using System;
using System.Xml.Linq;
using System.Linq;
using System.Web;
using System.Text;
using System.Text.RegularExpressions;
using static System.Runtime.InteropServices.JavaScript.JSType;

namespace xmlparser
{
    class Program
    {
        static void Main(string[] args)
        {

            XNamespace ns = "http://ijr.hu/schema/jogszabaly.xsd";

            string[] files = Directory.GetFiles(@"xml_files", "*.xml");

            string resultText = "";

            foreach (var filepath in files)
            {

                XDocument doc = XDocument.Load(filepath);

                var content = doc.Descendants(XName.Get("tartalom", ns.ToString())).FirstOrDefault();

                resultText += ExtractText(content);

            }
            resultText = RemoveTagsFromXmlLikeString(resultText);
            resultText = RemoveExtraSpaces(resultText);

            File.WriteAllText("output.txt", resultText);
        }


        static string ExtractText(XElement element)
        {
            var textBuilder = new StringBuilder();

            foreach (var node in element.DescendantNodesAndSelf())
            {
                textBuilder.Append((node as XText)?.Value ?? (node as XCData)?.Value);
                textBuilder.Append(" ");
            }

            return textBuilder.ToString();
        }

        static string RemoveTagsFromXmlLikeString(string input)
        {
            string pattern = @"<[^>]+?>";
            return Regex.Replace(input, pattern, "");
        }

        public static string RemoveExtraSpaces(string sender)
        {
            const RegexOptions options = RegexOptions.None;
            var regex = new Regex("[ ]{2,}", options);
            return regex.Replace(sender, " ").Trim();
        }

    }
}