// 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.Composition;
using System.Diagnostics.CodeAnalysis;
using System.Text;
using Microsoft.CodeAnalysis.CodeFixes;
using Microsoft.CodeAnalysis.CSharp.Analyzers.SimplifyInterpolation;
using Microsoft.CodeAnalysis.CSharp.Syntax;
using Microsoft.CodeAnalysis.SimplifyInterpolation;
 
namespace Microsoft.CodeAnalysis.CSharp.SimplifyInterpolation
{
    [ExportCodeFixProvider(LanguageNames.CSharp, Name = PredefinedCodeFixProviderNames.SimplifyInterpolation), Shared]
    internal class CSharpSimplifyInterpolationCodeFixProvider : AbstractSimplifyInterpolationCodeFixProvider<
        InterpolationSyntax, ExpressionSyntax, InterpolationAlignmentClauseSyntax,
        InterpolationFormatClauseSyntax, InterpolatedStringExpressionSyntax>
    {
        [ImportingConstructor]
        [SuppressMessage("RoslynDiagnosticsReliability", "RS0033:Importing constructor should be [Obsolete]", Justification = "Used in test code: https://github.com/dotnet/roslyn/issues/42814")]
        public CSharpSimplifyInterpolationCodeFixProvider()
        {
        }
 
        protected override AbstractSimplifyInterpolationHelpers GetHelpers() => CSharpSimplifyInterpolationHelpers.Instance;
 
        protected override InterpolationSyntax WithExpression(InterpolationSyntax interpolation, ExpressionSyntax expression)
            => interpolation.WithExpression(expression);
 
        protected override InterpolationSyntax WithAlignmentClause(InterpolationSyntax interpolation, InterpolationAlignmentClauseSyntax alignmentClause)
            => interpolation.WithAlignmentClause(alignmentClause);
 
        protected override InterpolationSyntax WithFormatClause(InterpolationSyntax interpolation, InterpolationFormatClauseSyntax formatClause)
            => interpolation.WithFormatClause(formatClause);
 
        protected override string Escape(InterpolatedStringExpressionSyntax interpolatedString, string formatString)
        {
            var result = new StringBuilder();
            if (interpolatedString.StringStartToken.Kind() == SyntaxKind.InterpolatedVerbatimStringStartToken)
            {
                foreach (var c in formatString)
                {
                    // in a verbatim string, the only char we have to escape is the double-quote char
                    if (c == '"')
                    {
                        result.Append(c);
                    }
 
                    result.Append(c);
                }
            }
            else
            {
                // In a normal string we have to escape quotes and we have to escape an 
                // escape character itself.
                foreach (var c in formatString)
                {
                    if (c is '"' or '\\')
                    {
                        result.Append('\\');
                    }
 
                    result.Append(c);
                }
            }
 
            return result.ToString();
        }
    }
}