using System;
using System.Collections;
using System.Collections.Generic;

// ElementaryExtensions API:
using ElementaryExtensions;

namespace MiscellaneousDemo {

//**************************************************************************************************
static partial class Program {
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

/// <summary>
/// Usage of <see cref="ЄArith"/> class.
/// </summary>
static bool ArithAlgDemo()
{
   int nDialogItemIdx=
      ЄConsole.NumberedListDialog
      (
         "Arithmetic algorithm over collection (array):",
         new string[]
         {
            "Average value of double precision numbers (built-in type)",
            "Average value of complex numbers (single or double precision)",
         },
         "Cancel"
      );
   if (nDialogItemIdx<0)
      return false;
   ЄConsole.Print();
   switch (nDialogItemIdx)
   {
   case 0:
      double[] adNumbers=new double[]
      {
         15.34, -15e-1, 19.67e2, 47.1354, 3157.0009
      };
      PrintNumbers(adNumbers);
      PrintCalcResult(Avg(adNumbers));
      break;
   case 1:
      // Explicit conversion to Real type is used, because Complex type may be based
      // either on Single (float) or on Double (double).
      Complex[] acNumbers=new Complex[]
      {
         new Complex( (Real)  4.37 , (Real) 37.2108  ),
         new Complex( (Real)(-5.08), (Real) 21.07    ),
         new Complex( (Real)  8.623, (Real)(-0.3457) )
      };
      PrintNumbers(acNumbers);
      PrintCalcResult(Avg(acNumbers));
      break;
   default:
      throw new ЄDeadCodeBranchException();
   }
   return true;
}

/// <summary>
/// Average value calculation -- algorithm over collection of values of indeterminate type.
/// </summary>
/// <remarks>
/// This method is identical to <see cref="ЄArith.Avg"/> static method (one of its overloads).
/// </remarks>
public static T Avg<T>(IEnumerable<T> collection) where T: struct
{
   T sum=default(T);
   int nCount=0;
   foreach (T elem in collection)
   {
      sum=ЄArith.Oper_Addition(sum,elem);
      nCount++;
   }
   if (nCount==0)
      throw new InvalidOperationException(
         "Attempt to calculate average of empty set of values." );
   return ЄArith.Oper_Division( sum,
      ЄArith.GenerateValueFrom<T,int>(nCount) );
}

/// <summary>
/// Helper function for arithmetic algorithm demo.
/// </summary>
static void PrintNumbers(IEnumerable numCollection)
{
   ЄConsole.TypeInformation("Numbers");
   ЄConsole.Type(": ");
   bool bNextElement=false;
   foreach (object obNumber in numCollection)
   {
      if (bNextElement)
         ЄConsole.Type(", ");
      ЄConsole.TypeIntensive(obNumber);
      bNextElement=true;
   }
   ЄConsole.Print();
}

/// <summary>
/// Helper function for arithmetic algorithm demo.
/// </summary>
static void PrintCalcResult(object obSum)
{
   ЄConsole.TypeInformation("Average");
   ЄConsole.Type(": ");
   ЄConsole.PrintExclamation(obSum);
}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
} // Program
//**************************************************************************************************

} // MiscellaneousDemo