// 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 additional information about the context in which a signature help request is triggered.
/// <para>
/// See the <see href="https://microsoft.github.io/language-server-protocol/specifications/specification-current/#signatureHelpContext">Language Server Protocol specification</see> for additional information.
/// </para>
/// </summary>
/// <remarks>Since LSP 3.15</remarks>
internal sealed class SignatureHelpContext
{
    /// <summary>
    /// Gets or sets the <see cref="SignatureHelpTriggerKind"/> indicating how the signature help was triggered.
    /// </summary>
    [JsonPropertyName("triggerKind")]
    public SignatureHelpTriggerKind TriggerKind
    {
        get;
        set;
    }
 
    /// <summary>
    /// Gets or sets the character that caused signature help to be triggered.
    /// <para>
    /// This is defined when <see cref="TriggerCharacter"/> when is not
    /// <see cref="SignatureHelpTriggerKind.TriggerCharacter"/>.
    /// </para>
    /// </summary>
    [JsonPropertyName("triggerCharacter")]
    [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
    public string? TriggerCharacter
    {
        get;
        set;
    }
 
    /// <summary>
    /// Gets or sets a value indicating whether signature help was already showing when it was triggered.
    /// <para>
    /// Retriggers occur when the signature help is already active and can be 
    /// caused by actions such as typing a trigger character, a cursor move, or 
    /// document content changes.
    /// </para>
    /// </summary>
    [JsonPropertyName("isRetrigger")]
    public bool IsRetrigger
    {
        get;
        set;
    }
 
    /// <summary>
    /// The currently active <see cref="SignatureHelp"/>.
    /// <para>
    /// The <see cref="ActiveSignatureHelp"/> has its <see cref="SignatureHelp.ActiveSignature"/>
    /// updated based on the user navigating through available signatures.
    /// </para>
    /// </summary>
    [JsonPropertyName("activeSignatureHelp")]
    [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
    public SignatureHelp? ActiveSignatureHelp
    {
        get;
        set;
    }
}