/euler002/Euler002b.adb

pragma License ( GPL );
------------------------------------------------------------------------------
-- Author: darkestkhan                                                      --
-- Email:  darkestkhan@gmail.com                                            --
-- License: GNU GPLv3 or any later as published by Free Software Foundation --
-- ( see license.txt file )                                                 --
-- Copyright Š 2011 darkestkhan                                             --
------------------------------------------------------------------------------
-- This Program is Free Software: You Can Redistribute It and/or Modify     --
-- It Under The Terms of The GNU General Public License As Published By     --
-- The Free Software Foundation, Either Version 3 of The License, or        --
-- (at Your Option) Any Later Version.                                      --
--                                                                          --
-- This Program is Distributed in The Hope That It Will Be Useful,          --
-- But WITHOUT ANY WARRANTY; Without Even The Implied Warranty of           --
-- MERCHANTABILITY or FITNESS for A PARTICULAR PURPOSE.  See The            --
-- GNU General Public License for More Details.                             --
--                                                                          --
-- You Should Have Received A Copy of The GNU General Public License        --
-- Along with This Program.  if not, See <Http://Www.Gnu.Org/Licenses/>.    --
------------------------------------------------------------------------------
with Ada.Task_Identification;
with TTY; -- it is at <https://github.com/darkestkhan/tty>
with Ada.Command_Line;
with Ada.IO_Exceptions;
procedure Euler002b is

  Terminal: TTY.TTY;
  Argc: constant Integer := Ada.Command_Line.Argument_Count;

  function Sum_Even_Fib ( Limit: in Integer ) return Integer is
    Sum: Integer := 0;
    First: Integer := 1;
    Second: Integer := 2;
    Fib: Integer := Second;
  begin
    while Fib < Limit loop
      if Fib mod 2 = 0 then
        Sum := Sum + Fib;
      end if;
      Fib := First + Second;
      First := Second;
      Second := Fib;
    end loop;
    return Sum;
  exception
    when constraint_error => return -1;
  end Sum_Even_Fib;

  task type Calculate ( Arg: Integer );
  task body Calculate is
    Sum: Integer;
  begin
    Sum := Sum_Even_Fib ( Limit => Arg );
    if Sum = -1 then
      Terminal.Write_Line ( "The sum of even terms of Fibonacci series below " & Arg'img  & " is greater than integer'last" );
      Ada.Task_Identification.Abort_Task ( Ada.Task_Identification.Current_Task );
    else
      Terminal.Write_Line ( "The sum of even terms of Fibonacii series below " & Arg'img & " equals " & Sum'img );
    end if;
  end Calculate;

  type Calculate_Array is array ( Integer range <> ) of access Calculate;
  Calculates: Calculate_Array ( 1 .. Argc );

  function Create ( Arg: in Integer ) return access Calculate is
  begin
    return new Calculate ( Arg => Arg );
  end Create;

  task type Creator;
  task body Creator is
    Arg: Integer;
  begin
    if Argc < 1 then
      Terminal.Write_Line ( "Usage: " & Ada.Command_Line.Command_Name & " [int] ... " );
      Ada.Task_Identification.Abort_Task ( Ada.Task_Identification.Current_Task );
    end if;

    for Index in 1 .. Argc loop
      Arg := Integer'Value ( Ada.Command_Line.Argument ( Index );
      Calculates ( Index ) := Create ( Arg => Arg );
    end loop;
  exception
    when Ada.IO_Exceptions.Data_Error => Terminal.Write_Line ( "One of arguments was too big. Aborting. Aborting." );
                                    Ada.Task_Identification.Abort_Task ( Ada.Task_Identification.Current_Task );
  end Creator;

  God: Creator;

begin
  null;
end Euler002b;