unit uOPCClient;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, System.Win.ComObj;

const
  ITEMMAX = 8;
  VAL_CTRL_SPACE = 8;
  VAL_CTRL_TOP = 192;
  VAL_CTRL_LEFT = 16;
  VAL_ITEMNAME_HEIGHT = 24;
  VAL_ITEMNAME_WIDTH = 88;
  VAL_VALUE_HEIGHT = 24;
  VAL_VALUE_WIDTH = 48;
  VAL_TIME_HEIGHT = 24;
  VAL_TIME_WIDTH = 128;
  VAL_QUALITY_HEIGHT = 24;
  VAL_QUALITY_WIDTH = 40;
  VAL_TYPE_HEIGHT = 24;
  VAL_TYPE_WIDTH = 56;  // VarType 표시 칸

type
  TfOPCClient = class(TForm)
    Label5: TLabel;
    Label1: TLabel;
    Label2: TLabel;
    Label3: TLabel;
    Label4: TLabel;
    txtSvrName: TEdit;
    btnConnect: TButton;
    btnRead: TButton;
    btnWrite: TButton;
    btnAdvise: TButton;
    btnAsyncRead: TButton;
    btnAsyncWrite: TButton;
    txtUpdateRate: TEdit;
    Label6: TLabel;
    procedure FormCreate(Sender: TObject);
    procedure btnConnectClick(Sender: TObject);
    procedure btnReadClick(Sender: TObject);
    procedure btnWriteClick(Sender: TObject);
    procedure btnAdviseClick(Sender: TObject);
    procedure btnAsyncReadClick(Sender: TObject);
    procedure btnAsyncWriteClick(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
  private
    txtItemName: array[0..ITEMMAX-1] of TEdit;
    txtValue: array[0..ITEMMAX-1] of TEdit;
    txtTime: array[0..ITEMMAX-1] of TEdit;
    txtQuality: array[0..ITEMMAX-1] of TEdit;
    txtType: array[0..ITEMMAX-1] of TEdit;  // VarType 표시 칸

    OPCServer: OLEVariant;
    OPCGroup: OLEVariant;
    OPCItemObjects: array[1..ITEMMAX] of OLEVariant;
    sH: array[1..ITEMMAX] of Integer;
    FItemVarTypes: array[1..ITEMMAX] of Integer;  // Read 시 저장한 각 아이템의 실제 VarType
    bConnect: Boolean;
    wTransID: Integer;

    procedure SetupUI;
    procedure SyncDataToUI(ItemValues, Qualities, TimeStamps: OLEVariant);
  public
  end;

var
  fOPCClient: TfOPCClient;

implementation

{$R *.dfm}

procedure TfOPCClient.FormCreate(Sender: TObject);
begin
  SetupUI;
  bConnect := False;
  wTransID := 1000;
end;

procedure TfOPCClient.FormDestroy(Sender: TObject);
begin
  if bConnect then
    btnConnectClick(Self);
end;

procedure TfOPCClient.SetupUI;
var
  i: Integer;
begin
  for i := 0 to ITEMMAX - 1 do
  begin
    txtItemName[i] := TEdit.Create(Self);
    txtItemName[i].Parent := Self;
    txtItemName[i].Top := VAL_CTRL_TOP + (VAL_ITEMNAME_HEIGHT + VAL_CTRL_SPACE) * i;
    txtItemName[i].Left := VAL_CTRL_LEFT;
    txtItemName[i].Width := VAL_ITEMNAME_WIDTH;
    txtItemName[i].Height := VAL_ITEMNAME_HEIGHT;
    txtItemName[i].Text := 'SYSTEM.Tag00'+IntToStr(i+2);

    txtValue[i] := TEdit.Create(Self);
    txtValue[i].Parent := Self;
    txtValue[i].Top := VAL_CTRL_TOP + (VAL_VALUE_HEIGHT + VAL_CTRL_SPACE) * i;
    txtValue[i].Left := VAL_CTRL_LEFT + VAL_ITEMNAME_WIDTH + VAL_CTRL_SPACE;
    txtValue[i].Width := VAL_VALUE_WIDTH;
    txtValue[i].Height := VAL_VALUE_HEIGHT;

    txtTime[i] := TEdit.Create(Self);
    txtTime[i].Parent := Self;
    txtTime[i].Top := VAL_CTRL_TOP + (VAL_TIME_HEIGHT + VAL_CTRL_SPACE) * i;
    txtTime[i].Left := txtValue[i].Left + VAL_VALUE_WIDTH + VAL_CTRL_SPACE;
    txtTime[i].Width := VAL_TIME_WIDTH;
    txtTime[i].Height := VAL_TIME_HEIGHT;

