using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        int[] array = new int[] { 12, 13, 55, 7, 22, 16, 2, 102, 22};

        var list = array.ToList();

        list.ForEach(x=>Console.WriteLine(x));

        //var results2 = array.Select((x,y)=> new { Index = y, Value = x }).ToList();

        //results2.ForEach(x=>Console.WriteLine(x));

        //var results = array.Select(x=>x).OrderBy(x=>x).ToList();

        //results.ForEach(x=>Console.WriteLine(x));

        var transactions = new List<Transaction>();

        transactions.Add(new Transaction() {Id = 10002211, Date = new DateTime(2021,05,22), Amount = 201.22, Name = "Purchase 1", Description = "Client expenses"});

        transactions.Add(new Transaction() {Id = 10000111, Date = new DateTime(2020,02,11), Amount = 2000, Name = "Purchase 2", Description = "Rent expense"});

        transactions.Add(new Transaction() {Id = 20023342, Date = new DateTime(2019,01,18), Amount = 199.97, Name = "Purchase 3", Description = "Registration costs"});

        ///var results = transactions.OrderBy(x=>x.Id).ToList();

        var totalSum = transactions.Sum(x=>x.Amount);

        var average = transactions.Average(x=>x.Amount);

        var averageRounded = Math.Round(average, 2);

        var mathString = String.Format("Total cost: {0}, Average: {1}", totalSum, averageRounded);

        //Console.WriteLine(mathString);

        //Order by transaction Id

        //var results = transactions.OrderBy(x=>x.Id);

        //Group by transaction Id

        /*

        var results = transactions.GroupBy(x=>x.Id>20000000);

        foreach (var group in results)

        {

            if (group.Key == true)

            {

                Console.WriteLine("Transactions greater than 20000000");

            } else

            {

                Console.WriteLine("Transactions not greater than 2000000");

            }

            foreach (var s in group)

            {

                Console.WriteLine(s.Id);

            }

        }*/

        //Group by Transaction Name

        var results = transactions.GroupBy(x=>x.Name);

        foreach (var group in results)

        {

            Console.WriteLine(String.Format("Group: {0}", group.Key));

            foreach(var s in group)

            {

                Console.WriteLine(s.Name);

            }

        }

        //foreach (var transaction in results)

        //{

            //var outputString = string.Format("Transaction Id: {0}-Date: {1}-Amount: {2}-Name: {3}-Description: {4}", transaction.Id, transaction.Date, transaction.Amount, transaction.Name, transaction.Description);

            //Console.WriteLine(outputString);

        //}

    }

    private class Transaction

    {

        public int Id {get; set;}

        public DateTime Date {get; set;}

        public double Amount {get; set;}

        public string Name {get; set;}

        public string Description {get; set;}

    }

}