-- S.MG, 2018
  -- Tester for UDP communications relying on libudp and libmt

with Ada.Calendar; use Ada.Calendar; -- for local time
with Ada.Calendar.Time_Zones; use Ada.Calendar.Time_Zones; -- UTC_Time_Offset
with Ada.Calendar.Formatting; use Ada.Calendar.Formatting; -- for unix-like
with Interfaces; use Interfaces;

with UDP;
with MT;

package UDP_Tester is

  -- knobs for Tester, change as required

  -- used for obtaining Unix-like time from value ret by Ada.Calendar.Clock
  Epoch         : constant Time     := Formatting.Time_Of(1970, 1, 1, 0.0);

  -- Header of each packet is: 
      -- 4 octets local time unix format; 
      -- 2 octets total length of message (header+payload)
  Header_Len    : constant Positive := 6;
  -- packages sent will be between Header_Len and Max_Len
  Max_Len       : constant Positive := 2048;

  -- helper methods
  procedure Create_If_Not_Exists( Filename: in String; Header: in String);

  -- will send messages with lengths between Header_Len and Max_Len
  -- messages are sent at 1 second intervals (i.e. 1 second between 2 messages)
  -- sizes are chosen based on MT prng with seed = unixtime when sender starts
  -- payloads are simply I mod 256 where I is position of octet in message
  -- data for all sent messages is logged in a .txt file in current dir
  -- if the log files exist, new content will be APPENDED to it
  -- if the log file does not exist, it will be created
  procedure Sender( Receiver_IP: in String; 
                    Receiver_Port: in Unsigned_16;
                    Sender_Port: in Unsigned_16 );

  -- receiver method with endless loop, receiving UDP messages on given port
  -- data for all received messages is logged in a .txt file in current dir
  -- an additional err log contains any octets that are different from expected
  -- if the log files exist, new content will be APPENDED to it
  -- if the log file does not exist, it will be created
  procedure Receiver( Receiver_Port: in Unsigned_16 );


end UDP_Tester;