    txtQuality[i] := TEdit.Create(Self);
    txtQuality[i].Parent := Self;
    txtQuality[i].Top := VAL_CTRL_TOP + (VAL_QUALITY_HEIGHT + VAL_CTRL_SPACE) * i;
    txtQuality[i].Left := txtTime[i].Left + VAL_TIME_WIDTH + VAL_CTRL_SPACE;
    txtQuality[i].Width := VAL_QUALITY_WIDTH;
    txtQuality[i].Height := VAL_QUALITY_HEIGHT;
    txtQuality[i].ReadOnly := True;

    txtType[i] := TEdit.Create(Self);
    txtType[i].Parent := Self;
    txtType[i].Top := VAL_CTRL_TOP + (VAL_TYPE_HEIGHT + VAL_CTRL_SPACE) * i;
    txtType[i].Left := txtQuality[i].Left + VAL_QUALITY_WIDTH + VAL_CTRL_SPACE;
    txtType[i].Width := VAL_TYPE_WIDTH;
    txtType[i].Height := VAL_TYPE_HEIGHT;
    txtType[i].ReadOnly := True;
    txtType[i].Color := $00F0F0F0;  // 연회색 배경
  end;
end;

procedure TfOPCClient.btnConnectClick(Sender: TObject);
var
  i: Integer;
  StepMsg: string;
  AddedItem: OLEVariant;
begin
  if Trim(txtSvrName.Text) = '' then
  begin
    ShowMessage('Server Name is not registered.');
    Exit;
  end;

  if not bConnect then
  begin
    try
      StepMsg := 'CreateOleObject';
      // Create OPC Server using Late Binding
      OPCServer := CreateOleObject('OPC.Automation.1');

      StepMsg := 'OPCServer.Connect';
      OPCServer.Connect(txtSvrName.Text, EmptyParam);

      StepMsg := 'OPCGroups.Add';
      OPCGroup := OPCServer.OPCGroups.Add('Group1');

      StepMsg := 'Set UpdateRate';
      OPCGroup.UpdateRate := StrToIntDef(txtUpdateRate.Text, 1000);

      StepMsg := 'Set IsActive';
      OPCGroup.IsActive := True;

      StepMsg := 'Set IsSubscribed';
      OPCGroup.IsSubscribed := False;

      StepMsg := 'AddItem (Loop)';
      // 태그 이름이 입력된 슬롯만 AddItem 등록 (빈 슬롯은 스킵)
      for i := 1 to ITEMMAX do
      begin
        if Trim(txtItemName[i - 1].Text) = '' then
        begin
          OPCItemObjects[i] := Unassigned;
          sH[i] := 0;
          txtItemName[i - 1].Enabled := False;
          Continue;
        end;
        AddedItem := OPCGroup.OPCItems.AddItem(txtItemName[i - 1].Text, i);
        OPCItemObjects[i] := AddedItem;
        sH[i] := AddedItem.ServerHandle;
        txtItemName[i - 1].Enabled := False;
      end;

      bConnect := True;
      btnConnect.Caption := 'Disconnect';
      btnRead.Enabled := True;
      btnWrite.Enabled := True;
      btnAdvise.Enabled := True;
      txtSvrName.Enabled := False;
    except
      on E: Exception do
      begin
        ShowMessage('Connection failed at [' + StepMsg + ']: ' + E.Message);
        Exit;
      end;
    end;
  end
  else
  begin
    try
      if not VarIsEmpty(OPCGroup) then
        OPCServer.OPCGroups.RemoveAll;
      if not VarIsEmpty(OPCServer) then
        OPCServer.Disconnect;
    except
    end;

    for i := 1 to ITEMMAX do
      OPCItemObjects[i] := Unassigned;
      
    OPCGroup := Unassigned;
    OPCServer := Unassigned;

    bConnect := False;
    btnConnect.Caption := 'Connect';
    btnRead.Enabled := False;
    btnWrite.Enabled := False;
    btnAdvise.Enabled := False;
    btnAsyncRead.Enabled := False;
    btnAsyncWrite.Enabled := False;
    txtSvrName.Enabled := True;

    for i := 1 to ITEMMAX do
      txtItemName[i - 1].Enabled := True;
  end;
end;

procedure TfOPCClient.btnReadClick(Sender: TObject);
var
  i: Integer;
  ItemValue: OLEVariant;
  Quality: OLEVariant;
  TimeStamp: OLEVariant;
begin
  if not bConnect then Exit;

  try
    for i := 1 to ITEMMAX do
    begin
      // 빈 슬롯 스킵
      if VarIsEmpty(OPCItemObjects[i]) or VarIsNull(OPCItemObjects[i]) then
        Continue;

