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

namespace CodePlay.Core.Pipeline.Converters;

/// <summary>
/// 模式匹配转换器 - is 表达式、关系模式等
/// </summary>
public class PatternMatchingConverter : ILineConverter
{
    public int Priority => 60;
    
    public string Convert(string line, ConversionContext context)
    {
        var result = line;
        
        // 类型模式：obj is string s → obj instanceof String
        result = Regex.Replace(result, 
            @"(\w+)\s+is\s+(\w+)\s+(\w+)", 
            "$1 instanceof $2");
        
        // null 模式：is null / is not null
        result = Regex.Replace(result, @"\s+is\s+null\b", " == null");
        result = Regex.Replace(result, @"\s+is\s+not\s+null\b", " != null");
        
        // 关系模式：is (> 0 and < 10) → > 0 && < 10 (简化处理)
        result = ConvertRelationalPatterns(result);
        
        return result;
    }
    
    private string ConvertRelationalPatterns(string line)
    {
        var result = line;
        
        // and 模式
        result = Regex.Replace(result, 
            @"is\s*\(\s*>\s*([\d.]+)\s+and\s+<\s*([\d.]+)\s*\)", 
            "> $1 && < $2");
        
        result = Regex.Replace(result,
            @"is\s*\(\s*>=\s*([\d.]+)\s+and\s+<=\s*([\d.]+)\s*\)",
            ">= $1 && <= $2");
        
        // or 模式
        result = Regex.Replace(result,
            @"is\s*\(\s*<\s*([\d.]+)\s+or\s+>\s*([\d.]+)\s*\)",
            "< $1 || > $2");
        
        // 单独的关系运算符
        result = Regex.Replace(result, @"is\s*>\s*([\d.]+)", "> $1");
        result = Regex.Replace(result, @"is\s*<\s*([\d.]+)", "< $1");
        result = Regex.Replace(result, @"is\s*>=\s*([\d.]+)", ">= $1");
        result = Regex.Replace(result, @"is\s*<=\s*([\d.]+)", "<= $1");
        
        return result;
    }
}