using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO;

namespace WTWProgram
{
    class Program
    {
        static void Main(string[] args)
        {
            //Open file and declare lists to store the data columns
            var reader = new StreamReader(File.OpenRead(@"C:\Users\Harald\Documents\CVs\WTW TEST\InputData.csv"));
            List<string> Products = new List<string>();
            List<int> Origins = new List<int>();
            List<int> Developments = new List<int>();
            List<double> IncValues = new List<double>();

            //Read from file and split columns on commas
            while (!reader.EndOfStream)
            {
                var line = reader.ReadLine();
                var values = line.Split(',');
                int i;
                double j;

                //TryParse is used to return values of 0 for the column headings.
                Products.Add(values[0]);
                if (int.TryParse(values[1], out i)) Origins.Add(i);
                if (int.TryParse(values[2], out i)) Developments.Add(i);
                if (double.TryParse(values[3], out j)) IncValues.Add(j);
            }

            //Calculate the range of years, the starting year and the quantity of different products
            int Range = Developments.Max() - Origins.Min() + 1;
            int Start = Origins.Min();
            int ProductCount = Products.Distinct().ToList().Count() -1;

            Console.Write(Start + "," + Range);

            //Calculate the size of the triangles to be filled
            int TriangleSize=0;

            for(int i=0;i<Range;i++)
            {
                TriangleSize = TriangleSize + Range - i;
            }

            //Create an array to hold the triangles of cumulative values
            double[,] CumuValues = new double[ProductCount,TriangleSize];

            //This index will be used to increment the row of the above array
            int Row = 0;

            for (int i=1;i<Products.Count();i++)
            {
                int k = i - 1; //Index for the year lists and Incvalues

                //Calculate the appropriate starting point in the row using the triangle number equation.
                int Diff = Origins[k] - Start;
                Diff = Diff * (Diff + 1) / 2;

                //Calculate the number of development years from the origin
                int DevYrs = Developments[k] - Origins[k];

                //Calculate the cumulative value
                double Cumu = 0.0;

                for (int j = 0; j <= DevYrs; j++)
                {
                    Cumu = Cumu + IncValues[k - j];
                }

                CumuValues[Row, Diff + DevYrs - 1] = Cumu;



                if(Products[k]!=Products[i])
                {
                    Console.Write("\n" + Products[i]);
                }

                if (Developments[i] == Developments.Max())
                {

                    for (int x = 0; x < TriangleSize; x++)
                    {
                        Console.Write("," + CumuValues[Row, x]);
                    }
                    Row++;
                }


            }

            Console.ReadKey();
        }
    }
}