      OPCItemObjects[i].Read(Integer(1), ItemValue, Quality, TimeStamp);

      // CanonicalDataType: 서버가 선언한 태그의 원본 타입 (VarType(ItemValue)와 다를 수 있음)
      // Write 시 반드시 이 타입을 사용해야 E_INVALIDARG를 피할 수 있음
      FItemVarTypes[i] := OPCItemObjects[i].CanonicalDataType;
      case FItemVarTypes[i] of
        varSmallInt: txtType[i-1].Text := 'Short';
        varInteger:  txtType[i-1].Text := 'Int';
        varSingle:   txtType[i-1].Text := 'Float';
        varDouble:   txtType[i-1].Text := 'Double';
        varBoolean:  txtType[i-1].Text := 'Bool';
        varOleStr:   txtType[i-1].Text := 'String';
        varByte:     txtType[i-1].Text := 'Byte';
        varWord:     txtType[i-1].Text := 'Word';
        varLongWord: txtType[i-1].Text := 'DWord';
        varInt64:    txtType[i-1].Text := 'Int64';
      else
        txtType[i-1].Text := 'CDT' + IntToStr(FItemVarTypes[i]);
      end;

      txtValue[i - 1].Text := VarToStr(ItemValue);
      if not VarIsEmpty(TimeStamp) and not VarIsNull(TimeStamp) then
        txtTime[i - 1].Text := DateTimeToStr(VarToDateTime(TimeStamp));
      if not VarIsEmpty(Quality) and not VarIsNull(Quality) then
        txtQuality[i - 1].Text := VarToStr(Quality);
    end;
  except
    on E: Exception do ShowMessage('Read Error: ' + E.Message);
  end;
end;

procedure TfOPCClient.btnWriteClick(Sender: TObject);
var
  i, cnt: Integer;
  ServerHandles: OLEVariant;
  ItemValues: OLEVariant;
  Errors: OLEVariant;
  targetVT: Integer;
  inputText: string;

  ItemValue: OLEVariant;
  Quality: OLEVariant;
  TimeStamp: OLEVariant;

begin
  if not bConnect then Exit;

  // 유효한 아이템 수 집계
  cnt := 0;
  for i := 1 to ITEMMAX do
    if not VarIsEmpty(OPCItemObjects[i]) and not VarIsNull(OPCItemObjects[i]) then
      Inc(cnt);
  if cnt = 0 then Exit;

  // OPCGroup.SyncWrite() 사용: OPCItem.Write()는 IDispatch 경유 시
  // VT_I2(Short) 마샬링 문제로 0x80070057(E_INVALIDARG)이 발생하는 경우가 있음
  ServerHandles := VarArrayCreate([1, cnt], varInteger);
  ItemValues    := VarArrayCreate([1, cnt], varVariant);
  // Errors는 반드시 미리 배열로 초기화해야 함 (Unassigned 전달 시 DISP_E_TYPEMISMATCH 발생)
  Errors        := VarArrayCreate([1, cnt], varInteger);

  cnt := 0;
  for i := 1 to ITEMMAX do
  begin
    if VarIsEmpty(OPCItemObjects[i]) or VarIsNull(OPCItemObjects[i]) then Continue;

    inputText := Trim(txtValue[i - 1].Text);
    if inputText = '' then Continue;

    Inc(cnt);
    ServerHandles[cnt] := sH[i];

    // CanonicalDataType 기반으로 올바른 타입의 Variant 생성
    // ※ VarAsType() 대신 Delphi 직접 캐스팅 사용:
    //   varVariant 배열 요소에 VarAsType 결과를 넣으면 VT_VARIANT|VT_I2 로 이중 래핑되어
    //   SyncWrite에서 DISP_E_TYPEMISMATCH가 발생할 수 있음
    targetVT := FItemVarTypes[i];
    if targetVT = 0 then targetVT := varSmallInt;

