If provided, this is used in place of <see cref="SignatureHelp.ActiveParameter"/>.
        /// </para>
        /// </summary>
        /// <remarks>Since LSP 3.16</remarks>
        [JsonPropertyName("activeParameter")]
        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
        public int? ActiveParameter { get; init; }
    }
}