// Copyright (c) .NET Foundation and contributors. All rights reserved.
// Licensed under the MIT license. See LICENSE file in the project root for full license information.

using System;
using System.Collections.Immutable;
using System.Composition;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using ILLink.CodeFixProvider;
using ILLink.RoslynAnalyzer;
using ILLink.Shared;
using Microsoft.CodeAnalysis;
using Microsoft.CodeAnalysis.CodeActions;
using Microsoft.CodeAnalysis.CodeFixes;
using Microsoft.CodeAnalysis.CSharp.Syntax;
using Microsoft.CodeAnalysis.Editing;
using Microsoft.CodeAnalysis.Simplification;

namespace ILLink.CodeFix
{
    [ExportCodeFixProvider(LanguageNames.CSharp, Name = nameof(DynamicallyAccessedMembersCodeFixProvider)), Shared]
    public sealed class DynamicallyAccessedMembersCodeFixProvider : Microsoft.CodeAnalysis.CodeFixes.CodeFixProvider
    {
        private static ImmutableArray<DiagnosticDescriptor> GetSupportedDiagnostics()
        {
            // Commented-out are currently unsupported Generic Parameter DiagnosticIDs
            var diagDescriptorsArrayBuilder = ImmutableArray.CreateBuilder<DiagnosticDescriptor>();
            diagDescriptorsArrayBuilder.Add(DiagnosticDescriptors.GetDiagnosticDescriptor(DiagnosticId.DynamicallyAccessedMembersMismatchParameterTargetsParameter));
            diagDescriptorsArrayBuilder.Add(DiagnosticDescriptors.GetDiagnosticDescriptor(DiagnosticId.DynamicallyAccessedMembersMismatchParameterTargetsMethodReturnType));
            diagDescriptorsArrayBuilder.Add(DiagnosticDescriptors.GetDiagnosticDescriptor(DiagnosticId.DynamicallyAccessedMembersMismatchParameterTargetsField));
            diagDescriptorsArrayBuilder.Add(DiagnosticDescriptors.GetDiagnosticDescriptor(DiagnosticId.DynamicallyAccessedMembersMismatchParameterTargetsThisParameter));
            // diagDescriptorsArrayBuilder.Add(DiagnosticDescriptors.GetDiagnosticDescriptor(DiagnosticId.DynamicallyAccessedMembersMismatchParameterTargetsGenericParameter));
            diagDescriptorsArrayBuilder.Add(DiagnosticDescriptors.GetDiagnosticDescriptor(DiagnosticId.DynamicallyAccessedMembersMismatchMethodReturnTypeTargetsParameter));
            diagDescriptorsArrayBuilder.Add(DiagnosticDescriptors.GetDiagnosticDescriptor(DiagnosticId.DynamicallyAccessedMembersMismatchMethodReturnTypeTargetsMethodReturnType));
            diagDescriptorsArrayBuilder.Add(DiagnosticDescriptors.GetDiagnosticDescriptor(DiagnosticId.DynamicallyAccessedMembersMismatchMethodReturnTypeTargetsField));
            diagDescriptorsArrayBuilder.Add(DiagnosticDescriptors.GetDiagnosticDescriptor(DiagnosticId.DynamicallyAccessedMembersMismatchMethodReturnTypeTargetsThisParameter));
            // diagDescriptorsArrayBuilder.Add(DiagnosticDescriptors.GetDiagnosticDescriptor(DiagnosticId.DynamicallyAccessedMembersMismatchMethodReturnTypeTargetsGenericParameter));
            diagDescriptorsArrayBuilder.Add(DiagnosticDescriptors.GetDiagnosticDescriptor(DiagnosticId.DynamicallyAccessedMembersMismatchFieldTargetsParameter));
            diagDescriptorsArrayBuilder.Add(DiagnosticDescriptors.GetDiagnosticDescriptor(DiagnosticId.DynamicallyAccessedMembersMismatchFieldTargetsMethodReturnType));
            diagDescriptorsArrayBuilder.Add(DiagnosticDescriptors.GetDiagnosticDescriptor(DiagnosticId.DynamicallyAccessedMembersMismatchFieldTargetsField));
            diagDescriptorsArrayBuilder.Add(DiagnosticDescriptors.GetDiagnosticDescriptor(DiagnosticId.DynamicallyAccessedMembersMismatchFieldTargetsThisParameter));
            // diagDescriptorsArrayBuilder.Add(DiagnosticDescriptors.GetDiagnosticDescriptor(DiagnosticId.DynamicallyAccessedMembersMismatchFieldTargetsGenericParameter));
            diagDescriptorsArrayBuilder.Add(DiagnosticDescriptors.GetDiagnosticDescriptor(DiagnosticId.DynamicallyAccessedMembersMismatchThisParameterTargetsParameter));
            diagDescriptorsArrayBuilder.Add(DiagnosticDescriptors.GetDiagnosticDescriptor(DiagnosticId.DynamicallyAccessedMembersMismatchThisParameterTargetsMethodReturnType));
            diagDescriptorsArrayBuilder.Add(DiagnosticDescriptors.GetDiagnosticDescriptor(DiagnosticId.DynamicallyAccessedMembersMismatchThisParameterTargetsField));
            diagDescriptorsArrayBuilder.Add(DiagnosticDescriptors.GetDiagnosticDescriptor(DiagnosticId.DynamicallyAccessedMembersMismatchThisParameterTargetsThisParameter));
            // diagDescriptorsArrayBuilder.Add(DiagnosticDescriptors.GetDiagnosticDescriptor(DiagnosticId.DynamicallyAccessedMembersMismatchThisParameterTargetsGenericParameter));
            diagDescriptorsArrayBuilder.Add(DiagnosticDescriptors.GetDiagnosticDescriptor(DiagnosticId.DynamicallyAccessedMembersMismatchTypeArgumentTargetsParameter));
            diagDescriptorsArrayBuilder.Add(DiagnosticDescriptors.GetDiagnosticDescriptor(DiagnosticId.DynamicallyAccessedMembersMismatchTypeArgumentTargetsMethodReturnType));
            diagDescriptorsArrayBuilder.Add(DiagnosticDescriptors.GetDiagnosticDescriptor(DiagnosticId.DynamicallyAccessedMembersMismatchTypeArgumentTargetsField));
            diagDescriptorsArrayBuilder.Add(DiagnosticDescriptors.GetDiagnosticDescriptor(DiagnosticId.DynamicallyAccessedMembersMismatchTypeArgumentTargetsThisParameter));
            diagDescriptorsArrayBuilder.Add(DiagnosticDescriptors.GetDiagnosticDescriptor(DiagnosticId.DynamicallyAccessedMembersMismatchTypeArgumentTargetsGenericParameter));
            diagDescriptorsArrayBuilder.Add(DiagnosticDescriptors.GetDiagnosticDescriptor(DiagnosticId.DynamicallyAccessedMembersMismatchOnMethodParameterBetweenOverrides));
            diagDescriptorsArrayBuilder.Add(DiagnosticDescriptors.GetDiagnosticDescriptor(DiagnosticId.DynamicallyAccessedMembersMismatchOnMethodReturnValueBetweenOverrides));
            // diagDescriptorsArrayBuilder.Add(DiagnosticDescriptors.GetDiagnosticDescriptor(DiagnosticId.DynamicallyAccessedMembersMismatchOnImplicitThisBetweenOverrides));
            // diagDescriptorsArrayBuilder.Add(DiagnosticDescriptors.GetDiagnosticDescriptor(DiagnosticId.DynamicallyAccessedMembersMismatchOnGenericParameterBetweenOverrides));

