unit Unit1;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants,
  System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, IdBaseComponent, IdComponent, idsync,
  IdTCPConnection, IdTCPClient, Vcl.StdCtrls, Vcl.ExtCtrls;

type
  TForm1 = class(TForm)
    MemoReceive: TMemo;
    Button1: TButton;
    Client: TIdTCPClient;
    Button2: TButton;
    procedure FormCreate(Sender: TObject);
    procedure Button1Click(Sender: TObject);
    procedure ClientConnected(Sender: TObject);
    procedure ClientDisconnected(Sender: TObject);
    procedure Button2Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

  TReadingThread = class(TThread)
  protected
    FConn: TIdTCPConnection;
    procedure Execute; override;
    procedure DoTerminate; override;
  public
    constructor Create(AConn: TIdTCPConnection); reintroduce;
  end;

  TLog = class(TidSync)
  protected
    FMsg: String;
    procedure DoSynchronize; override;
  public
    constructor Create(const AMsg: String);
    class procedure AddMsg(const AMsg: String);
  end;

var
  Form1: TForm1;
  rt: TReadingThread = nil;

implementation

var
  oldStatusReceive: string = 'Disconnected';
  oldStatusSend: string = 'Disconnected';
  TelegramNr: string = '00';
  sendCounter: Integer = 1;
  CommissionNumber: Integer = 1;

{$R *.dfm}

constructor TReadingThread.Create(AConn: TIdTCPConnection);
begin
  TLog.AddMsg('DEBUG: TReadingThread.Create');
  FConn := AConn;
  inherited Create(False);
end;

procedure TReadingThread.Execute;
var
  cmd, tcpStringSend: string;
begin
  TLog.AddMsg('DEBUG: TReadingThread.Execute');

  while not Terminated do
  begin
    cmd := FConn.IOHandler.ReadLn(#3);
    cmd := trim(cmd);
    TLog.AddMsg('DEBUG: TReadingThread.Execute. Cmd: ' + cmd);
    TelegramNr := copy(cmd, 1, 2);
    tcpStringSend := #2 + TelegramNr + '001050QU' + #3;
    FConn.IOHandler.WriteLn(tcpStringSend);
  end;
end;

procedure TReadingThread.DoTerminate;
begin
  TLog.AddMsg('DEBUG: TReadingThread.DoTerminate');
  inherited;
end;

constructor TLog.Create(const AMsg: string);
begin
  inherited Create;
  FMsg := AMsg;
end;

procedure TLog.DoSynchronize;
begin
  Form1.MemoReceive.Lines.Add(FMsg);
end;

class procedure TLog.AddMsg(const AMsg: string);
begin
  with Create(AMsg) do
    try
      Synchronize;
    finally
      Free;
    end;
end;

procedure TForm1.Button1Click(Sender: TObject);
var
  Host: string;
  Port: Integer;
begin
  Host := '192.168.100.74';
  Port := StrToInt('4100');

  Client.Host := Host;
  Client.Port := Port;

  try
    Client.Connect;
  except
    on E: Exception do
      TLog.AddMsg('Error: ' + E.Message);
  end;
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
  try
    Client.Disconnect;
  except
    on E: Exception do
      TLog.AddMsg('Error: ' + E.Message);
  end;
end;

procedure TForm1.ClientConnected(Sender: TObject);
begin
  TLog.AddMsg('DEBUG: TForm1.clientConnected');
  rt := TReadingThread.Create(Client);
end;

procedure TForm1.ClientDisconnected(Sender: TObject);
begin
  TLog.AddMsg('DEBUG: TForm1.clientDisconnected');
  if rt <> nil then
  begin
    rt.Terminate;
    rt.WaitFor;
    FreeAndNil(rt);
  end;
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  MemoReceive.Clear;
end;

end.