    case targetVT of
      varSmallInt: ItemValues[cnt] := SmallInt(StrToIntDef(inputText, 0));
      varInteger:  ItemValues[cnt] := Integer(StrToIntDef(inputText, 0));
      varByte:     ItemValues[cnt] := Byte(StrToIntDef(inputText, 0));
      varWord:     ItemValues[cnt] := Word(StrToIntDef(inputText, 0));
      varLongWord: ItemValues[cnt] := LongWord(StrToInt64Def(inputText, 0));
      varInt64:    ItemValues[cnt] := Int64(StrToInt64Def(inputText, 0));
      varSingle:   ItemValues[cnt] := Single(StrToFloatDef(inputText, 0.0));
      varDouble:   ItemValues[cnt] := Double(StrToFloatDef(inputText, 0.0));
      varBoolean:  ItemValues[cnt] := (inputText <> '0') and (inputText <> '');
      varOleStr:   ItemValues[cnt] := inputText;
    else
      ItemValues[cnt] := inputText;  // 알 수 없는 타입 → 문자열로 전송
    end;
  end;

  if cnt = 0 then Exit;

  try
//    OPCGroup.SyncWrite(Integer(cnt), ServerHandles, ItemValues, Errors);


//    OPCItemObjects[1].Read(Integer(1), ItemValue, Quality, TimeStamp);

    OPCItemObjects[1].write(Integer(1), ServerHandles, Integer(1), Errors);


    ShowMessage('Write 완료!');
  except
    on E: EOleException do
      ShowMessage('Write Error [0x' + IntToHex(E.ErrorCode, 8) + ']: ' + E.Message +
        #13#10 + 'CanonicalDataType: ' + IntToStr(targetVT) +
        #13#10 + '입력값: ' + inputText);
    on E: Exception do
      ShowMessage('Write Error [' + E.ClassName + ']: ' + E.Message);
  end;
end;

procedure TfOPCClient.btnAdviseClick(Sender: TObject);
begin
  try
    OPCGroup.IsActive := not OPCGroup.IsActive;
    OPCGroup.IsSubscribed := OPCGroup.IsActive;

    if OPCGroup.IsActive then
    begin
      btnAdvise.Caption := 'Unadvise';
      btnAsyncRead.Enabled := True;
      btnAsyncWrite.Enabled := True;
      btnReadClick(Self);
    end
    else
    begin
      btnAdvise.Caption := 'Advise';
      btnAsyncRead.Enabled := False;
      btnAsyncWrite.Enabled := False;
    end;
  except
    on E: Exception do ShowMessage('Advise Error: ' + E.Message);
  end;
end;

procedure TfOPCClient.btnAsyncReadClick(Sender: TObject);
var
  i: Integer;
  ServerHandles: OLEVariant;
  Errors: OLEVariant;
  CancelID: Integer;
begin
  Inc(wTransID);
  ServerHandles := VarArrayCreate([1, ITEMMAX], varInteger);
  for i := 1 to ITEMMAX do ServerHandles[i] := sH[i];
//                            OPCItemObjects[i].Read(Integer(1), ItemValue, Quality, TimeStamp);
  try
    Errors := Unassigned;
    OPCGroup.AsyncRead(Integer(ITEMMAX), ServerHandles, Errors, Integer(wTransID), CancelID);
  except
    on E: Exception do ShowMessage('AsyncRead Error: ' + E.Message);
  end;
end;

procedure TfOPCClient.btnAsyncWriteClick(Sender: TObject);
var
  i: Integer;
  ServerHandles: OLEVariant;
  ItemValues: OLEVariant;
  Errors: OLEVariant;
  CancelID: Integer;
begin
  Inc(wTransID);
  ServerHandles := VarArrayCreate([1, ITEMMAX], varInteger);
  ItemValues := VarArrayCreate([1, ITEMMAX], varVariant);

  for i := 1 to ITEMMAX do
  begin
    ServerHandles[i] := sH[i];
    ItemValues[i] := txtValue[i - 1].Text;
  end;

  try
    Errors := Unassigned;
    OPCGroup.AsyncWrite(Integer(ITEMMAX), ServerHandles, ItemValues, Errors, Integer(wTransID), CancelID);
  except
    on E: Exception do ShowMessage('AsyncWrite Error: ' + E.Message);
  end;
end;

procedure TfOPCClient.SyncDataToUI(ItemValues, Qualities, TimeStamps: OLEVariant);
var
  i: Integer;
begin
  for i := 1 to ITEMMAX do
  begin
    if not VarIsEmpty(ItemValues[i]) then
      txtValue[i - 1].Text := VarToStr(ItemValues[i]);
    if not VarIsEmpty(TimeStamps[i]) then
      txtTime[i - 1].Text := DateTimeToStr(VarToDateTime(TimeStamps[i]));
    if not VarIsEmpty(Qualities[i]) then
      txtQuality[i - 1].Text := VarToStr(Qualities[i]);
  end;
end;

end.