// 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 System.Threading;
using Microsoft.VisualStudio.LanguageServices.Implementation.Interop;
using Microsoft.VisualStudio.LanguageServices.Implementation.Utilities;
using Microsoft.VisualStudio.TextManager.Interop;
 
namespace Microsoft.VisualStudio.LanguageServices.Implementation.CodeModel.InternalElements
{
    public sealed class CodeFunctionWithEventHandler : CodeFunction, Interop.IEventHandler
    {
        internal static new EnvDTE.CodeFunction Create(
           CodeModelState state,
           FileCodeModel fileCodeModel,
           SyntaxNodeKey nodeKey,
           int? nodeKind)
        {
            var element = new CodeFunctionWithEventHandler(state, fileCodeModel, nodeKey, nodeKind);
            var result = (EnvDTE.CodeFunction)ComAggregate.CreateAggregatedObject(element);
 
            fileCodeModel.OnCodeElementCreated(nodeKey, (EnvDTE.CodeElement)result);
 
            return result;
        }
 
        internal static new EnvDTE.CodeFunction CreateUnknown(
           CodeModelState state,
           FileCodeModel fileCodeModel,
           int nodeKind,
           string name)
        {
            var element = new CodeFunctionWithEventHandler(state, fileCodeModel, nodeKind, name);
            return (EnvDTE.CodeFunction)ComAggregate.CreateAggregatedObject(element);
        }
 
        private CodeFunctionWithEventHandler(
            CodeModelState state,
            FileCodeModel fileCodeModel,
            SyntaxNodeKey nodeKey,
            int? nodeKind)
            : base(state, fileCodeModel, nodeKey, nodeKind)
        {
        }
 
        private CodeFunctionWithEventHandler(
            CodeModelState state,
            FileCodeModel fileCodeModel,
            int nodeKind,
            string name)
            : base(state, fileCodeModel, nodeKind, name)
        {
        }
 
        public int AddHandler(string bstrEventName)
        {
            var node = LookupNode();
            var semanticModel = GetSemanticModel();
 
            FileCodeModel.PerformEdit(document =>
            {
                return CodeModelService.AddHandlesClause(document, bstrEventName, node, CancellationToken.None);
            });
 
            return VSConstants.S_OK;
        }
 
        public int RemoveHandler(string bstrEventName)
        {
            var node = LookupNode();
            var semanticModel = GetSemanticModel();
 
            FileCodeModel.PerformEdit(document =>
            {
                return CodeModelService.RemoveHandlesClause(document, bstrEventName, node, CancellationToken.None);
            });
 
            return VSConstants.S_OK;
        }
 
        public int GetHandledEvents(out IVsEnumBSTR ppUnk)
        {
            var node = LookupNode();
            var semanticModel = GetSemanticModel();
            var handledEvents = CodeModelService.GetHandledEventNames(node, semanticModel);
            ppUnk = new VsEnumBSTR(handledEvents);
 
            return VSConstants.S_OK;
        }
 
        public int HandlesEvent(string bstrEventName, out bool result)
        {
            var node = LookupNode();
            var semanticModel = GetSemanticModel();
 
            result = CodeModelService.HandlesEvent(bstrEventName, node, semanticModel);
 
            return VSConstants.S_OK;
        }
    }
}