.net to parse an edi file

parse-edi-file.cs

using System.Text;
using EdiEngine;
using EdiEngine.Runtime;
using Newtonsoft.Json;

namespace ParseEDI;
class Program
{
    static async Task Main(string[] args)
    {
        Console.WriteLine("Hello, World!");
//using https://github.com/olmelabs/EdiEngine/wiki/Reading-EDI-and-Writing-JSON-or-XML
//sample.txt has the edi data from an 850
        
        string data = await  ReadTextFileAsync("/Users/victorpacheco/Desktop/YouTube/sample.txt");

        //Console.WriteLine(data);
        Parse850(data);


        Console.ReadLine();
    }

    static void Parse850(string edi)
    {
       
            EdiDataReader r = new EdiDataReader();
            EdiBatch b = r.FromString(edi);

            //Serialize the whole batch to JSON
            JsonDataWriter w1 = new JsonDataWriter();
            string json = w1.WriteToString(b);

            Console.WriteLine(json);

        Console.WriteLine("-----");
   

       var items = ExportItems(b.Interchanges);

       

        File.WriteAllText("/Users/victorpacheco/Desktop/YouTube/sample-items-po-"+items[1] +".csv", items[0]);

    }
    
    static string[] ExportItems(List<EdiInterchange> ediInterchange) {
        var sb = new StringBuilder();
        string deli = ",";
        string po = string.Empty;

        foreach (var interchange in ediInterchange)
        {
            foreach (var group in interchange.Groups)
            {
                
                foreach (var transaction in group.Transactions)
                {
                    po = string.Empty;
                    foreach (var content in transaction.Content)
                    {
                        if (content.Name.Equals("BEG")) {

                            var poData = content as EdiSegment;
                            if (poData != null) {
                                var poSegment = poData.Content as List<DataElementBase>;

                                po = poSegment[2].Val;
                            }
                            


                        }

                        if (content.Name.Equals("L_PO1")) {

                            var items = content as EdiEngine.Runtime.EdiLoop;

                            if (items != null) {

                                foreach (var itemContent in items.Content)
                                {
                                    var segment = itemContent as EdiSegment;

                                    if (segment != null) {
                                        if (segment.Name.Equals("PO1"))
                                            {

                                            foreach (var segmentContent in segment.Content)
                                            {
                                                var data = segmentContent as EdiSimpleDataElement;
                                                if (data != null)
                                                {
                                                    var value = data.Val;
                                                    sb.Append(value + deli);
                                                }

                                            }

                                            sb.Append("\n");
                                        }
                                        

                                    }
                                    
                                }
                            }
                            
                            
                        }
                    }
                }
            }
        }

        return new string[2]{ sb.ToString(),po};
    }

    static async Task<string> ReadTextFileAsync(string filename) {
        
        char[] result;
        StringBuilder builder = new StringBuilder();

        using (StreamReader reader = File.OpenText(filename))
        {
            result = new char[reader.BaseStream.Length];
            await reader.ReadAsync(result, 0, (int)reader.BaseStream.Length);
        }


        foreach (char c in result)
        {
           
            builder.Append(c.ToString().Replace("\n",""));
            
        }
        
        return builder.ToString();
    }
}