using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using static System.IO.File;
using static System.Threading.Tasks.Parallel;

namespace potokC
{
    class Program
    {
        static void Main(string[] args)
        {
            const string delimiters = " ,.!?-";

            var inputFilename = "text2.txt";
            var outputFilename = "output2.html";
            var dictionaryFilename = "dictionary2.txt";

            var dictionary = new HashSet<string>(ReadAllLines(dictionaryFilename));

            var textLines = ReadAllLines(inputFilename, Encoding.UTF8);

            var wordsToMark = new ConcurrentBag<string>();
            for (var i = 0; i < textLines.Length; i++)
            {
                var words = textLines[i].Split(delimiters.ToCharArray(), options: StringSplitOptions.RemoveEmptyEntries)
                    .Distinct()
                    .ToArray();

                ForEach(words, (word) =>
                {
                    if (dictionary.Contains(word))
                        wordsToMark.Add(word);
                });

                foreach (var word in wordsToMark)
                    textLines[i] = textLines[i].Replace(word, MarkWord(word));
            }

            WriteAllLines(outputFilename, textLines, Encoding.UTF8);
        }

        static string MarkWord(string word) => $"<b><i>{word}</b></i>";
    }
}