// 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.CodeAnalysis.Editor.Implementation.IntelliSense.SignatureHelp;
using Microsoft.CodeAnalysis.Editor.Options;
using Microsoft.CodeAnalysis.Editor.Shared.Extensions;
using Microsoft.CodeAnalysis.Editor.Shared.Utilities;
using Microsoft.CodeAnalysis.Options;
using Microsoft.VisualStudio.Text.Editor.Commanding;
using Microsoft.VisualStudio.Text.Editor.Commanding.Commands;
 
namespace Microsoft.CodeAnalysis.Editor.CommandHandlers
{
    internal abstract class AbstractSignatureHelpCommandHandler
    {
        protected readonly IThreadingContext ThreadingContext;
        private readonly SignatureHelpControllerProvider _controllerProvider;
        private readonly IGlobalOptionService _globalOptions;
 
        public AbstractSignatureHelpCommandHandler(
            IThreadingContext threadingContext,
            SignatureHelpControllerProvider controllerProvider,
            IGlobalOptionService globalOptions)
        {
            ThreadingContext = threadingContext;
            _controllerProvider = controllerProvider;
            _globalOptions = globalOptions;
        }
 
        protected bool TryGetController(EditorCommandArgs args, out Controller controller)
        {
            this.ThreadingContext.ThrowIfNotOnUIThread();
 
            // If args is `InvokeSignatureHelpCommandArgs` then sig help was explicitly invoked by the user and should
            // be shown whether or not the option is set.
            var languageName = args.SubjectBuffer.GetLanguageName();
            if (args is not InvokeSignatureHelpCommandArgs &&
                languageName != null &&
                !_globalOptions.GetOption(SignatureHelpViewOptionsStorage.ShowSignatureHelp, languageName))
            {
                controller = null;
                return false;
            }
 
            controller = _controllerProvider.GetController(args.TextView, args.SubjectBuffer);
            return controller is not null;
        }
    }
}