HtmlParser

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Formats.Tar;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;

namespace HtmlParser
{
    internal class Element
    {
        public Element()
        {
        }

        private void GetTag(string line, string tagName)
        {
            var pattern = "<" + tagName + " (.*)>(.*)";

            var regex = new Regex(pattern);

            var match = regex.Match(line);

            if (match.Success)
            {
                Console.WriteLine(match.Groups[0].Value);

                string attr = GetAttr(match.Groups[0].Value, "href");



                Console.WriteLine(attr);

                attr = GetQueryString(attr, "genre_item");

                Console.WriteLine(attr);

                attr = GetAttr(match.Groups[0].Value, "class");

                Console.WriteLine(attr);

                string value = GetValue(match.Groups[0].Value, tagName);

                Console.WriteLine(value);
            }
        }

        public string GetTag1(string line, string tagName)
        {
            var rtn = string.Empty;

                var pattern = "<" + tagName + " (.*)>(.*)";

                var regex = new Regex(pattern);

                var match = regex.Matches(line);

            foreach (Match item in match)
            {
                Console.WriteLine(item.Value);

                string attr = GetAttr(item.Value, "href");

                Console.WriteLine(attr);

                attr = GetQueryString(item.Value, "genre_item");

                Console.WriteLine(attr);

                attr = GetAttr(item.Value, "class");

                Console.WriteLine(attr);

                string value = GetValue(item.Value, tagName);

                Console.WriteLine(value);

                rtn = item.Value;
            }

            return rtn;
        }

        private string GetAttr(string str, string attrPattern)
        {
            attrPattern += "=\"";

            var rtn = string.Empty;
            int i = 0;
            bool flag = true;
            int max = attrPattern.Length;

            StringBuilder sb = new StringBuilder();

            bool attrFlag = false;

            while (i < str.Length)
            {
                foreach (char c in attrPattern)
                {
                    if (str[i] == c)
                    {
                        i++;
                        attrFlag = true;
                    }
                    else
                    {
                        attrFlag = false;
                        break;
                    }
                }

                if (attrFlag)
                {
                    break;
                }

                i++;
            }

            if (attrFlag)
            {
                while (i < str.Length)
                {
                    if (str[i] == '\"')
                    {
                        flag |= false;

                        i += 1;

                        break;
                    }


                    if (flag)
                    {
                        try
                        {
                            sb.Append(str[i]);
                        }
                        catch (Exception ex)
                        {
                        }
                    }

                    i++;
                }
            }

            return sb.ToString();
        }

        private string GetValue(string str, string attrPattern)
        {
            var Pattern = "";
            var rtn = string.Empty;
            int i = 0;
            bool flag = true;

            StringBuilder sb = new StringBuilder();

            bool attrFlag = false;

            while (i < str.Length)
            {

                if (str[i] == '>')
                {
                    attrFlag = true;
                    i++;
                    break;
                }

                i++;
            }

            if (attrFlag)
            {
                while (i < str.Length)
                {
                    foreach (char c in Pattern)
                    {
                        if (str[i] == c)
                        {
                            i++;
                            flag = true;
                        }
                        else
                        {
                            flag = false;
                            break;
                        }
                    }

                    if (!flag)
                    {
                        try
                        {
                            sb.Append(str[i]);
                        }
                        catch (Exception ex)
                        {
                        }
                    }

                    i++;
                }
            }

            return sb.ToString();
        }

        private string GetQueryString(string str, string attrPattern)
        {
            attrPattern += "=";

            var rtn = string.Empty;
            int i = 0;
            bool flag = true;
            int max = attrPattern.Length;

            StringBuilder sb = new StringBuilder();

            bool attrFlag = false;

            while (i < str.Length)
            {
                foreach (char c in attrPattern)
                {
                    try
                    {
                        if (str[i] == c)
                        {
                            i++;
                            attrFlag = true;
                        }
                        else
                        {
                            attrFlag = false;
                            break;
                        }
                    }
                    catch (Exception ex)
                    {
                        break;
                    }
                }

                if (attrFlag)
                {
                    break;
                }

                i++;
            }

            if (attrFlag)
            {
                while (i < str.Length)
                {
                    if (str[i] == '\"')
                    {
                        flag |= false;

                        i += 1;

                        break;
                    }


                    if (flag)
                    {
                        try
                        {
                            sb.Append(str[i]);
                        }
                        catch (Exception ex)
                        {
                        }
                    }

                    i++;
                }
            }

            return sb.ToString();
        }

    }
    internal class Parser
    {
        public Parser()
        {
            var html = string.Empty;
            var filename = @"C:\path\to\dir\1.txt";

            using (var sr = new StreamReader(filename, System.Text.Encoding.UTF8))
            {
                while (sr.Peek() > -1)
                {
                    var line = sr.ReadLine();

                    var element = new Element();
                    var str = element.GetTag1(line, "a");
                }
            }
        }
    }
}