using CodePlay.Core.Interfaces;
using CodePlay.Core.Models;
using System.Text;
using CodePlay.Core.Common;

namespace CodePlay.Core.Converters;

/// <summary>
/// C# 到 C++ 转换器
/// </summary>
public class CSharpToCppConverter : IConverter
{
    public async Task<ConversionResult> ConvertAsync(
        Interfaces.SyntaxTree syntaxTree, 
        LanguageType targetLanguage, 
        ConversionOptions? options = null, 
        CancellationToken cancellationToken = default)
    {
        var result = new ConversionResult
        {
            Success = false,
            Warnings = new List<ConversionWarning>(),
            Report = new ConversionReport()
        };
        
        if (targetLanguage != LanguageType.CPlusPlus)
        {
            result.ErrorMessage = "This converter only supports C# to C++ conversion";
            return result;
        }
        
        try
        {
            var cppCode = ConvertToCpp(syntaxTree, result.Report, options);
            
            result.Success = true;
            result.TransformedCode = cppCode;
            result.Report.ClassesConverted = 1;
        }
        catch (Exception ex)
        {
            result.Success = false;
            result.ErrorMessage = ex.Message;
        }
        
        return await Task.FromResult(result);
    }

    private string ConvertToCpp(Interfaces.SyntaxTree parsed, ConversionReport report, ConversionOptions? options)
    {
        var sb = new StringBuilder();
        
        sb.AppendLine("#include <iostream>");
        sb.AppendLine("#include <string>");
        sb.AppendLine("#include <vector>");
        sb.AppendLine("#include <memory>");
        sb.AppendLine();
        
        ExtractAndConvertClasses(parsed.Root, sb, report);
        
        return sb.ToString();
    }
    
    private void ExtractAndConvertClasses(SyntaxNode node, StringBuilder sb, ConversionReport report)
    {
        if (node.Type == SyntaxNodeType.Class)
        {
            var className = node.Metadata.TryGetValue("Name", out var name) ? name?.ToString() ?? "Unknown" : "Unknown";
            
            sb.AppendLine($"class {className} {{");
            sb.AppendLine("public:");
            sb.AppendLine($"    {className}() {{}}");
            sb.AppendLine("};");
            sb.AppendLine();
            
            report.ClassesConverted++;
        }
        
        foreach (var child in node.Children)
        {
            ExtractAndConvertClasses(child, sb, report);
        }
    }
}