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

namespace CodePlay.Core.Pipeline.Converters;

/// <summary>
/// LINQ 转 Stream 转换器
/// </summary>
public class LinqToStreamConverter : ILineConverter
{
    public int Priority => 80;
    
    public string Convert(string line, ConversionContext context)
    {
        var result = line;
        
        result = Regex.Replace(result, @"\.Where\(", ".filter(");
        result = Regex.Replace(result, @"\.Select\(", ".map(");
        result = Regex.Replace(result, @"\.OrderBy\(", ".sorted(");
        result = Regex.Replace(result, @"\.OrderByDescending\(", ".sorted((a, b) -> b.compareTo(a))(");
        result = Regex.Replace(result, @"\.ThenBy\(", ".thenComparing(");
        result = Regex.Replace(result, @"\.ToList\(\)", ".collect(Collectors.toList())");
        result = Regex.Replace(result, @"\.ToArray\(\)", ".toArray(new Object[0])");
        result = Regex.Replace(result, @"\.FirstOrDefault\(\)", ".findFirst().orElse(null)");
        result = Regex.Replace(result, @"\.FirstOrDefault\((.+?)\)", ".filter($1).findFirst().orElse(null)");
        result = Regex.Replace(result, @"\.First\(\)", ".findFirst().get()");
        result = Regex.Replace(result, @"\.FirstOrDefault\b", ".findFirst().orElse(null)");
        result = Regex.Replace(result, @"\.LastOrDefault\(\)", ".reduce((first, second) -> second).orElse(null)");
        result = Regex.Replace(result, @"\.Any\(", ".anyMatch(");
        result = Regex.Replace(result, @"\.All\(", ".allMatch(");
        result = Regex.Replace(result, @"\.Count\(\)", ".count()");
        result = Regex.Replace(result, @"\.Sum\(\)", ".mapToInt(x -> x).sum()");
        result = Regex.Replace(result, @"\.Distinct\(\)", ".distinct()");
        result = Regex.Replace(result, @"\.Take\(", ".limit(");
        result = Regex.Replace(result, @"\.Skip\(", ".skip(");
        result = Regex.Replace(result, @"\.TakeWhile\(", ".takeWhile(");
        result = Regex.Replace(result, @"\.SkipWhile\(", ".dropWhile(");
        result = Regex.Replace(result, @"\.Reverse\(\)", ".reduce((first, second) -> Stream.of(second, first).collect(Collectors.toList())).flatMap(List::stream)");
        result = Regex.Replace(result, @"\.Union\(", ".concat(");
        result = Regex.Replace(result, @"\.Intersect\(", ".filter(x -> other.contains(x)) // Intersect: ");
        result = Regex.Replace(result, @"\.Except\(", ".filter(x -> !other.contains(x)) // Except: ");
        result = Regex.Replace(result, @"\.GroupBy\((.+?)\)", ".collect(Collectors.groupingBy($1)) // GroupBy result needs further processing");
        result = Regex.Replace(result, @"\.Aggregate\((.+?),\s*(.+?),\s*(.+?)\)", ".reduce($1, $2, $3)");
        
        return result;
    }
}