// 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;
using System.Collections.Immutable;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.CodeAnalysis.CodeActions;
using Microsoft.CodeAnalysis.CodeFixes;
using Microsoft.CodeAnalysis.Diagnostics;
using Microsoft.CodeAnalysis.Editing;
using Microsoft.CodeAnalysis.Shared.Extensions;
 
namespace Microsoft.CodeAnalysis.QualifyMemberAccess
{
    internal abstract class AbstractQualifyMemberAccessCodeFixprovider<TSimpleNameSyntax, TInvocationSyntax>
        : SyntaxEditorBasedCodeFixProvider
        where TSimpleNameSyntax : SyntaxNode
        where TInvocationSyntax : SyntaxNode
    {
        protected abstract string GetTitle();
        protected abstract TSimpleNameSyntax? GetNode(Diagnostic diagnostic, CancellationToken cancellationToken);
 
        public sealed override ImmutableArray<string> FixableDiagnosticIds
            => ImmutableArray.Create(IDEDiagnosticIds.AddThisOrMeQualificationDiagnosticId);
 
        public override Task RegisterCodeFixesAsync(CodeFixContext context)
        {
            var title = GetTitle();
            RegisterCodeFix(context, title, title);
            return Task.CompletedTask;
        }
 
        protected override Task FixAllAsync(
            Document document, ImmutableArray<Diagnostic> diagnostics,
            SyntaxEditor editor, CodeActionOptionsProvider fallbackOptions, CancellationToken cancellationToken)
        {
            var generator = document.GetRequiredLanguageService<SyntaxGenerator>();
 
            foreach (var diagnostic in diagnostics)
            {
                var node = GetNode(diagnostic, cancellationToken);
                if (node != null)
                {
                    var qualifiedAccess =
                        generator.MemberAccessExpression(
                            generator.ThisExpression(),
                            node.WithLeadingTrivia())
                        .WithLeadingTrivia(node.GetLeadingTrivia());
 
                    editor.ReplaceNode(node, qualifiedAccess);
                }
            }
 
            return Task.CompletedTask;
        }
    }
}