--- libraries
WITH Ada.Text_IO; USE Ada.Text_IO;
WITH Ada.Integer_Text_IO; use Ada.Integer_Text_IO;

--- main block
PROCEDURE Zadanie2 IS
--- constants
   Lenght_Date_Const: CONSTANT Positive := 11;
   --- variables
   Date: String(1..Lenght_Date_Const);
   Lenght_Date: Integer :=0;

   type DateRecord is
      record
         Day: Integer := 0; --pointer to be used to check correctness of given day (range 1-31)
         Month: Integer := 0;   --pointer to be used to check correctness of given month (range 1-12)
         Year: Integer :=0; --pointer containing the year (last for chars from string)
      end record;

   type DatePtr is access DateRecord;   DatePtr1: DatePtr;

   --- function block
   function CheckDate ( Date: in String) return Boolean is
   begin
      -- here date will be splitted using '-' as regexp and than all three parts will be checked for their correctness
      DatePtr1 := new DateRecord;
      DatePtr1.Day := Integer'Value(Date(Date'First..Date'First+1));
      DatePtr1.Month := Integer'Value(Date(Date'First+3..Date'First+4));
      DatePtr1.Year := Integer'Value(Date(Date'First+6..Date'First+9));

      if (DatePtr1.Day <= 0 or else DatePtr1.Day > 31) then
         return false;
      elsif (DatePtr1.Month <= 0 or else DatePtr1.Month > 12) then
         return false;
      end if;

      return true;
   end CheckDate;

   function isLeap ( year : in Integer) return Boolean is
   begin
      if ( ( (
              ( year mod 4 ) = 0 ) AND ( ( year mod 100 ) /= 0 ) )
          or else ( ( year mod 400 ) = 0 ) ) then
         return true;
      end if;
      return false;     --returns false if above condition is not true
   end isLeap;

   FUNCTION Tommorow ( date_ptr : in DatePtr ) RETURN String IS
   BEGIN
      -- this function will calculate the tommorow day along with checking conditions for leap year and checking if we have the last day of month, of year
      -- and so on
      -- checking Leap Year Condition
      if ( isLeap(date_ptr.Year) and date_ptr.Month = 2 and date_ptr.Day = 29) then
         -- so the year is leap, February is present, and there is the last day of it
         date_ptr.Month := date_ptr.Month + 1;
         date_ptr.Day := 1;
         -- missing returning date
      else
         -- the year is not leap
         -- two conditions
         -- 1. for even months
         -- 2. for odd months
         if date_ptr.Month mod 2 = 0 then   --month is even -> has 30 days
            if date_ptr.Day >= 1 or else date_ptr.Day <30 then
               date_ptr.Day := date_ptr.Day + 1;
            else                --the last day of month
               date_ptr.Day := 1;
               if date_ptr.Month = 12 then      --December so year must be incremented also
                  date_ptr.Month := 1;
                  date_ptr.Year := date_ptr.Year + 1;
               else             --Any other even month different than December
                  date_ptr.Month := date_ptr.Month + 1;
               end if;
            end if;
         else                   -- month is odd -> has 31 days
            if date_ptr.Day >= 1 or else date_ptr.Day <31 then
               date_ptr.Day := date_ptr.Day + 1;
            else                --the last day of month
               date_ptr.Day := 1;
               date_ptr.Month := date_ptr.Month + 1;
            end if;
         end if;
         return ("dd-mm-rrrr");     --here should be date concated from scraps (date_ptr.Day etc)
      end if;
   END Tommorow;

BEGIN
   Put_Line("Hello - program zadanie6");
   Put("Podaj date, pamietajac ze program akceptuje date w formacie dd-mm-rrrr");
   New_Line(3);
   Put("Data ->"); Get_Line(date,lenght_date);
   New_Line;
   Put("Podales date -> "); Put(Date(1..Lenght_Date));
   New_Line(2); Put("-----------------------"); New_Line(2);
   IF CheckDate(Date) THEN
      Put_Line("Podales prawidlowa date");
      Put("Jutro bedziemy mieli wiec ->"); Put(Tommorow(DatePtr1));
   ELSE
      Put_Line("Data nieprawidlowa, koniec programu");
   END IF;
END;
--- end of main block