xml-file-hanlder-exercise-2.cs

 public static class ConsoleExtension
    {
        public static void ToConsole<T>(this IEnumerable<T> s, string header)
        {
            Console.WriteLine($"*********BEGIN {header}**************");
            foreach (T item in s)
            {
                Console.WriteLine(item);
            }
            Console.WriteLine($"*********END {header}**************");
            Console.ReadLine();
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            Console.InputEncoding = Encoding.Unicode;
            Console.OutputEncoding = Encoding.Unicode;

            XDocument doc = XDocument.Load("http://users.nik.uni-obuda.hu/prog3/_data/war_of_westeros.xml");

            //Q1 - How many houses participated?

            var q1Attacker = from battle in doc.Descendants("battle")
                             group battle by new
                             {
                                 attacker = battle.Element("attacker").Element("house")
                             } into g
                             select (new { house = g.Key.attacker?.Value });

            var q1Defender = from battle in doc.Descendants("battle")
                             group battle by new
                             {
                                 attacker = battle.Element("defender").Element("house")
                             } into g
                             select (new { house = g.Key.attacker?.Value });

            var q1 = from battle in q1Attacker.Concat(q1Defender)
                     where battle.house != null
                     group battle by battle.house into g
                     select new { house = g.Key };
            //q1.ToConsole("QUERY 1");
            Console.WriteLine($"QUERY 1\n{q1.Count()}");
            Console.ReadLine();

            //Q2 - List the battles with the „ambush” type!
            var q2 = doc.Descendants("battle").Where(battle => battle.Element("type")?.Value == "ambush").Select(battle => battle.Element("name")?.Value);
            q2.ToConsole("QUERY 2");

            //Q3 - How many battles are there where the defending army won and there was a major capture?

            var q3 = doc.Descendants("battle").Where(battle => battle.Element("outcome")?.Value == "defender" && battle.Element("majorcapture")?.Value == "1").Select(battle => battle.Element("name")?.Value);
            //q3.ToConsole("QUERY 3");
            Console.WriteLine($"QUERY 3\n{q3.Count()}");
            Console.ReadLine();

            //Q4 - How many battles were won by the Stark house?

            var q4 = doc.Descendants("battle").Where(battle => (battle.Element("attacker").Element("house")?.Value == "Stark" && battle.Element("outcome")?.Value == "attacker") ||
            (battle.Element("defender").Element("house")?.Value == "Stark" && battle.Element("outcome")?.Value == "defender")).
            Select(battle => battle.Element("name")?.Value);

            //q4.ToConsole("QUERY 4");
            Console.WriteLine($"QUERY 4\n{q4.Count()}");
            Console.ReadLine();

            //Q5 - Which battles had more than 2 participating houses?

            var q5 = from battle in doc.Descendants("battle")
                     let attacker = battle.Element("attacker").Element("house")?.Value
                     let defender = battle.Element("defender").Element("house")?.Value
                     select new { battle.Element("name")?.Value, attacker, defender };
            q5.ToConsole("QUERY 5");

            //Q6 - Which are the 3 most violent regions?

            var q6 = from battle in doc.Descendants("battle")
                     group battle by battle.Element("region")?.Value into g
                     select new { Region = g.Key, count = doc.Descendants("battle").Count(q => q.Element("region")?.Value == g.Key) };

            q6.OrderByDescending(g => g.count).Take(3).ToConsole("QUERY 7");

            //Q7 - Which one is the most violent region?

            var q7 = q6.OrderByDescending(g => g.count).FirstOrDefault();
            Console.WriteLine(q7);
            Console.ReadLine();

            //Q9 - List the houses ordered descending by the number of battles won!


            var q9attacker = from battle in doc.Descendants("battle")
                             where battle.Element("outcome")?.Value == "attacker"
                             select new
                             {
                                 winner = battle.Element("attacker").Element("house")?.Value,
                                 loser = battle.Element("defender").Element("house")?.Value

                             };

            var q9defender = from battle in doc.Descendants("battle")
                             where battle.Element("outcome")?.Value == "defender"
                             select new
                             {
                                 winner = battle.Element("defender").Element("house")?.Value,
                                 loser = battle.Element("attacker").Element("house")?.Value

                             };
            var q9 = from battle in q9attacker.Concat(q9defender)
                     select new { house = battle, count = q9attacker.Concat(q9defender).Count(x => x.winner == battle.winner) };

            q9.OrderByDescending(c => c.count).ToConsole("QUERY 9");

            //Q11 - List the three commanders who attacked the most often!

            var q11attacker = from commander in (from battle in doc.Descendants("battle")
                                                 where battle.Element("attacker").Element("commanders") != null
                                                 select new
                                                 {
                                                     attacker = battle.Element("attacker").Element("commanders")
                                                 })
                              select new
                              {
                                  commander = commander.attacker.Element("commander")?.Value,
                              };

            var q11attackerGroup = from commander in q11attacker
                                   group commander by commander.commander into g
                                   select new { commander = g.Key };

            var q11defender = from commander in (from battle in doc.Descendants("battle")
                                                 where battle.Element("defender").Element("commanders") != null
                                                 select new
                                                 {
                                                     defender = battle.Element("defender").Element("commanders")
                                                 })
                              select new
                              {
                                  commander = commander.defender.Element("commander")?.Value,
                              };

            var q11defenderGroup = from commander in q11defender
                                   group commander by commander.commander into g
                                   select new { commander = g.Key };

            var q11 = from commander in q11attackerGroup.Concat(q11defenderGroup)
                      group commander by commander.commander into g
                      select new { commander = g.Key, count = q11attackerGroup.Concat(q11defenderGroup).Count(x=> x.commander == g.Key) };

            q11.OrderByDescending(x => x.count).Take(3).ToConsole("QUERY 11");


        }
    }