library Project2;

{ Important note about DLL memory management: ShareMem must be the
  first unit in your library's USES clause AND your project's (select
  Project-View Source) USES clause if your DLL exports any procedures or
  functions that pass strings as parameters or function results. This
  applies to all strings passed to and from your DLL--even those that
  are nested in records and classes. ShareMem is the interface unit to
  the BORLNDMM.DLL shared memory manager, which must be deployed along
  with your DLL. To avoid using BORLNDMM.DLL, pass string information
  using PChar or ShortString parameters. }

uses
  SysUtils,
  Classes,
  IdBaseComponent, IdComponent, IdTCPConnection,
  IdTCPClient, IdFTP;

{$R *.res}

Type
  TFTPContainer = Class(TObject)
  Private
   FIdFTP: TIdFTP;
  Public
    procedure FTPOnStatus(ASender: TObject; const AStatus: TIdStatus;  const AStatusText: string);
    Constructor Create;
    Destructor Destroy; override;
  End;

// create an instance and return it as an integer/handle
Function Initialize : Integer; stdcall;
Var FTPContainer : TFTPContainer;
Begin
  FTPContainer := TFTPContainer.Create;
  Result := Integer(FTPContainer); // typecast FTPContainer as integer and return it
End;

// free the instance (the user must supply the integer/handle which they got from the call to Initialize
Procedure DeInitialize(Handle : Integer); stdcall;
Begin
  TFTPContainer(Handle).Free; // typecast handle back to FTPContainer and free it
End;

{ CONNECT TO THE FTP SERVER }
function FTPConnect(Handle : Integer; AHost: String; APort: Integer; AUserName, APassword: String; APassive: Boolean = True): Boolean; stdcall;
Var FTPContainer : TFTPContainer;
begin
  FTPContainer := TFTPContainer(Handle); // typecast handle back to FTPContainer
  with FTPContainer.FIdFTP do
  begin
    Host := AHost;
    Port := APort;
    Username := AUserName;
    Password := APassword;
    Passive := APassive;
    Connect;

    if Connected then
      Result := True
    else
      Result := False;
  end;
end;

{ EVENTS }
constructor TFTPContainer.Create;
begin
  FIdFTP := TIdFTP.Create(nil);
  FIdFTP.OnStatus := FTPOnStatus;
  // assign the rest of the events here
end;

destructor TFTPContainer.Destroy;
begin
  FidFTP.Free;
  inherited;
end;


procedure TFTPContainer.FTPOnStatus(ASender: TObject;
  const AStatus: TIdStatus; const AStatusText: string);
begin
  // do something
end;

Exports
  Initialize,
  DeInitialize,
  FTPConnect;

end.