using System;
using System.Collections.Generic;
using System.IO;
using System.Text.RegularExpressions;
using System.Xml;
using System.Xml.Serialization;

namespace FeedAnalyzer
{
    [System.Serializable()]
    public class FeedItem
    {
        public string Title { get; set; }
        public string Sumary { get; set; }
        public DateTime Date { get; set; }
        public string Link { get; set; }
        public string Categories { get; set; }
    }

    class Program
    {
        static void Main(string[] args)
        {
            TwoWordAnalysis();
            Console.WriteLine("ok");
            Console.ReadKey();
        }

        static void TwoWordAnalysis()
        {
            List<FeedItem> list = LoadFeeds("data.xml");
            Console.WriteLine(list.Count + " loaded");
            StreamReader keywordsFile = new StreamReader("keywords.txt");
            StreamWriter output = new StreamWriter("output.txt");

            List<string> keywords = new List<string>();
            while (keywordsFile.EndOfStream == false)
                keywords.Add(keywordsFile.ReadLine());

            string[] keywordArray = keywords.ToArray();

            for (int x = 0; x < keywordArray.Length - 1; x++)
            {
                for (int y = x + 1; y < keywordArray.Length; y++)
                {
                    int num = 0;

                    Regex regex1 = new Regex(String.Join(String.Empty, "\\b", keywordArray[x], " ", keywordArray[y], "\\b"), RegexOptions.IgnoreCase);
                    Regex regex2 = new Regex(String.Join(String.Empty, "\\b", keywordArray[y], " ", keywordArray[x], "\\b"), RegexOptions.IgnoreCase);

                    foreach (FeedItem f in list)
                        num += regex1.Matches(String.Join(" ", f.Title, f.Sumary)).Count + regex2.Matches(String.Join(" ", f.Title, f.Sumary)).Count;

                    if (num > 0)
                    {
                        output.WriteLine(String.Join(" ", num, keywordArray[x], keywordArray[y]));
                    }
                }
            }
            output.Close();
        }

        public static List<FeedItem> LoadFeeds(string fileName)
        {
            List<FeedItem> list = new List<FeedItem>();
            try
            {
                XmlReaderSettings settings = new XmlReaderSettings();
                settings.CheckCharacters = false;
                XmlSerializer s = new XmlSerializer(typeof(FeedItem[]));
                XmlReader reader = XmlReader.Create(new StreamReader(fileName), settings);
                FeedItem[] array = (FeedItem[])s.Deserialize(reader);
                list.AddRange(array);
                reader.Close();
            }
            catch (Exception exc)
            {
                Console.WriteLine(exc.Message);
                Console.WriteLine(exc.StackTrace);
                return null;
            }
            return list;
        }
    }
}