with Ada.Calendar;
use Ada.Calendar;
generic
   Laps_Time : Day_Duration := 86400.0;
             
package Computing is
 
   subtype Laps_Type is Duration range 0.0..(Laps_Time * 2.0)-1.0;
 
   type Step_Record is
      record
         Tempo : Float := 120.0;
         Hours : Laps_Type := 0.0;
      end record;
   type Step_Set is array (Positive range <> ) of Step_Record;
 
   type Step_Sequencer_Record(Size : Positive) is
      record
         Set : Step_Set(1..Size);
      end record;
 
   type Bar_Type;
   type Bar_Access is access all Bar_Type;
   type Bar_Type(Step_Max : Positive) is
      record
         Steps : Step_Sequencer_Record(Step_Max);
         Next  : Bar_Access;
      end record;
 
   type Bar_Sequencer_Record is
      record
         Left_Min  : Bar_Access;
         Left_Max  : Bar_Access;
         Right_Max : Bar_Access;
      end record;
 
   type Buffered_Bar_Sequencer_record is
      record
         Bar_Sequencer : Bar_Sequencer_Record;
         Current       : Bar_Access;
         Left          : Bar_Access;
         Right         : Bar_Access;
      end record;
 
 
   procedure Inssert_Bars_Before
     (Buffered_Bar_Sequencer : in out Buffered_Bar_Sequencer_Record;
      Left, Right,           : in out Bar_Access;
      Bars                   : in Bar_Sequence_Record);
   procedure Remove_Bars_Between
     (Buffered_Bar_Sequencer : in out Buffered_Bar_Sequencer_Record;
      Left, Right,           : in out Bar_Access);
end Computing;

Right_Max : constant Bar_Access := new Bar_Type ' (1, (1, (others => (120.0, Laps_Type'Last))), Next => null);
   Left_Max  : constant Bar_Access := new Bar_Type ' (1, (1, (others => (120.0, Laps_Time-1.0))), Next => Right_max);
   Left_Min  : constant Bar_Access := new Bar_Type ' (1, (1, (others => (120.0, 0.0))), Next => Left_Max);
 
 
   type Buffered_Bar_Sequencer_record is
      record
     Bar_Sequencer : Bar_Sequencer_Record := (Left_Min, Left_Max, Right_Max);
     Current       : Bar_Access := Left_Min;
     Left          : Bar_Access := Left_Min;
     Right         : Bar_Access := Left_Min;
     In_Loop       : Boolean := False;
      end record;
 
 
   procedure Initialize(Bufferd_Bar_Sequencer : out Buffered_Bar_Sequencer_Record;
            In_Loop : in Boolean := False) is
   begin
      Bufferd_Bar_Sequencer.current := Bufferd_Bar_Sequencer.Bar_Sequencer.Left_Min;
      Bufferd_Bar_Sequencer.Left := Bufferd_Bar_Sequencer.Bar_Sequencer.Left_Min;
      Bufferd_Bar_Sequencer.Right := Bufferd_Bar_Sequencer.Bar_Sequencer.Left_Max;     
      Bufferd_Bar_Sequencer.In_Loop := In_Loop;      
      if In_Loop then
     if Bufferd_Bar_Sequencer.Left /= null then
        Bufferd_Bar_Sequencer.Right.Next := 
          Bufferd_Bar_Sequencer.Left;
     end if;
      end if;
       
   end Initialize;

function Set_Next
     (Buffered_Bar_Sequencer : in out Buffered_Bar_Sequencer_Record) return Boolean is
   begin
      if Buffered_Bar_Sequencer.Current.Next /= null then 
     Buffered_Bar_Sequencer.Current := 
       Buffered_Bar_Sequencer.Current.Next;     
     if Buffered_Bar_Sequencer.Left.Next /= null then
        Buffered_Bar_Sequencer.Left := 
          Buffered_Bar_Sequencer.Left.next;
     end if;
     if Buffered_Bar_Sequencer.Right.Next /= null then
        Buffered_Bar_Sequencer.Right := 
          Buffered_Bar_Sequencer.Right.next;
     end if;     
     return True;
      else
     return False;
      end if;     
   end Set_Next;

procedure Play (Widget : access Gtk_Widget_Record'class;
                   Main_Window : in Ultrason_Access) is
          
      
      
   begin
            
      Main_Window.Transport_Play := 
    Ultrason_G_Source.Timeout_Add(1, 
                      Set_Next'Access,
                      Main_Window);
      
      
   end Play;

function Set_Next (Ultrason : Ultrason_Access) return Boolean is
      Verax : Boolean := My_Computing.Set_Next(Ultrason.Buffered_Bar_Sequencer);
   begin
      if Verax then
     Set_Text(Ultrason.Position, Formatting.Image(Ultrason.Buffered_Bar_Sequencer.Current.Steps.Set(1).Hours, true));
     Set_Text(Ultrason.Cursor_Left, Formatting.Image(Ultrason.Buffered_Bar_Sequencer.Left.Steps.Set(1).Hours, true));
     Set_Text(Ultrason.Cursor_Right, Formatting.Image(Ultrason.Buffered_Bar_Sequencer.right.Steps.Set(1).Hours, true));
      end if;
      return Verax;
      
   end Set_Next;