// 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.Linq;
using Microsoft.CodeAnalysis.CSharp.Syntax;
using Microsoft.CodeAnalysis.LanguageService;
using Microsoft.CodeAnalysis.Operations;

namespace Microsoft.CodeAnalysis.CSharp.ConvertIfToSwitch;

internal sealed partial class CSharpConvertIfToSwitchCodeRefactoringProvider
{
    private sealed class CSharpAnalyzer(ISyntaxFacts syntaxFacts, Feature features) : Analyzer(syntaxFacts, features)
    {
        public override bool HasUnreachableEndPoint(IOperation operation)
            => !operation.SemanticModel.AnalyzeControlFlow(operation.Syntax).EndPointIsReachable;

        // We do not offer a fix if the if-statement contains a break-statement, e.g.
        //
        //      while (...)
        //      {
        //          if (...) {
        //              break;
        //          }
        //      }
        //
        // When the 'break' moves into the switch, it will have different flow control impact.
        public override bool CanConvert(IConditionalOperation operation)
            => !operation.SemanticModel.AnalyzeControlFlow(operation.Syntax).ExitPoints.Any(static n => n.IsKind(SyntaxKind.BreakStatement));

        public override bool CanImplicitlyConvert(SemanticModel semanticModel, SyntaxNode syntax, ITypeSymbol targetType)
        {
            return syntax is ExpressionSyntax expressionSyntax &&
                semanticModel.ClassifyConversion(expressionSyntax, targetType).IsImplicit;
        }
    }
}