// 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.Collections.Generic;
using System.Collections.Immutable;
using System.Composition;
using System.Diagnostics.CodeAnalysis;
using System.Linq;
using Microsoft.CodeAnalysis.CodeRefactorings;
using Microsoft.CodeAnalysis.CSharp.Extensions;
using Microsoft.CodeAnalysis.CSharp.Syntax;
using Microsoft.CodeAnalysis.UseNamedArguments;

namespace Microsoft.CodeAnalysis.CSharp.UseNamedArguments;

using static SyntaxFactory;

[ExtensionOrder(After = PredefinedCodeRefactoringProviderNames.IntroduceVariable)]
[ExportCodeRefactoringProvider(LanguageNames.CSharp, Name = PredefinedCodeRefactoringProviderNames.UseNamedArguments), Shared]
internal sealed class CSharpUseNamedArgumentsCodeRefactoringProvider : AbstractUseNamedArgumentsCodeRefactoringProvider
{
    private abstract class BaseAnalyzer<TSyntax, TSyntaxList> : Analyzer<TSyntax, TSyntax, TSyntaxList>
        where TSyntax : SyntaxNode
        where TSyntaxList : SyntaxNode
    {
        protected abstract ExpressionSyntax GetArgumentExpression(TSyntax argumentSyntax);

        protected sealed override SyntaxNode? GetReceiver(SyntaxNode argument)
            => argument.Parent?.Parent;

        protected sealed override bool IsLegalToAddNamedArguments(ImmutableArray<IParameterSymbol> parameters, int argumentCount)
            => !parameters.Last().IsParams || parameters.Length >= argumentCount;

        protected override bool SupportsNonTrailingNamedArguments(ParseOptions options)
            => options.LanguageVersion() >= LanguageVersion.CSharp7_2;

        protected override bool IsImplicitIndexOrRangeIndexer(ImmutableArray<IParameterSymbol> parameters, TSyntax argument, SemanticModel semanticModel)
        {
            // There is no direct way to tell if an implicit range or index indexer was used.
            // The heuristic we use here is to check if the parameter doesn't fit the method it's being used with. 
            // The easiest way to check that is to see if the argType only has at most an explicit conversion 
            // to the indexers parameter types.

            var argType = semanticModel.GetTypeInfo(GetArgumentExpression(argument)).Type;
            if (argType?.ContainingNamespace is { Name: nameof(System), ContainingNamespace.IsGlobalNamespace: true } &&
                (argType.Name == "Range" || argType.Name == "Index"))
            {
                var conversion = semanticModel.Compilation.ClassifyConversion(argType, parameters[0].Type);
                if (!conversion.Exists || conversion.IsExplicit)
                {
                    return true;
                }
            }

            return false;
        }
    }

    private sealed class ArgumentAnalyzer :
        BaseAnalyzer<ArgumentSyntax, BaseArgumentListSyntax>
    {
        protected override bool IsPositionalArgument(ArgumentSyntax node)
            => node.NameColon == null;

        protected override SeparatedSyntaxList<ArgumentSyntax> GetArguments(BaseArgumentListSyntax argumentList)
            => argumentList.Arguments;

        protected override BaseArgumentListSyntax WithArguments(
            BaseArgumentListSyntax argumentList, IEnumerable<ArgumentSyntax> namedArguments, IEnumerable<SyntaxToken> separators)
            => argumentList.WithArguments(SeparatedList(namedArguments, separators));

        protected override ArgumentSyntax WithName(ArgumentSyntax argument, string name)
            => argument.WithNameColon(NameColon(name.ToIdentifierName()));

        protected override ExpressionSyntax GetArgumentExpression(ArgumentSyntax argumentSyntax)
            => argumentSyntax.Expression;
    }

    private sealed class AttributeArgumentAnalyzer :
        BaseAnalyzer<AttributeArgumentSyntax, AttributeArgumentListSyntax>
    {
        protected override bool IsPositionalArgument(AttributeArgumentSyntax argument)
            => argument is { NameColon: null, NameEquals: null };

        protected override SeparatedSyntaxList<AttributeArgumentSyntax> GetArguments(AttributeArgumentListSyntax argumentList)
            => argumentList.Arguments;

        protected override AttributeArgumentListSyntax WithArguments(
            AttributeArgumentListSyntax argumentList, IEnumerable<AttributeArgumentSyntax> namedArguments, IEnumerable<SyntaxToken> separators)
            => argumentList.WithArguments(SeparatedList(namedArguments, separators));

        protected override AttributeArgumentSyntax WithName(AttributeArgumentSyntax argument, string name)
            => argument.WithNameColon(NameColon(name.ToIdentifierName()));

        protected override ExpressionSyntax GetArgumentExpression(AttributeArgumentSyntax argumentSyntax)
            => argumentSyntax.Expression;
    }

    [ImportingConstructor]
    [SuppressMessage("RoslynDiagnosticsReliability", "RS0033:Importing constructor should be [Obsolete]", Justification = "Used in test code: https://github.com/dotnet/roslyn/issues/42814")]
    public CSharpUseNamedArgumentsCodeRefactoringProvider()
        : base(new ArgumentAnalyzer(), new AttributeArgumentAnalyzer())
    {
    }
}