            return diagDescriptorsArrayBuilder.ToImmutable();
        }

        public static ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics => GetSupportedDiagnostics();

        public sealed override ImmutableArray<string> FixableDiagnosticIds => SupportedDiagnostics.Select(dd => dd.Id).ToImmutableArray();

        private static LocalizableResourceString CodeFixTitle => new LocalizableResourceString(nameof(Resources.DynamicallyAccessedMembersCodeFixTitle), Resources.ResourceManager, typeof(Resources));

        private static string FullyQualifiedAttributeName => DynamicallyAccessedMembersAnalyzer.FullyQualifiedDynamicallyAccessedMembersAttribute;

        private static readonly string[] AttributeOnReturn = {
            DiagnosticId.DynamicallyAccessedMembersMismatchMethodReturnTypeTargetsParameter.AsString(),
            DiagnosticId.DynamicallyAccessedMembersMismatchMethodReturnTypeTargetsMethodReturnType.AsString(),
            DiagnosticId.DynamicallyAccessedMembersMismatchMethodReturnTypeTargetsField.AsString(),
            DiagnosticId.DynamicallyAccessedMembersMismatchMethodReturnTypeTargetsThisParameter.AsString(),
            DiagnosticId.DynamicallyAccessedMembersMismatchOnMethodReturnValueBetweenOverrides.AsString()
        };

        private static readonly string[] AttributeOnGeneric = {
            DiagnosticId.DynamicallyAccessedMembersMismatchTypeArgumentTargetsParameter.AsString(),
            DiagnosticId.DynamicallyAccessedMembersMismatchTypeArgumentTargetsMethodReturnType.AsString(),
            DiagnosticId.DynamicallyAccessedMembersMismatchTypeArgumentTargetsField.AsString(),
            DiagnosticId.DynamicallyAccessedMembersMismatchTypeArgumentTargetsThisParameter.AsString(),
            DiagnosticId.DynamicallyAccessedMembersMismatchTypeArgumentTargetsGenericParameter.AsString(),
            DiagnosticId.DynamicallyAccessedMembersMismatchOnGenericParameterBetweenOverrides.AsString()
        };

        public sealed override FixAllProvider GetFixAllProvider()
        {
            // See https://github.com/dotnet/roslyn/blob/master/docs/analyzers/FixAllProvider.md for more information on Fix All Providers
            return WellKnownFixAllProviders.BatchFixer;
        }

        public override async Task RegisterCodeFixesAsync(CodeFixContext context)
        {
            var document = context.Document;
            var diagnostic = context.Diagnostics[0];
            var codeFixTitle = CodeFixTitle.ToString();

            if (await document.GetSyntaxRootAsync(context.CancellationToken).ConfigureAwait(false) is not { } root)
                return;
            if (diagnostic.AdditionalLocations.Count == 0)
                return;
            if (root.FindNode(diagnostic.AdditionalLocations[0].SourceSpan, getInnermostNodeForTie: true) is not SyntaxNode targetNode)
                return;
            if (diagnostic.Properties["attributeArgument"] is not string stringArgs || stringArgs.Contains(","))
                return;

            context.RegisterCodeFix(CodeAction.Create(
                title: CodeFixTitle.ToString(),
                createChangedDocument: ct => AddAttributeAsync(
                    document,
                    targetNode,
                    stringArgs,
                    addAsReturnAttribute: AttributeOnReturn.Contains(diagnostic.Id),
                    addGenericParameterAttribute: AttributeOnGeneric.Contains(diagnostic.Id),
                    ct),
                equivalenceKey: codeFixTitle), diagnostic);
        }

        private static async Task<Document> AddAttributeAsync(
            Document document,
            SyntaxNode targetNode,
            string stringArguments,
            bool addAsReturnAttribute,
            bool addGenericParameterAttribute,
            CancellationToken cancellationToken)
        {
            if (await document.GetSemanticModelAsync(cancellationToken).ConfigureAwait(false) is not { } model)
                return document;
            if (model.Compilation.GetBestTypeByMetadataName(FullyQualifiedAttributeName) is not { } attributeSymbol)
                return document;

            var editor = await DocumentEditor.CreateAsync(document, cancellationToken).ConfigureAwait(false);
            var generator = editor.Generator;
            SyntaxNode[] attributeArguments = [generator.AttributeArgument(generator.MemberAccessExpression(generator.DottedName("System.Diagnostics.CodeAnalysis.DynamicallyAccessedMemberTypes"), stringArguments))];
            var attribute = generator.Attribute(
                generator.TypeExpression(attributeSymbol), attributeArguments)
                .WithAdditionalAnnotations(Simplifier.Annotation, Simplifier.AddImportsAnnotation);

            if (addAsReturnAttribute)
            {
                // don't use AddReturnAttribute because it's the same as AddAttribute https://github.com/dotnet/roslyn/pull/63084
                editor.ReplaceNode(targetNode, (d, g) => g.AddReturnAttributes(d, [attribute]));
            }
            else if (addGenericParameterAttribute)
            {
                // AddReturnAttributes currently doesn't support adding attributes to type arguments https://github.com/dotnet/roslyn/pull/63292
                var newNode = (TypeParameterSyntax)targetNode;
                var nodeWithAttribute = newNode.AddAttributeLists((AttributeListSyntax)attribute);
                editor.ReplaceNode(targetNode, nodeWithAttribute);
            }
            else
            {
                editor.AddAttribute(targetNode, attribute);
            }
            return editor.GetChangedDocument();
        }
    }
}